Endangered and Threatened Wildlife and Plants; Endangered Species Act Listing Determination for Alewife and Blueback Herring, 28630-28666 [2019-12908]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 118 (Wednesday, June 19, 2019)]
[Notices]
[Pages 28630-28666]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-12908]



[[Page 28629]]

Vol. 84

Wednesday,

No. 118

June 19, 2019

Part II





 Department of Commerce





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 National Oceanic and Atmospheric Administration





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 Endangered and Threatened Wildlife and Plants; Endangered Species Act 
Listing Determination for Alewife and Blueback Herring; Notice

Federal Register / Vol. 84 , No. 118 / Wednesday, June 19, 2019 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[Docket No. 170718681-9471-01]
RIN 0648-XF575


Endangered and Threatened Wildlife and Plants; Endangered Species 
Act Listing Determination for Alewife and Blueback Herring

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; 12-month finding and availability of status review 
document.

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SUMMARY: We, NMFS, have completed a comprehensive status review under 
the Endangered Species Act (ESA) for alewife (Alosa pseudoharengus) and 
blueback herring (Alosa aestivalis). The status review identified four 
alewife distinct population segments (DPSs): Canada, Northern New 
England, Southern New England, and Mid-Atlantic. Based on the best 
scientific and commercial data available including the Status Review 
Report, we have determined that listing the alewife rangewide or as any 
of the identified DPSs as threatened or endangered under the ESA is not 
warranted at this time. The status review also identified three 
blueback herring DPSs: Canada/Northern New England, Mid-Atlantic, and 
Southern Atlantic. Based on the best scientific and commercial data 
available, we have determined that listing blueback herring rangewide 
or as any of the identified DPSs as threatened or endangered under the 
ESA is not warranted at this time.

DATES: This finding was made on June 19, 2019.

ADDRESSES: The status review document for alewife and blueback herring 
is available electronically at: www.nmfs.noaa.gov/pr/species/notwarranted.htm. You may also obtain a copy by submitting a request to 
the Protected Resources Division, NMFS GARFO, 55 Great Republic Drive, 
Gloucester, MA 01930, Attention: Alewife and Blueback Herring 12-month 
Finding.

FOR FURTHER INFORMATION CONTACT: Jean Higgins, NMFS Greater Atlantic 
Regional Fisheries Office, 978-281-9345.

SUPPLEMENTARY INFORMATION: 

Background

    On August 12, 2013, we determined that listing alewife and blueback 
herring (collectively, ``river herring''): As threatened or endangered 
under the Endangered Species Act (ESA) (16 U.S.C. 1531 et seq.) was not 
warranted (78 FR 48943). However, we also noted that there were 
significant data deficiencies. In that determination, we committed to 
revisiting the status of both species in three to five years, a period 
after which ongoing scientific studies, including a river herring stock 
assessment update by the Atlantic States Marine Fisheries Commission 
(ASMFC), would be completed.
    The Natural Resources Defense Council and Earthjustice (the 
Plaintiffs) filed suit against NMFS on February 10, 2015, in the U.S. 
District Court in Washington, DC, challenging our decision not to list 
blueback herring as threatened or endangered. The Plaintiffs also 
challenged our determination that the Mid-Atlantic stock complex of 
blueback herring is not a DPS. On March 25, 2017, the court vacated the 
blueback herring listing determination and remanded the listing 
determination to us (Natural Resources Defense Council, Inc., et al. v. 
Samuel D. Rauch, National Marine Fisheries Services, 1:15-cv-00198 
(D.D.C.)). As part of a negotiated agreement with the Plaintiffs, we 
committed to publishing a revised listing determination for blueback 
herring by January 31, 2019; the publication date was extended by the 
court to June 19, 2019.
    We announced the initiation of an alewife and blueback herring 
status review in the Federal Register on August 15, 2017 (82 FR 38672). 
At that time, we also opened a 60-day solicitation period for new 
scientific and commercial data on alewife and blueback herring to help 
ensure that we were informed by the best available scientific and 
commercial information.

