Proposed Rule To List the Sunflower Sea Star as Threatened Under the Endangered Species Act, 16212-16229 [2023-05340]
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Federal Register / Vol. 88, No. 51 / Thursday, March 16, 2023 / Proposed Rules
§ 367.40 Fees Under the Unified Carrier
Registration Plan and Agreement for
Registration Years Beginning in 2024 and
Each Subsequent Registration Year
Thereafter.
3. Add a new § 367.40 to read as
follows:
■
TABLE 1 TO § 367.40—FEES UNDER THE UNIFIED CARRIER REGISTRATION PLAN AND AGREEMENT FOR REGISTRATION
YEARS BEGINNING IN 2024 AND EACH SUBSEQUENT REGISTRATION YEAR THEREAFTER
Number of commercial motor vehicles owned or operated by exempt or
non-exempt motor carrier, motor private carrier, or freight forwarder
Bracket
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B6
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21–100 .....................................................................................................................
101–1,000 ................................................................................................................
1,001 and above ......................................................................................................
Issued under authority delegated in 49 CFR
1.87.
Robin Hutcheson,
Administrator.
[FR Doc. 2023–05292 Filed 3–15–23; 8:45 am]
BILLING CODE 4910–EX–P
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
50 CFR Part 223
[Docket No. 230309–0070; RTID 0648–
XR120]
Proposed Rule To List the Sunflower
Sea Star as Threatened Under the
Endangered Species Act
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Proposed rule; request for
comments.
AGENCY:
We, NMFS, have completed a
comprehensive status review for the
sunflower sea star, Pycnopodia
helianthoides, in response to a petition
to list this species as threatened or
endangered under the Endangered
Species Act (ESA). Based on the best
scientific and commercial information
available, including the draft status
review report, and after taking into
account efforts being made to protect
the species, we have determined that
the sunflower sea star is likely to
become an endangered species within
the foreseeable future throughout its
range. Therefore, we propose to list the
sunflower sea star as a threatened
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SUMMARY:
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species under the ESA. Should the
proposed listing be finalized, any
protective regulations under section 4(d)
of the ESA would be proposed in a
separate Federal Register notice. We do
not propose to designate critical habitat
at this time because it is not currently
determinable. We are soliciting
information to inform our final listing
determination, as well as the
development of potential protective
regulations and critical habitat
designation.
DATES: Comments on the proposed rule
to list the sunflower sea star must be
received by May 15, 2023. Public
hearing requests must be made by May
1, 2023.
ADDRESSES: You may submit comments
on this document, identified by NOAA–
NMFS–2021–0130, by either of the
following methods:
• Electronic Submissions: Submit all
electronic public comments via the
Federal e-Rulemaking Portal. Go to
www.regulations.gov and enter NOAA–
NMFS–2021–0130 in the Search box.
Click on the ‘‘Comment’’ icon, complete
the required fields, and enter or attach
your comments.
• Mail: Submit written comments to
Dayv Lowry, NMFS West Coast Region
Lacey Field Office, 1009 College St. SE,
Lacey, WA 98503, USA.
• Fax: 360–753–9517; Attn: Dayv
Lowry.
Instructions: Comments sent by any
other method, to any other address or
individual, or received after the end of
the comment period, may not be
considered by NMFS. All comments
received are a part of the public record
and will generally be posted for public
viewing on www.regulations.gov
without change. All personally
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Fee per entity
for exempt or
non-exempt
motor carrier,
motor private
carrier, or
freight
forwarder
Fee per entity
for broker or
leasing
company
$37
111
221
769
3,670
35,836
$37
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identifying information (e.g., name,
address), confidential business
information, or otherwise sensitive
information submitted voluntarily by
the sender will be publicly accessible.
NMFS will accept anonymous
comments (enter ‘‘N/A’’ in the required
fields if you wish to remain
anonymous).
The petition, draft status review
report (Lowry et al. 2022), Federal
Register notices, and the list of
references can be accessed
electronically online at: https://
www.fisheries.noaa.gov/species/
sunflower-sea-star. The peer review
plan and charge to peer reviewers are
available at https://www.noaa.gov/
organization/information-technology/
peer-review-plans.
FOR FURTHER INFORMATION CONTACT:
Dayv Lowry, NMFS, West Coast Region
Lacey Field Office, (253) 317–1764.
SUPPLEMENTARY INFORMATION:
Background
On August 18, 2021, we received a
petition from the Center for Biological
Diversity to list the sunflower sea star
(Pycnopodia helianthoides) as a
threatened or endangered species under
the ESA. On December 27, 2021, we
published a positive 90-day finding (86
FR 73230, December 27, 2021)
announcing that the petition presented
substantial scientific or commercial
information indicating that the
petitioned action may be warranted. We
also announced the initiation of a status
review of the species, as required by
section 4(b)(3)(A) of the ESA, and
requested information to inform the
agency’s decision on whether this
species warrants listing as threatened or
endangered.
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Listing Species Under the Endangered
Species Act
To make a determination whether a
species is threatened or endangered
under the ESA, we first consider
whether it constitutes a ‘‘species’’ as
defined under section 3 of the ESA, and
then whether the status of the species
qualifies it for listing as either
threatened or endangered. Section 3 of
the ESA defines species to include
subspecies and, for any vertebrate
species, any distinct population
segment (DPS) which interbreeds when
mature (16 U.S.C. 1532(16)). Because
the sunflower sea star is an invertebrate,
the ESA does not permit us to consider
listing DPSs.
Section 3 of the ESA defines an
endangered species as ‘‘any species
which is in danger of extinction
throughout all or a significant portion of
its range’’ and a threatened species as
one ‘‘which is likely to become an
endangered species within the
foreseeable future throughout all or a
significant portion of its range.’’ Thus,
in the context of the ESA, we interpret
an ‘‘endangered species’’ to be one that
is presently in danger of extinction,
while a ‘‘threatened species’’ is not
currently in danger of extinction, but is
likely to become so in the foreseeable
future (that is, at a later time). The
primary statutory difference between a
threatened and endangered species is
the timing of when a species is in
danger of extinction, either presently
(endangered) or not presently but within
the foreseeable future (threatened).
Being in danger of extinction
‘‘presently’’ does not mean that the
possible extinction event is necessarily
now.
When we consider whether a species
qualifies as threatened under the ESA,
we must consider the meaning of the
term ‘‘foreseeable future.’’ It is
appropriate to interpret ‘‘foreseeable
future’’ as the horizon over which
predictions about the conservation
status of the species can be reasonably
relied upon. What constitutes the
foreseeable future for a particular
species depends on factors such as life
history parameters, habitat
characteristics, availability of data, the
nature of specific threats, the ability to
predict impacts from threats, and the
reliability of forecasted effects of these
threats on the status of the species
under consideration. Because a species
may be susceptible to a variety of threats
for which different data are available, or
which operate across different time
scales, the foreseeable future may not be
reducible to a discrete number of years.
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Section 4(a)(1) of the ESA requires us
to determine whether a species is
endangered or threatened throughout all
or a significant portion of its range as a
result of any one, or a combination of,
the following factors: (1) the present or
threatened destruction, modification, or
curtailment of its habitat or range; (2)
overutilization for commercial,
recreational, scientific, or educational
purposes; (3) disease or predation; (4)
the inadequacy of existing regulatory
mechanisms; or (5) other natural or
manmade factors affecting its continued
existence (16 U.S.C. 1533(a)(1)). We are
also required to make listing
determinations based solely on the best
scientific and commercial data
available, after conducting a review of
the species’ status and after taking into
account efforts, if any, being made by
any state or foreign nation (or
subdivision thereof) to protect the
species (16 U.S.C. 1533(b)(1)(A)).
Status Review
After publishing the 90-day finding
indicating that listing may be warranted
for the sunflower sea star, the NMFS
West Coast Regional Office convened a
Status Review Team (SRT) composed of
marine biologists, ecologists,
statisticians, and natural resource
managers from the NMFS Alaska and
West Coast Regional Offices; NMFS
Alaska, Northwest, and Southwest
Fisheries Science Centers; United States
Geological Survey; and Monterey Bay
National Marine Sanctuary. This team
also received input from state,
provincial, tribal, non-profit, and
academic experts. The SRT compiled
and synthesized all available
information into a comprehensive draft
status review report (Lowry et al. 2022,
see ADDRESSES section). The draft status
review report summarizes the best
available scientific and commercial
information on the biology, ecology, life
history, and status of the sunflower sea
star, as well as stressors and threats
facing the species. The SRT also
considered information submitted by
the public in response to our 90-day
petition finding (86 FR 73230; December
27, 2021).
The draft status review report is
undergoing independent peer review as
required by the Office of Management
and Budget (OMB) Final Information
Quality Bulletin for Peer Review (M–
05–03; December 16, 2004) concurrent
with public review of this proposed
rule. Independent specialists were
selected from the academic and
scientific community, with expertise in
sea star biology, conservation policy,
and applied natural resource
management. The peer reviewers were
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asked to evaluate the adequacy,
appropriateness, and application of data
used in the status review, including the
extinction risk analysis. The peer review
plan and charge statement are available
on NOAA’s website (see ADDRESSES
section). All peer reviewer comments
will be made publicly available and
addressed prior to dissemination of the
final status review report and
publication of the final listing decision.
Below is a summary of the biology
and ecology of the sunflower sea star,
accompanied by an evaluation of threats
facing the species, and resulting
extinction risk. This information is
presented in greater detail in the draft
status review report (Lowry et al. 2022),
which is available on our website (see
ADDRESSES section). In addition to
evaluating the status review, we
independently applied the statutory
provisions of the ESA, including
evaluation of protective efforts set forth
in section 4(b)(1)(A) and our regulations
regarding listing determinations at 50
CFR part 424, to making our
determination that the sunflower sea
star meets the definition of a threatened
species under the ESA.
Description, Life History, and Ecology
of the Petitioned Species
Species Taxonomy and Description
The sunflower sea star was originally
described as Asterias helianthoides by
Brandt (1835), a species of sea star
unique in having 16 to 20 rays (arms)
and found in coastal marine waters near
Sitka, Alaska. Stimpson (1861) later
designated it as the type species of the
new genus Pycnopodia and as the only
known species of the family
Pycnopodiidae. Fisher (1922) described
the Pacific starfish Lysastrosoma
anthosticta as a new species, stating it
was closely related to Pycnopodia, and
subsequent authors have included only
these two species in the subfamily
Pycnopodiinae. Pycnopodia
helianthoides has no known synonyms,
and the validity of the species has not
been questioned in the taxonomic
literature. Therefore, based on the best
available scientific and commercial
information, we find that the scientific
consensus is that P. helianthoides is a
taxonomically distinct species and,
therefore, meets the definition of
‘‘species’’ pursuant to section 3 of the
ESA. Below, we evaluate whether this
species warrants listing as endangered
or threatened under the ESA throughout
all or a significant portion of its range.
The sunflower sea star is among the
largest sea stars in the world, reaching
over 1 meter (m) in total diameter from
ray tip to ray tip across the central disk.
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The sunflower sea star and closely
related Pacific starfish are distinguished
from other co-occurring sea stars by
their greatly reduced abactinal (dorsal)
skeleton with no actinal plates, and by
their prominently crossed pedicellariae
(Fisher 1928). Very young sunflower sea
stars generally have fewer than a dozen
arms, and additional arms are added by
budding in symmetrical pairs as the
individual grows. Other sea stars in the
northern Pacific Ocean with many arms
include several sun stars of the genera
Solaster, Crossaster, and Rathbunaster;
however, these species generally have 8
to 17 arms, as opposed to the 16 to 20
arms commonly found in the sunflower
sea star, and all of the sun stars are
considerably smaller and less massive
(Fisher 1906).
Range, Distribution, and Habitat Use
The documented geographic range of
the sunflower sea star spans the
Northeastern Pacific Ocean from the
Aleutian Islands to Baja California
(Sakashita 2020). This range includes 33
degrees of latitude (3,663 km) across
western coasts of the continental United
States, Canada, and northern Mexico.
The farthest reaches of sunflower sea
star observations include:
northernmost—Bettles Bay, Anchorage,
Alaska (Gravem et al., 2021);
westernmost—central and eastern
Aleutian Islands (Kuluk Bay, Adak
Island east to Unalaska Island, Samalga
Pass, and Nikolski) (Feder 1980; O’Clair
and O’Clair 1998; Jewett et al. 2015;
Gravem et al. 2021); and
southernmost—Bahia Asuncio´n, Baja
California Sur, Mexico (Gravem et al.
2021). The sunflower sea star is
generally most common from the Alaska
Peninsula to Monterey, California.
The sunflower sea star has no clear
associations with specific habitat types
or features and is considered a habitat
generalist (Gravem et al. 2021 and
citations therein). The large geographic
and depth range of the sunflower sea
star indicates this species is well
adapted for a wide variety of
environmental conditions and habitat
types. The species is found along both
outer coasts and inside waters, which
consist of glacial fjords, sounds,
embayments, and tidewater glaciers.
Preferring temperate waters, they
inhabit kelp forests and rocky intertidal
shoals (Hodin et al. 2021), but are
regularly found in eelgrass meadows as
well (Dean and Jewett 2001; Gravem et
al. 2021). Sunflower sea stars occupy a
wide range of benthic substrates
including mud, sand, shell, gravel, and
rocky bottoms while roaming in search
of prey (Konar et al. 2019; Lambert et al.
2000). They occur in the low intertidal
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and subtidal zones to a depth of 435 m
but are most common at depths less
than 25 m and rare in waters deeper
than 120 m (Fisher 1928; Lambert 2000;
Hemery et al. 2016; Gravem et al. 2021).
This characterization of their prevalence
across depth ranges, however, may be
biased by: (1) differential sampling
methods and effort, with SCUBA-based
observations dominating records; and
(2) the propensity to record all sea stars
as ‘‘sea star unidentified’’ when they
occur as incidental bycatch in various
survey and fishery records.
Reproduction, Growth, and Longevity
Most sea star species, including the
sunflower sea star, have separate sexes
that are externally indistinguishable
from one another, and each ray of an
adult contains a pair of gonads (Chia
and Walker 1991). In the sunflower sea
star, gonads are elongated, branched
sacs that fill the length of each ray when
ripe (Chia and Walker 1991). Gametes
are broadcast through gonopores on
each ray into the surrounding seawater
and fertilization occurs externally.
Fertilized larvae develop through
pelagic planktotrophic stages, capturing
food with ciliary bands (Strathmann
1971; 1978; Byrne 2013).
A number of environmental factors,
such as food availability, seawater
temperature, photoperiod, salinity, and
the lunar cycle, may control seasonality
of sea star reproductive cycles (Chia and
Walker 1991; Pearse et al. 1986).
Although the reproductive season of
several Northeast Pacific sea stars have
been estimated by following oocytediameter frequency distributions (e.g.,
Farmanfarmaian et al. 1958; Mauzey
1966; Pearse and Eernisse 1982), to the
best of our knowledge no one has
conducted such studies in free-ranging
sunflower sea stars. However, a number
of researchers have estimated
reproductive seasonality of the species
based on observations of either field or
laboratory spawning. Mortenson (1921)
reported that sunflower sea stars breed
from May through June at Nanaimo,
British Columbia, while Greer (1962)
collected adult broodstock from the
intertidal zone at San Juan Island,
Washington, and reported spawning in
March and April. Feder (1980) obtained
fertilizable eggs from December through
June in California, and Strathmann
(1987) stated that spawning occurs from
late March through July, peaking from
May through June with some large
males spawning into December and
January. More recently, Hodin et al.
(2021) suggested that the reproductive
season for females begins in November
through January and ends in April and
May in Washington. It is possible that
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a slightly altered photoperiod and
constant availability of food for these
lab-held specimens, however, may have
caused individuals to exhibit altered
reproductive seasonality, explaining the
apparent discrepancy. Hodin et al.
(2021) also note that the reproductive
season for females occurs later in
Alaska.
Typically, sea stars with
planktotrophic larval (i.e., reliant on
planktonic prey) development from the
Northwest Pacific Ocean spawn in late
winter or early spring, which provides
the best growing conditions for their
offspring by synchronizing their
occurrence with the spring
phytoplankton bloom (Menge 1975;
Strathmann 1987). The spawning
seasons of several other sea stars with
planktotrophic larval development in
the Pacific Northwest and on the U.S.
West Coast occurs between March and
August (Mortensen 1921;
Farmanfarmaian et al. 1958; Mauzey
1966; Feder 1980; Fraser et al. 1981;
Pearse and Eernisse 1982; Strathmann
1987; Pearse et al. 1988; Sanford and
Menge 2007). In addition, many
temperate sea stars, such as the ochre
star (Pisaster ochraceus), have seasonal,
cyclical feeding patterns, such that
feeding activity is reduced during the
late fall and winter (Feder 1980; Mauzey
1966; Sanford and Menge 2007). This
may also be the case for the sunflower
sea star but direct documentation of this
phenomenon is lacking. Planktotrophic
larvae of the sunflower sea star
developing during winter (November to
February) in the Northeast Pacific Ocean
would be at a distinct disadvantage due
to the scarcity of planktonic algae at that
time.
We were unable to find direct
estimates of fecundity for female
sunflower sea stars anywhere in the
literature or in unpublished records.
However, Strathmann (1987) states that
ripe ovaries of specimens about 60 cm
across may weigh 400 to 800 grams (g).
Comparing this estimate with fecundity
estimates for the ochre star, a Northeast
Pacific sea star that has similar egg size
and reproductive strategy, may give
some insight to potential fecundity of
the sunflower sea star. Menge (1974)
estimated that a typically sized female
ochre star weighing 400 g wet weight
would produce ∼40 million eggs,
representing an average of 9 to 10
percent of wet weight being put into
reproductive effort. As the wet weight of
ochre stars ranges up to 650 g (Menge
1975), a female of this size could spawn
considerably many more than 40
million eggs in a season. However,
Fraser et al. (1981) believed that
Menge’s (1974) estimate of 40 million
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eggs for a 400 g adult was somewhat
high and calculated that a specimen
weighing 315 g would produce ∼8
million total eggs. Given that sunflower
sea stars can grow to a massive five
kilograms (kg) (Fisher 1928; Lambert
2000), and assuming sunflower sea stars
and ochre stars invest similar resources
into reproductive efforts, it is
conceivable that a 4.5 kg female
sunflower sea star could produce
upwards of 114 million eggs in a
gonadal cycle using the conservative
estimate of Fraser et al. (1981). This
level of potential egg production is
comparable to estimates for the crownof-thorns sea star, Acanthaster spp.
(Babcock et al. 2016), potentially
making the sunflower sea star one of the
most fecund sea stars in the world. This
high potential fecundity is debatable,
however, given recent observations of
gonad size in captive sunflower sea
stars. Hodin et al. (2021) noted that even
when reproductively mature, gonads
tend to be no more than a few
centimeters in length, which is small
relative to other sea stars of the
Northwest Pacific Ocean.
Regarding size at sexual maturity,
near Bremerton, Washington, KjerskogAgersborg (1918) noted that maturity is
not entirely dependent on size. While
females are on the average larger than
males, immature individuals of both
sexes were found across a broad range
of sizes—including some of the largest
individuals sampled. In a status
assessment conducted for the
International Union for Conservation of
Nature (IUCN), Gravem et al. (2021)
state that no studies have been
conducted specifically on the age at
maturity for the sunflower sea star, but
estimate it to be at least five years based
on the age of first reproduction for the
ochre star (Menge 1975; Chia and
Walker 1991).
Without additional information on the
size at first maturity, fecundity,
reproductive seasonality, and
reproductive senescence of the
sunflower sea star, and how these
demographic parameters vary
throughout the range of the species, it is
impossible to accurately predict annual
reproductive output of populations or to
adequately evaluate resiliency and
rebound potential in response to
environmental perturbations.
Indications from other sea stars,
however, suggest that reproductively
viable females can produce at least tens
of millions of eggs annually, possibly for
several decades. Under appropriate
environmental conditions, this
represents considerable reproductive
and recruitment potential.
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Sea stars may modify their behavior
during spawning in ways that improve
the chances of egg fertilization,
including aggregating, modifying their
positions and postures, and spawning
synchronously (Strathmann 1987; Chia
and Walker 1991; Dams et al. 2018).
Although many sea stars appear to
aggregate during spawning (Strathmann
1987; Minchin 1987; Chia and Walker
1991; Babcock and Mundy 1992;
Raymond et al. 2007; Himmelman et al.
2008; Dams et al. 2018), it is uncertain
whether sunflower sea stars do so.
Kjerskog-Agersborg (1918) studied
sunflower sea stars in Puget Sound at
Bremerton, WA, and suggested that
individuals migrated to shallower
waters during the spawning season and
were present in large aggregations at this
time of year. A number of other sea stars
move into shallow water during the
spawning season, supporting that
movement into shallow water may be an
adaptive behavior that promotes
fertilization (Babcock et al. 2000). Some
fertilization rate modeling results for the
crown-of-thorns sea star Acanthaster
spp. (Babcock et al. 1994) indicate that
shallower water increases fertilization
rates relative to deeper water because of
reduced dilution of gametes in waters
shallower than 5 m (Babcock et al.
2000).
Many sea stars arch their bodies
upward, remaining in contact with the
substratum by the tips of their arms
during spawning. This posture elevates
the gonopores through which gametes
are shed into the flow field (Galtsoff and
Loosanoff 1939; Strathmann 1987;
Minchin 1987; Chia and Walker 1991;
Dams et al. 2018). Dams et al. (2018)
used laboratory experimentation and
theoretical modeling to show that an
arched posture promoted downstream
dispersion of gametes and was more
effective than stars lying in the flat
position. It is common knowledge that
sunflower sea stars also arch their
bodies upward in this characteristic
spawning posture. Although we were
unable to locate specific reference in the
scientific literature, there are numerous
photographs and depictions of
sunflower sea stars assuming this
spawning posture on the internet (e.g.,
https://www.kuow.org/stories/scientistsrace-to-rescue-world-s-fastest-sea-starfrom-oblivion).
Since released gametes (especially
sperm) may remain viable for as little as
two hours (Strathmann 1987; Benzie
and Dixon 1994), many sea stars
increase the chances of egg fertilization
by spawning synchronously (Feder and
Christensen 1966; Babcock and Mundy
1992; Babcock et al. 1994; Mercier and
Hamel 2013). In many published
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observations of sea star spawning, males
consistently spawned before females
(Mercier and Hamel 2013). Even though
synchronous spawning is necessary for
successful fertilization to occur,
synchronization must be accompanied
by relatively close proximity for
successful fertilization (Mercier and
Hamel 2013). There is conflicting
information regarding whether
synchronous aggregative spawning is
exhibited by the sunflower sea star, but
evidence from ecologically similar sea
star species and anecdotal observations
for the sunflower sea star strongly
suggest this is the case. If this is the
case, when population abundance
declines below levels that ensure
contact of distributed eggs and sperm
with one another, Allee effects may
hinder population persistence and/or
recovery (Lundquist and Botsford 2004;
2011). Standard population models
predict that a reduction in adult density
should be associated with a decrease in
intraspecific competition leading to an
increase in growth rate, survival, and
gamete production. However, these
advantages may be countered by
decreases in the rate of successful
fertilization among sparsely distributed
individuals (Levitan 1995; Levitan and
Sewell 1998; Gascoigne and Lipcius
2004). Fertilization success may be a
limiting factor in reproduction, and
hence recruitment. We did not find
published data from directed studies of
natural fertilization success in the
sunflower sea star.
Several researchers have, with varying
degrees of success, attempted to rear
sunflower sea stars and describe early
embryonic and larval development
through to metamorphosis (Mortensen
1921; Greer 1962; Strathmann 1970;
1978; Chia and Walker 1991; Hodin et
al. 2021). Greer (1962) reported that
time from fertilization to metamorphosis
for larvae from San Juan Islands,
Washington, ranged from 60 to 70 days
when reared at 10 to 12 °C. Strathmann
(1978) reported that time from
fertilization through to settling ranged
from 90 to 146 days at natural local
water temperatures (7 to 13 °C)
encountered in the San Juan Islands,
Washington, in the late 1960s. Hodin et
al. (2021) reared sunflower sea stars
from Washington at 9 °C and 14 °C and
observed first spontaneous settlement of
larvae at seven weeks when held at 10
to 11 °C. Peak metamorphosis occurred
at eight weeks in larvae derived from
Alaskan broodstock, compared to 11
weeks for larvae from Washington
broodstock. Hodin et al. (2021) reported
that larvae first became competent to
metamorphose at seven weeks post-
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fertilization at 10 to 11 °C, compared to
the nine weeks reported by Greer (1962)
when reared at 10 to 12 °C. Together,
these studies indicate that larval
duration may be as short as seven weeks
or as long as 21, and that temperature
is a key parameter determining the
extent of this period.
Unlike the pentaradial symmetry of
adult sea stars, larvae are bilaterally
symmetrical (Chia and Walker 1991).
The bipinnaria larva is characterized by
two bilaterally symmetrical ciliary
bands and an open, functional gut
(McEdward et al. 2002). Both the
bipinnaria, and the later-stage
brachiolaria, ingest diatoms and other
single-celled algae, and may also utilize
dissolved organic matter nutritionally
(Chia and Walker 1991). Bipinnaria
larvae of the sunflower sea star were
estimated to form on the fifth (Greer
1962) or sixth day (Hodin et al. 2021)
after fertilization.
To understand the population
dynamics of the sunflower sea star on a
range-wide basis it is crucial to develop
an understanding of larval longevity and
capacity for dispersal. Time from egg
fertilization to metamorphosis for the
sunflower sea star under various
conditions has been described as 49 to
77 days (Hodin et al. 2021), 60 to 70
days (Greer 1962), and 90 to 146 days
(Strathmann 1978). As noted by Gravem
et al. (2021), broadcast spawning with a
long pelagic larval duration has the
potential for broad larval dispersal,
especially in open coastal areas with
few geographic barriers. Along more
heterogeneous, complex shorelines like
those found inside the Salish Sea or
Southeast Alaska, however, complex
flow patterns may result in localized
entrainment of larval and reduce
dispersal capacity.
Minimum and maximum dispersal
periods based on laboratory studies of
planktotrophic larvae reveal how
varying environmental and nutritional
conditions influence the extent of the
planktonic period (Pechenik 1990).