Listing Species Under the ESA

    We are responsible for determining whether species are threatened 
or endangered under the ESA (16 U.S.C. 1531 et seq.). To make this 
determination, we first consider whether a group of organisms 
constitutes a ``species'' under section 3 of the ESA (16 U.S.C. 1532), 
and then consider whether the status of the species qualifies it for 
listing as either threatened or endangered. Section 3 of the ESA 
defines species to include any subspecies of fish or wildlife or 
plants, and any distinct population segment of any species of 
vertebrate fish or wildlife which interbreeds when mature. On February 
7, 1996, NMFS and the U.S. Fish and Wildlife Service (USFWS; together, 
the Services) adopted a policy describing what constitutes a DPS of a 
taxonomic species (DPS Policy; 61 FR 4722). Under the DPS Policy, we 
consider the following when identifying a DPS: (1) The discreteness of 
the population segment in relation to the remainder of the species or 
subspecies to which it belongs; and (2) the significance of the 
population segment to the species or subspecies to which it belongs.
    Section 3 of the ESA further 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, we 
interpret an ``endangered species'' to be one that is presently in 
danger of extinction. A ``threatened species,'' on the other hand, is 
not presently in danger of extinction, but is likely to become so in 
the foreseeable future. In other words, the primary statutory 
difference between a threatened and endangered species is the timing of 
when a species may be in danger of extinction, either presently 
(endangered) or in the foreseeable future (threatened).
    Section 4(a)(1) of the ESA also requires us to determine whether 
any species is endangered or threatened as a result of any of the 
following five factors: The present or threatened destruction, 
modification, or curtailment of its habitat or range; overutilization 
for commercial, recreational, scientific, or educational purposes; 
disease or predation; the inadequacy of existing regulatory mechanisms; 
or other natural or manmade factors affecting its continued existence 
(16 U.S.C. 1533(a)(1)(A)-(E)). Section 4(b)(1)(A) of the ESA requires 
us to make listing determinations based solely on the best scientific 
and commercial data available after conducting a review of the status 
of the species and after taking into account efforts being made by any 
state or foreign nation or political subdivision thereof to protect the 
species. In evaluating the efficacy of formalized domestic conservation 
efforts that have yet to be implemented or demonstrate effectiveness, 
we rely on the Services' joint Policy on Evaluation of Conservation 
Efforts When Making Listing Decisions (PECE; 68 FR 15100; March 28, 
2003).

Status Review

    As noted above, we had committed to revisiting the listing 
determination for alewife and blueback herring in the 2013 listing 
determination; accordingly,

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although the Plaintiffs only challenged our findings related to 
blueback herring, we did a comprehensive status review of alewife and 
blueback herring. As part of the status review, we formed a status 
review team (SRT) composed of scientists from NMFS' Northeast Fisheries 
Science Center (NEFSC), USFWS, NMFS' Greater Atlantic Regional 
Fisheries Office, Delaware Division of Fish and Wildlife, Massachusetts 
Division of Marine Fisheries, New York Department of Environmental 
Conservation, and South Carolina Department of Natural Resources. SRT 
members had scientific expertise in river herring biology/ecology and/
or expertise in population ecology or fisheries management. We tasked 
the SRT with multiple assessments for both species including the 
requests from the 2011 petition that NMFS list blueback herring 
rangewide or alternatively, as DPSs, and to provide a thorough status 
review for both species. First, the SRT was asked to compile and review 
the best available information and to assess the overall risk of 
extinction facing alewife and blueback herring rangewide now and in the 
foreseeable future. Second, the SRT was tasked with identifying any 
DPSs within these populations and asked to assess the risk of 
extinction facing each identified DPS of alewife and blueback herring 
now and in the foreseeable future. Third, the SRT was asked to consider 
whether, within the species rangewide or within any identified DPSs, a 
significant portion of the range may exist, and if so, whether the 
portion is at risk of extinction now or in the foreseeable future.
    In order to complete the status review, the SRT considered a 
variety of scientific information from the literature, unpublished 
documents, and direct communications with researchers working on 
alewife and blueback herring, as well as technical information 
submitted to NMFS. Information that was not previously peer-reviewed 
was formally reviewed by the SRT. The SRT evaluated all factors 
highlighted by the petitioners as well as additional factors that may 
contribute to alewife and blueback herring vulnerability.
    The Status Review Report for alewife and blueback herring (NMFS 
2019), summarized in sections below, compiles the best available 
information on the status of the species as required by the ESA, 
provides an evaluation of the discreteness and significance of these 
populations in terms of the DPS Policy, and assesses the extinction 
risk of the species and any DPS, focusing primarily on threats related 
to the five statutory factors set forth above. The status review report 
is available electronically at the website listed in ADDRESSES.
    The status review report underwent independent peer review as 
required by the Office of Management and Budget Final Information 
Quality Bulletin for Peer Review (M-05-03; December 16, 2004). The 
status review report was peer reviewed by three independent specialists 
selected from government, academic, and scientific communities, with 
expertise in biology, conservation and management, and specific 
knowledge of river herring and similar species. The peer reviewers were 
asked to evaluate the adequacy, quality, and completeness of the data 
considered and whether uncertainties in these data were identified and 
characterized in the status review report, as well as to evaluate the 
findings made in the ``Assessment of Extinction Risk'' section of the 
report. Peer Reviewers were also asked to identify any information 
missing or lacking justification, or whether information was applied 
incorrectly in reaching conclusions. The SRT addressed peer reviewer 
comments prior to finalizing the status review report. Comments 
received are posted online at www.cio.noaa.gov/services_programs/prplans/IDXXX.html.
    We subsequently reviewed the status review report, the cited 
references, and the peer review comments, and believe the status review 
report, upon which this 12-month finding is based, provides the best 
available scientific and commercial information on alewife and blueback 
herring. Much of the information discussed below on alewife and 
blueback herring biology, genetic diversity, distribution, abundance, 
threats, and extinction risk is attributable to the status review 
report. However, in making the 12-month finding determination, we have 
independently applied the statutory provisions of the ESA, including 
evaluation of the factors set forth in section 4(a)(1)(A)-(E) and our 
regulations regarding listing determinations (50 CFR part 424).