Basch and Pearse (1996) showed that
sea star larvae grown in phytoplanktonrich conditions had greater survival,
were in better condition, settled and
metamorphosed sooner, and produced
larger juveniles compared to larvae
grown in low food concentrations.
Planktotrophic larvae of many sea star
species can delay metamorphosis in the
absence of suitable settlement cues
(Metaxas 2013), and are capable of longrange dispersal (Scheltema 1986;
Metaxas 2013). Although mortality of
sea star larvae during the planktonic
larval stage has not been measured, it is
expected to be high (Metaxas 2013), and
it is likely that delaying metamorphosis
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would expose larvae to an additional
period of predatory pressure (Basch and
Pearse 1996) and stress associated with
limited food availability. Strathmann
(1978) found the maximum time to
settlement in culture for sunflower sea
star to be 21 weeks and emphasized that
the duration of pelagic larval life is
important in recruitment dynamics and,
ultimately, to the distribution of a
species.
Sea star larvae may respond to a suite
of biological, chemical, and/or physical
cues that induce metamorphosis and
settlement, including the presence of
coralline algae, microbial films, and
kelp (Metaxas 2013). Hodin et al. (2021)
state that competent sunflower sea star
larvae will settle spontaneously, as well
as in response to a variety of natural
biofilms. Settlement is greatly enhanced
when larvae are presented with a
biofilm collected in the presence of
adult sunflower sea stars, or if larvae are
exposed to fronds of the articulated
coralline alga, Calliarthron
tuberculosum.
It is generally accepted that
planktotrophic larvae are typically
dispersed considerable distances away
from adult populations and have little
impact on recruitment to the natal
habitat (Sewall and Watson 1993;
Robles 2013). However, Sewell and
Watson (1993) described a situation at
the semi-enclosed bay of Boca del
Infierno (Nootka Island, British
Columbia) where larvae were entrained
and settled within the adult habitat,
contributing to the source population.
During three years between 1987 and
1991, sunflower sea star recruits were
observed on Sargassum muticum on the
floor of the channel leading into the bay
(Sewell and Watson 1993). In general,
sea stars are thought to have relatively
low annual recruitment punctuated by
unusually strong settlement in some
years (Sanford and Menge 2007), the socalled boom and bust cycle
characteristic of a broad diversity of
marine fishes and invertebrates with
planktonic larval dispersal (e.g.,
McLatchie et al. 2017; Schnedler-Meyer
et al. 2018).
Larvae of sea stars are capable of
regenerating lost body parts much like
adults (Vickery and McClintock 1998;
Vickery et al. 2002; Allen et al. 2018)
and may also reproduce asexually
through the process of larval cloning—
budding off of tissue fragments that
regenerate into complete larvae (Bosch
et al. 1989; Rao et al. 1993; Jaeckle 1994;
Knott et al. 2003). Recently, Hodin et al.
(2021) reported that larvae of the
sunflower sea star also have the
capability to clone in a laboratory
setting, describing cloning as
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‘‘commonplace’’ in all larval cultures.
The degree to which larval sunflower
sea stars clone in nature may have
profound implications for life history
(e.g., fecundity, dispersal distance),
population dynamics, and population
genetic structure (Knott et al. 2003;
Balser 2004; Rogers-Bennett and Rogers
2008; Allen et al. 2018; 2019).
In a recent review of asexual
reproduction in larval invertebrates,
Allen et al. (2018) tabulated the
potential benefits of larval cloning as:
(1) increasing female fecundity without
an apparent increase in resource
allocation to reproduction; (2)
increasing the likelihood that a member
of a genet (i.e., group of cloned
individuals) survives; (3) increasing the
probability that a member of a genet will
locate a suitable settlement site by
sampling a greater geographic area; and
(4) reducing the genet’s susceptibility to
predation and other loss by increasing
the number and decreasing the size of
propagules. On the other hand, Allen et
al. (2018) listed likely costs associated
with larval cloning as: (1) a decrease in
larval feeding rate during fission; (2) a
decrease in larval growth rate; (3) an
increase in the time to metamorphosis;
and (4) a decrease in juvenile size.
Larval cloning has the potential to alter
several aspects of sunflower sea star life
history by increasing actualized
fecundity, larval dispersal distance, and
chances of successful settlement of a
larva or at least its genetically identical
clone (Bosch et al. 1989; Balser 2004;
Rogers-Bennett and Rogers 2008; Allen
et al. 2019). Balser (2004) noted that
cloning serves to increase female
fecundity to >1 juvenile per egg, altering
recruitment intensity. Without
additional information about
environmental impacts on cloning rate,
this lack of a one-to-one relationship
between female productivity and
realized recruitment potential
complicates estimation of stock-recruit
relationships. Allen et al. (2019)
emphasized that ignoring the impacts of
planktonic cloning meant that both
realized reproductive output and larval
dispersal period had been
underestimated in prior population
modeling efforts for sea stars (RogersBennett and Rogers 2008). To date,
evidence of the existence of sexually
mature sea star individuals in wild
populations that originated from cloned
larvae is lacking for any species (Knott
et al. 2003), including the sunflower sea
star. Thus, despite a demonstrated
capacity to clone as larvae, estimates of
female fecundity considered in the draft
status review report (Lowry et al. 2022)
are limited to gross estimates of egg
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production on a seasonal basis, which,
as noted above, are tenuous at best.
No studies have been conducted to
establish natural growth rates
throughout the lifespan of the sunflower
sea star, due in part to the difficulty of
tagging and effectively tracking
individuals. The IUCN assessment for
the sunflower sea star lists several
observations of juvenile growth rates
from anecdotal observations and
laboratory studies as being between 3
and 8 cm/yr, and 2 cm/yr for mid-sized
individuals (Gravem et al. 2021). Hodin
et al. (2021) reared post-metamorphic,
laboratory-cultured sunflower sea stars
and the fastest growing individuals were
able to reach a diameter of 3 cm in 288
days (about 9.5 months) post-settlement.
Juveniles reared by Hodin et al. (2021)
grew slowly for several months after
settlement, but grew faster after they
reached about 10 cm in diameter, at
which time they could feed on live
juvenile bivalves. Laboratory estimates
may not be entirely representative of
growth rates in the field because sea star
growth is affected by water temperature
and food availability (Gooding et al.
2009; Deaker et al. 2020; Dealer and
Byrne 2022). Sea star growth rate also
generally decreases with increasing size
of individuals (Carlson and Pfister 1999;
Keesing 2017). Some sea stars can
persist for long periods with little or no
food (Nauen 1978; Deaker et al. 2020;
Byrne et al. 2021), potentially
complicating estimates of age based on
size and resulting in episodic growth
only when resources are adequate to
exceed base metabolic needs.
In one of the few published reports of
sunflower sea star growth under
pseudonatural conditions, Miller (1995)
described growth of juveniles found on
settlement collectors (i.e., Astroturfcoated PVC tubes) on the Oregon coast.
When fed crushed prey, juveniles grew
from a mean arm length (AL) of 0.41
mm at first sampling, to a mean AL of
3.65 mm at 63 days, and 5 to 6 mm AL
at 99 days. Thus, juveniles increased in
size by a factor of nearly nine times after
two months and up to 14 times after
three months from sampling (Miller
1995).
In response to the call for public
comments on our 90-day finding for the
petition to list the sunflower sea star
under the ESA (86 FR 73230; December
27, 2021), we received a dataset
demonstrating growth of putative
cohorts of juvenile sunflower sea stars
from Holmes Harbor on the east side of
Whidbey Island, in the Southern Salish
Sea, Washington (K. Collins, pers.
comm., March 20, 2022). During
repeated SCUBA-based sampling of the
size distribution of populations of
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sunflower sea stars at several index sites
between March of 2020 and 2022,
recruitment pulses of individuals could
be identified from frequency of
occurrence data. Between March of 2020
and March of 2021, the average diameter
of one such group of juvenile sunflower
sea stars increased 7.99 cm, from ∼9 to
17 cm. This annual growth rate aligns
with the rapid growth period identified
by Hodin et al. (2021), concomitant with
the ability to consume small bivalves.
While this estimate is for one small
population in the Salish Sea and is
cohort-based rather than based on
tracking target individuals, it provides
insight into the growth of juvenile
sunflower sea stars that is not available
elsewhere.
The longevity of sunflower sea stars
in the wild is unknown, as is the age at
first reproduction (as noted above) and
the period over which a mature
individual is capable of reproducing,
but these parameters are needed to
calculate generation time. It is also
unknown if, or how much, any of these
crucial life history parameters vary
across the range of the species. The
IUCN assessment for the sunflower sea
star used a generic echinoderm equation
to estimate generation times as 20.5 to
65 years or 27 to 37 years, depending on
maximum longevity (reaching
maximum size observed of 95 to 100 cm
diameter) or more typical longevity
(time to reach 50 cm diameter)
estimated from two different growth
models (Gravem et al. 2021). These
generation time figures utilized an
estimated age at first reproduction of
five years, based on the ochre star and
other species, as this information is not
available for the sunflower sea star
(Gravem et al. 2021).
Diet and Feeding
Larval and pre-metamorphic
sunflower sea stars are planktonic
feeders and no data exist to suggest a
prey preference at this stage. The diet of
adult sunflower sea stars generally
consists of benthic and mobile
epibenthic invertebrates, including sea
urchins, snails, crab, sea cucumbers,
and other sea stars (Mauzey et al. 1968;
Shivji et al. 1983), and appears to be
driven largely by prey availability. Sea
urchins were the major dietary
component in the intertidal regions
along the outer coast of Washington in
a study by Mauzey et al. (1968). For
sunflower sea stars inhabiting kelp
forests in central California, however, 79
percent of the diet was gastropods, and
only four sea urchins were found in the
guts of 41 adults (Herrlinger 1983).
Sunflower sea stars also feed on sessile
invertebrates, such as barnacles and
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various bivalves (Mauzey et al. 1968).
Mussels are a common prey in intertidal
regions in Alaska (Paul and Feder 1975).
Clams can also constitute a major
proportion of their diet, with up to 72
percent coming from clams at subtidal
sites within Puget Sound (Mauzey et al.
1968). Adults excavate clams from soft
or mixed-substrate bottoms by digging
with one or more arms (Smith 1961;
Mauzey et al. 1968). Sunflower sea stars
locate their prey using chemical signals
in the water and on substrate, and may
show preference for dead or damaged
prey (Brewer and Konar 2005), likely
due to reduced energy expenditure
associated with catching and subduing
active prey; thus they occasionally
scavenge fish, seabirds, and octopus
(Shivji et al. 1983).
Population Demographics and Structure
Prior to the onset of the coast-wide
sea star wasting syndrome (SSWS)
pandemic in 2013 (see evaluation of
threats below), directed population
monitoring for the sunflower sea star
was haphazard and typically the result
of short-term research projects rather
than long-term monitoring programs.
Such efforts were rarely focused on the
sunflower sea star itself, but it was often
included as one component of the local
invertebrate assemblage, and generally it
was secondary to the primary species of
interest. Indigenous peoples occupying
lands along the Pacific Coast of North
America from Alaska to California have
long known of the sunflower sea star,
have included the species in artistic
works, and have recognized the
important ecological role it plays.
However, no oral histories or other
traditional ecological knowledge that
directly addressed long-term population
distribution or abundance could be
found. In response to the 90-day finding
on the petition to list the sunflower sea
star (86 FR 73230; December 27, 2021),
several First Nation and tribal entities
contacted us to provide recent
monitoring data, which was integrated
into the draft status review report as
much as possible (Lowry et al. 2022).
Most of the datasets lacked pre-2013
(i.e., before the SSWS pandemic)
occurrence records, however, and could
not be used to quantitatively evaluate
trends in abundance or density relative
to baseline values.
Recent descriptions of sunflower sea
star distribution and population
declines by Harvell et al. (2019),
Gravem et al. (2021), and Hamilton et al.
(2021) relied on datasets gathered either
exclusively or predominantly during the
21st century and, in some cases, as a
direct response to losses due to SSWS.
The most intense loss occurred over just
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a few years from 2013 through 2017,
generally commencing later in more
northern portions of the range, and
impacts varied by region. Hence, our
understanding of the historical
abundance of the sunflower sea star is
patchy in both time and space, with
substantial gaps.
Summary data presented in Gravem et
al. (2021) indicate that prior to the 2013
through 2017 SSWS outbreak the
sunflower sea star was fairly common
throughout its range, with localized
variation linked to prey availability and
various physiochemical variables.
Starting in 2012, Konar et al. (2019)
assessed rocky intertidal populations in
the Gulf of Alaska and described
sunflower sea stars prior to the 2016
wasting outbreak as ‘‘common’’ toward
the northwest part of the species’ range
in the Katmai National Park and
Preserve near Kodiak Island, AK (0.038/
m2 in 2012 and 0.048/m2 in 2016,
respectively). Abundances during this
pre-pandemic period varied
geographically, from infrequent in
Kachemak Bay (<0.005 m2), to fairly
common in the Kenai Fjords National
Park (∼0.075/m2), and common in
western Prince William Sound (average
0.233/m2) (Konar et al. 2019). In
subtidal rocky reefs near Torch Bay,
Southeast Alaska, densities were high
(0.09 ± 0.055/m2) in the 1980s (Duggins
1983). In Howe Sound, near Vancouver,
British Columbia, densities were high at
0.43 ± 0.76/m2 in 2009 and 2010 before
the SSWS pandemic (Schultz et al.
2016). Montecino-LaTorre et al. (2016)
found that sunflower sea star abundance
averaged 6 to 14 individuals per roving
diver survey throughout much of the
Salish Sea from 2006 through 2013. In
deep water habitats off the coasts of
Washington, Oregon, and California,
2004 through 2014 pre-outbreak
biomass averaged 3.11, 1.73, and 2.78
kg/10 ha, respectively (Harvell et al.
2019). In 2019, a remotely operated
vehicle survey of the Juan de Fuca
Canyon encountered a number of large
sunflower sea stars at depths ranging
from 150 to 350 m (OCNMS 2019).
While population connections between
these sea stars and those in shallow
water remain unknown, this suggests
that deep waters may serve as a biomass
reservoir for the species (J. Waddell,
Olympic Coast National Marine
Sanctuary, pers. comm., March 15,
2022).
Along the north and central California
coastline, average population densities
were 0.01–0.12/m2 prior to 2013
(Rogers-Bennett and Catton 2019). The
oldest density records come from kelp
forests near central California in
Monterey Bay, where densities were
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0.03/m2 in 1980 and 1981 (Herrlinger
1983). More recently in central
California, densities were even lower
and fluctuated from 0.01–0.02/m2
between 1999 and 2011 (Smith et al.
2021). In southern California, sites in
the Channel Islands have been studied
extensively, and from 1982 through
2014 densities ranged from 0 to 0.25/m2
(Bonaviri et al. 2017), from 1996
through 1998 they were 0 to 0.02 m2
(Eckert 2007), from 2003 through 2007
they were 0 to 0.07m2 (Rassweiler et al.
2010), and from 2010 through 2012 they
were ∼0.10 to 0.14/m2 (Eisaguirre et al.
2020).
The pattern of decline by latitude as
a consequence of the SSWS pandemic
in 2013 (see evaluation of threats below)
is striking. Hamilton et al. (2021) noted
a 94.3 percent decline throughout the
range of the sunflower sea star after the
outbreak of SSWS. The 12 regions
defined by Hamilton et al. (2021)
encompass the known range of the
sunflower sea star, and each region
exhibited a decline in density and
occurrence from approximately 2013
through 2017, with populations in the
six more northern regions characterized
by less severe declines (40 to 96 percent
declines) than those in the six regions
spanning from Cape Flattery, WA, to
Baja, MX, where the sunflower sea star
is now exceptionally rare (99.6 to 100
percent declines). Furthermore, while
anecdotal observations indicate
recruitment continues in the U.S.
portion of the Salish Sea, British
Columbia, and Alaska, few of these
juveniles appear to survive to adulthood
(A. Gehman, University of British
Columbia and the Hakai Institute, pers.
comm., February 16, 2022). We are not
aware of any observations of sunflower
sea star recruits or adults in California
or Mexico since 2017 despite continued
survey effort in these areas.
There are not, to date, any range-wide
or regional assessments of systematic
variation in life history parameters,
morphological characteristics, genetic
traits, or other attributes that can be
used to delineate specific populations of
sunflower sea stars. As such, we have
no direct biological data to establish that
the species is anything but a single,
panmictic population throughout its
range. As habitat generalists that use a
wide variety of substrates over a broad
depth range, and dietary generalists that
consume diverse prey based largely on
prey availability and encounter rate,
differentiation of subpopulations is not
expected to be driven by strong
selection for particular environmental
needs. In the 2020 IUCN status
assessment report (Gravem et al. 2021),
putative population segments were
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identified largely based on a
combination of legal and geographic
boundaries/barriers and data provided
in response to a broad request
distributed to natural resource managers
and academic researchers. For instance,
data from both trawl and SCUBA diving
surveys were considered together to
describe population trends in a region
defined as ‘‘Washington outer coast,’’
which spanned from Cape Flattery to
the Washington-Oregon border.
Because sunflower sea stars are
relatively sessile in the settled juvenile
through adult life stages, any population
structuring is likely attributable to
dispersion during the pelagic larval
phase. This is a common feature of
broadcast spawning, benthic, marine
organisms, and population breaks in
such organisms are typically associated
with strong biogeographic features
where current flows diverge or stop (i.e.,
Queen Charlotte Sound, Point
Conception), if such features exist.
Within a given biogeographic region,
such organisms typically exhibit either
genetic homogeneity for species with
prolonged pelagic larval phases or, for
species with shorter pelagic larval
duration, a stepping-stone dispersal
resulting in isolation-by-distance.
Within the historical range of the
sunflower sea star, there are two major
biogeographic regions (Longhurst 2007),
the ‘‘Alaska Coastal Downwelling
Province’’ and the ‘‘California Current
Province.’’ These regions are essentially
formed by the bifurcation of the North
Pacific Current into the northwardflowing Alaska Current and the
southward-flowing California Current.
This bifurcation occurs in the vicinity of
Vancouver Island, though the exact
location varies with shifting climatic
conditions and bulk water transport
processes, with a transition zone
between Queen Charlotte Sound and
Cape Flattery (Cummins and Freeland
2007).
For some echinoderm species that
have been more thoroughly examined,
regional variation in phenotypic and
genetic traits along the west coast of
North America have been documented.
Bat stars (Patiria miniata) largely
overlap with the sunflower sea star in
geographic range and depth
distribution, and share similar
planktonic larval duration, so can
potentially be used as a proxy to make
demographic inferences. Keever et al.
(2009) used a combination of
mitochondrial and nuclear markers to
study bat stars range-wide and provided
support for two genetically distinct
populations, essentially split across
Longhurst’s (2007) biogeographic
provinces. Within the California Current
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Province there was little detectable
genetic structure, but within the Alaska
Coastal Downwelling Province there
was a high degree of structure,
potentially as a consequence of the
geographic complexity within this
region as compared with the California
Coast Province. Gene flow simulations
showed that larvae of the bat star don’t
disperse far despite a relatively long
pelagic larval duration (Sunday et al.
2014). The red sea urchin
(Strongylocentrotus franciscanus) also
overlaps in range, depth, and duration
of planktonic dispersal with sunflower
sea star but shows no clear signal of
genetic partitioning (Debenham et al.
2000) throughout its range. Similarly,
the ochre star exhibits similar life
history parameters but shows no genetic
partitioning (Harley et al. 2006).
Overall, the lack of demonstrated
genetic structure in these co-occurring
echinoderm species suggests that
sunflower sea stars may also lack
population structure, but no genetic
studies currently exist that would allow
us to confirm or refute this assumption.
Assessment of Extinction Risk
Using the best available scientific and
commercial data relevant to sunflower
sea star demography and threats, the
SRT undertook an assessment of
extinction risk for the species. The
ability to measure or document risk
factors and quantify their explicit
impacts to marine species is often
limited, and quantitative estimates of
abundance and life history information
are sometimes lacking altogether.
Therefore, in assessing extinction risk of
this data-limited species, we relied on
both qualitative and quantitative
information. In previous NMFS status
reviews, assessment teams have used a
risk matrix method to organize and
summarize the professional judgment of
members. This approach is described in
detail by Wainwright and Kope (1999)
and has been used in Pacific salmonid
status reviews, as well as in reviews of
various marine mammals, bony fishes,
elasmobranchs, and invertebrates (see
https://www.nmfs.noaa.gov/pr/species/
for links to these reviews). In the risk
matrix approach, the condition of a
species is summarized according to four
viable population factors: abundance,
growth rate/productivity, spatial
structure/connectivity, and diversity
(McElhany et al. 2000). These viable
population factors reflect concepts that
are well-founded in conservation
biology and that, individually and
collectively, provide strong indicators of
extinction risk. Employing these
concepts, the SRT conducted a
demographic risk analysis for the
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sunflower sea star to determine
population viability. Likewise, the SRT
performed a threats assessment by
scoring the severity of current threats to
the species and their likely impact on
population status into the foreseeable
future. The summary of demographic
risks and threats obtained by this
approach was then considered to
determine the species’ overall level of
extinction risk, ranked either low,
moderate, or high, both currently and in
the foreseeable future. Further details on
the approach and results are available in
Lowry et al. (2022).
For the assessment of extinction risk
for the sunflower sea star, the
‘‘foreseeable future’’ was considered to
extend out 30 years based on several
lines of evidence, though numerous
assumptions had to be made due to
missing information. Limited data are
available regarding sunflower sea star
longevity, age at sexual maturity, size at
sexual maturity, fecundity, reproductive
life span, spawning frequency, and
other fundamental biological attributes.
Further, the degree to which these
parameters might vary over the range of
the species is unknown. Gravem et al.
(2021) estimated the generation time of
the sunflower sea star to vary between
20.5 and 65 years based on a generalized
echinoderm model, but used an estimate
of 27 to 37 years for the 2020 IUCN
assessment. Monitoring data for the
sunflower sea star at locations spread
throughout its range documented
extremely rapid, dramatic declines from
2013 to 2017 as a consequence of SSWS.
Despite considerable research since, the
causative agent of SSWS remains
elusive, as does the environmental
trigger or triggers that led to the
pandemic. Extending and augmenting
the analysis of Gravem et al. (2021),
Lowry et al. (2022) demonstrated that if
post-pandemic negative trends in
population abundance continue,
extinction risk is high in the immediate
and foreseeable future. If pre-pandemic
population growth rates resume,
however, the likelihood of long-term
persistence is moderate to high,
depending on region. Which of these
scenarios is more likely depends on
disease resistance, current local
population dynamics, and a myriad of
environmental factors affecting both the
sunflower sea star and the SSWS
agent(s). If individuals that survived the
pandemic are able to successfully
reproduce over the next several years,
and ocean conditions are adequate to
support larval survival and settlement, a
substantive recruitment pulse could
result. Whether the causative agent of
SSWS exists in an environmental or
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biological reserve, however, is also
unknown. If it does, any recruitment
pulse could be short lived and
individuals may not survive to
reproduce themselves. There is a high
level of uncertainty regarding potential
outcomes, and predictive capacity is
limited as a consequence of the unique
combination of ocean conditions and
disease prevalence in recent years.
After considering the best available
information on sunflower sea star life
history (including its mean generation
time), projected abundance trends,
likelihood of a resurgence of SSWS to
pandemic levels, and current and future
management measures, the SRT
concluded that after 30 years
uncertainty in these factors became too
great to reliably predict the biological
status of the species. Though potential
threats like nearshore habitat
degradation and anthropogenic climate
change can be projected further into the
future, the SRT concluded that the
impacts of these threats on the
sunflower sea star could not be
adequately predicted given the
behavioral patterns of the species with
regard to habitat use and diet. Whether
population segments occupying deep
waters will fare better than those in the
shallows, and to what degree these
populations are linked, cannot be
adequately predicted given limited
knowledge of sunflower sea star biology
and demography. Given the
demonstrated capacity of SSWS to kill
billions of individuals across the entire
range of the species over just a few
years, the SRT felt that reliably
assessing the effects of additional
threats on species viability beyond the
temporal range of 30 years was not
possible.
Demographic Risk Analysis
Methods
The SRT reviewed all relevant
biological and commercial data and
information for the sunflower sea star,
including: current abundance relative to
historical abundance estimates, and
trends in survey data; what is known
about individual growth rate and
productivity in relation to other species,
and its effect on population growth rate;
spatial and temporal distribution
throughout its range; possible threats to
morphological, physiological, and
genetic integrity and diversity; and
natural and human-influenced factors
that likely cause variability in survival
and abundance. Each team member then
assigned a risk score to each of the four
viable population criteria (abundance,
productivity, spatial distribution, and
diversity) throughout the whole of the
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species’ range. Risks for each criterion
were ranked on a scale of 0 (unknown
risk) to 3 (high risk) using the following
definitions:
0 = Unknown: Information/data for
this demographic factor is unavailable
or highly uncertain, such that the
contribution of this factor to the
extinction risk of the species cannot be
determined.
1 = Low risk: It is unlikely that the
particular factor directly contributes
significantly to the species’ current risk
of extinction, or will contribute
significantly in the foreseeable future
(30 years).
2 = Moderate risk: It is likely that the
particular factor directly contributes
significantly to the species’ current risk
of extinction, or will contribute
significantly in the foreseeable future
(30 years), but does not in itself
currently constitute a danger of
extinction.
3 = High risk: It is highly likely that
the particular factor directly contributes
significantly to the species’ current risk
of extinction, or will contribute
significantly in the foreseeable future
(30 years).
Team members were given a template
to fill out and asked to score each
criterion’s contribution to extinction
risk. Scores were provided to the team
lead, anonymized, then shared with the
entire team, which discussed the range
of perspectives and the supporting data/
information upon which they were
based. Team members were given the
opportunity to revise scores after the
discussion, if they felt their initial
analysis had missed any pertinent data
discussed in the group setting. Final
scores were reviewed and considered,
then synthesized, to arrive at the overall
demographic risk determination from
the team. Further details are available in
Lowry et al. (2022).
Abundance
Severe declines in nearly all available
datasets, range-wide from 2013 through
2017 are readily apparent, with little
evidence of recent recruitment or
rebound (Gravem et al. 2021; Lowry et
al. 2022). While variability in
abundance estimates was high prior to
the SSWS pandemic and boom/bust
cycling was apparent in many areas,
detection rates have been very low since
approximately 2015 in the majority of
time series datasets. Datasets from the
Oregon and California coasts are notable
because they report several years of
regular observation of sunflower sea
stars leading up to 2013, followed by
several years of absence at the same
index sites. In locations where
individuals continued to be detected
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after the pandemic, like in northern
Oregon, density decreased by an order
of magnitude or more. Data providers
for these time series categorize the near
or total loss of sunflower sea stars in
their survey area as local or functional
extirpation, but other researchers and
the public have reported juveniles in
several of these areas (e.g., the Channel
Islands), demonstrating that some
reproduction and settlement is
occurring. In areas where adults have
not been detected for several years, the
potential for deleterious stochastic
events, such as marine heat waves, to
destroy what remains of the population
is likely to be considerably increased.
Abundance prior to the SSWS pandemic
was substantially greater in northern
portions of the range from Alaska to the
Salish Sea, and declines in these areas
were less pronounced (Gravem et al.
2021; Lowry et al. 2022).
The current range-wide (i.e., global)
population estimate for the sunflower
sea star is nearly 600 million
individuals, based on a compilation of
the best available science and
information (Gravem et al. 2021). While
substantial, this represents less than 10
percent of the estimated abundance
prior to 2013 and likely reflects an even
greater decrease in biomass due to the
loss of adults from SSWS. However,
there is considerable uncertainty in this
global abundance estimate and in
regional estimates that contribute to it.
Low sampling effort prior to the SSWS
pandemic, depth-biased disparities in
data richness, inadequate speciesspecific documentation of occurrence,
and missing information about several
crucial life history parameters all
contribute to this uncertainty. While
confidence is relatively high in
estimates from more southerly,
nearshore areas that are well-sampled
via SCUBA, the majority of the species’
range consists of deep, cold, and/or
northern waters that are less well
sampled. How segments of the
population in these poorly sampled
areas contribute to and are connected
with the overall health and stability of
the species remains largely unknown.
Sunflower sea stars in these areas are
less susceptible to impacts from
nearshore stressors and could serve as
source populations to support
population rebound, but evidence to
support this role is lacking. Based on
the broad geographic range over which
the remaining population is spread, the
generalist nature of the sunflower sea
star with regard to both habitat use and
diet, and the possibility that deep-water
individuals may serve as source
populations to bolster recovery, the
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team concluded that the current state of
the abundance criterion was a moderate
factor in affecting extinction risk in the
foreseeable future.
Productivity
Little is known about the natural
productivity of the sunflower sea star on
both an individual and population
basis. Lack of information about growth
rate, longevity, age at maturity,
fecundity, natural mortality, the
influence of larval cloning, and other
fundamental biological attributes
requires that broad assumptions be
applied and proxy species used to
inform estimates on both regional and
range-wide bases. Regardless of the
values of nearly all of these parameters,
however, the loss of approximately 90
percent of the global population of the
sunflower sea star from 2013 through
2017 is likely to have had profound
impacts on population-level
productivity. The standing crop of
individuals capable of generating new
recruits has been decreased, possibly to
levels where productivity will be
compromised on a regional or global
basis. The combined factors of spatial
distribution of individuals across the
seascape and ocean conditions are
crucial to dictating whether
productivity is sufficient to allow
population rebound. Broadly dispersed
individuals may lack the ability to find
mates, further reducing realized
productivity despite abundance being
high enough to theoretically result in
population persistence.
As a broadcast spawner with
indeterminate growth, traits shared with
many other echinoderms, the capacity
for allometric increases in fecundity and
high reproductive output certainly
exists in the sunflower sea star. Hodin
et al. (2021) noted that gonads are small
in sunflower sea stars compared to other
sea stars but also documented prolonged
periods over which spawning
apparently occurs (i.e., gonads are ripe).
If the SSWS pandemic resulted in the
loss of the large, most reproductively
valuable individuals across both
nearshore and deep-water habitats, it
could take a decade or more for subadults to mature, settlement to occur at
detectable levels, and population
rebounds to be documented. There is
evidence in some areas that recruitment
has occurred, demonstrating that local
productivity is still occurring, but it
may be years before these individuals
reach maturity and spawn. The ongoing
threat of another SSWS pandemic
dictates that caution is warranted when
predicting population growth rate into
the foreseeable future.
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Provided reproduction continues to
occur, even on a local basis, the
prolonged planktonic period of larval
sunflower sea stars affords the
opportunity for substantial dispersal
prior to settlement. During this period,
however, larvae are at the mercy of
prevailing currents, temperature
variation, and a suite of biophysical
variables that affect survival. Even if
populations maintain relatively high
levels of productivity, recent conditions
in the northeast Pacific Ocean have not
been favorable to larval survival for
many species due to repeated marine
heat waves, falling pH, and localized
oxygen minimum zones. Additionally,
given the predominant flow regime
along the Pacific West Coast of North
America, propagules are expected to be
carried both northward and southward
from British Columbia following the
North Pacific Current as it bifurcates
into the Alaska and California Currents,
respectively. Given the distance larvae
must travel with the currents,
populations in British Columbia are not
expected to contribute markedly to
repopulation in the southern portion of
the range off Oregon, California, and
Mexico. While the Davidson
Countercurrent and California
Undercurrent may seasonally carry
propagules northward from Mexico and
California (Thomas and Krassovski
2010), abundance of the sunflower sea
star in this portion of the range is not
currently likely to be high enough to
serve as a source population to areas off
Washington, Oregon, or northern
California. Studies of connectivity
across the range of the sunflower sea
star will be crucial to evaluating how
large-scale population patterns are
affected by local and regional
productivity in the future.
Taking into account the many
unknowns about life history, population
level reproductive capacity, and
functional implications of
environmental conditions on population
connectivity in the foreseeable future,
the productivity criterion was scored as
a moderate contributor to overall
extinction risk over the foreseeable
future, though there was considerable
variation in individual team member
scores. Depensatory impacts from
abundance declines have likely
decreased productivity on a local and
regional scale, but the adults that
remain are assumed to live long enough
that opportunities to mate will manifest
in time, provided they are able to find
one another and mate. Until more is
known about the underlying biology of
the species, this parameter, and its
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effects on long-term viability, will
remain poorly defined.
Spatial Distribution and Connectivity
Despite substantial population
declines from 2013 through 2017,
sunflower sea stars still occupy the
whole of their historic range from
Alaska to northern Mexico, though in
nearshore areas from the outer coast of
Washington to Mexico the species is
now rare where it was once common
(Gravem et al. 2021; Lowery et al. 2022).
Natural resource managers and
researchers in the contiguous United
States consider several local
populations off Oregon and California to
be functionally extirpated, but reports of
newly settled juveniles and occasional
adults in these regions demonstrate
continued occupancy (Gravem et al.
2021; Lowery et al. 2022). With so few
individuals, a new wave of SSWS or
other catastrophic event could eliminate
the species in these areas. However, the
lack of adequate sampling of deep
waters and patchy encounter reporting
in bottom-contact fisheries with a high
likelihood of interaction (e.g.,
crustacean pot/trap fisheries) introduces
sufficient uncertainty to preclude
stating that sunflower sea stars have
been extirpated throughout this
southern portion of their range.
Spatial distribution and connectivity
are integrally related with the
abundance and productivity criteria.
Species occurrence, density, habitat use,
and intraspecific interaction rate,
alongside environmental parameters,
ultimately determine population
productivity and abundance. As a
habitat generalist with broad resilience
to physiochemical environmental
variables, the sunflower sea star utilizes
most available benthic habitats from the
nearshore down to several hundred
meters deep throughout its range. Loss
of over 90 percent of the population in
southern portions of the range almost
certainly resulted in population
fragmentation, but the only areas where
data exist to confirm this are shallow,
SCUBA-accessible habitats. Kelp forests
and rocky reefs, in particular, are well
sampled and may represent key habitats
for the sunflower sea star, but regular
occurrence on mud, sand, and other
soft-bottom habitats is also well
documented. Undersampled, deepwater habitats represent the majority of
suitable habitat for the sunflower sea
star by area, however, additional effort
is needed to characterize both how
individuals in these waters are
distributed and how they are connected
with populations in shallow waters.
Less accessible nearshore areas, largely
those associated with sparsely
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populated areas, also suffer from
undersampling.
Direct evidence to assess the
connectivity of sunflower sea star
populations at various geographic scales
is lacking. Without meristic,
morphological, physiological, and/or
genetic studies to demonstrate
similarities or differences among
population segments linkages cannot be
adequately evaluated. Broad
assumptions can be made about larval
distribution as a consequence of
prevailing flow patterns, but evidence
both for and against connections over
large geographic scales for echinoderm
populations on the Pacific Coast exist.
Population declines associated with the
SSWS pandemic were severe enough
that historic patterns of spatial
distribution and connectivity could
have been obliterated in the last decade,
and may continue to change into the
foreseeable future.
After taking into account the best
available information on both the
historic and present spatial distribution
of the sunflower sea star, spatial
distribution was determined to have a
moderate contribution to extinction risk.
This was largely due to evidence of
population fragmentation in nearshore
areas and several data series
demonstrating very low abundance
across broad portions of the range.
Connectivity could not be adequately
assessed due to a lack of data.
Diversity
Systematic comparisons of
morphology, life history, behavior,
physiology, genetic traits, and other
aspects of diversity do not exist for the
sunflower sea star. While some authors
note that animals in the northern
portion of the range grow to a large
diameter and mass, this general
statement is not supported by data. As
a result of this lack of information,
adequately evaluating the impact of this
parameter on extinction risk is difficult.
Data from proxy species, such as the
ochre star, demonstrate that variation in
physical characteristics such as color
can be both genetically and ecologically
controlled in sea stars (Harley et al.
2006; Raimondi et al. 2007). While
examples exist of echinoderm species
with both substantial population
structuring and a complete lack of
population structure on the West Coast,
where the sunflower sea star falls along
this spectrum could not be determined
due to the lack of fundamental
biological knowledge pertinent to
population dynamics. As a result, this
criterion was determined to have an
unknown contribution to overall
extinction risk.
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Threats Assessment
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Methods
As noted above, section 4(a)(1) of the
ESA requires the agency to determine
whether the species is endangered or
threatened because of any one, or a
combination of, a specific set of threat
factors. Similar to the demographic risk
analysis, SRT members were given a
template to fill out and asked to rank
each threat in terms of its contribution
to the extinction risk of the species
throughout the whole of the species’
range. Specific threats falling within the
section 4(a)(1) categories were identified
from sources included in the status
review report, and included as line
items in the scoring template (Lowry et
al. 2022). Below are the definitions that
the Team used for scoring:
0 = Unknown: The current level of
information is insufficient for this
threat, such that its contribution to the
extinction risk of the species cannot be
determined.
1 = Low: It is unlikely that the threat
is currently significantly contributing to
the species’ risk of extinction, or will
significantly contribute in the
foreseeable future (30 years).
2 = Moderate: It is likely that this
threat will contribute significantly to the
species’ risk of extinction in the
foreseeable future (30 years), but does
not in itself constitute a danger of
extinction currently.
3 = High: It is highly likely that this
threat contributes significantly to the
species’ risk of extinction currently.
The template also included a column
in which team members could identify
interactions between the threat being
evaluated and specific demographic
parameters from the viable population
criteria analysis, as well as other section
4(a)(1) threats.
Scores were provided to the team
lead, anonymized, and then the range of
perspectives and the supporting data/
information upon which they were
based was discussed. Interactions
among threats and specific demographic
parameters, or other threats, were also
discussed to ensure that scoring
adequately accounted for these
relationships. Team members were then
given the opportunity to revise scores
after the discussion if they felt their
initial analysis had missed any
pertinent data discussed in the group
setting. Scores were then reviewed,
considered, and synthesized to arrive at
an overall threats risk determination.
Results of this threats assessment are
summarized below, and further details
are available in Lowry et al. (2022).
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The Present or Threatened Destruction,
Modification, or Curtailment of Its
Habitat or Range
The sunflower sea star is a habitat
generalist known to occur in association
with a broad diversity of substrate types,
grades of structural complexity, and
biogenic habitat components. Habitat
degradation and modification in
nearshore areas of the Pacific Coast as
a consequence of direct human
influence is largely concentrated in
urbanized centers around estuaries and
embayments, with considerable tracts of
sparsely populated, natural shoreline in
between. This is especially true of the
northern portion of the range. In
urbanized areas, nearshore modification
to accommodate infrastructure has
dramatically changed the available
habitat over the last two hundred years.
The relative importance of specific
habitats to the range-wide health and
persistence of the sunflower sea star is
difficult to quantify, however, because
suitable habitat occurs well beyond the
depth range where most sampling
occurs. Human impacts on nearshore
habitats and species of the Pacific Coast
have long been recognized, and marine
protected areas, sanctuaries, and other
place-based conservation measures have
been created in a variety of jurisdictions
in recent decades. While these measures
have not explicitly targeted the
sunflower sea star, many of them are
centered on sensitive habitats (e.g., kelp
forests) and provide protections to the
ecosystem at large, including sunflower
sea stars and their prey. Under current
nearshore management practices, the
sunflower sea star has persisted in
urban seascapes at apparently healthy
population levels until very recently,
when SSWS resulted in the death of 90
percent or more of the population. As a
result, the SRT determined that
nearshore habitat destruction or
modification was a low-level
contributor to overall extinction risk
(Lowry et al. 2022), although systematic
sampling is needed to establish whether
certain habitat types are critical to
specific life stages or behaviors for the
sunflower sea star.
Sunflower sea stars also occur on
benthic habitats to depths of several
hundred meters, and anthropogenic
stressors affecting these offshore waters
are markedly different from those
affecting the nearshore. Quantifying
impacts to sunflower sea star habitat in
deeper waters is more complicated,
however, and less information is
available to support a rigorous
evaluation. Fishing with bottom-contact
gear, laying communications or
electrical cables, mineral and oil
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exploration, and various other human
activities have direct influence on
benthic habitats in offshore waters of
the North Pacific Ocean. The activities
are highly likely to interact with
sunflower sea stars at some level, but
data are lacking regarding both the
distribution of individuals in these
deeper waters and impacts from
particular stressors. As a result, the SRT
determined that effective assessment of
the contribution of deep-water habitat
modification or destruction on overall
extinction risk of the species could not
be conducted. Geographic input of all
potential stressors in these deep waters
is likely to be small relative to the
documented range of the sunflower sea
star and the SRT determined that the
species’ adaptability and resilience are
unlikely to make habitat impacts in
these areas a substantial threat (Lowry et
al. 2022).
Curtailment of the range of the
sunflower sea star has not yet been
demonstrated, despite the fact that,
since the SSWS pandemic, the species
has become rare from the Washington
coast south to California, areas where it
once was common. The total population
estimate for this region still stands at
over five million individuals (Gravem et
al. 2021) and their range north of
Washington is vast. Population
fragmentation as a consequence of
dramatic losses in abundance could
result in range curtailment in the
foreseeable future, but occasional
reports of juvenile sunflower sea stars at
locations along the West Coast as far
south as the Channel Islands
demonstrate that local extirpation has
not yet occurred. If juveniles do not
mature and successfully reproduce
because of a resurgence of SSWS to
pandemic levels, or some other factor, a
substantial reduction in distribution
could occur at the southern extent of the
currently documented range. A minority
opinion within the SRT was that range
curtailment has already occurred from
Neah Bay, WA, southward and that
remnant populations would soon be
eliminated by natural demographic
processes.
Overutilization for Commercial,
Recreational, Scientific, or Educational
Purposes
There are no substantial current or
historical fisheries directed at the
sunflower sea star, but recreational
harvest is allowed or permitted in
Alaska, British Columbia, California,
and Mexico and occurs at unquantified
levels. Whether collected individuals
are held for a short period before being
released or permanently removed from
the population is unknown. Impacts
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from recreational harvest cannot be
evaluated because data are not available
on either an aggregate or speciesspecific basis; however, market drivers
for this species are minimal and human
consumption is not known to occur. As
a result, the SRT determined that
recreational harvest impacts are a minor
factor affecting extinction risk.
Recreational harvest and trade may
become a greater concern in the
foreseeable future in areas where
abundance levels are extremely low or
declining. Additional regulations
prohibiting retention could offset
impacts from this potential threat.
Fishery bycatch impacts to the
sunflower sea star are a low-level
concern for a variety of fisheries that use
bottom-contact gear. This includes
fisheries for benthic fishes and
invertebrates that employ trawls, pots,
traps, nets, and, to a limited degree,
hook-and-line. Information to quantify
the encounter rate in specific fisheries is
largely lacking, as are data
demonstrating direct impacts of these
encounters, and frequent aggregation of
all sea star catch into a single reporting
category precludes a species-specific
assessment. That said, these potential
risks are offset by the following
observations: (1) the majority of
commercial trawl fisheries occur in
waters outside of preferred sunflower
sea star depth zones (<25 m or 82 ft),
based on the information regarding
highest documented densities (Gravem
et al. 2021); and (2) sunflower sea stars
are anecdotally reported as being
resilient to handling stress during
regular fishing operations, though postrelease monitoring is not reported in the
literature. Post-release, handling-related
stress could exacerbate symptoms of
SSWS or increase susceptibility to other
sources of mortality. This could make
handling during fisheries a greater
threat in regions where population
abundance is especially low, such as
from coastal Washington to the southern
extent of the species’ range.
Unfortunately, systematic reporting of
encounters with sunflower sea stars
does not occur at this time.
The collection, drying, and trade of
small ‘‘sunflower stars’’ is noted in
Gravem et al. (2021) and in the ESAlisting petition received from the Center
for Biological Diversity. This practice
predominantly affects small stars under
15.25 cm in diameter and the retailers
that offer these curios often do not list
the species, site of collection, or other
details necessary to determine whether
populations of sunflower sea star are
being directly impacted. Given that sea
stars can be collected in Alaska, British
Columbia, and Mexico, and in
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California seaward of a tidal exclusion
zone, a more thorough evaluation of
retail offerings is needed. Without
additional information, the SRT
unanimously decided that this threat
has an unknown, but likely negligible,
impact on extinction risk in the
foreseeable future due to a lack of
demand and no evidence of a
substantial market.
Disease or Predation
Disease, specifically SSWS, was
identified by the SRT as the single
greatest threat affecting the persistence
of the sunflower sea star both now and
into the foreseeable future (Lowry et al.
2022). While the etiology of the disease
as well as what trigger(s) resulted in its
rapid spread to pandemic levels remain
unknown (Hewson et al. 2018), the
widespread occurrence of, and impacts
from, the disease from 2013 through
2017 are broadly documented. Initially,
SSWS was thought to be caused by one,
or a suite, of densoviruses (Paraviridae;
Hewson et al. 2014; 2018); however,
subsequent studies determined that the
disease is more complex. A number of
factors ranging from environmental
stressors to the microbiome in the sea
stars may play a role (Lloyd and Pespeni
2018; Konar et al. 2019; Aquino et al.
2021). Ocean warming has also been
linked to outbreaks, hastening disease
progression and severity (Harvell et al.
2019; Aalto et al. 2020). Regardless of
the pathogen’s unknown etiology to
date, stress and rapid degeneration
ultimately result with symptomatic sea
stars suffering from abnormally twisted
arms, white lesions, loss of body tissue,
arm loss, disintegration, and death.
During the 2013–2017 pandemic,
populations of sunflower sea stars were
diminished range wide, and in southern
portions of the range estimated losses
are on the order of 95 percent or more.
There was considerable variation in the
degree of impact associated with depth,
latitude, and (sometimes) recent
temperature regime, but projected losses
in all regions where data were sufficient
amounted to approximately 90 percent
or more (Gravem et al. 2021). Lowry et
al. (2022) demonstrate that these
declines have continued at least through
2021 in most regions, though recent
settlement events have been recorded in
the Salish Sea and Alaska. Whether new
cohorts will survive long enough to
reproduce, or succumb to SSWS, is
highly uncertain. Whether reproductive
adults that survived the SSWS
pandemic will demonstrate resistance or
immunity to future outbreaks is also
crucial to whether the species will
survive. If impacts from SSWS continue
at a level that resulted in population
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declines of greater than 90 percent over
a 5-year timespan, extinction risk would
be very high for the sunflower sea star.
If population growth rates are able to
return to pre-pandemic levels in coming
years, the likelihood of population
persistence is moderate in the Alaska
Region and the British Columbia and
Salish Sea Region, but lower in the West
Coast Region from Washington to
Mexico (Lowry et al. 2022).
There is no evidence that other
known diseases constitute substantial
threats to the continued persistence of
the sunflower sea star now or in the
foreseeable future. However, the SRT
noted that a complicating factor is that
the physiological response of sea stars to
numerous stressors (e.g., high
temperature, low dissolved oxygen) is to
develop lesions, autotomize arms, and/
or disintegrate (Lowry et al. 2022).
These symptoms, and the ultimate
outcome of disintegration, are shared
with SSWS, making it possible that a
suite of disease pathogens or stressors
jointly contribute to the observed
syndrome. As the end result of any such
disease is mortality within just a few
days, the threat from disease still
remains high whether SSWS is caused
by a single pathogen or many.
Very few predators are known to
consume adult sunflower sea stars and
this is not expected to change even
under generous projections of ecosystem
changes as a consequence of global
climate change or other factors.
Predation risk is likely highest during
the planktonic larval phase when
indiscriminate filter feeders consume
small larvae and selective pickers target
larger, more developed individuals. The
prolonged duration of the larval period
could enhance this risk, but there is no
evidence to suggest that current risks of
predation are any higher than they were
prior to the pandemic when populations
were healthy. Additionally, while the
fecundity of the sunflower sea star is not
well known, even conservative
estimates suggest that an individual
female likely produces millions of eggs
in a single spawning event. As such, the
SRT determined that predation is not
likely to substantially contribute to
extinction risk, now or in the
foreseeable future (Lowry et al. 2022).
Inadequacy of Existing Regulatory
Mechanisms
As noted above, in Washington and
Oregon harvest and collection of
sunflower sea stars are not allowed, but
in Alaska, British Columbia, California,
and Mexico recreational harvest is
permitted. Though data are not available
to determine how intensive this harvest
is, human consumption is not known to
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occur and large markets for dried or
otherwise processed specimens do not
exist. Considering this information, the
SRT determined that the current harvest
and collection regulations do not
contribute substantially to extinction
risk, nor are they likely to in the
foreseeable future (Lowry et al. 2022).
Inconsistency of regulations across
jurisdictions could complicate
enforcement, however, unless
coordinated efforts to standardize or
reconcile rules occur. It may also
become necessary in the foreseeable
future to propose and publicize
handling recommendations for bycaught
sunflower sea stars to reduce handling
stress and mortality, should data
support that this is a more significant
threat than currently recognized. Draft
handling recommendations are
currently under development within
NOAA Fisheries for use in scientific
surveys and will be adapted, as needed,
for fisheries.
A patchwork of place-based
conservation measures exists across the
known range of the sunflower sea star
that are designed to protect ecologically
sensitive and/or important habitats and
species. While none of these are
specifically directed at conservation of
the sunflower sea star or its habitat,
many of them provide indirect
protection to the species, its habitat, and
its prey.
Current regulations to control
anthropogenic climate change are likely
insufficient to have a measurable impact
on trends in changing ocean conditions,
and resulting ecological effects, by the
end of the century (Fro¨licher and Joos,
2010; Ahmadi Dehrashid et al. 2022).
The effectiveness of regulations
controlling anthropogenic climate
change is a considerable concern
because such regulations affect stressors
like elevated sea surface temperature
and lowered pH, which have sweeping
effects on marine prey base and living
conditions (Doney et al. 2012). Elevated
ocean temperatures likely contributed to
the decline of the sunflower sea star
because warmer water temperatures are
correlated with accelerated rates of
SSWS transmission and diseaseinduced mortality; therefore the lack of
adequate regulations to stall the impacts
of climate change also presents a direct
concern for the long-term viability of the
sunflower sea star. There is uncertainty
regarding ways in which additional
climate change regulations could affect
the extinction risk of the sunflower sea
star without a better understanding of
the relationships between climate
change impacts (especially temperature
stress), SSWS dynamics, and speciesspecific disease vulnerability.
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The SRT identified considerable
uncertainty regarding what regulatory
mechanisms might effectively reduce
extinction risk as a consequence of
SSWS (Lowry et al. 2022). While a given
disease can sometimes be isolated to a
geographic region or eliminated by a
combination of quarantine, transport
embargos of specimens carrying the
pathogen, or the administration of
vaccines, these actions all require
considerable knowledge of the disease
itself. In the case of SSWS, the pathogen
has not yet been identified, the cause
may be several pathogens with similar
etiologies, and the disease has been
observed across the full geographic
range of the species. For these reasons,
while existing regulatory mechanisms
are insufficient to address the threat of
SSWS, the SRT determined that it is
unlikely that any effective regulatory
approaches will arise in the foreseeable
future without considerable research
(Lowry et al. 2022).
Other Natural or Man-Made Factors
Affecting Its Continued Existence
Direct impacts of environmental
pollutants to the sunflower sea star are
unknown, but they likely have similar
effects to those seen in other marine
species, given physiologically similar
processes. Reductions in individual
health and disruption of nutrient
cycling through food webs are hallmarks
of industrial chemicals, heavy metals,
and other anthropogenic contaminants.
With the sunflower sea star representing
a monotypic genus, the SRT noted
substantial uncertainty involved with
projecting potential impacts into the
foreseeable future, and decided that
extrapolating effects of specific
chemicals or suites of chemicals to
range-wide population viability is
impossible (Lowry et al. 2022). Any
impacts that do exist are likely to be
more intensive near their source, such
as urban bays and estuaries, though
many persistent contaminants are
known to bioaccumulate in some
organisms and spread over long
distances over the course of decades or
more.
The addition of anthropogenically
released greenhouse gasses into the
atmosphere since the industrial
revolution has resulted in climate
change that is affecting organisms and
environments on a global basis. While
direct linkages between climate change
and sunflower sea star population status
have not been made in the literature,
impacts to prey base, habitat, and SSWS
can all be inferred from available data.