Description, Life History, and Ecology of the Petitioned Species

Distribution and Habitat Use

    Collectively, blueback herring and alewives are known as river 
herring. River herring are found along the Atlantic coast of North 
America, from the southern Gulf of St. Lawrence, Canada to the 
southeastern United States (Mullen et al. 1986, Schultz et al. 2009). 
The coastal ranges of the two species overlap. Blueback herring range 
from Nova Scotia south to the St. Johns River, Florida, and alewives 
range from Labrador and Newfoundland south to North Carolina, though 
their occurrence in the extreme southern range is less common (Collette 
and Klein-MacPhee 2002, ASMFC 2009a). In Canada, river herring (often 
referred to as gaspereau) have been monitored at varying frequencies in 
the St. Croix, St. John, Gaspereau, Tusket, Margaree and Miramichi 
River (J. Gibson, pers. comm) and are reportedly most abundant in the 
Miramichi, Margaree, LaHave, Tusket, Shubenacadie and Saint John Rivers 
(DFO 2001). River herring are proportionally less abundant in smaller 
coastal rivers and streams (DFO 2001). Generally, blueback herring in 
Canada occur in fewer rivers than alewives and are less abundant in 
rivers where both species coexist (DFO 2001).
    River herring are anadromous, meaning that they mature in the 
marine environment and then migrate up coastal rivers to estuaries and 
into freshwater rivers, ponds, and lake habitats to spawn (Collette and 
Klein-MacPhee 2002, ASMFC 2009a). In general, adult river herring are 
found at depths less than 328 feet (ft) (100 meters (m)) in waters 
along the continental shelf (Neves 1981, ASMFC 2009a, Schultz et al. 
2009).
    River herring are highly migratory, pelagic, schooling species with 
seasonal spawning migrations cued by water temperature (Collette and 
Klein-MacPhee 2002, Schultz et al. 2009). The spawning migration for 
alewives typically occurs when water temperatures range from 50-64 
[deg]F (10-18 [deg]C) and for blueback herring when temperatures range 
from 57-77 [deg]F (14-25 [deg]C; Klauda et al. 1991). Due to this 
temperature-dependent spawning, river herring may return to rivers to 
spawn as early as December or January in the southern portions and as 
late as July and August in the northern portions of their ranges (ASMFC 
2009a; DFO 2001).
    Blueback herring and alewives consume a variety of zooplankton. 
Blueback herring subsist chiefly on ctenophores, calanoid copepods, 
amphipods, mysids and other pelagic shrimps, and small fishes while at 
sea (Bigelow and Schroeder 1953, Brooks and Dodson 1965, Neves 1981, 
Stone 1986, Stone and Daborn 1987, Scott and Scott 1988, Bowman et al. 
2000). Alewives consume euphausiids, calanoid copepods, mysids, 
hyrperiid amphipods, chaetognaths, pteropods, decapod larvae, and salps 
(Edwards and Bowman, 1979, Neves 1981, Vinogradov 1984, Stone and 
Daborn 1987, Bowman et al. 2000).
    Little is known about their habitat preference in the marine 
environment; however, marine distributions of fish