Ecosystem change rooted in climate
forcers has already been demonstrated
in nearshore ecosystems of the north
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Pacific Ocean (e.g., Bonaviri et al. 2017;
Berry et al. 2021), resulting in prey base
instability that adds additional stress to
struggling populations. See above for a
discussion of how climate change may
link to progression and severity of
SSWS outbreak as a consequence of
changes in sea surface temperature and
physiochemical properties of marine
waters.
Larval life stages of numerous shellforming marine organisms are highly
sensitive to chemical composition of
pelagic waters, such that ocean
acidification can increase physiological
stress and decrease survival in a broad
array of organisms. Additionally, life
stages of various planktonic organisms
are sensitive to temperature, with
elevated temperature increasing
metabolic rate and, thus, nutritional
requirements. Furthermore, some
marine organisms rely on seasonal shifts
in temperature and other environmental
cues to identify suitable spawning
times, aligning planktonic feeding
periods of larvae with phytoplankton
blooms. Changes in the spatiotemporal
availability and quality of prey affect
planktotrophic larvae and may result in
reduced growth, delayed settlement,
starvation, and various other negative
outcomes. Though the planktonic diet of
sunflower sea star larvae has not been
adequately described, it is likely that
they consume shell-forming organisms
to various degrees depending on
spatiotemporal variability in abundance,
quality, and encounter rate. Nearshore
benthic communities can also be
affected in myriad ways by elevated
carbon dioxide levels, reduced pH,
increased temperature, and other
physiochemical changes resulting from
anthropogenic climate change. While
these effects of climate change are
unlikely to affect the sunflower sea star
across its full range simultaneously, the
SRT noted that decreases in habitat
suitability are likely on a localized basis
and such stressors could exacerbate
consequences of low abundance,
especially in southern portions of the
range (Lowry et al. 2022). High levels of
uncertainty regarding complex
interactions among climate-related
stressors and their impacts on sunflower
sea star population viability, however,
make it impossible to adequately project
effects on extinction risk into the
foreseeable future.
Overall Extinction Risk Summary
Throughout the Range of the Species
Little is known about several
fundamental biological aspects of the
sunflower sea star, such as age at
maturity, longevity, growth rate,
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reproductive output, population
resiliency, and population connectivity.
What is known is that the species is a
broadcast spawner, utilizes a broad
range of habitats and prey, and has a
broad geographic distribution, all of
which buffer the species against
catastrophic events and reduce overall
extinction risk. The abundance and
density of the species have clearly
declined recently throughout the vast
majority of its range; however, data are
highly uncertain in deep waters and less
accessible/well surveyed regions.
Additionally, most current SCUBA- and
trawl-based protocols fail to sample
small individuals (e.g., those less than 5
cm as measured from arm-tip to armtip), making characterization of
population status incomplete. In some
areas, functional extirpation is likely
within the foreseeable future of 30 years
due to a lack of mate availability, which
constrains reproductive capacity and
limits settlement of new cohorts. Best
available estimates indicate that the
remaining range-wide abundance of the
sunflower sea star is approximately 600
million individuals, with the highest
abundances in Alaska and British
Columbia, primarily in deeper water (at
lower densities than observed in
shallow, scuba-accessible depths).
Given the widespread impacts of
SSWS from 2013 through 2017, it is
likely that surviving sunflower sea stars
were exposed, giving hope (but no
direct evidence) that they bear some
resistance to the causative agent of the
disease, though this agent remains
unknown. SSWS is the single greatest
threat to the sunflower sea star on a
range-wide basis, and may be
exacerbated by global warming, ocean
acidification, toxic contaminants, and
other processes that generate
physiological stress in individuals. A
conclusive link has not been
demonstrated but is likely given
physiology and known stressors of this,
and other, sea star species. Regions most
likely to be impacted by climate change
factors are in the south, where the
sunflower sea star population was most
heavily impacted by the SSWS
pandemic. Fishing pressure (including
bycatch), the curio trade, and habitat
degradation are threats, but are not
anticipated to have population-level
impacts in the next 30 years. Regional
variability in threat severity could result
in total loss of the species in the
southern portion of its geographic range,
but whether the loss of this portion of
the population may compromise the
long-term viability of the species is
unknown. Overall, threats to population
persistence exist, with high uncertainty
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about potential impacts, and with
trajectories in many areas continuing
downward. As a result of this analysis
of aspects of species viability and
threats facing the species, we conclude
that the sunflower sea star is at
moderate risk of extinction now and in
the foreseeable future throughout its
range.
Significant Portion of Its Range
Under the ESA, a species may warrant
listing if it is in danger of extinction
now or in the foreseeable future
throughout all or a significant portion of
its range. Having concluded that the
sunflower sea star is at moderate risk of
extinction now and in the foreseeable
future throughout all of its range, the
SRT next conducted an assessment to
determine whether it may currently be
in danger of extinction in any identified
significant portion of its range (SPR). If
a species is in danger of extinction in an
SPR, the species qualifies for listing as
an endangered species (79 FR 37578;
July 1, 2014). In 2014, the USFWS and
NMFS issued a joint policy on
interpretation of the phrase ‘‘significant
portion of its range’’ (SPR Policy, 79 FR
37578; July 1, 2014). The SPR Policy set
out a biologically-based approach for
interpreting this phrase that examines
the contributions of the members of the
species in the ‘‘portion’’ to the
conservation and viability of the species
as a whole. More specifically, the SPR
Policy established a threshold for
determining whether a portion is
‘‘significant’’ that involved considering
whether the hypothetical loss of the
members in the portion would cause the
overall species to become threatened or
endangered. This threshold definition of
‘‘significant’’ was subsequently
invalidated in two District Court cases,
which held that it set too high a
standard to allow for an independent
basis for listing species—i.e. it did not
give independent meaning to the phrase
‘‘throughout . . . a significant portion of
its range’’ (Center for Biological
Diversity, et al. v. Jewell, 248 F. Supp.
3d 946, 958 (D. Ariz. 2017); Desert
Survivors v. DOI 321 F. Supp. 3d. 1011
(N.D. Cal., 2018). However, those courts
did not take issue with the fundamental
approach of evaluating significance in
terms of the biological significance of a
particular portion of the range to the
overall species. While the SRT did not
rely on the definition of ‘‘significant’’ in
the policy when conducting their
analysis, they did use a biological
approach to assessing whether any
portions of the sea star’s range are
‘‘significant.’’
To identify potential SPRs for the
sunflower sea star, the SRT considered
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the following: (1) is there one or more
population segment at higher risk of
extinction relative to population
segments elsewhere in the range; and (2)
is the higher-risk population segment
biologically significant to the overall
viability of the species. To analyze
whether a portion qualifies as
significant the SRT considered the
viability characteristics of abundance,
productivity, spatial distribution, and
genetic diversity. Ultimately, the goal of
this analysis was to determine whether
the sunflower sea star is in danger of
extinction in a significant portion of its
range.
To help in identifying potential SPRs,
SRT members were provided a base map
of the northeast Pacific Ocean labeled
with several geophysical features either
referenced in the IUCN status
assessment of the sunflower sea star
(Gravem et al. 2021) or known to be
associated with demographic breaks in
a variety of other marine organisms.
Team members independently
considered all data and information
available on a regional basis to generate
proposed areas that could potentially
represent SPRs, that is, areas that have
a reasonable likelihood of being at high
risk of extinction and that have a
reasonable likelihood of being
biologically significant to the species.
These portions were highlighted on the
map, and detailed justifications
provided regarding the intensity of
specific threats to, and biological
significance of, the population segment
in the identified portion(s). Because
there are theoretically an infinite
number of ways in which a species’
range may be divided for purposed of an
SPR analysis, only those portions that
the SRT identified as ones where the
species has a reasonable likelihood of
being both at higher risk of extinction
relative to the rest of the range and
biologically significant to the overall
species were considered further in the
analysis.
After considering all available
biological, geographic, and flow regime
data available; evaluating issues of data
resolution, representativeness, and
availability; and drawing on proxy
species where necessary, the SRT
delineated three portions in which
trends in biological viability, threat
intensity, and likely biological
significance were internally consistent.
These were: (1) all waters of the range
north of Dixon Entrance (i.e., waters of
Alaska; Portion 1); (2) coastal British
Columbia and the Salish Sea (Portion 2);
and (3) all waters of the range south of
Cape Flattery, to Baja California, Mexico
(Portion 3). In waters shallower than 25
m, where assessment data are most
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readily available and comprehensive
(Gravem et al. 2021; Lowry et al. 2022),
over 72 percent of the pre-pandemic
abundance of sunflower sea stars
occupied Portion 1. Portion 2 is
estimated to have held approximately
17.5 percent of the population. Despite
being geographically extensive, Portion
3 was estimated to be occupied by the
remainder of the species, just under 10
percent of the total shallow-water
population. It is worth noting that
nearly 45 percent of the pre-pandemic
population was estimated to occupy
waters deeper than 25 m, which are
disproportionately located off of Alaska
and coastal British Columbia, further
amplifying these patterns. Taken
together, the SRT determined that these
estimates indicate the existence of a
population center in the North Pacific,
a transition zone along coastal British
Columbia and into the Salish Sea, and
a southward extension of the species
through temperate waters at limited
abundance/density until thinning out in
the subtropics around the Southern
California Bight.
The population center of the
sunflower sea star is in Alaskan waters,
and the population segment here was
less impacted by SSWS with
considerably more individuals surviving
(over 275 million in shallow waters and
as many as 400 million in deep waters
[Gravem et al. 2021]) and no apparent
reduction in spatial distribution. Given
this, the SRT determined that the
population segment occupying Portion 1
is not at higher risk of extinction than
the species overall. Because the status of
the species in Portion 1 does not differ
from the status throughout the range,
the SRT did not continue the analysis
further to determine whether Portion 1
constitutes a significant portion of the
species’ range.
Conversely, waters of Portion 3 are
estimated to have held less than ten
percent of the pre-pandemic population
of species and saw losses >95 percent
from 2013 to 2017, with few signs of
recovery. While it is possible
individuals in this portion that survived
the pandemic are disease resistant, or
contain genes for thermal tolerance or
adaptability to other environmental
parameters, data do not exist at this time
to support this assertion. Furthermore,
being at the southern end of a current
system that flows predominantly
southward it is unlikely that these traits
could be naturally transmitted into
northern populations via planktonic
drift. Taken together, this caused the
SRT to conclude that while risk of
extinction may be higher in the
southern portion of the range due to
dramatically decreased abundance,
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density, and frequency of occurrence
post pandemic, this population segment
is not likely to be biologically
significant relative to the overall
viability of the species. As such, Portion
3 does not constitute a significant
portion of the range for ESA status
assessment purposes.
Portion 2 is situated where currents
flow both north and south into other
portions of the range, uniquely
positioning it to serve as a biologically
significant population with regard to
long-term persistence of the sunflower
sea star. Higher abundance within the
region may allow the population here to
contribute to population viability in
Southeast Alaska, the Washington coast,
and beyond. In addition, while there is
recruitment to offshore sites, and
relatively healthy populations in some
glacial fjords, there is evidence of
source/sink dynamics (i.e., areas of high
reproductive capacity within the region
produce larvae that settle elsewhere in
the region) within Portion 2. The
possibility of disease resistance in these
remaining individuals cannot be
discounted, but has not been
demonstrated. Persistent low encounter
rates in the region, however, suggest a
degree of resiliency despite ongoing
occurrence of the causative agent of the
disease (whatever it may be) in the
environment. The Salish Sea region is
influenced by a number of other threats,
such as toxic contamination, pressure
from a diversity of fisheries, and
extensive habitat degradation and
destruction associated with creation and
maintenance of human infrastructure.
To assess whether these threats elevated
overall extinction risk to high in the
biologically significant Portion 2, a
second overall extinction risk scoring
sheet was distributed and team
members independently assessed this
region. Though there is a high degree of
uncertainty with regard to the potential
impact of SSWS and other threats on the
population segment in this portion, the
SRT determined that overall extinction
risk in Portion 2 is moderate, matching
that of the range-wide assessment and
thereby precluding assignment of high
extinction risk to the species based on
status within this particular portion of
its range.
Given the best available information,
we find that the sunflower sea star is at
a moderate risk of extinction throughout
its range, as well as within Portion 2
(the British Columbia Coast and Salish
Sea), the only portion of the range
determined to be biologically
significant. Without efforts to better
understand the etiology of SSWS and
identify paths to address its impacts on
the sunflower sea star, the species is on
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a trajectory in which its overall
abundance will likely significantly
decline within the foreseeable future,
eventually reaching the point where the
species’ continued persistence will be in
jeopardy. These declines are likely to be
exacerbated by anthropogenic climate
change and the resulting impacts on
biogeochemical aspects of habitats
occupied by the species. Although the
species is not currently in danger of
extinction throughout its range, it will
likely become an endangered species
within the foreseeable future.
Protective Efforts
Having found that the sunflower sea
star is likely to become in danger of
extinction throughout its range within
the foreseeable future, we next
considered protective efforts as required
under section 4(b)(1)(A) of the ESA. The
focus of this evaluation is to determine
whether protective efforts are being
made and, if so, whether they are
effective in ameliorating the threats we
have identified to the species and thus,
potentially, avert the need for listing. As
we already considered the adequacy of
existing regulatory efforts associated
with fisheries and place-based
ecosystem protections in our evaluation
of threats above, we consider other
conservation efforts in this section.
Following the 2020 IUCN assessment
of the sunflower sea star (Gravem et al.
2021), the species was conferred
Critically Endangered status on the Red
List of Threatened Species (https://
www.iucnredlist.org/species/
178290276/197818455). Subsequent to
this, The Nature Conservancy convened
a working group made up of state, tribal,
Federal, and provincial government;
academic; and non-profit partners to
create a roadmap to recovery for the
species. This document uses the best
available science and information to
identify specific, targeted research and
management efforts needed to address
what workgroup participants identify as
the greatest threats facing long-term
persistence of the sunflower sea star
(Heady et al. 2022). Many contributors
to this document provided data and
knowledge to the SRT to ensure all of
the most recent research was captured
in our analysis (Lowry et al. 2022). The
roadmap also includes an inventory of
knowledge gaps that can be used as a
guidance tool by partner organizations
to coordinate collaborative research and
management directed at sunflower sea
star recovery (Heady et al. 2022), in
many ways paralleling the structure and
intent of a formal recovery plan under
the ESA.
While we find that protective efforts
associated with the roadmap to recovery
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will help increase public and scientific
knowledge about the sunflower sea star
and SSWS, and will likely result in
multinational coordination on both
research and management, such actions
alone do not significantly alter the
extinction risk for the sunflower sea star
to the point where it would not be in
danger of extinction in the foreseeable
future. We seek additional information
on these and other conservation efforts
in our public comment process (see
Public Comments Solicited on Proposed
Listing below).
Determination
Section 4(b)(1)(A) of the ESA requires
that listing determinations are based
solely on the best scientific and
commercial information and data
available after conducting a review of
the status of the species and taking into
account those efforts, if any, being made
by any state or foreign nation, or
political subdivisions thereof, to protect
and conserve the species. We have
independently reviewed the best
available scientific and commercial
information including the petition,
public comments submitted on the 90day finding (86 FR 73230; December 27,
2021), the status review report (Lowry et
al. 2022), and other published and
unpublished information, and have
consulted with species experts and
individuals familiar with the sunflower
sea star.
As summarized above, and in Lowry
et al. (2022), we assessed the ESA
section 4(a)(1) factors both individually
and collectively for the sunflower sea
star, throughout its range and in
portions of its range, and conclude that
the species faces ongoing threats from
SSWS and direct (i.e., physiological)
and indirect (i.e., ecological)
consequences of anthropogenic climate
change. Over 90 percent of the
abundance of the species was lost over
the period from 2013 to 2017, there are
few positive signs of recovery, and we
do not yet know the etiology of SSWS.
Likely linkages of SSWS with
environmental parameters that are
projected to worsen with ongoing
climate change suggest that impacts on
the species from SSWS will likely
persist and potentially worsen over the
foreseeable future throughout the range.
We found no evidence of protective
efforts for the conservation of the
sunflower sea star that would eliminate
or adequately reduce threats to the
species to the point where it would not
necessitate listing under the ESA.
Therefore, we conclude that the
sunflower sea star is likely to become an
endangered species in the foreseeable
future throughout its range from threats
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of disease and anthropogenic climate
change. As such, we have determined
that the sunflower sea star meets the
definition of a threatened species and
propose to list it is as such throughout
its range under the ESA.
Effects of Listing
Measures provided for species of fish
or wildlife listed as endangered or
threatened under the ESA include:
development of recovery plans (16
U.S.C. 1533(f)); designation of critical
habitat, to the maximum extent prudent
and determinable (16 U.S.C.
1533(a)(3)(A)); and the requirement for
Federal agencies to consult with NMFS
under section 7 of the ESA to ensure the
actions they fund, conduct, and
authorize are not likely to jeopardize the
continued existence of the species or
result in adverse modification or
destruction of any designated critical
habitat (16 U.S.C. 1536(a)(2)). Certain
prohibitions, including prohibitions
against ‘‘taking’’ and importing, apply
with respect to endangered species
under section 9 (16 U.S.C. 1538), and,
at the discretion of the Secretary, some
or all of these prohibitions may be
applied to threatened species under the
authority of section 4(d) (16 U.S.C.
1533(d)). Other benefits to species from
ESA listing include recognition of the
species’ status and threats, which can
promote voluntary conservation actions
by Federal and state agencies, foreign
entities, private groups, and individuals.
Identifying Section 7 Conference and
Consultation Requirements
Section 7(a)(4) of the ESA and
implementing regulations require
Federal agencies to confer with us on
actions likely to jeopardize the
continued existence of species proposed
for listing, or that result in the
destruction or adverse modification of
proposed critical habitat. If a proposed
species is ultimately listed, Federal
agencies must consult under section
7(a)(2) on any action they authorize,
fund, or carry out if those actions may
affect the listed species or its critical
habitat to ensure that such actions are
not likely to jeopardize the species or
result in destruction or adverse
modification of critical habitat should it
be designated. At this time, based on the
currently available data and
information, we determine that
examples of Federal actions that may
affect the sunflower sea star include, but
are not limited to: discharge of pollution
from point and non-point sources,
contaminated waste disposal, dredging,
marine cable laying, pile-driving,
development of nearshore
infrastructure, development of water
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quality standards, military activities,
and fisheries management practices.
None of the actions on this list were
scored as moderate or high risk to the
sunflower sea stars or identified as a
significant cause of their recent
population decline. Their effects, even if
small, would be subject to section 7
consultations if the sea star sunflower is
listed as threatened. For example,
Federal fisheries were identified as low
risk, and for specific fisheries that
employ bottom contact gear and have
known or presumed bycatch, we would
anticipate evaluating the relatively low
risk, then focusing on measures to
minimize or better understand effects,
such as species identification and
reporting by fishery observers and
development of safe handling practices.
Critical Habitat
Critical habitat is defined in the ESA
(16 U.S.C. 1532(5)(A)) as: (1) the specific
areas within the geographical area
occupied by a species, at the time it is
listed in accordance with the ESA, on
which are found those physical or
biological features (a) essential to the
conservation of the species and (b)
which may require special management
considerations or protection; and (2)
specific areas outside the geographical
area occupied by a species at the time
it is listed upon a determination that
such areas are essential for the
conservation of the species.
‘‘Conservation’’ means the use of all
methods and procedures needed to
bring the species to the point at which
listing under the ESA is no longer
necessary. Section 4(a)(3)(A) of the ESA
requires that, to the maximum extent
prudent and determinable, critical
habitat be designated concurrently with
the listing of a species. Designations of
critical habitat must be based on the
best scientific data available and must
take into consideration the economic,
national security, and other relevant
impacts of specifying any particular area
as critical habitat. When developing
critical habitat designations we often
seek data and public comment on these
aspects such as: (1) maps and specific
information describing the amount,
distribution, and use type (e.g.,
spawning) of the habitat, as well as any
additional information on occupied and
unoccupied habitat areas; (2) the
reasons why any specific area of habitat
should or should not be determined to
be critical habitat as provided by
sections 3(5)(A) and 4(b)(2) of the ESA;
(3) information regarding the benefits of
designating particular areas as critical
habitat; (4) current or planned activities
in the areas that might qualify for
designation and their possible impacts;
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(5) any foreseeable economic or other
potential impacts resulting from
designation, and, in particular, any
impacts on small entities; (6) whether
specific unoccupied areas may be
essential for the conservation of the
species; and (7) individuals who could
serve as peer reviewers in connection
with a proposed critical habitat
designation, including persons with
biological and economic expertise
relevant to the species, region, and
designation of critical habitat.
As part of the status review process
(Lowry et al. 2022) and proposed
threatened listing we have conducted an
exhaustive review of available
information on many of the above
elements, particularly related to
distribution, habitat use, and biological
features. Sunflower sea stars are habitat
generalists, occurring on a wide array of
abiotic and biotic substrates over a
broad depth range. Few systematic
surveys have been conducted to
differentiate habitat use, such as
spawning/rearing, or identify features
across different depths, latitudes,
substrates, temperatures, or other
potentially important biological
parameters. At this time, we find that
critical habitat for the sunflower sea star
is not determinable because data
sufficient to perform the required
analyses are lacking. Specifically, we do
not have sufficient information
regarding physical and biological
habitat features associated with
sunflower sea star occurrence that may
be essential to their conservation.
We therefore seek public input on
physical and biological habitat features
and areas that are essential to the
conservation of the sunflower sea star in
U.S. waters. If we determine that
designation of critical habitat is prudent
and determinable in the future, we will
publish a proposed designation of
critical habitat for the sunflower sea star
in a separate rule.
Protective Regulations Under Section
4(d) of the ESA
In the case of threatened species, ESA
section 4(d) gives the Secretary
discretion to determine whether, and to
what extent, to extend the prohibitions
of section 9 to the species, and
authorizes the issuance of regulations
necessary and advisable for the
conservation of the species. Thus, we
have flexibility under section 4(d) to
tailor protective regulations, taking into
account the effectiveness of available
conservation measures. The 4(d)
protective regulations may prohibit,
with respect to threatened species, some
or all of the acts which section 9(a) of
the ESA prohibits with respect to
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endangered species. We are not
proposing such regulations at this time,
given the minimal impacts of habitat
degradation/destruction, fisheries, trade,
and manmade factors (other than
climate change described above), but we
may consider potential protective
regulations pursuant to section 4(d) for
the sunflower sea star in a future
rulemaking. For example, the impacts of
the specific threats that could
potentially be addressed through a 4(d)
rule, such as pollution, collection/trade,
or fisheries, were all identified as low
risk. Therefore, at this time we conclude
that management under 4(d) would be
unlikely to provide meaningful
protection. In order to inform our
consideration of appropriate protective
regulations for the species in the future
if our understanding of threats evolves,
we are seeking information from the
public on threats to the sunflower sea
star and possible measures for its
conservation.
Role of Peer Review
The intent of peer review is to ensure
that listings are based on the best
scientific and commercial data
available. In December 2004, OMB
issued a Final Information Quality
Bulletin for Peer Review establishing
minimum peer review standards, a
transparent process for public
disclosure of peer review planning, and
opportunities for public participation.
The OMB Bulletin, implemented under
the Information Quality Act (Pub. L.
106–554), is intended to enhance the
quality and credibility of the Federal
Government’s scientific information,
and applies to influential or highly
influential scientific information
disseminated on or after June 16, 2005.
To satisfy our requirements under the
OMB Bulletin, we are obtaining
independent peer review of the status
review report concurrent with the
public comment period associated with
this proposed rule. All comments will
be considered and addressed prior to
publication of the final rule in which we
make the decision whether to list the
sunflower sea star.
Public Comments Solicited on Proposed
Listing
To ensure that the final action
resulting from this proposal will be as
accurate and effective as possible, we
solicit comments and suggestions from
the public, other governmental agencies,
the scientific community, industry,
tribal entities, environmental groups,
and any other interested parties.
Comments are encouraged on all aspects
of this proposal (See DATES and
ADDRESSES). We are particularly
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interested in: (1) new or updated
information regarding the range,
distribution, and abundance of the
sunflower sea star; (2) new or updated
information regarding the genetics and
population structure of the sunflower
sea star; (3) new or updated information
regarding past or current habitat
occupancy by the sunflower sea star; (4)
new or updated biological or other
relevant data concerning any threats to
the sunflower sea star (e.g., landings of
the species, illegal taking of the species);
(5) information on commercial trade or
curio collection of the sunflower sea
star; (6) recent observations or sampling
of the sunflower sea star; (7) current or
planned activities within the range of
the sunflower sea star and their possible
impact on the species; and (8) efforts
being made to protect the sunflower sea
star.
Public Comments Solicited on Critical
Habitat
As noted above, we have concluded
that critical habitat is not currently
determinable for the sunflower sea star.
We request information that would
contribute to consideration of critical
habitat in the future, such as new data
describing the quality and extent of
habitat for the sunflower sea star,
information on what might constitute
physical and biological habitat features
and areas that are essential to the
conservation of the species, whether
such features may require special
management considerations or
protection, or identification of areas
outside the occupied geographical area
that may be essential to the conservation
of the species and that are under U.S.
jurisdiction.
In addition, as part of any potential
critical habitat designation we may
propose, we would also need to
consider the economic impact, impact
on national security, and any other
relevant impact of designating any
particular area as critical habitat as
required under section 4(b)(2) of the
ESA. Therefore, we are also soliciting
information to inform these types of
analyses, including information
regarding: (1) activities or other threats
to the essential features of occupied
habitat or activities that could be
affected by designating a particular area
as critical habitat; and (2) the positive
and negative economic, national
security, and other relevant impacts,
including benefits to the recovery of the
species, likely to result if particular
areas are designated as critical habitat.
References
A complete list of the references used
in this proposed rule is available at
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https://www.fisheries.noaa.gov/species/
sunflower-sea-star and upon request
(see ADDRESSES).