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are often linked to environmental variables, such as prey availability 
and predation, along with seascape features. Studies have shown that 
alewife and blueback herring distribution is linked to bottom 
temperature, salinity, and depth (Neves 1981, Bethoney et al. 2014, 
Lynch et al. 2015). Recent papers described marine co-occurrences of 
alewife and blueback herring with Atlantic herring and mackerel (Turner 
et al. 2016, Turner et al. 2017), providing further evidence, in 
addition to observed ``bycatch'' estimates (Bethoney et al. 2014), that 
river herring school with Atlantic herring and mackerel. Turner et al. 
(2016) modeled associations of alewife and blueback herring, finding 
that alewife and blueback herring distributions overlapped with 
Atlantic herring (68-72 percent correct predictions) and Atlantic 
mackerel (57-69 percent correct predictions).
    Cieri (2012) analyzed NMFS bottom trawl survey data to identify 
seasonal population clusters of river herring along the East Coast of 
the United States (N Carolina to Maine; covering the continental shelf 
and the U.S. Exclusive Economic Zone (EEZ)). The spring trawl survey 
(1968-2008 NMFS Spring Bottom Trawl Survey) indicates that river 
herring are widespread across the survey area (sampling locations vary 
by year; the spring trawl occurs from North Carolina to Nova Scotia; 
sampling occurs at depths ~18 m to ~300 m (~60 ft to 984 ft)). Highest 
occurrences during the spring were off Maine's Downeast coast (roughly 
from Penobscot Bay north-eastwards to the Canadian border) and areas 
offshore, near Cape Ann and Cape Cod in Massachusetts, and a large area 
between Block Island, Rhode Island, and Long Island Sound. During the 
summer (1948-1995 NMFS Bottom Trawl Survey), river herring occurred 
less frequently across the survey area, with most river herring along 
the New England coast north of Rhode Island, and the highest 
occurrences off Downeast, Maine and south of Cape Cod, Massachusetts. 
During the fall survey (1963-2008 NMFS bottom trawl surveys), the 
occurrence of river herring shifted northward, with highest occurrences 
north of Cape Cod, along the Maine Coast to the Bay of Fundy, and 
another cluster off the eastern shore of Nova Scotia.
    Seasonal migrations have been observed in the marine environment as 
described above but are not well understood (NMFS 2012a). Hypothesized 
overwintering areas and migration pathways were presented at the NMFS 
2012 Stock Structure workshop, but little tagging data existed at that 
time to confirm any one theory. The working group from the 2012 
workshop was not able to determine the migration patterns and mixing 
patterns of alewife and blueback herring in the ocean, though they 
strongly suspected regional stock mixing (NMFS 2012a). Therefore, the 
conclusion that came out of the 2012 Stock Structure workshop was that, 
based on available data, the ocean phase of alewife and blueback 
herring was of mixed stocks.
    Sparse tagging data is available to help elucidate these marine 
migrations of alewife and blueback herring. In 1985-1986, approximately 
19,000 river herring were tagged and released in the upper Bay of 
Fundy, Nova Scotia (Rulifson et al. 1987). With an overall recapture 
rate of 0.39, Rulifson et al. (1987) received returns of alewife tags 
from freshwater locations in Nova Scotia, and marine locations in Nova 
Scotia and Massachusetts; whereas, blueback herring tags were returned 
from freshwater locations in Maryland and North Carolina, and marine 
locations in Nova Scotia. The authors suspected from this recapture 
data that alewives and blueback herring tagged in the Bay of Fundy were 
of different origins, hypothesizing that alewives were likely regional 
fish from as far away as New England, while the blueback herring 
recaptures were likely not regional fish, but those of U.S. origin from 
the mid-Atlantic region. However, the low tag return numbers from 
outside of Nova Scotia (n=2) made it difficult to generalize about the 
natal rivers of blueback herring caught in the Bay of Fundy. More 
recent work with acoustic tags (n=13 alewives and n=12 blueback 
herring) in the Hudson River by Eakin (2017) demonstrated in-river 
residence times ranged from two to three weeks, with fish exiting the 
system three to six days post-spawn. Marine migration was also detected 
from four blueback herring (2 male, 2 female) showing coastal movements 
over a six-month period (June to November) from the Hudson River to 
Penobscot Bay off the coast of Maine. The study also demonstrates the 
potential of using acoustic tagging to tease out marine movements of 
alewife and blueback herring in future studies.

Landlocked Populations

    Landlocked populations of alewives and blueback herring also exist. 
Landlocked alewife populations occur in many freshwater lakes and ponds 
from Canada to North Carolina as well as the Great Lakes (Rothschild 
1966, Boaze and Lackey 1974). Many landlocked alewife populations occur 
as a result of stocking to provide a forage base for game fish species 
(Palkovacs et al. 2007).
    Recent efforts to assess the evolutionary origins of landlocked 
alewives indicate that they rapidly diverged from their anadromous 
cousins between 300 and 5,000 years ago and now represent a discrete 
life history variant of the species, Alosa pseudoharengus (Palkovacs et 
al. 2007). Given their relatively recent divergence from anadromous 
populations, one plausible explanation for the existence of landlocked 
populations may be the construction of dams by either Native Americans 
or early colonial settlers that precluded the downstream migration of 
juvenile herring (Palkovacs et al. 2007). Since their divergence, 
landlocked alewives evolved to possess significantly different 
mouthparts than their anadromous cousins, including narrower gapes and 
smaller gill raker spacings to take advantage of year round 
availability of smaller prey in freshwater lakes and ponds (Palkovacs 
et al. 2007). Furthermore, the landlocked alewife, compared to its 
anadromous cousin, matures earlier, has a smaller adult body size, and 
reduced fecundity (Palkovacs et al. 2007). At this time, there is no 
substantive information that would suggest that landlocked populations 
can or would revert back to an anadromous life history if they had the 
opportunity to do so.
    The discrete life history and morphological differences between the 
two life history variants (anadromous and landlocked) provide 
substantial evidence that upon evolving to landlocked, landlocked 
populations become largely independent and separate from anadromous 
populations and occupy largely separate ecological niches (Palkovacs 
and Post 2008). There is the possibility that landlocked alewife and 
blueback herring may have the opportunity to mix with anadromous river 
herring during high discharge years and through dam removals that could 
provide passage over dams and access to historic spawning habitats 
restored for anadromous populations, where it did not previously exist.
    A Memorandum of Understanding (MOU) between the Services regarding 
jurisdictional responsibilities and listing procedures under the ESA 
was signed August 28, 1974. This MOU states that NMFS shall have 
jurisdiction over species ``which either (1) reside the major portion 
of their lifetimes in marine waters; or (2) are species which spend 
part of their lifetimes in estuarine waters, if the major portion of 
the remaining time (the time which is not spent in estuarine waters) is 
spent in marine waters.''

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    Given that landlocked populations of river herring remain in 
freshwater throughout their life history and are genetically divergent 
from the anadromous species, pursuant to the aforementioned MOU, NMFS 
did not include the landlocked populations of alewife and blueback 
herring in the review of the status of the species in 2013 (78 FR 
48943) and did not include landlocked populations in this status 
review.

Reproduction and Growth

    Overall, alewife and blueback herring are habitat generalists found 
over a wide variety of substrates, depths, and temperatures in 
freshwater lakes and ponds, river, estuaries, and the Atlantic Ocean. 
The substrate preferred for spawning varies greatly and can include 
gravel, detritus, and submerged aquatic vegetation. Alewives prefer 
spawning over sand or gravel bottoms (Galligan 1962), usually in quiet 
waters of ponds and coves (Marcy 1967, Loesch and Lund 1977). Blueback 
herring prefer spawning over hard substrates, where the flow is 
relatively swift (Loesch and Lund 1977). Nursery areas include 
freshwater and semi-brackish waters to fully saline waters for both 
species (Gahagan 2012, Turner et al. 2014, Payne Wynne et al. 2015).
    Alewife and blueback herring are fast growing, quick to mature 
species with a high fecundity rate. Estimates of fecundity for alewife 
range from 45,800 to 400,000 eggs (Foster and Goodbred 1978, Klauda et 
al. 1991, Loesch and Lund 1977). Estimates of fecundity for blueback 
herring range from 30,000 to 400,000 eggs (Loesch 1981, Jessop 1993). 
Fecundity estimates range widely based on the length and weight of the 
females (Schmidt and Limburg 1989) and geographic recruitment (Gainias 
et al. 2015). Both species spawn three to four times throughout the 
spawning season (McBride et al. 2010, Gainias et al. 2015). Recent 
literature has shown that some Alosa species, including alewife, are 
indeterminate spawners (Hyle et al. 2014, Gainas et al. 2015, McBride 
et al. 2016). For indeterminate spawners, the potential annual 
fecundity is not fixed before the onset of spawning. In these species, 
eggs can develop at any time during the spawning season. This is likely 
the case for blueback herring but more research is needed.
    Incubation time depends on temperature (i.e., low water 
temperatures results in slow development) and is estimated to take two 
to four days after deposit for blueback herring (Klauda et al. 1991, 
Jones et al. 1978). Incubation time for alewives takes between two to 
six days depending on temperature (Mansueti 1956, Jones et al. 1978).