Classification
National Environmental Policy Act
The 1982 amendments to the ESA, in
section 4(b)(1)(A), restrict the
information that may be considered
when assessing species for listing. Based
on this limitation of criteria for a listing
decision and the opinion in Pacific
Legal Foundation v. Andrus, 657 F. 2d
829 (6th Cir. 1981), NMFS has
concluded that ESA listing actions are
not subject to the environmental
assessment requirements of the National
Environmental Policy Act (NEPA).
Executive Order 12866, Regulatory
Flexibility Act, and Paperwork
Reduction Act
As noted in the Conference Report on
the 1982 amendments to the ESA,
economic impacts cannot be considered
when assessing the status of a species.
Therefore, the economic analysis
requirements of the Regulatory
Flexibility Act are not applicable to the
listing process. In addition, this
proposed rule is exempt from review
under Executive Order 12866. This
proposed rule does not contain a
collection-of-information requirement
for the purposes of the Paperwork
Reduction Act.
PART 223—THREATENED MARINE
AND ANADROMOUS SPECIES
1. The authority citation for part 223
continues to read as follows:
■
Executive Order 13132, Federalism
Executive Order 13132 requires
agencies to take into account any
federalism impacts of regulations under
development. It includes specific
directives for consultation in situations
where a regulation will preempt state
law or impose substantial direct
compliance costs on state and local
governments (unless required by
statute). Neither of those circumstances
is applicable to this action.
List of Subjects in 50 CFR Part 223
Endangered and threatened species.
Authority: 16 U.S.C. 1531–1543; subpart B,
§ 223.201–202 also issued under 16 U.S.C.
1361 et seq.; 16 U.S.C. 5503(d) for
§ 223.206(d)(9).
2. Amend § 223.102, in paragraph (e),
by adding a new table subheading for
‘‘Echinoderms’’ before the ‘‘Molluscs’’
subheading, and adding a new entry for
‘‘Sunflower Sea Star’’ under the
‘‘Echinoderms’’ table subheading to read
as follows:
■
§ 223.102 Enumeration of threatened
marine and anadromous species.
*
Dated: March 10, 2023.
Samuel D. Rauch, III,
Deputy Assistant Administrator for
Regulatory Programs, National Marine
Fisheries Service.
*
*
(e) * * *
*
*
For the reasons set out in the
preamble, NOAA proposes to amend 50
CFR part 223 as follows:
Species 1
Common name
Scientific name
*
*
Critical
habitat
Citation(s) for listing determination(s)
Description of
listed entity
*
*
*
*
ESA
rules
*
Echinoderms
Sunflower Sea
Star.
Pycnopodia
helianthoides.
*
Entire species ...
*
[Insert Federal Register citation and date when published as a final rule].
*
*
*
NA ...............
*
1 Species
NA.
*
includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement, see 61 FR 4722, February 7,
1996), and evolutionarily significant units (ESUs) (for a policy statement, see 56 FR 58612, November 20, 1991).
[FR Doc. 2023–05340 Filed 3–15–23; 8:45 am]
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Agencies
[Federal Register Volume 88, Number 51 (Thursday, March 16, 2023)]
[Proposed Rules]
[Pages 16212-16229]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-05340]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 223
[Docket No. 230309-0070; RTID 0648-XR120]
Proposed Rule To List the Sunflower Sea Star as Threatened Under
the Endangered Species Act
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: We, NMFS, have completed a comprehensive status review for the
sunflower sea star, Pycnopodia helianthoides, in response to a petition
to list this species as threatened or endangered under the Endangered
Species Act (ESA). Based on the best scientific and commercial
information available, including the draft status review report, and
after taking into account efforts being made to protect the species, we
have determined that the sunflower sea star is likely to become an
endangered species within the foreseeable future throughout its range.
Therefore, we propose to list the sunflower sea star as a threatened
species under the ESA. Should the proposed listing be finalized, any
protective regulations under section 4(d) of the ESA would be proposed
in a separate Federal Register notice. We do not propose to designate
critical habitat at this time because it is not currently determinable.
We are soliciting information to inform our final listing
determination, as well as the development of potential protective
regulations and critical habitat designation.
DATES: Comments on the proposed rule to list the sunflower sea star
must be received by May 15, 2023. Public hearing requests must be made
by May 1, 2023.
ADDRESSES: You may submit comments on this document, identified by
NOAA-NMFS-2021-0130, by either of the following methods:
Electronic Submissions: Submit all electronic public
comments via the Federal e-Rulemaking Portal. Go to www.regulations.gov
and enter NOAA-NMFS-2021-0130 in the Search box. Click on the
``Comment'' icon, complete the required fields, and enter or attach
your comments.
Mail: Submit written comments to Dayv Lowry, NMFS West
Coast Region Lacey Field Office, 1009 College St. SE, Lacey, WA 98503,
USA.
Fax: 360-753-9517; Attn: Dayv Lowry.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
www.regulations.gov without change. All personally identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
The petition, draft status review report (Lowry et al. 2022),
Federal Register notices, and the list of references can be accessed
electronically online at: https://www.fisheries.noaa.gov/species/sunflower-sea-star. The peer review plan and charge to peer reviewers
are available at https://www.noaa.gov/organization/information-technology/peer-review-plans.
FOR FURTHER INFORMATION CONTACT: Dayv Lowry, NMFS, West Coast Region
Lacey Field Office, (253) 317-1764.
SUPPLEMENTARY INFORMATION:
Background
On August 18, 2021, we received a petition from the Center for
Biological Diversity to list the sunflower sea star (Pycnopodia
helianthoides) as a threatened or endangered species under the ESA. On
December 27, 2021, we published a positive 90-day finding (86 FR 73230,
December 27, 2021) announcing that the petition presented substantial
scientific or commercial information indicating that the petitioned
action may be warranted. We also announced the initiation of a status
review of the species, as required by section 4(b)(3)(A) of the ESA,
and requested information to inform the agency's decision on whether
this species warrants listing as threatened or endangered.
[[Page 16213]]
Listing Species Under the Endangered Species Act
To make a determination whether a species is threatened or
endangered under the ESA, we first consider whether it constitutes a
``species'' as defined under section 3 of the ESA, and then whether the
status of the species qualifies it for listing as either threatened or
endangered. Section 3 of the ESA defines species to include subspecies
and, for any vertebrate species, any distinct population segment (DPS)
which interbreeds when mature (16 U.S.C. 1532(16)). Because the
sunflower sea star is an invertebrate, the ESA does not permit us to
consider listing DPSs.
Section 3 of the ESA defines an endangered species as ``any species
which is in danger of extinction throughout all or a significant
portion of its range'' and a threatened species as one ``which is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range.'' Thus, in the
context of the ESA, we interpret an ``endangered species'' to be one
that is presently in danger of extinction, while a ``threatened
species'' is not currently in danger of extinction, but is likely to
become so in the foreseeable future (that is, at a later time). The
primary statutory difference between a threatened and endangered
species is the timing of when a species is in danger of extinction,
either presently (endangered) or not presently but within the
foreseeable future (threatened). Being in danger of extinction
``presently'' does not mean that the possible extinction event is
necessarily now.
When we consider whether a species qualifies as threatened under
the ESA, we must consider the meaning of the term ``foreseeable
future.'' It is appropriate to interpret ``foreseeable future'' as the
horizon over which predictions about the conservation status of the
species can be reasonably relied upon. What constitutes the foreseeable
future for a particular species depends on factors such as life history
parameters, habitat characteristics, availability of data, the nature
of specific threats, the ability to predict impacts from threats, and
the reliability of forecasted effects of these threats on the status of
the species under consideration. Because a species may be susceptible
to a variety of threats for which different data are available, or
which operate across different time scales, the foreseeable future may
not be reducible to a discrete number of years.
Section 4(a)(1) of the ESA requires us to determine whether a
species is endangered or threatened throughout all or a significant
portion of its range as a result of any one, or a combination of, the
following factors: (1) the present or threatened destruction,
modification, or curtailment of its habitat or range; (2)
overutilization for commercial, recreational, scientific, or
educational purposes; (3) disease or predation; (4) the inadequacy of
existing regulatory mechanisms; or (5) other natural or manmade factors
affecting its continued existence (16 U.S.C. 1533(a)(1)). We are also
required to make listing determinations based solely on the best
scientific and commercial data available, after conducting a review of
the species' status and after taking into account efforts, if any,
being made by any state or foreign nation (or subdivision thereof) to
protect the species (16 U.S.C. 1533(b)(1)(A)).
Status Review
After publishing the 90-day finding indicating that listing may be
warranted for the sunflower sea star, the NMFS West Coast Regional
Office convened a Status Review Team (SRT) composed of marine
biologists, ecologists, statisticians, and natural resource managers
from the NMFS Alaska and West Coast Regional Offices; NMFS Alaska,
Northwest, and Southwest Fisheries Science Centers; United States
Geological Survey; and Monterey Bay National Marine Sanctuary. This
team also received input from state, provincial, tribal, non-profit,
and academic experts. The SRT compiled and synthesized all available
information into a comprehensive draft status review report (Lowry et
al. 2022, see ADDRESSES section). The draft status review report
summarizes the best available scientific and commercial information on
the biology, ecology, life history, and status of the sunflower sea
star, as well as stressors and threats facing the species. The SRT also
considered information submitted by the public in response to our 90-
day petition finding (86 FR 73230; December 27, 2021).
The draft status review report is undergoing independent peer
review as required by the Office of Management and Budget (OMB) Final
Information Quality Bulletin for Peer Review (M-05-03; December 16,
2004) concurrent with public review of this proposed rule. Independent
specialists were selected from the academic and scientific community,
with expertise in sea star biology, conservation policy, and applied
natural resource management. The peer reviewers were asked to evaluate
the adequacy, appropriateness, and application of data used in the
status review, including the extinction risk analysis. The peer review
plan and charge statement are available on NOAA's website (see
ADDRESSES section). All peer reviewer comments will be made publicly
available and addressed prior to dissemination of the final status
review report and publication of the final listing decision.
Below is a summary of the biology and ecology of the sunflower sea
star, accompanied by an evaluation of threats facing the species, and
resulting extinction risk. This information is presented in greater
detail in the draft status review report (Lowry et al. 2022), which is
available on our website (see ADDRESSES section). In addition to
evaluating the status review, we independently applied the statutory
provisions of the ESA, including evaluation of protective efforts set
forth in section 4(b)(1)(A) and our regulations regarding listing
determinations at 50 CFR part 424, to making our determination that the
sunflower sea star meets the definition of a threatened species under
the ESA.
Description, Life History, and Ecology of the Petitioned Species
Species Taxonomy and Description
The sunflower sea star was originally described as Asterias
helianthoides by Brandt (1835), a species of sea star unique in having
16 to 20 rays (arms) and found in coastal marine waters near Sitka,
Alaska. Stimpson (1861) later designated it as the type species of the
new genus Pycnopodia and as the only known species of the family
Pycnopodiidae. Fisher (1922) described the Pacific starfish
Lysastrosoma anthosticta as a new species, stating it was closely
related to Pycnopodia, and subsequent authors have included only these
two species in the subfamily Pycnopodiinae. Pycnopodia helianthoides
has no known synonyms, and the validity of the species has not been
questioned in the taxonomic literature. Therefore, based on the best
available scientific and commercial information, we find that the
scientific consensus is that P. helianthoides is a taxonomically
distinct species and, therefore, meets the definition of ``species''
pursuant to section 3 of the ESA. Below, we evaluate whether this
species warrants listing as endangered or threatened under the ESA
throughout all or a significant portion of its range.
The sunflower sea star is among the largest sea stars in the world,
reaching over 1 meter (m) in total diameter from ray tip to ray tip
across the central disk.
[[Page 16214]]
The sunflower sea star and closely related Pacific starfish are
distinguished from other co-occurring sea stars by their greatly
reduced abactinal (dorsal) skeleton with no actinal plates, and by
their prominently crossed pedicellariae (Fisher 1928). Very young
sunflower sea stars generally have fewer than a dozen arms, and
additional arms are added by budding in symmetrical pairs as the
individual grows. Other sea stars in the northern Pacific Ocean with
many arms include several sun stars of the genera Solaster, Crossaster,
and Rathbunaster; however, these species generally have 8 to 17 arms,
as opposed to the 16 to 20 arms commonly found in the sunflower sea
star, and all of the sun stars are considerably smaller and less
massive (Fisher 1906).
Range, Distribution, and Habitat Use
The documented geographic range of the sunflower sea star spans the
Northeastern Pacific Ocean from the Aleutian Islands to Baja California
(Sakashita 2020). This range includes 33 degrees of latitude (3,663 km)
across western coasts of the continental United States, Canada, and
northern Mexico. The farthest reaches of sunflower sea star
observations include: northernmost--Bettles Bay, Anchorage, Alaska
(Gravem et al., 2021); westernmost--central and eastern Aleutian
Islands (Kuluk Bay, Adak Island east to Unalaska Island, Samalga Pass,
and Nikolski) (Feder 1980; O'Clair and O'Clair 1998; Jewett et al.
2015; Gravem et al. 2021); and southernmost--Bahia Asunci[oacute]n,
Baja California Sur, Mexico (Gravem et al. 2021). The sunflower sea
star is generally most common from the Alaska Peninsula to Monterey,
California.
The sunflower sea star has no clear associations with specific
habitat types or features and is considered a habitat generalist
(Gravem et al. 2021 and citations therein). The large geographic and
depth range of the sunflower sea star indicates this species is well
adapted for a wide variety of environmental conditions and habitat
types. The species is found along both outer coasts and inside waters,
which consist of glacial fjords, sounds, embayments, and tidewater
glaciers. Preferring temperate waters, they inhabit kelp forests and
rocky intertidal shoals (Hodin et al. 2021), but are regularly found in
eelgrass meadows as well (Dean and Jewett 2001; Gravem et al. 2021).
Sunflower sea stars occupy a wide range of benthic substrates including
mud, sand, shell, gravel, and rocky bottoms while roaming in search of
prey (Konar et al. 2019; Lambert et al. 2000). They occur in the low
intertidal and subtidal zones to a depth of 435 m but are most common
at depths less than 25 m and rare in waters deeper than 120 m (Fisher
1928; Lambert 2000; Hemery et al. 2016; Gravem et al. 2021). This
characterization of their prevalence across depth ranges, however, may
be biased by: (1) differential sampling methods and effort, with SCUBA-
based observations dominating records; and (2) the propensity to record
all sea stars as ``sea star unidentified'' when they occur as
incidental bycatch in various survey and fishery records.
Reproduction, Growth, and Longevity
Most sea star species, including the sunflower sea star, have
separate sexes that are externally indistinguishable from one another,
and each ray of an adult contains a pair of gonads (Chia and Walker
1991). In the sunflower sea star, gonads are elongated, branched sacs
that fill the length of each ray when ripe (Chia and Walker 1991).
Gametes are broadcast through gonopores on each ray into the
surrounding seawater and fertilization occurs externally. Fertilized
larvae develop through pelagic planktotrophic stages, capturing food
with ciliary bands (Strathmann 1971; 1978; Byrne 2013).
A number of environmental factors, such as food availability,
seawater temperature, photoperiod, salinity, and the lunar cycle, may
control seasonality of sea star reproductive cycles (Chia and Walker
1991; Pearse et al. 1986). Although the reproductive season of several
Northeast Pacific sea stars have been estimated by following oocyte-
diameter frequency distributions (e.g., Farmanfarmaian et al. 1958;
Mauzey 1966; Pearse and Eernisse 1982), to the best of our knowledge no
one has conducted such studies in free-ranging sunflower sea stars.
However, a number of researchers have estimated reproductive
seasonality of the species based on observations of either field or
laboratory spawning. Mortenson (1921) reported that sunflower sea stars
breed from May through June at Nanaimo, British Columbia, while Greer
(1962) collected adult broodstock from the intertidal zone at San Juan
Island, Washington, and reported spawning in March and April. Feder
(1980) obtained fertilizable eggs from December through June in
California, and Strathmann (1987) stated that spawning occurs from late
March through July, peaking from May through June with some large males
spawning into December and January. More recently, Hodin et al. (2021)
suggested that the reproductive season for females begins in November
through January and ends in April and May in Washington. It is possible
that a slightly altered photoperiod and constant availability of food
for these lab-held specimens, however, may have caused individuals to
exhibit altered reproductive seasonality, explaining the apparent
discrepancy. Hodin et al. (2021) also note that the reproductive season
for females occurs later in Alaska.
Typically, sea stars with planktotrophic larval (i.e., reliant on
planktonic prey) development from the Northwest Pacific Ocean spawn in
late winter or early spring, which provides the best growing conditions
for their offspring by synchronizing their occurrence with the spring
phytoplankton bloom (Menge 1975; Strathmann 1987). The spawning seasons
of several other sea stars with planktotrophic larval development in
the Pacific Northwest and on the U.S. West Coast occurs between March
and August (Mortensen 1921; Farmanfarmaian et al. 1958; Mauzey 1966;
Feder 1980; Fraser et al. 1981; Pearse and Eernisse 1982; Strathmann
1987; Pearse et al. 1988; Sanford and Menge 2007). In addition, many
temperate sea stars, such as the ochre star (Pisaster ochraceus), have
seasonal, cyclical feeding patterns, such that feeding activity is
reduced during the late fall and winter (Feder 1980; Mauzey 1966;
Sanford and Menge 2007). This may also be the case for the sunflower
sea star but direct documentation of this phenomenon is lacking.
Planktotrophic larvae of the sunflower sea star developing during
winter (November to February) in the Northeast Pacific Ocean would be
at a distinct disadvantage due to the scarcity of planktonic algae at
that time.
We were unable to find direct estimates of fecundity for female
sunflower sea stars anywhere in the literature or in unpublished
records. However, Strathmann (1987) states that ripe ovaries of
specimens about 60 cm across may weigh 400 to 800 grams (g). Comparing
this estimate with fecundity estimates for the ochre star, a Northeast
Pacific sea star that has similar egg size and reproductive strategy,
may give some insight to potential fecundity of the sunflower sea star.
Menge (1974) estimated that a typically sized female ochre star
weighing 400 g wet weight would produce ~40 million eggs, representing
an average of 9 to 10 percent of wet weight being put into reproductive
effort. As the wet weight of ochre stars ranges up to 650 g (Menge
1975), a female of this size could spawn considerably many more than 40
million eggs in a season. However, Fraser et al. (1981) believed that
Menge's (1974) estimate of 40 million
[[Page 16215]]
eggs for a 400 g adult was somewhat high and calculated that a specimen
weighing 315 g would produce ~8 million total eggs. Given that
sunflower sea stars can grow to a massive five kilograms (kg) (Fisher
1928; Lambert 2000), and assuming sunflower sea stars and ochre stars
invest similar resources into reproductive efforts, it is conceivable
that a 4.5 kg female sunflower sea star could produce upwards of 114
million eggs in a gonadal cycle using the conservative estimate of
Fraser et al. (1981). This level of potential egg production is
comparable to estimates for the crown-of-thorns sea star, Acanthaster
spp. (Babcock et al. 2016), potentially making the sunflower sea star
one of the most fecund sea stars in the world. This high potential
fecundity is debatable, however, given recent observations of gonad
size in captive sunflower sea stars. Hodin et al. (2021) noted that
even when reproductively mature, gonads tend to be no more than a few
centimeters in length, which is small relative to other sea stars of
the Northwest Pacific Ocean.
Regarding size at sexual maturity, near Bremerton, Washington,
Kjerskog-Agersborg (1918) noted that maturity is not entirely dependent
on size. While females are on the average larger than males, immature
individuals of both sexes were found across a broad range of sizes--
including some of the largest individuals sampled. In a status
assessment conducted for the International Union for Conservation of
Nature (IUCN), Gravem et al. (2021) state that no studies have been
conducted specifically on the age at maturity for the sunflower sea
star, but estimate it to be at least five years based on the age of
first reproduction for the ochre star (Menge 1975; Chia and Walker
1991).
Without additional information on the size at first maturity,
fecundity, reproductive seasonality, and reproductive senescence of the
sunflower sea star, and how these demographic parameters vary
throughout the range of the species, it is impossible to accurately
predict annual reproductive output of populations or to adequately
evaluate resiliency and rebound potential in response to environmental
perturbations. Indications from other sea stars, however, suggest that
reproductively viable females can produce at least tens of millions of
eggs annually, possibly for several decades. Under appropriate
environmental conditions, this represents considerable reproductive and
recruitment potential.
Sea stars may modify their behavior during spawning in ways that
improve the chances of egg fertilization, including aggregating,
modifying their positions and postures, and spawning synchronously
(Strathmann 1987; Chia and Walker 1991; Dams et al. 2018). Although
many sea stars appear to aggregate during spawning (Strathmann 1987;
Minchin 1987; Chia and Walker 1991; Babcock and Mundy 1992; Raymond et
al. 2007; Himmelman et al. 2008; Dams et al. 2018), it is uncertain
whether sunflower sea stars do so. Kjerskog-Agersborg (1918) studied
sunflower sea stars in Puget Sound at Bremerton, WA, and suggested that
individuals migrated to shallower waters during the spawning season and
were present in large aggregations at this time of year. A number of
other sea stars move into shallow water during the spawning season,
supporting that movement into shallow water may be an adaptive behavior
that promotes fertilization (Babcock et al. 2000). Some fertilization
rate modeling results for the crown-of-thorns sea star Acanthaster spp.
(Babcock et al. 1994) indicate that shallower water increases
fertilization rates relative to deeper water because of reduced
dilution of gametes in waters shallower than 5 m (Babcock et al. 2000).
Many sea stars arch their bodies upward, remaining in contact with
the substratum by the tips of their arms during spawning. This posture
elevates the gonopores through which gametes are shed into the flow
field (Galtsoff and Loosanoff 1939; Strathmann 1987; Minchin 1987; Chia
and Walker 1991; Dams et al. 2018). Dams et al. (2018) used laboratory
experimentation and theoretical modeling to show that an arched posture
promoted downstream dispersion of gametes and was more effective than
stars lying in the flat position. It is common knowledge that sunflower
sea stars also arch their bodies upward in this characteristic spawning
posture. Although we were unable to locate specific reference in the
scientific literature, there are numerous photographs and depictions of
sunflower sea stars assuming this spawning posture on the internet
(e.g., https://www.kuow.org/stories/scientists-race-to-rescue-world-s-fastest-sea-star-from-oblivion).
Since released gametes (especially sperm) may remain viable for as
little as two hours (Strathmann 1987; Benzie and Dixon 1994), many sea
stars increase the chances of egg fertilization by spawning
synchronously (Feder and Christensen 1966; Babcock and Mundy 1992;
Babcock et al. 1994; Mercier and Hamel 2013). In many published
observations of sea star spawning, males consistently spawned before
females (Mercier and Hamel 2013). Even though synchronous spawning is
necessary for successful fertilization to occur, synchronization must
be accompanied by relatively close proximity for successful
fertilization (Mercier and Hamel 2013). There is conflicting
information regarding whether synchronous aggregative spawning is
exhibited by the sunflower sea star, but evidence from ecologically
similar sea star species and anecdotal observations for the sunflower
sea star strongly suggest this is the case. If this is the case, when
population abundance declines below levels that ensure contact of
distributed eggs and sperm with one another, Allee effects may hinder
population persistence and/or recovery (Lundquist and Botsford 2004;
2011). Standard population models predict that a reduction in adult
density should be associated with a decrease in intraspecific
competition leading to an increase in growth rate, survival, and gamete
production. However, these advantages may be countered by decreases in
the rate of successful fertilization among sparsely distributed
individuals (Levitan 1995; Levitan and Sewell 1998; Gascoigne and
Lipcius 2004). Fertilization success may be a limiting factor in
reproduction, and hence recruitment. We did not find published data
from directed studies of natural fertilization success in the sunflower
sea star.
Several researchers have, with varying degrees of success,
attempted to rear sunflower sea stars and describe early embryonic and
larval development through to metamorphosis (Mortensen 1921; Greer
1962; Strathmann 1970; 1978; Chia and Walker 1991; Hodin et al. 2021).
Greer (1962) reported that time from fertilization to metamorphosis for
larvae from San Juan Islands, Washington, ranged from 60 to 70 days
when reared at 10 to 12 [deg]C. Strathmann (1978) reported that time
from fertilization through to settling ranged from 90 to 146 days at
natural local water temperatures (7 to 13 [deg]C) encountered in the
San Juan Islands, Washington, in the late 1960s. Hodin et al. (2021)
reared sunflower sea stars from Washington at 9 [deg]C and 14 [deg]C
and observed first spontaneous settlement of larvae at seven weeks when
held at 10 to 11 [deg]C. Peak metamorphosis occurred at eight weeks in
larvae derived from Alaskan broodstock, compared to 11 weeks for larvae
from Washington broodstock. Hodin et al. (2021) reported that larvae
first became competent to metamorphose at seven weeks post-
[[Page 16216]]
fertilization at 10 to 11 [deg]C, compared to the nine weeks reported
by Greer (1962) when reared at 10 to 12 [deg]C. Together, these studies
indicate that larval duration may be as short as seven weeks or as long
as 21, and that temperature is a key parameter determining the extent
of this period.
Unlike the pentaradial symmetry of adult sea stars, larvae are
bilaterally symmetrical (Chia and Walker 1991). The bipinnaria larva is
characterized by two bilaterally symmetrical ciliary bands and an open,
functional gut (McEdward et al. 2002). Both the bipinnaria, and the
later-stage brachiolaria, ingest diatoms and other single-celled algae,
and may also utilize dissolved organic matter nutritionally (Chia and
Walker 1991). Bipinnaria larvae of the sunflower sea star were
estimated to form on the fifth (Greer 1962) or sixth day (Hodin et al.
2021) after fertilization.
To understand the population dynamics of the sunflower sea star on
a range-wide basis it is crucial to develop an understanding of larval
longevity and capacity for dispersal. Time from egg fertilization to
metamorphosis for the sunflower sea star under various conditions has
been described as 49 to 77 days (Hodin et al. 2021), 60 to 70 days
(Greer 1962), and 90 to 146 days (Strathmann 1978). As noted by Gravem
et al. (2021), broadcast spawning with a long pelagic larval duration
has the potential for broad larval dispersal, especially in open
coastal areas with few geographic barriers. Along more heterogeneous,
complex shorelines like those found inside the Salish Sea or Southeast
Alaska, however, complex flow patterns may result in localized
entrainment of larval and reduce dispersal capacity.
Minimum and maximum dispersal periods based on laboratory studies
of planktotrophic larvae reveal how varying environmental and
nutritional conditions influence the extent of the planktonic period
(Pechenik 1990). Basch and Pearse (1996) showed that sea star larvae
grown in phytoplankton-rich conditions had greater survival, were in
better condition, settled and metamorphosed sooner, and produced larger
juveniles compared to larvae grown in low food concentrations.
Planktotrophic larvae of many sea star species can delay metamorphosis
in the absence of suitable settlement cues (Metaxas 2013), and are
capable of long-range dispersal (Scheltema 1986; Metaxas 2013).
Although mortality of sea star larvae during the planktonic larval
stage has not been measured, it is expected to be high (Metaxas 2013),
and it is likely that delaying metamorphosis would expose larvae to an
additional period of predatory pressure (Basch and Pearse 1996) and
stress associated with limited food availability. Strathmann (1978)
found the maximum time to settlement in culture for sunflower sea star
to be 21 weeks and emphasized that the duration of pelagic larval life
is important in recruitment dynamics and, ultimately, to the
distribution of a species.
Sea star larvae may respond to a suite of biological, chemical,
and/or physical cues that induce metamorphosis and settlement,
including the presence of coralline algae, microbial films, and kelp
(Metaxas 2013). Hodin et al. (2021) state that competent sunflower sea
star larvae will settle spontaneously, as well as in response to a
variety of natural biofilms. Settlement is greatly enhanced when larvae
are presented with a biofilm collected in the presence of adult
sunflower sea stars, or if larvae are exposed to fronds of the
articulated coralline alga, Calliarthron tuberculosum.
It is generally accepted that planktotrophic larvae are typically
dispersed considerable distances away from adult populations and have
little impact on recruitment to the natal habitat (Sewall and Watson
1993; Robles 2013). However, Sewell and Watson (1993) described a
situation at the semi-enclosed bay of Boca del Infierno (Nootka Island,
British Columbia) where larvae were entrained and settled within the
adult habitat, contributing to the source population. During three
years between 1987 and 1991, sunflower sea star recruits were observed
on Sargassum muticum on the floor of the channel leading into the bay
(Sewell and Watson 1993). In general, sea stars are thought to have
relatively low annual recruitment punctuated by unusually strong
settlement in some years (Sanford and Menge 2007), the so-called boom
and bust cycle characteristic of a broad diversity of marine fishes and
invertebrates with planktonic larval dispersal (e.g., McLatchie et al.
2017; Schnedler-Meyer et al. 2018).
Larvae of sea stars are capable of regenerating lost body parts
much like adults (Vickery and McClintock 1998; Vickery et al. 2002;
Allen et al. 2018) and may also reproduce asexually through the process
of larval cloning--budding off of tissue fragments that regenerate into
complete larvae (Bosch et al. 1989; Rao et al. 1993; Jaeckle 1994;
Knott et al. 2003). Recently, Hodin et al. (2021) reported that larvae
of the sunflower sea star also have the capability to clone in a
laboratory setting, describing cloning as ``commonplace'' in all larval
cultures. The degree to which larval sunflower sea stars clone in
nature may have profound implications for life history (e.g.,
fecundity, dispersal distance), population dynamics, and population
genetic structure (Knott et al. 2003; Balser 2004; Rogers-Bennett and
Rogers 2008; Allen et al. 2018; 2019).
In a recent review of asexual reproduction in larval invertebrates,
Allen et al. (2018) tabulated the potential benefits of larval cloning
as: (1) increasing female fecundity without an apparent increase in
resource allocation to reproduction; (2) increasing the likelihood that
a member of a genet (i.e., group of cloned individuals) survives; (3)
increasing the probability that a member of a genet will locate a
suitable settlement site by sampling a greater geographic area; and (4)
reducing the genet's susceptibility to predation and other loss by
increasing the number and decreasing the size of propagules. On the
other hand, Allen et al. (2018) listed likely costs associated with
larval cloning as: (1) a decrease in larval feeding rate during
fission; (2) a decrease in larval growth rate; (3) an increase in the
time to metamorphosis; and (4) a decrease in juvenile size. Larval
cloning has the potential to alter several aspects of sunflower sea
star life history by increasing actualized fecundity, larval dispersal
distance, and chances of successful settlement of a larva or at least
its genetically identical clone (Bosch et al. 1989; Balser 2004;
Rogers-Bennett and Rogers 2008; Allen et al. 2019). Balser (2004) noted
that cloning serves to increase female fecundity to >1 juvenile per
egg, altering recruitment intensity. Without additional information
about environmental impacts on cloning rate, this lack of a one-to-one
relationship between female productivity and realized recruitment
potential complicates estimation of stock-recruit relationships. Allen
et al. (2019) emphasized that ignoring the impacts of planktonic
cloning meant that both realized reproductive output and larval
dispersal period had been underestimated in prior population modeling
efforts for sea stars (Rogers-Bennett and Rogers 2008). To date,
evidence of the existence of sexually mature sea star individuals in
wild populations that originated from cloned larvae is lacking for any
species (Knott et al. 2003), including the sunflower sea star. Thus,
despite a demonstrated capacity to clone as larvae, estimates of female
fecundity considered in the draft status review report (Lowry et al.
2022) are limited to gross estimates of egg
[[Page 16217]]
production on a seasonal basis, which, as noted above, are tenuous at
best.
No studies have been conducted to establish natural growth rates
throughout the lifespan of the sunflower sea star, due in part to the
difficulty of tagging and effectively tracking individuals. The IUCN
assessment for the sunflower sea star lists several observations of
juvenile growth rates from anecdotal observations and laboratory
studies as being between 3 and 8 cm/yr, and 2 cm/yr for mid-sized
individuals (Gravem et al. 2021). Hodin et al. (2021) reared post-
metamorphic, laboratory-cultured sunflower sea stars and the fastest
growing individuals were able to reach a diameter of 3 cm in 288 days
(about 9.5 months) post-settlement. Juveniles reared by Hodin et al.
(2021) grew slowly for several months after settlement, but grew faster
after they reached about 10 cm in diameter, at which time they could
feed on live juvenile bivalves. Laboratory estimates may not be
entirely representative of growth rates in the field because sea star
growth is affected by water temperature and food availability (Gooding
et al. 2009; Deaker et al. 2020; Dealer and Byrne 2022). Sea star
growth rate also generally decreases with increasing size of
individuals (Carlson and Pfister 1999; Keesing 2017). Some sea stars
can persist for long periods with little or no food (Nauen 1978; Deaker
et al. 2020; Byrne et al. 2021), potentially complicating estimates of
age based on size and resulting in episodic growth only when resources
are adequate to exceed base metabolic needs.
In one of the few published reports of sunflower sea star growth
under pseudonatural conditions, Miller (1995) described growth of
juveniles found on settlement collectors (i.e., Astroturf-coated PVC
tubes) on the Oregon coast. When fed crushed prey, juveniles grew from
a mean arm length (AL) of 0.41 mm at first sampling, to a mean AL of
3.65 mm at 63 days, and 5 to 6 mm AL at 99 days. Thus, juveniles
increased in size by a factor of nearly nine times after two months and
up to 14 times after three months from sampling (Miller 1995).
In response to the call for public comments on our 90-day finding
for the petition to list the sunflower sea star under the ESA (86 FR
73230; December 27, 2021), we received a dataset demonstrating growth
of putative cohorts of juvenile sunflower sea stars from Holmes Harbor
on the east side of Whidbey Island, in the Southern Salish Sea,
Washington (K. Collins, pers. comm., March 20, 2022). During repeated
SCUBA-based sampling of the size distribution of populations of
sunflower sea stars at several index sites between March of 2020 and
2022, recruitment pulses of individuals could be identified from
frequency of occurrence data. Between March of 2020 and March of 2021,
the average diameter of one such group of juvenile sunflower sea stars
increased 7.99 cm, from ~9 to 17 cm. This annual growth rate aligns
with the rapid growth period identified by Hodin et al. (2021),
concomitant with the ability to consume small bivalves. While this
estimate is for one small population in the Salish Sea and is cohort-
based rather than based on tracking target individuals, it provides
insight into the growth of juvenile sunflower sea stars that is not
available elsewhere.
The longevity of sunflower sea stars in the wild is unknown, as is
the age at first reproduction (as noted above) and the period over
which a mature individual is capable of reproducing, but these
parameters are needed to calculate generation time. It is also unknown
if, or how much, any of these crucial life history parameters vary
across the range of the species. The IUCN assessment for the sunflower
sea star used a generic echinoderm equation to estimate generation
times as 20.5 to 65 years or 27 to 37 years, depending on maximum
longevity (reaching maximum size observed of 95 to 100 cm diameter) or
more typical longevity (time to reach 50 cm diameter) estimated from
two different growth models (Gravem et al. 2021). These generation time
figures utilized an estimated age at first reproduction of five years,
based on the ochre star and other species, as this information is not
available for the sunflower sea star (Gravem et al. 2021).
Diet and Feeding
Larval and pre-metamorphic sunflower sea stars are planktonic
feeders and no data exist to suggest a prey preference at this stage.
The diet of adult sunflower sea stars generally consists of benthic and
mobile epibenthic invertebrates, including sea urchins, snails, crab,
sea cucumbers, and other sea stars (Mauzey et al. 1968; Shivji et al.
1983), and appears to be driven largely by prey availability. Sea
urchins were the major dietary component in the intertidal regions
along the outer coast of Washington in a study by Mauzey et al. (1968).
For sunflower sea stars inhabiting kelp forests in central California,
however, 79 percent of the diet was gastropods, and only four sea
urchins were found in the guts of 41 adults (Herrlinger 1983).
Sunflower sea stars also feed on sessile invertebrates, such as
barnacles and various bivalves (Mauzey et al. 1968). Mussels are a
common prey in intertidal regions in Alaska (Paul and Feder 1975).
Clams can also constitute a major proportion of their diet, with up to
72 percent coming from clams at subtidal sites within Puget Sound
(Mauzey et al. 1968). Adults excavate clams from soft or mixed-
substrate bottoms by digging with one or more arms (Smith 1961; Mauzey
et al. 1968). Sunflower sea stars locate their prey using chemical
signals in the water and on substrate, and may show preference for dead
or damaged prey (Brewer and Konar 2005), likely due to reduced energy
expenditure associated with catching and subduing active prey; thus
they occasionally scavenge fish, seabirds, and octopus (Shivji et al.
1983).
Population Demographics and Structure
Prior to the onset of the coast-wide sea star wasting syndrome
(SSWS) pandemic in 2013 (see evaluation of threats below), directed
population monitoring for the sunflower sea star was haphazard and
typically the result of short-term research projects rather than long-
term monitoring programs. Such efforts were rarely focused on the
sunflower sea star itself, but it was often included as one component
of the local invertebrate assemblage, and generally it was secondary to
the primary species of interest. Indigenous peoples occupying lands
along the Pacific Coast of North America from Alaska to California have
long known of the sunflower sea star, have included the species in
artistic works, and have recognized the important ecological role it
plays. However, no oral histories or other traditional ecological
knowledge that directly addressed long-term population distribution or
abundance could be found. In response to the 90-day finding on the
petition to list the sunflower sea star (86 FR 73230; December 27,
2021), several First Nation and tribal entities contacted us to provide
recent monitoring data, which was integrated into the draft status
review report as much as possible (Lowry et al. 2022). Most of the
datasets lacked pre-2013 (i.e., before the SSWS pandemic) occurrence
records, however, and could not be used to quantitatively evaluate
trends in abundance or density relative to baseline values.
Recent descriptions of sunflower sea star distribution and
population declines by Harvell et al. (2019), Gravem et al. (2021), and
Hamilton et al. (2021) relied on datasets gathered either exclusively
or predominantly during the 21st century and, in some cases, as a
direct response to losses due to SSWS. The most intense loss occurred
over just
[[Page 16218]]
a few years from 2013 through 2017, generally commencing later in more
northern portions of the range, and impacts varied by region. Hence,
our understanding of the historical abundance of the sunflower sea star
is patchy in both time and space, with substantial gaps.
Summary data presented in Gravem et al. (2021) indicate that prior
to the 2013 through 2017 SSWS outbreak the sunflower sea star was
fairly common throughout its range, with localized variation linked to
prey availability and various physiochemical variables. Starting in
2012, Konar et al. (2019) assessed rocky intertidal populations in the
Gulf of Alaska and described sunflower sea stars prior to the 2016
wasting outbreak as ``common'' toward the northwest part of the
species' range in the Katmai National Park and Preserve near Kodiak
Island, AK (0.038/m\2\ in 2012 and 0.048/m\2\ in 2016, respectively).
Abundances during this pre-pandemic period varied geographically, from
infrequent in Kachemak Bay (<0.005 m\2\), to fairly common in the Kenai
Fjords National Park (~0.075/m\2\), and common in western Prince
William Sound (average 0.233/m\2\) (Konar et al. 2019). In subtidal
rocky reefs near Torch Bay, Southeast Alaska, densities were high (0.09
0.055/m\2\) in the 1980s (Duggins 1983). In Howe Sound,
near Vancouver, British Columbia, densities were high at 0.43 0.76/m\2\ in 2009 and 2010 before the SSWS pandemic (Schultz et
al. 2016). Montecino-LaTorre et al. (2016) found that sunflower sea
star abundance averaged 6 to 14 individuals per roving diver survey
throughout much of the Salish Sea from 2006 through 2013. In deep water
habitats off the coasts of Washington, Oregon, and California, 2004
through 2014 pre-outbreak biomass averaged 3.11, 1.73, and 2.78 kg/10
ha, respectively (Harvell et al. 2019). In 2019, a remotely operated
vehicle survey of the Juan de Fuca Canyon encountered a number of large
sunflower sea stars at depths ranging from 150 to 350 m (OCNMS 2019).
While population connections between these sea stars and those in
shallow water remain unknown, this suggests that deep waters may serve
as a biomass reservoir for the species (J. Waddell, Olympic Coast
National Marine Sanctuary, pers. comm., March 15, 2022).
Along the north and central California coastline, average
population densities were 0.01-0.12/m\2\ prior to 2013 (Rogers-Bennett
and Catton 2019). The oldest density records come from kelp forests
near central California in Monterey Bay, where densities were 0.03/m\2\
in 1980 and 1981 (Herrlinger 1983). More recently in central
California, densities were even lower and fluctuated from 0.01-0.02/
m\2\ between 1999 and 2011 (Smith et al. 2021). In southern California,
sites in the Channel Islands have been studied extensively, and from
1982 through 2014 densities ranged from 0 to 0.25/m\2\ (Bonaviri et al.
2017), from 1996 through 1998 they were 0 to 0.02 m\2\ (Eckert 2007),
from 2003 through 2007 they were 0 to 0.07m\2\ (Rassweiler et al.
2010), and from 2010 through 2012 they were ~0.10 to 0.14/m\2\
(Eisaguirre et al. 2020).
The pattern of decline by latitude as a consequence of the SSWS
pandemic in 2013 (see evaluation of threats below) is striking.
Hamilton et al. (2021) noted a 94.3 percent decline throughout the
range of the sunflower sea star after the outbreak of SSWS. The 12
regions defined by Hamilton et al. (2021) encompass the known range of
the sunflower sea star, and each region exhibited a decline in density
and occurrence from approximately 2013 through 2017, with populations
in the six more northern regions characterized by less severe declines
(40 to 96 percent declines) than those in the six regions spanning from
Cape Flattery, WA, to Baja, MX, where the sunflower sea star is now
exceptionally rare (99.6 to 100 percent declines). Furthermore, while
anecdotal observations indicate recruitment continues in the U.S.
portion of the Salish Sea, British Columbia, and Alaska, few of these
juveniles appear to survive to adulthood (A. Gehman, University of
British Columbia and the Hakai Institute, pers. comm., February 16,
2022). We are not aware of any observations of sunflower sea star
recruits or adults in California or Mexico since 2017 despite continued
survey effort in these areas.
There are not, to date, any range-wide or regional assessments of
systematic variation in life history parameters, morphological
characteristics, genetic traits, or other attributes that can be used
to delineate specific populations of sunflower sea stars. As such, we
have no direct biological data to establish that the species is
anything but a single, panmictic population throughout its range. As
habitat generalists that use a wide variety of substrates over a broad
depth range, and dietary generalists that consume diverse prey based
largely on prey availability and encounter rate, differentiation of
subpopulations is not expected to be driven by strong selection for
particular environmental needs. In the 2020 IUCN status assessment
report (Gravem et al. 2021), putative population segments were
identified largely based on a combination of legal and geographic
boundaries/barriers and data provided in response to a broad request
distributed to natural resource managers and academic researchers. For
instance, data from both trawl and SCUBA diving surveys were considered
together to describe population trends in a region defined as
``Washington outer coast,'' which spanned from Cape Flattery to the
Washington-Oregon border.
Because sunflower sea stars are relatively sessile in the settled
juvenile through adult life stages, any population structuring is
likely attributable to dispersion during the pelagic larval phase. This
is a common feature of broadcast spawning, benthic, marine organisms,
and population breaks in such organisms are typically associated with
strong biogeographic features where current flows diverge or stop
(i.e., Queen Charlotte Sound, Point Conception), if such features
exist. Within a given biogeographic region, such organisms typically
exhibit either genetic homogeneity for species with prolonged pelagic
larval phases or, for species with shorter pelagic larval duration, a
stepping-stone dispersal resulting in isolation-by-distance. Within the
historical range of the sunflower sea star, there are two major
biogeographic regions (Longhurst 2007), the ``Alaska Coastal
Downwelling Province'' and the ``California Current Province.'' These
regions are essentially formed by the bifurcation of the North Pacific
Current into the northward-flowing Alaska Current and the southward-
flowing California Current. This bifurcation occurs in the vicinity of
Vancouver Island, though the exact location varies with shifting
climatic conditions and bulk water transport processes, with a
transition zone between Queen Charlotte Sound and Cape Flattery
(Cummins and Freeland 2007).
For some echinoderm species that have been more thoroughly
examined, regional variation in phenotypic and genetic traits along the
west coast of North America have been documented. Bat stars (Patiria
miniata) largely overlap with the sunflower sea star in geographic
range and depth distribution, and share similar planktonic larval
duration, so can potentially be used as a proxy to make demographic
inferences. Keever et al. (2009) used a combination of mitochondrial
and nuclear markers to study bat stars range-wide and provided support
for two genetically distinct populations, essentially split across
Longhurst's (2007) biogeographic provinces. Within the California
Current
[[Page 16219]]
Province there was little detectable genetic structure, but within the
Alaska Coastal Downwelling Province there was a high degree of
structure, potentially as a consequence of the geographic complexity
within this region as compared with the California Coast Province. Gene
flow simulations showed that larvae of the bat star don't disperse far
despite a relatively long pelagic larval duration (Sunday et al. 2014).
The red sea urchin (Strongylocentrotus franciscanus) also overlaps in
range, depth, and duration of planktonic dispersal with sunflower sea
star but shows no clear signal of genetic partitioning (Debenham et al.
2000) throughout its range. Similarly, the ochre star exhibits similar
life history parameters but shows no genetic partitioning (Harley et
al. 2006). Overall, the lack of demonstrated genetic structure in these
co-occurring echinoderm species suggests that sunflower sea stars may
also lack population structure, but no genetic studies currently exist
that would allow us to confirm or refute this assumption.
Assessment of Extinction Risk
Using the best available scientific and commercial data relevant to
sunflower sea star demography and threats, the SRT undertook an
assessment of extinction risk for the species. The ability to measure
or document risk factors and quantify their explicit impacts to marine
species is often limited, and quantitative estimates of abundance and
life history information are sometimes lacking altogether. Therefore,
in assessing extinction risk of this data-limited species, we relied on
both qualitative and quantitative information. In previous NMFS status
reviews, assessment teams have used a risk matrix method to organize
and summarize the professional judgment of members. This approach is
described in detail by Wainwright and Kope (1999) and has been used in
Pacific salmonid status reviews, as well as in reviews of various
marine mammals, bony fishes, elasmobranchs, and invertebrates (see
https://www.nmfs.noaa.gov/pr/species/ for links to these reviews). In
the risk matrix approach, the condition of a species is summarized
according to four viable population factors: abundance, growth rate/
productivity, spatial structure/connectivity, and diversity (McElhany
et al. 2000). These viable population factors reflect concepts that are
well-founded in conservation biology and that, individually and
collectively, provide strong indicators of extinction risk. Employing
these concepts, the SRT conducted a demographic risk analysis for the
sunflower sea star to determine population viability. Likewise, the SRT
performed a threats assessment by scoring the severity of current
threats to the species and their likely impact on population status
into the foreseeable future. The summary of demographic risks and
threats obtained by this approach was then considered to determine the
species' overall level of extinction risk, ranked either low, moderate,
or high, both currently and in the foreseeable future. Further details
on the approach and results are available in Lowry et al. (2022).
For the assessment of extinction risk for the sunflower sea star,
the ``foreseeable future'' was considered to extend out 30 years based
on several lines of evidence, though numerous assumptions had to be
made due to missing information. Limited data are available regarding
sunflower sea star longevity, age at sexual maturity, size at sexual
maturity, fecundity, reproductive life span, spawning frequency, and
other fundamental biological attributes. Further, the degree to which
these parameters might vary over the range of the species is unknown.
Gravem et al. (2021) estimated the generation time of the sunflower sea
star to vary between 20.5 and 65 years based on a generalized
echinoderm model, but used an estimate of 27 to 37 years for the 2020
IUCN assessment. Monitoring data for the sunflower sea star at
locations spread throughout its range documented extremely rapid,
dramatic declines from 2013 to 2017 as a consequence of SSWS. Despite
considerable research since, the causative agent of SSWS remains
elusive, as does the environmental trigger or triggers that led to the
pandemic. Extending and augmenting the analysis of Gravem et al.
(2021), Lowry et al. (2022) demonstrated that if post-pandemic negative
trends in population abundance continue, extinction risk is high in the
immediate and foreseeable future. If pre-pandemic population growth
rates resume, however, the likelihood of long-term persistence is
moderate to high, depending on region. Which of these scenarios is more
likely depends on disease resistance, current local population
dynamics, and a myriad of environmental factors affecting both the
sunflower sea star and the SSWS agent(s). If individuals that survived
the pandemic are able to successfully reproduce over the next several
years, and ocean conditions are adequate to support larval survival and
settlement, a substantive recruitment pulse could result. Whether the
causative agent of SSWS exists in an environmental or biological
reserve, however, is also unknown. If it does, any recruitment pulse
could be short lived and individuals may not survive to reproduce
themselves. There is a high level of uncertainty regarding potential
outcomes, and predictive capacity is limited as a consequence of the
unique combination of ocean conditions and disease prevalence in recent
years.
After considering the best available information on sunflower sea
star life history (including its mean generation time), projected
abundance trends, likelihood of a resurgence of SSWS to pandemic
levels, and current and future management measures, the SRT concluded
that after 30 years uncertainty in these factors became too great to
reliably predict the biological status of the species. Though potential
threats like nearshore habitat degradation and anthropogenic climate
change can be projected further into the future, the SRT concluded that
the impacts of these threats on the sunflower sea star could not be
adequately predicted given the behavioral patterns of the species with
regard to habitat use and diet. Whether population segments occupying
deep waters will fare better than those in the shallows, and to what
degree these populations are linked, cannot be adequately predicted
given limited knowledge of sunflower sea star biology and demography.
Given the demonstrated capacity of SSWS to kill billions of individuals
across the entire range of the species over just a few years, the SRT
felt that reliably assessing the effects of additional threats on
species viability beyond the temporal range of 30 years was not
possible.
Demographic Risk Analysis
Methods
The SRT reviewed all relevant biological and commercial data and
information for the sunflower sea star, including: current abundance
relative to historical abundance estimates, and trends in survey data;
what is known about individual growth rate and productivity in relation
to other species, and its effect on population growth rate; spatial and
temporal distribution throughout its range; possible threats to
morphological, physiological, and genetic integrity and diversity; and
natural and human-influenced factors that likely cause variability in
survival and abundance. Each team member then assigned a risk score to
each of the four viable population criteria (abundance, productivity,
spatial distribution, and diversity) throughout the whole of the
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species' range. Risks for each criterion were ranked on a scale of 0
(unknown risk) to 3 (high risk) using the following definitions:
0 = Unknown: Information/data for this demographic factor is
unavailable or highly uncertain, such that the contribution of this
factor to the extinction risk of the species cannot be determined.
1 = Low risk: It is unlikely that the particular factor directly
contributes significantly to the species' current risk of extinction,
or will contribute significantly in the foreseeable future (30 years).
2 = Moderate risk: It is likely that the particular factor directly
contributes significantly to the species' current risk of extinction,
or will contribute significantly in the foreseeable future (30 years),
but does not in itself currently constitute a danger of extinction.
3 = High risk: It is highly likely that the particular factor
directly contributes significantly to the species' current risk of
extinction, or will contribute significantly in the foreseeable future
(30 years).
Team members were given a template to fill out and asked to score
each criterion's contribution to extinction risk. Scores were provided
to the team lead, anonymized, then shared with the entire team, which
discussed the range of perspectives and the supporting data/information
upon which they were based. Team members were given the opportunity to
revise scores after the discussion, if they felt their initial analysis
had missed any pertinent data discussed in the group setting. Final
scores were reviewed and considered, then synthesized, to arrive at the
overall demographic risk determination from the team. Further details
are available in Lowry et al. (2022).
Abundance
Severe declines in nearly all available datasets, range-wide from
2013 through 2017 are readily apparent, with little evidence of recent
recruitment or rebound (Gravem et al. 2021; Lowry et al. 2022). While
variability in abundance estimates was high prior to the SSWS pandemic
and boom/bust cycling was apparent in many areas, detection rates have
been very low since approximately 2015 in the majority of time series
datasets. Datasets from the Oregon and California coasts are notable
because they report several years of regular observation of sunflower
sea stars leading up to 2013, followed by several years of absence at
the same index sites. In locations where individuals continued to be
detected after the pandemic, like in northern Oregon, density decreased
by an order of magnitude or more. Data providers for these time series
categorize the near or total loss of sunflower sea stars in their
survey area as local or functional extirpation, but other researchers
and the public have reported juveniles in several of these areas (e.g.,
the Channel Islands), demonstrating that some reproduction and
settlement is occurring. In areas where adults have not been detected
for several years, the potential for deleterious stochastic events,
such as marine heat waves, to destroy what remains of the population is
likely to be considerably increased. Abundance prior to the SSWS
pandemic was substantially greater in northern portions of the range
from Alaska to the Salish Sea, and declines in these areas were less
pronounced (Gravem et al. 2021; Lowry et al. 2022).
The current range-wide (i.e., global) population estimate for the
sunflower sea star is nearly 600 million individuals, based on a
compilation of the best available science and information (Gravem et
al. 2021). While substantial, this represents less than 10 percent of
the estimated abundance prior to 2013 and likely reflects an even
greater decrease in biomass due to the loss of adults from SSWS.
However, there is considerable uncertainty in this global abundance
estimate and in regional estimates that contribute to it. Low sampling
effort prior to the SSWS pandemic, depth-biased disparities in data
richness, inadequate species-specific documentation of occurrence, and
missing information about several crucial life history parameters all
contribute to this uncertainty. While confidence is relatively high in
estimates from more southerly, nearshore areas that are well-sampled
via SCUBA, the majority of the species' range consists of deep, cold,
and/or northern waters that are less well sampled. How segments of the
population in these poorly sampled areas contribute to and are
connected with the overall health and stability of the species remains
largely unknown. Sunflower sea stars in these areas are less
susceptible to impacts from nearshore stressors and could serve as
source populations to support population rebound, but evidence to
support this role is lacking. Based on the broad geographic range over
which the remaining population is spread, the generalist nature of the
sunflower sea star with regard to both habitat use and diet, and the
possibility that deep-water individuals may serve as source populations
to bolster recovery, the team concluded that the current state of the
abundance criterion was a moderate factor in affecting extinction risk
in the foreseeable future.
Productivity
Little is known about the natural productivity of the sunflower sea
star on both an individual and population basis. Lack of information
about growth rate, longevity, age at maturity, fecundity, natural
mortality, the influence of larval cloning, and other fundamental
biological attributes requires that broad assumptions be applied and
proxy species used to inform estimates on both regional and range-wide
bases. Regardless of the values of nearly all of these parameters,
however, the loss of approximately 90 percent of the global population
of the sunflower sea star from 2013 through 2017 is likely to have had
profound impacts on population-level productivity. The standing crop of
individuals capable of generating new recruits has been decreased,
possibly to levels where productivity will be compromised on a regional
or global basis. The combined factors of spatial distribution of
individuals across the seascape and ocean conditions are crucial to
dictating whether productivity is sufficient to allow population
rebound. Broadly dispersed individuals may lack the ability to find
mates, further reducing realized productivity despite abundance being
high enough to theoretically result in population persistence.
As a broadcast spawner with indeterminate growth, traits shared
with many other echinoderms, the capacity for allometric increases in
fecundity and high reproductive output certainly exists in the
sunflower sea star. Hodin et al. (2021) noted that gonads are small in
sunflower sea stars compared to other sea stars but also documented
prolonged periods over which spawning apparently occurs (i.e., gonads
are ripe). If the SSWS pandemic resulted in the loss of the large, most
reproductively valuable individuals across both nearshore and deep-
water habitats, it could take a decade or more for sub-adults to
mature, settlement to occur at detectable levels, and population
rebounds to be documented. There is evidence in some areas that
recruitment has occurred, demonstrating that local productivity is
still occurring, but it may be years before these individuals reach
maturity and spawn. The ongoing threat of another SSWS pandemic
dictates that caution is warranted when predicting population growth
rate into the foreseeable future.
[[Page 16221]]
Provided reproduction continues to occur, even on a local basis,
the prolonged planktonic period of larval sunflower sea stars affords
the opportunity for substantial dispersal prior to settlement. During
this period, however, larvae are at the mercy of prevailing currents,
temperature variation, and a suite of biophysical variables that affect
survival. Even if populations maintain relatively high levels of
productivity, recent conditions in the northeast Pacific Ocean have not
been favorable to larval survival for many species due to repeated
marine heat waves, falling pH, and localized oxygen minimum zones.
Additionally, given the predominant flow regime along the Pacific West
Coast of North America, propagules are expected to be carried both
northward and southward from British Columbia following the North
Pacific Current as it bifurcates into the Alaska and California
Currents, respectively. Given the distance larvae must travel with the
currents, populations in British Columbia are not expected to
contribute markedly to repopulation in the southern portion of the
range off Oregon, California, and Mexico. While the Davidson
Countercurrent and California Undercurrent may seasonally carry
propagules northward from Mexico and California (Thomas and Krassovski
2010), abundance of the sunflower sea star in this portion of the range
is not currently likely to be high enough to serve as a source
population to areas off Washington, Oregon, or northern California.
Studies of connectivity across the range of the sunflower sea star will
be crucial to evaluating how large-scale population patterns are
affected by local and regional productivity in the future.
Taking into account the many unknowns about life history,
population level reproductive capacity, and functional implications of
environmental conditions on population connectivity in the foreseeable
future, the productivity criterion was scored as a moderate contributor
to overall extinction risk over the foreseeable future, though there
was considerable variation in individual team member scores.
Depensatory impacts from abundance declines have likely decreased
productivity on a local and regional scale, but the adults that remain
are assumed to live long enough that opportunities to mate will
manifest in time, provided they are able to find one another and mate.
Until more is known about the underlying biology of the species, this
parameter, and its effects on long-term viability, will remain poorly
defined.
Spatial Distribution and Connectivity
Despite substantial population declines from 2013 through 2017,
sunflower sea stars still occupy the whole of their historic range from
Alaska to northern Mexico, though in nearshore areas from the outer
coast of Washington to Mexico the species is now rare where it was once
common (Gravem et al. 2021; Lowery et al. 2022). Natural resource
managers and researchers in the contiguous United States consider
several local populations off Oregon and California to be functionally
extirpated, but reports of newly settled juveniles and occasional
adults in these regions demonstrate continued occupancy (Gravem et al.
2021; Lowery et al. 2022). With so few individuals, a new wave of SSWS
or other catastrophic event could eliminate the species in these areas.
However, the lack of adequate sampling of deep waters and patchy
encounter reporting in bottom-contact fisheries with a high likelihood
of interaction (e.g., crustacean pot/trap fisheries) introduces
sufficient uncertainty to preclude stating that sunflower sea stars
have been extirpated throughout this southern portion of their range.
Spatial distribution and connectivity are integrally related with
the abundance and productivity criteria. Species occurrence, density,
habitat use, and intraspecific interaction rate, alongside
environmental parameters, ultimately determine population productivity
and abundance. As a habitat generalist with broad resilience to
physiochemical environmental variables, the sunflower sea star utilizes
most available benthic habitats from the nearshore down to several
hundred meters deep throughout its range. Loss of over 90 percent of
the population in southern portions of the range almost certainly
resulted in population fragmentation, but the only areas where data
exist to confirm this are shallow, SCUBA-accessible habitats. Kelp
forests and rocky reefs, in particular, are well sampled and may
represent key habitats for the sunflower sea star, but regular
occurrence on mud, sand, and other soft-bottom habitats is also well
documented. Undersampled, deep-water habitats represent the majority of
suitable habitat for the sunflower sea star by area, however,
additional effort is needed to characterize both how individuals in
these waters are distributed and how they are connected with
populations in shallow waters. Less accessible nearshore areas, largely
those associated with sparsely populated areas, also suffer from
undersampling.
Direct evidence to assess the connectivity of sunflower sea star
populations at various geographic scales is lacking. Without meristic,
morphological, physiological, and/or genetic studies to demonstrate
similarities or differences among population segments linkages cannot
be adequately evaluated. Broad assumptions can be made about larval
distribution as a consequence of prevailing flow patterns, but evidence
both for and against connections over large geographic scales for
echinoderm populations on the Pacific Coast exist. Population declines
associated with the SSWS pandemic were severe enough that historic
patterns of spatial distribution and connectivity could have been
obliterated in the last decade, and may continue to change into the
foreseeable future.
After taking into account the best available information on both
the historic and present spatial distribution of the sunflower sea
star, spatial distribution was determined to have a moderate
contribution to extinction risk. This was largely due to evidence of
population fragmentation in nearshore areas and several data series
demonstrating very low abundance across broad portions of the range.
Connectivity could not be adequately assessed due to a lack of data.
Diversity
Systematic comparisons of morphology, life history, behavior,
physiology, genetic traits, and other aspects of diversity do not exist
for the sunflower sea star. While some authors note that animals in the
northern portion of the range grow to a large diameter and mass, this
general statement is not supported by data. As a result of this lack of
information, adequately evaluating the impact of this parameter on
extinction risk is difficult. Data from proxy species, such as the
ochre star, demonstrate that variation in physical characteristics such
as color can be both genetically and ecologically controlled in sea
stars (Harley et al. 2006; Raimondi et al. 2007). While examples exist
of echinoderm species with both substantial population structuring and
a complete lack of population structure on the West Coast, where the
sunflower sea star falls along this spectrum could not be determined
due to the lack of fundamental biological knowledge pertinent to
population dynamics. As a result, this criterion was determined to have
an unknown contribution to overall extinction risk.
[[Page 16222]]
Threats Assessment
Methods
As noted above, section 4(a)(1) of the ESA requires the agency to
determine whether the species is endangered or threatened because of
any one, or a combination of, a specific set of threat factors. Similar
to the demographic risk analysis, SRT members were given a template to
fill out and asked to rank each threat in terms of its contribution to
the extinction risk of the species throughout the whole of the species'
range. Specific threats falling within the section 4(a)(1) categories
were identified from sources included in the status review report, and
included as line items in the scoring template (Lowry et al. 2022).
Below are the definitions that the Team used for scoring:
0 = Unknown: The current level of information is insufficient for
this threat, such that its contribution to the extinction risk of the
species cannot be determined.
1 = Low: It is unlikely that the threat is currently significantly
contributing to the species' risk of extinction, or will significantly
contribute in the foreseeable future (30 years).
2 = Moderate: It is likely that this threat will contribute
significantly to the species' risk of extinction in the foreseeable
future (30 years), but does not in itself constitute a danger of
extinction currently.
3 = High: It is highly likely that this threat contributes
significantly to the species' risk of extinction currently.
The template also included a column in which team members could
identify interactions between the threat being evaluated and specific
demographic parameters from the viable population criteria analysis, as
well as other section 4(a)(1) threats.
Scores were provided to the team lead, anonymized, and then the
range of perspectives and the supporting data/information upon which
they were based was discussed. Interactions among threats and specific
demographic parameters, or other threats, were also discussed to ensure
that scoring adequately accounted for these relationships. Team members
were then given the opportunity to revise scores after the discussion
if they felt their initial analysis had missed any pertinent data
discussed in the group setting. Scores were then reviewed, considered,
and synthesized to arrive at an overall threats risk determination.
Results of this threats assessment are summarized below, and further
details are available in Lowry et al. (2022).
The Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range
The sunflower sea star is a habitat generalist known to occur in
association with a broad diversity of substrate types, grades of
structural complexity, and biogenic habitat components. Habitat
degradation and modification in nearshore areas of the Pacific Coast as
a consequence of direct human influence is largely concentrated in
urbanized centers around estuaries and embayments, with considerable
tracts of sparsely populated, natural shoreline in between. This is
especially true of the northern portion of the range. In urbanized
areas, nearshore modification to accommodate infrastructure has
dramatically changed the available habitat over the last two hundred
years. The relative importance of specific habitats to the range-wide
health and persistence of the sunflower sea star is difficult to
quantify, however, because suitable habitat occurs well beyond the
depth range where most sampling occurs. Human impacts on nearshore
habitats and species of the Pacific Coast have long been recognized,
and marine protected areas, sanctuaries, and other place-based
conservation measures have been created in a variety of jurisdictions
in recent decades. While these measures have not explicitly targeted
the sunflower sea star, many of them are centered on sensitive habitats
(e.g., kelp forests) and provide protections to the ecosystem at large,
including sunflower sea stars and their prey. Under current nearshore
management practices, the sunflower sea star has persisted in urban
seascapes at apparently healthy population levels until very recently,
when SSWS resulted in the death of 90 percent or more of the
population. As a result, the SRT determined that nearshore habitat
destruction or modification was a low-level contributor to overall
extinction risk (Lowry et al. 2022), although systematic sampling is
needed to establish whether certain habitat types are critical to
specific life stages or behaviors for the sunflower sea star.
Sunflower sea stars also occur on benthic habitats to depths of
several hundred meters, and anthropogenic stressors affecting these
offshore waters are markedly different from those affecting the
nearshore. Quantifying impacts to sunflower sea star habitat in deeper
waters is more complicated, however, and less information is available
to support a rigorous evaluation. Fishing with bottom-contact gear,
laying communications or electrical cables, mineral and oil
exploration, and various other human activities have direct influence
on benthic habitats in offshore waters of the North Pacific Ocean. The
activities are highly likely to interact with sunflower sea stars at
some level, but data are lacking regarding both the distribution of
individuals in these deeper waters and impacts from particular
stressors. As a result, the SRT determined that effective assessment of
the contribution of deep-water habitat modification or destruction on
overall extinction risk of the species could not be conducted.
Geographic input of all potential stressors in these deep waters is
likely to be small relative to the documented range of the sunflower
sea star and the SRT determined that the species' adaptability and
resilience are unlikely to make habitat impacts in these areas a
substantial threat (Lowry et al. 2022).
Curtailment of the range of the sunflower sea star has not yet been
demonstrated, despite the fact that, since the SSWS pandemic, the
species has become rare from the Washington coast south to California,
areas where it once was common. The total population estimate for this
region still stands at over five million individuals (Gravem et al.
2021) and their range north of Washington is vast. Population
fragmentation as a consequence of dramatic losses in abundance could
result in range curtailment in the foreseeable future, but occasional
reports of juvenile sunflower sea stars at locations along the West
Coast as far south as the Channel Islands demonstrate that local
extirpation has not yet occurred. If juveniles do not mature and
successfully reproduce because of a resurgence of SSWS to pandemic
levels, or some other factor, a substantial reduction in distribution
could occur at the southern extent of the currently documented range. A
minority opinion within the SRT was that range curtailment has already
occurred from Neah Bay, WA, southward and that remnant populations
would soon be eliminated by natural demographic processes.
Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
There are no substantial current or historical fisheries directed
at the sunflower sea star, but recreational harvest is allowed or
permitted in Alaska, British Columbia, California, and Mexico and
occurs at unquantified levels. Whether collected individuals are held
for a short period before being released or permanently removed from
the population is unknown. Impacts
[[Page 16223]]
from recreational harvest cannot be evaluated because data are not
available on either an aggregate or species-specific basis; however,
market drivers for this species are minimal and human consumption is
not known to occur. As a result, the SRT determined that recreational
harvest impacts are a minor factor affecting extinction risk.
Recreational harvest and trade may become a greater concern in the
foreseeable future in areas where abundance levels are extremely low or
declining. Additional regulations prohibiting retention could offset
impacts from this potential threat.
Fishery bycatch impacts to the sunflower sea star are a low-level
concern for a variety of fisheries that use bottom-contact gear. This
includes fisheries for benthic fishes and invertebrates that employ
trawls, pots, traps, nets, and, to a limited degree, hook-and-line.
Information to quantify the encounter rate in specific fisheries is
largely lacking, as are data demonstrating direct impacts of these
encounters, and frequent aggregation of all sea star catch into a
single reporting category precludes a species-specific assessment. That
said, these potential risks are offset by the following observations:
(1) the majority of commercial trawl fisheries occur in waters outside
of preferred sunflower sea star depth zones (<25 m or 82 ft), based on
the information regarding highest documented densities (Gravem et al.
2021); and (2) sunflower sea stars are anecdotally reported as being
resilient to handling stress during regular fishing operations, though
post-release monitoring is not reported in the literature. Post-
release, handling-related stress could exacerbate symptoms of SSWS or
increase susceptibility to other sources of mortality. This could make
handling during fisheries a greater threat in regions where population
abundance is especially low, such as from coastal Washington to the
southern extent of the species' range. Unfortunately, systematic
reporting of encounters with sunflower sea stars does not occur at this
time.
The collection, drying, and trade of small ``sunflower stars'' is
noted in Gravem et al. (2021) and in the ESA-listing petition received
from the Center for Biological Diversity. This practice predominantly
affects small stars under 15.25 cm in diameter and the retailers that
offer these curios often do not list the species, site of collection,
or other details necessary to determine whether populations of
sunflower sea star are being directly impacted. Given that sea stars
can be collected in Alaska, British Columbia, and Mexico, and in
California seaward of a tidal exclusion zone, a more thorough
evaluation of retail offerings is needed. Without additional
information, the SRT unanimously decided that this threat has an
unknown, but likely negligible, impact on extinction risk in the
foreseeable future due to a lack of demand and no evidence of a
substantial market.
Disease or Predation
Disease, specifically SSWS, was identified by the SRT as the single
greatest threat affecting the persistence of the sunflower sea star
both now and into the foreseeable future (Lowry et al. 2022). While the
etiology of the disease as well as what trigger(s) resulted in its
rapid spread to pandemic levels remain unknown (Hewson et al. 2018),
the widespread occurrence of, and impacts from, the disease from 2013
through 2017 are broadly documented. Initially, SSWS was thought to be
caused by one, or a suite, of densoviruses (Paraviridae; Hewson et al.
2014; 2018); however, subsequent studies determined that the disease is
more complex. A number of factors ranging from environmental stressors
to the microbiome in the sea stars may play a role (Lloyd and Pespeni
2018; Konar et al. 2019; Aquino et al. 2021). Ocean warming has also
been linked to outbreaks, hastening disease progression and severity
(Harvell et al. 2019; Aalto et al. 2020). Regardless of the pathogen's
unknown etiology to date, stress and rapid degeneration ultimately
result with symptomatic sea stars suffering from abnormally twisted
arms, white lesions, loss of body tissue, arm loss, disintegration, and
death. During the 2013-2017 pandemic, populations of sunflower sea
stars were diminished range wide, and in southern portions of the range
estimated losses are on the order of 95 percent or more. There was
considerable variation in the degree of impact associated with depth,
latitude, and (sometimes) recent temperature regime, but projected
losses in all regions where data were sufficient amounted to
approximately 90 percent or more (Gravem et al. 2021). Lowry et al.
(2022) demonstrate that these declines have continued at least through
2021 in most regions, though recent settlement events have been
recorded in the Salish Sea and Alaska. Whether new cohorts will survive
long enough to reproduce, or succumb to SSWS, is highly uncertain.
Whether reproductive adults that survived the SSWS pandemic will
demonstrate resistance or immunity to future outbreaks is also crucial
to whether the species will survive. If impacts from SSWS continue at a
level that resulted in population declines of greater than 90 percent
over a 5-year timespan, extinction risk would be very high for the
sunflower sea star. If population growth rates are able to return to
pre-pandemic levels in coming years, the likelihood of population
persistence is moderate in the Alaska Region and the British Columbia
and Salish Sea Region, but lower in the West Coast Region from
Washington to Mexico (Lowry et al. 2022).
There is no evidence that other known diseases constitute
substantial threats to the continued persistence of the sunflower sea
star now or in the foreseeable future. However, the SRT noted that a
complicating factor is that the physiological response of sea stars to
numerous stressors (e.g., high temperature, low dissolved oxygen) is to
develop lesions, autotomize arms, and/or disintegrate (Lowry et al.
2022). These symptoms, and the ultimate outcome of disintegration, are
shared with SSWS, making it possible that a suite of disease pathogens
or stressors jointly contribute to the observed syndrome. As the end
result of any such disease is mortality within just a few days, the
threat from disease still remains high whether SSWS is caused by a
single pathogen or many.
Very few predators are known to consume adult sunflower sea stars
and this is not expected to change even under generous projections of
ecosystem changes as a consequence of global climate change or other
factors. Predation risk is likely highest during the planktonic larval
phase when indiscriminate filter feeders consume small larvae and
selective pickers target larger, more developed individuals. The
prolonged duration of the larval period could enhance this risk, but
there is no evidence to suggest that current risks of predation are any
higher than they were prior to the pandemic when populations were
healthy. Additionally, while the fecundity of the sunflower sea star is
not well known, even conservative estimates suggest that an individual
female likely produces millions of eggs in a single spawning event. As
such, the SRT determined that predation is not likely to substantially
contribute to extinction risk, now or in the foreseeable future (Lowry
et al. 2022).
Inadequacy of Existing Regulatory Mechanisms
As noted above, in Washington and Oregon harvest and collection of
sunflower sea stars are not allowed, but in Alaska, British Columbia,
California, and Mexico recreational harvest is permitted. Though data
are not available to determine how intensive this harvest is, human
consumption is not known to
[[Page 16224]]
occur and large markets for dried or otherwise processed specimens do
not exist. Considering this information, the SRT determined that the
current harvest and collection regulations do not contribute
substantially to extinction risk, nor are they likely to in the
foreseeable future (Lowry et al. 2022). Inconsistency of regulations
across jurisdictions could complicate enforcement, however, unless
coordinated efforts to standardize or reconcile rules occur. It may
also become necessary in the foreseeable future to propose and
publicize handling recommendations for bycaught sunflower sea stars to
reduce handling stress and mortality, should data support that this is
a more significant threat than currently recognized. Draft handling
recommendations are currently under development within NOAA Fisheries
for use in scientific surveys and will be adapted, as needed, for
fisheries.
A patchwork of place-based conservation measures exists across the
known range of the sunflower sea star that are designed to protect
ecologically sensitive and/or important habitats and species. While
none of these are specifically directed at conservation of the
sunflower sea star or its habitat, many of them provide indirect
protection to the species, its habitat, and its prey.
Current regulations to control anthropogenic climate change are
likely insufficient to have a measurable impact on trends in changing
ocean conditions, and resulting ecological effects, by the end of the
century (Fr[ouml]licher and Joos, 2010; Ahmadi Dehrashid et al. 2022).
The effectiveness of regulations controlling anthropogenic climate
change is a considerable concern because such regulations affect
stressors like elevated sea surface temperature and lowered pH, which
have sweeping effects on marine prey base and living conditions (Doney
et al. 2012). Elevated ocean temperatures likely contributed to the
decline of the sunflower sea star because warmer water temperatures are
correlated with accelerated rates of SSWS transmission and disease-
induced mortality; therefore the lack of adequate regulations to stall
the impacts of climate change also presents a direct concern for the
long-term viability of the sunflower sea star. There is uncertainty
regarding ways in which additional climate change regulations could
affect the extinction risk of the sunflower sea star without a better
understanding of the relationships between climate change impacts
(especially temperature stress), SSWS dynamics, and species-specific
disease vulnerability.
The SRT identified considerable uncertainty regarding what
regulatory mechanisms might effectively reduce extinction risk as a
consequence of SSWS (Lowry et al. 2022). While a given disease can
sometimes be isolated to a geographic region or eliminated by a
combination of quarantine, transport embargos of specimens carrying the
pathogen, or the administration of vaccines, these actions all require
considerable knowledge of the disease itself. In the case of SSWS, the
pathogen has not yet been identified, the cause may be several
pathogens with similar etiologies, and the disease has been observed
across the full geographic range of the species. For these reasons,
while existing regulatory mechanisms are insufficient to address the
threat of SSWS, the SRT determined that it is unlikely that any
effective regulatory approaches will arise in the foreseeable future
without considerable research (Lowry et al. 2022).
Other Natural or Man-Made Factors Affecting Its Continued Existence
Direct impacts of environmental pollutants to the sunflower sea
star are unknown, but they likely have similar effects to those seen in
other marine species, given physiologically similar processes.
Reductions in individual health and disruption of nutrient cycling
through food webs are hallmarks of industrial chemicals, heavy metals,
and other anthropogenic contaminants. With the sunflower sea star
representing a monotypic genus, the SRT noted substantial uncertainty
involved with projecting potential impacts into the foreseeable future,
and decided that extrapolating effects of specific chemicals or suites
of chemicals to range-wide population viability is impossible (Lowry et
al. 2022). Any impacts that do exist are likely to be more intensive
near their source, such as urban bays and estuaries, though many
persistent contaminants are known to bioaccumulate in some organisms
and spread over long distances over the course of decades or more.
The addition of anthropogenically released greenhouse gasses into
the atmosphere since the industrial revolution has resulted in climate
change that is affecting organisms and environments on a global basis.
While direct linkages between climate change and sunflower sea star
population status have not been made in the literature, impacts to prey
base, habitat, and SSWS can all be inferred from available data.
Ecosystem change rooted in climate forcers has already been
demonstrated in nearshore ecosystems of the north Pacific Ocean (e.g.,
Bonaviri et al. 2017; Berry et al. 2021), resulting in prey base
instability that adds additional stress to struggling populations. See
above for a discussion of how climate change may link to progression
and severity of SSWS outbreak as a consequence of changes in sea
surface temperature and physiochemical properties of marine waters.
Larval life stages of numerous shell-forming marine organisms are
highly sensitive to chemical composition of pelagic waters, such that
ocean acidification can increase physiological stress and decrease
survival in a broad array of organisms. Additionally, life stages of
various planktonic organisms are sensitive to temperature, with
elevated temperature increasing metabolic rate and, thus, nutritional
requirements. Furthermore, some marine organisms rely on seasonal
shifts in temperature and other environmental cues to identify suitable
spawning times, aligning planktonic feeding periods of larvae with
phytoplankton blooms. Changes in the spatiotemporal availability and
quality of prey affect planktotrophic larvae and may result in reduced
growth, delayed settlement, starvation, and various other negative
outcomes. Though the planktonic diet of sunflower sea star larvae has
not been adequately described, it is likely that they consume shell-
forming organisms to various degrees depending on spatiotemporal
variability in abundance, quality, and encounter rate. Nearshore
benthic communities can also be affected in myriad ways by elevated
carbon dioxide levels, reduced pH, increased temperature, and other
physiochemical changes resulting from anthropogenic climate change.
While these effects of climate change are unlikely to affect the
sunflower sea star across its full range simultaneously, the SRT noted
that decreases in habitat suitability are likely on a localized basis
and such stressors could exacerbate consequences of low abundance,
especially in southern portions of the range (Lowry et al. 2022). High
levels of uncertainty regarding complex interactions among climate-
related stressors and their impacts on sunflower sea star population
viability, however, make it impossible to adequately project effects on
extinction risk into the foreseeable future.
Overall Extinction Risk Summary
Throughout the Range of the Species
Little is known about several fundamental biological aspects of the
sunflower sea star, such as age at maturity, longevity, growth rate,
[[Page 16225]]
reproductive output, population resiliency, and population
connectivity. What is known is that the species is a broadcast spawner,
utilizes a broad range of habitats and prey, and has a broad geographic
distribution, all of which buffer the species against catastrophic
events and reduce overall extinction risk. The abundance and density of
the species have clearly declined recently throughout the vast majority
of its range; however, data are highly uncertain in deep waters and
less accessible/well surveyed regions. Additionally, most current
SCUBA- and trawl-based protocols fail to sample small individuals
(e.g., those less than 5 cm as measured from arm-tip to arm-tip),
making characterization of population status incomplete. In some areas,
functional extirpation is likely within the foreseeable future of 30
years due to a lack of mate availability, which constrains reproductive
capacity and limits settlement of new cohorts. Best available estimates
indicate that the remaining range-wide abundance of the sunflower sea
star is approximately 600 million individuals, with the highest
abundances in Alaska and British Columbia, primarily in deeper water
(at lower densities than observed in shallow, scuba-accessible depths).
Given the widespread impacts of SSWS from 2013 through 2017, it is
likely that surviving sunflower sea stars were exposed, giving hope
(but no direct evidence) that they bear some resistance to the
causative agent of the disease, though this agent remains unknown. SSWS
is the single greatest threat to the sunflower sea star on a range-wide
basis, and may be exacerbated by global warming, ocean acidification,
toxic contaminants, and other processes that generate physiological
stress in individuals. A conclusive link has not been demonstrated but
is likely given physiology and known stressors of this, and other, sea
star species. Regions most likely to be impacted by climate change
factors are in the south, where the sunflower sea star population was
most heavily impacted by the SSWS pandemic. Fishing pressure (including
bycatch), the curio trade, and habitat degradation are threats, but are
not anticipated to have population-level impacts in the next 30 years.
Regional variability in threat severity could result in total loss of
the species in the southern portion of its geographic range, but
whether the loss of this portion of the population may compromise the
long-term viability of the species is unknown. Overall, threats to
population persistence exist, with high uncertainty about potential
impacts, and with trajectories in many areas continuing downward. As a
result of this analysis of aspects of species viability and threats
facing the species, we conclude that the sunflower sea star is at
moderate risk of extinction now and in the foreseeable future
throughout its range.
Significant Portion of Its Range
Under the ESA, a species may warrant listing if it is in danger of
extinction now or in the foreseeable future throughout all or a
significant portion of its range. Having concluded that the sunflower
sea star is at moderate risk of extinction now and in the foreseeable
future throughout all of its range, the SRT next conducted an
assessment to determine whether it may currently be in danger of
extinction in any identified significant portion of its range (SPR). If
a species is in danger of extinction in an SPR, the species qualifies
for listing as an endangered species (79 FR 37578; July 1, 2014). In
2014, the USFWS and NMFS issued a joint policy on interpretation of the
phrase ``significant portion of its range'' (SPR Policy, 79 FR 37578;
July 1, 2014). The SPR Policy set out a biologically-based approach for
interpreting this phrase that examines the contributions of the members
of the species in the ``portion'' to the conservation and viability of
the species as a whole. More specifically, the SPR Policy established a
threshold for determining whether a portion is ``significant'' that
involved considering whether the hypothetical loss of the members in
the portion would cause the overall species to become threatened or
endangered. This threshold definition of ``significant'' was
subsequently invalidated in two District Court cases, which held that
it set too high a standard to allow for an independent basis for
listing species--i.e. it did not give independent meaning to the phrase
``throughout . . . a significant portion of its range'' (Center for
Biological Diversity, et al. v. Jewell, 248 F. Supp. 3d 946, 958 (D.
Ariz. 2017); Desert Survivors v. DOI 321 F. Supp. 3d. 1011 (N.D. Cal.,
2018). However, those courts did not take issue with the fundamental
approach of evaluating significance in terms of the biological
significance of a particular portion of the range to the overall
species. While the SRT did not rely on the definition of
``significant'' in the policy when conducting their analysis, they did
use a biological approach to assessing whether any portions of the sea
star's range are ``significant.''
To identify potential SPRs for the sunflower sea star, the SRT
considered the following: (1) is there one or more population segment
at higher risk of extinction relative to population segments elsewhere
in the range; and (2) is the higher-risk population segment
biologically significant to the overall viability of the species. To
analyze whether a portion qualifies as significant the SRT considered
the viability characteristics of abundance, productivity, spatial
distribution, and genetic diversity. Ultimately, the goal of this
analysis was to determine whether the sunflower sea star is in danger
of extinction in a significant portion of its range.
To help in identifying potential SPRs, SRT members were provided a
base map of the northeast Pacific Ocean labeled with several
geophysical features either referenced in the IUCN status assessment of
the sunflower sea star (Gravem et al. 2021) or known to be associated
with demographic breaks in a variety of other marine organisms. Team
members independently considered all data and information available on
a regional basis to generate proposed areas that could potentially
represent SPRs, that is, areas that have a reasonable likelihood of
being at high risk of extinction and that have a reasonable likelihood
of being biologically significant to the species. These portions were
highlighted on the map, and detailed justifications provided regarding
the intensity of specific threats to, and biological significance of,
the population segment in the identified portion(s). Because there are
theoretically an infinite number of ways in which a species' range may
be divided for purposed of an SPR analysis, only those portions that
the SRT identified as ones where the species has a reasonable
likelihood of being both at higher risk of extinction relative to the
rest of the range and biologically significant to the overall species
were considered further in the analysis.
After considering all available biological, geographic, and flow
regime data available; evaluating issues of data resolution,
representativeness, and availability; and drawing on proxy species
where necessary, the SRT delineated three portions in which trends in
biological viability, threat intensity, and likely biological
significance were internally consistent. These were: (1) all waters of
the range north of Dixon Entrance (i.e., waters of Alaska; Portion 1);
(2) coastal British Columbia and the Salish Sea (Portion 2); and (3)
all waters of the range south of Cape Flattery, to Baja California,
Mexico (Portion 3). In waters shallower than 25 m, where assessment
data are most
[[Page 16226]]
readily available and comprehensive (Gravem et al. 2021; Lowry et al.
2022), over 72 percent of the pre-pandemic abundance of sunflower sea
stars occupied Portion 1. Portion 2 is estimated to have held
approximately 17.5 percent of the population. Despite being
geographically extensive, Portion 3 was estimated to be occupied by the
remainder of the species, just under 10 percent of the total shallow-
water population. It is worth noting that nearly 45 percent of the pre-
pandemic population was estimated to occupy waters deeper than 25 m,
which are disproportionately located off of Alaska and coastal British
Columbia, further amplifying these patterns. Taken together, the SRT
determined that these estimates indicate the existence of a population
center in the North Pacific, a transition zone along coastal British
Columbia and into the Salish Sea, and a southward extension of the
species through temperate waters at limited abundance/density until
thinning out in the subtropics around the Southern California Bight.
The population center of the sunflower sea star is in Alaskan
waters, and the population segment here was less impacted by SSWS with
considerably more individuals surviving (over 275 million in shallow
waters and as many as 400 million in deep waters [Gravem et al. 2021])
and no apparent reduction in spatial distribution. Given this, the SRT
determined that the population segment occupying Portion 1 is not at
higher risk of extinction than the species overall. Because the status
of the species in Portion 1 does not differ from the status throughout
the range, the SRT did not continue the analysis further to determine
whether Portion 1 constitutes a significant portion of the species'
range.
Conversely, waters of Portion 3 are estimated to have held less
than ten percent of the pre-pandemic population of species and saw
losses >95 percent from 2013 to 2017, with few signs of recovery. While
it is possible individuals in this portion that survived the pandemic
are disease resistant, or contain genes for thermal tolerance or
adaptability to other environmental parameters, data do not exist at
this time to support this assertion. Furthermore, being at the southern
end of a current system that flows predominantly southward it is
unlikely that these traits could be naturally transmitted into northern
populations via planktonic drift. Taken together, this caused the SRT
to conclude that while risk of extinction may be higher in the southern
portion of the range due to dramatically decreased abundance, density,
and frequency of occurrence post pandemic, this population segment is
not likely to be biologically significant relative to the overall
viability of the species. As such, Portion 3 does not constitute a
significant portion of the range for ESA status assessment purposes.
Portion 2 is situated where currents flow both north and south into
other portions of the range, uniquely positioning it to serve as a
biologically significant population with regard to long-term
persistence of the sunflower sea star. Higher abundance within the
region may allow the population here to contribute to population
viability in Southeast Alaska, the Washington coast, and beyond. In
addition, while there is recruitment to offshore sites, and relatively
healthy populations in some glacial fjords, there is evidence of
source/sink dynamics (i.e., areas of high reproductive capacity within
the region produce larvae that settle elsewhere in the region) within
Portion 2. The possibility of disease resistance in these remaining
individuals cannot be discounted, but has not been demonstrated.
Persistent low encounter rates in the region, however, suggest a degree
of resiliency despite ongoing occurrence of the causative agent of the
disease (whatever it may be) in the environment. The Salish Sea region
is influenced by a number of other threats, such as toxic
contamination, pressure from a diversity of fisheries, and extensive
habitat degradation and destruction associated with creation and
maintenance of human infrastructure. To assess whether these threats
elevated overall extinction risk to high in the biologically
significant Portion 2, a second overall extinction risk scoring sheet
was distributed and team members independently assessed this region.
Though there is a high degree of uncertainty with regard to the
potential impact of SSWS and other threats on the population segment in
this portion, the SRT determined that overall extinction risk in
Portion 2 is moderate, matching that of the range-wide assessment and
thereby precluding assignment of high extinction risk to the species
based on status within this particular portion of its range.
Given the best available information, we find that the sunflower
sea star is at a moderate risk of extinction throughout its range, as
well as within Portion 2 (the British Columbia Coast and Salish Sea),
the only portion of the range determined to be biologically
significant. Without efforts to better understand the etiology of SSWS
and identify paths to address its impacts on the sunflower sea star,
the species is on a trajectory in which its overall abundance will
likely significantly decline within the foreseeable future, eventually
reaching the point where the species' continued persistence will be in
jeopardy. These declines are likely to be exacerbated by anthropogenic
climate change and the resulting impacts on biogeochemical aspects of
habitats occupied by the species. Although the species is not currently
in danger of extinction throughout its range, it will likely become an
endangered species within the foreseeable future.
Protective Efforts
Having found that the sunflower sea star is likely to become in
danger of extinction throughout its range within the foreseeable
future, we next considered protective efforts as required under section
4(b)(1)(A) of the ESA. The focus of this evaluation is to determine
whether protective efforts are being made and, if so, whether they are
effective in ameliorating the threats we have identified to the species
and thus, potentially, avert the need for listing. As we already
considered the adequacy of existing regulatory efforts associated with
fisheries and place-based ecosystem protections in our evaluation of
threats above, we consider other conservation efforts in this section.
Following the 2020 IUCN assessment of the sunflower sea star
(Gravem et al. 2021), the species was conferred Critically Endangered
status on the Red List of Threatened Species (https://www.iucnredlist.org/species/178290276/197818455). Subsequent to this,
The Nature Conservancy convened a working group made up of state,
tribal, Federal, and provincial government; academic; and non-profit
partners to create a roadmap to recovery for the species. This document
uses the best available science and information to identify specific,
targeted research and management efforts needed to address what
workgroup participants identify as the greatest threats facing long-
term persistence of the sunflower sea star (Heady et al. 2022). Many
contributors to this document provided data and knowledge to the SRT to
ensure all of the most recent research was captured in our analysis
(Lowry et al. 2022). The roadmap also includes an inventory of
knowledge gaps that can be used as a guidance tool by partner
organizations to coordinate collaborative research and management
directed at sunflower sea star recovery (Heady et al. 2022), in many
ways paralleling the structure and intent of a formal recovery plan
under the ESA.
While we find that protective efforts associated with the roadmap
to recovery
[[Page 16227]]
will help increase public and scientific knowledge about the sunflower
sea star and SSWS, and will likely result in multinational coordination
on both research and management, such actions alone do not
significantly alter the extinction risk for the sunflower sea star to
the point where it would not be in danger of extinction in the
foreseeable future. We seek additional information on these and other
conservation efforts in our public comment process (see Public Comments
Solicited on Proposed Listing below).
Determination
Section 4(b)(1)(A) of the ESA requires that listing determinations
are based solely on the best scientific and commercial information and
data available after conducting a review of the status of the species
and taking into account those efforts, if any, being made by any state
or foreign nation, or political subdivisions thereof, to protect and
conserve the species. We have independently reviewed the best available
scientific and commercial information including the petition, public
comments submitted on the 90-day finding (86 FR 73230; December 27,
2021), the status review report (Lowry et al. 2022), and other
published and unpublished information, and have consulted with species
experts and individuals familiar with the sunflower sea star.
As summarized above, and in Lowry et al. (2022), we assessed the
ESA section 4(a)(1) factors both individually and collectively for the
sunflower sea star, throughout its range and in portions of its range,
and conclude that the species faces ongoing threats from SSWS and
direct (i.e., physiological) and indirect (i.e., ecological)
consequences of anthropogenic climate change. Over 90 percent of the
abundance of the species was lost over the period from 2013 to 2017,
there are few positive signs of recovery, and we do not yet know the
etiology of SSWS. Likely linkages of SSWS with environmental parameters
that are projected to worsen with ongoing climate change suggest that
impacts on the species from SSWS will likely persist and potentially
worsen over the foreseeable future throughout the range.
We found no evidence of protective efforts for the conservation of
the sunflower sea star that would eliminate or adequately reduce
threats to the species to the point where it would not necessitate
listing under the ESA. Therefore, we conclude that the sunflower sea
star is likely to become an endangered species in the foreseeable
future throughout its range from threats of disease and anthropogenic
climate change. As such, we have determined that the sunflower sea star
meets the definition of a threatened species and propose to list it is
as such throughout its range under the ESA.
Effects of Listing
Measures provided for species of fish or wildlife listed as
endangered or threatened under the ESA include: development of recovery
plans (16 U.S.C. 1533(f)); designation of critical habitat, to the
maximum extent prudent and determinable (16 U.S.C. 1533(a)(3)(A)); and
the requirement for Federal agencies to consult with NMFS under section
7 of the ESA to ensure the actions they fund, conduct, and authorize
are not likely to jeopardize the continued existence of the species or
result in adverse modification or destruction of any designated
critical habitat (16 U.S.C. 1536(a)(2)). Certain prohibitions,
including prohibitions against ``taking'' and importing, apply with
respect to endangered species under section 9 (16 U.S.C. 1538), and, at
the discretion of the Secretary, some or all of these prohibitions may
be applied to threatened species under the authority of section 4(d)
(16 U.S.C. 1533(d)). Other benefits to species from ESA listing include
recognition of the species' status and threats, which can promote
voluntary conservation actions by Federal and state agencies, foreign
entities, private groups, and individuals.
Identifying Section 7 Conference and Consultation Requirements
Section 7(a)(4) of the ESA and implementing regulations require
Federal agencies to confer with us on actions likely to jeopardize the
continued existence of species proposed for listing, or that result in
the destruction or adverse modification of proposed critical habitat.
If a proposed species is ultimately listed, Federal agencies must
consult under section 7(a)(2) on any action they authorize, fund, or
carry out if those actions may affect the listed species or its
critical habitat to ensure that such actions are not likely to
jeopardize the species or result in destruction or adverse modification
of critical habitat should it be designated. At this time, based on the
currently available data and information, we determine that examples of
Federal actions that may affect the sunflower sea star include, but are
not limited to: discharge of pollution from point and non-point
sources, contaminated waste disposal, dredging, marine cable laying,
pile-driving, development of nearshore infrastructure, development of
water quality standards, military activities, and fisheries management
practices. None of the actions on this list were scored as moderate or
high risk to the sunflower sea stars or identified as a significant
cause of their recent population decline. Their effects, even if small,
would be subject to section 7 consultations if the sea star sunflower
is listed as threatened. For example, Federal fisheries were identified
as low risk, and for specific fisheries that employ bottom contact gear
and have known or presumed bycatch, we would anticipate evaluating the
relatively low risk, then focusing on measures to minimize or better
understand effects, such as species identification and reporting by
fishery observers and development of safe handling practices.
Critical Habitat
Critical habitat is defined in the ESA (16 U.S.C. 1532(5)(A)) as:
(1) the specific areas within the geographical area occupied by a
species, at the time it is listed in accordance with the ESA, on which
are found those physical or biological features (a) essential to the
conservation of the species and (b) which may require special
management considerations or protection; and (2) specific areas outside
the geographical area occupied by a species at the time it is listed
upon a determination that such areas are essential for the conservation
of the species. ``Conservation'' means the use of all methods and
procedures needed to bring the species to the point at which listing
under the ESA is no longer necessary. Section 4(a)(3)(A) of the ESA
requires that, to the maximum extent prudent and determinable, critical
habitat be designated concurrently with the listing of a species.
Designations of critical habitat must be based on the best scientific
data available and must take into consideration the economic, national
security, and other relevant impacts of specifying any particular area
as critical habitat. When developing critical habitat designations we
often seek data and public comment on these aspects such as: (1) maps
and specific information describing the amount, distribution, and use
type (e.g., spawning) of the habitat, as well as any additional
information on occupied and unoccupied habitat areas; (2) the reasons
why any specific area of habitat should or should not be determined to
be critical habitat as provided by sections 3(5)(A) and 4(b)(2) of the
ESA; (3) information regarding the benefits of designating particular
areas as critical habitat; (4) current or planned activities in the
areas that might qualify for designation and their possible impacts;
[[Page 16228]]
(5) any foreseeable economic or other potential impacts resulting from
designation, and, in particular, any impacts on small entities; (6)
whether specific unoccupied areas may be essential for the conservation
of the species; and (7) individuals who could serve as peer reviewers
in connection with a proposed critical habitat designation, including
persons with biological and economic expertise relevant to the species,
region, and designation of critical habitat.
As part of the status review process (Lowry et al. 2022) and
proposed threatened listing we have conducted an exhaustive review of
available information on many of the above elements, particularly
related to distribution, habitat use, and biological features.
Sunflower sea stars are habitat generalists, occurring on a wide array
of abiotic and biotic substrates over a broad depth range. Few
systematic surveys have been conducted to differentiate habitat use,
such as spawning/rearing, or identify features across different depths,
latitudes, substrates, temperatures, or other potentially important
biological parameters. At this time, we find that critical habitat for
the sunflower sea star is not determinable because data sufficient to
perform the required analyses are lacking. Specifically, we do not have
sufficient information regarding physical and biological habitat
features associated with sunflower sea star occurrence that may be
essential to their conservation.
We therefore seek public input on physical and biological habitat
features and areas that are essential to the conservation of the
sunflower sea star in U.S. waters. If we determine that designation of
critical habitat is prudent and determinable in the future, we will
publish a proposed designation of critical habitat for the sunflower
sea star in a separate rule.
Protective Regulations Under Section 4(d) of the ESA
In the case of threatened species, ESA section 4(d) gives the
Secretary discretion to determine whether, and to what extent, to
extend the prohibitions of section 9 to the species, and authorizes the
issuance of regulations necessary and advisable for the conservation of
the species. Thus, we have flexibility under section 4(d) to tailor
protective regulations, taking into account the effectiveness of
available conservation measures. The 4(d) protective regulations may
prohibit, with respect to threatened species, some or all of the acts
which section 9(a) of the ESA prohibits with respect to endangered
species. We are not proposing such regulations at this time, given the
minimal impacts of habitat degradation/destruction, fisheries, trade,
and manmade factors (other than climate change described above), but we
may consider potential protective regulations pursuant to section 4(d)
for the sunflower sea star in a future rulemaking. For example, the
impacts of the specific threats that could potentially be addressed
through a 4(d) rule, such as pollution, collection/trade, or fisheries,
were all identified as low risk. Therefore, at this time we conclude
that management under 4(d) would be unlikely to provide meaningful
protection. In order to inform our consideration of appropriate
protective regulations for the species in the future if our
understanding of threats evolves, we are seeking information from the
public on threats to the sunflower sea star and possible measures for
its conservation.
Role of Peer Review
The intent of peer review is to ensure that listings are based on
the best scientific and commercial data available. In December 2004,
OMB issued a Final Information Quality Bulletin for Peer Review
establishing minimum peer review standards, a transparent process for
public disclosure of peer review planning, and opportunities for public
participation. The OMB Bulletin, implemented under the Information
Quality Act (Pub. L. 106-554), is intended to enhance the quality and
credibility of the Federal Government's scientific information, and
applies to influential or highly influential scientific information
disseminated on or after June 16, 2005. To satisfy our requirements
under the OMB Bulletin, we are obtaining independent peer review of the
status review report concurrent with the public comment period
associated with this proposed rule. All comments will be considered and
addressed prior to publication of the final rule in which we make the
decision whether to list the sunflower sea star.
Public Comments Solicited on Proposed Listing
To ensure that the final action resulting from this proposal will
be as accurate and effective as possible, we solicit comments and
suggestions from the public, other governmental agencies, the
scientific community, industry, tribal entities, environmental groups,
and any other interested parties. Comments are encouraged on all
aspects of this proposal (See DATES and ADDRESSES). We are particularly
interested in: (1) new or updated information regarding the range,
distribution, and abundance of the sunflower sea star; (2) new or
updated information regarding the genetics and population structure of
the sunflower sea star; (3) new or updated information regarding past
or current habitat occupancy by the sunflower sea star; (4) new or
updated biological or other relevant data concerning any threats to the
sunflower sea star (e.g., landings of the species, illegal taking of
the species); (5) information on commercial trade or curio collection
of the sunflower sea star; (6) recent observations or sampling of the
sunflower sea star; (7) current or planned activities within the range
of the sunflower sea star and their possible impact on the species; and
(8) efforts being made to protect the sunflower sea star.
Public Comments Solicited on Critical Habitat
As noted above, we have concluded that critical habitat is not
currently determinable for the sunflower sea star. We request
information that would contribute to consideration of critical habitat
in the future, such as new data describing the quality and extent of
habitat for the sunflower sea star, information on what might
constitute physical and biological habitat features and areas that are
essential to the conservation of the species, whether such features may
require special management considerations or protection, or
identification of areas outside the occupied geographical area that may
be essential to the conservation of the species and that are under U.S.
jurisdiction.
In addition, as part of any potential critical habitat designation
we may propose, we would also need to consider the economic impact,
impact on national security, and any other relevant impact of
designating any particular area as critical habitat as required under
section 4(b)(2) of the ESA. Therefore, we are also soliciting
information to inform these types of analyses, including information
regarding: (1) activities or other threats to the essential features of
occupied habitat or activities that could be affected by designating a
particular area as critical habitat; and (2) the positive and negative
economic, national security, and other relevant impacts, including
benefits to the recovery of the species, likely to result if particular
areas are designated as critical habitat.
References
A complete list of the references used in this proposed rule is
available at
[[Page 16229]]
https://www.fisheries.noaa.gov/species/sunflower-sea-star and upon
request (see ADDRESSES).
Classification
National Environmental Policy Act
The 1982 amendments to the ESA, in section 4(b)(1)(A), restrict the
information that may be considered when assessing species for listing.
Based on this limitation of criteria for a listing decision and the
opinion in Pacific Legal Foundation v. Andrus, 657 F. 2d 829 (6th Cir.
1981), NMFS has concluded that ESA listing actions are not subject to
the environmental assessment requirements of the National Environmental
Policy Act (NEPA).
Executive Order 12866, Regulatory Flexibility Act, and Paperwork
Reduction Act
As noted in the Conference Report on the 1982 amendments to the
ESA, economic impacts cannot be considered when assessing the status of
a species. Therefore, the economic analysis requirements of the
Regulatory Flexibility Act are not applicable to the listing process.
In addition, this proposed rule is exempt from review under Executive
Order 12866. This proposed rule does not contain a collection-of-
information requirement for the purposes of the Paperwork Reduction
Act.
Executive Order 13132, Federalism
Executive Order 13132 requires agencies to take into account any
federalism impacts of regulations under development. It includes
specific directives for consultation in situations where a regulation
will preempt state law or impose substantial direct compliance costs on
state and local governments (unless required by statute). Neither of
those circumstances is applicable to this action.
List of Subjects in 50 CFR Part 223
Endangered and threatened species.
Dated: March 10, 2023.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For the reasons set out in the preamble, NOAA proposes to amend 50
CFR part 223 as follows:
PART 223--THREATENED MARINE AND ANADROMOUS SPECIES
0
1. The authority citation for part 223 continues to read as follows:
Authority: 16 U.S.C. 1531-1543; subpart B, Sec. 223.201-202
also issued under 16 U.S.C. 1361 et seq.; 16 U.S.C. 5503(d) for
Sec. 223.206(d)(9).
0
2. Amend Sec. 223.102, in paragraph (e), by adding a new table
subheading for ``Echinoderms'' before the ``Molluscs'' subheading, and
adding a new entry for ``Sunflower Sea Star'' under the ``Echinoderms''
table subheading to read as follows:
Sec. 223.102 Enumeration of threatened marine and anadromous
species.
* * * * *
(e) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species \1\
----------------------------------------------------------------------------------- Citation(s) for listing
Description of listed determination(s) Critical habitat ESA rules
Common name Scientific name entity
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Echinoderms
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sunflower Sea Star............... Pycnopodia Entire species........... [Insert Federal Register NA.................. NA.
helianthoides. citation and date when
published as a final
rule].
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Species includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement, see 61 FR 4722, February 7, 1996), and
evolutionarily significant units (ESUs) (for a policy statement, see 56 FR 58612, November 20, 1991).
[FR Doc. 2023-05340 Filed 3-15-23; 8:45 am]
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