Population Structure

    The population structure of these species has been examined using 
various tools, including otolith chemistry and genetics (see Population 
Structure section of the Status Review Report for additional 
information, NMFS 2019). While otolith chemistry studies focused 
largely on assigning fish to rivers of natal origin with some success 
(Gahagan et al. 2012, Turner et al. 2015), genetic analyses found 
evidence for regional structure within each species (McBride et al. 
2014, Palkovacs et al. 2014, Hasselman et al. 2014; Hasselman et al. 
2016; Ogburn et al. 2017, Baetscher et al. 2017, Reid et al. 2018). 
Early genetic studies relied largely on microsatellite markers and were 
limited in geographic scope (see Genetic Studies section of NMFS 2019 
for a detailed account); however, recent studies using single 
nucleotide polymorphisms (SNP) have expanded the evaluation of 
population structure for these species across most of their ranges.
    SNPs are small genetic variations that occur in a genome. These 
variations are used as molecular markers in genetic research and help 
to overcome limitations associated with microsatellite analyses when 
applied to fisheries management, which includes a lack of portability 
across laboratories and instruments (Reid et al. 2018).
    SNPs were developed using 96 individual loci for alewife and for 
blueback herring by Baetscher et al. (2017). This study evaluated river 
herring samples across portions of the U.S. range for self-assignment 
to populations of origin and to three alewife and four blueback herring 
regional groupings identified by Palkovacs et al. (2014). While self-
assignments to population of origin were lower (at around 67 percent), 
assignment to regional groupings was 93 percent for alewives and 96 
percent for blueback herring. Structure cluster analysis showed similar 
results to previous regional stock structure groupings, with the 
addition of two additional blueback herring populations (Peticodiac and 
Margaree).
    Recent work by Reid et al. (2018) built on Baetscher et al.'s work 
by increasing the geographic range and number of rivers sampled for 
each species, sampling across almost the entire range of these species. 
This study included river herring from 108 locations (genotyping over 
8,000 fish) ranging from Florida to Newfoundland using SNP markers 
developed by Baetcher et al. (2017). A STRUCTURE analysis of the 
genetic data supported four distinct geographic groupings for alewife 
and five for blueback herring (STRUCTURE refers to software that is one 
of the most widely used population analysis tools for assessing 
patterns of genetic structure in samples). The study identified the 
following four regional groupings for alewife: (1) Canada, including: 
Garnish River and Otter Pond, Newfoundland to Saint John River, New 
Brunswick; (2) Northern New England, including: St. Croix River, ME to 
Merrimack River, NH; (3) Southern New England, including: Parker River, 
MA to Carll's River, NY; and (4) Mid Atlantic, including: Hudson River, 
NY to Alligator River, NC. The study also identified the following five 
regional groupings for blueback herring: (1) Canada/Northern New 
England, including: Margaree River, Nova Scotia to Kennebec River, ME; 
(2) Mid New England, including: Oyster River, NH to Parker River, MA; 
(3) Southern New England, including: Mystic River, MA to Gilbert-Stuart 
Pond, RI; (4) Mid Atlantic, including: Connecticut River, CT to Neuse 
River, NC; and (5) Southern Atlantic, including: Cape Fear River, NC to 
St. Johns River, FL.
    Because the similarity in geographic naming of these stock 
complexes may make them difficult to distinguish between species, 
hereafter, we preface alewife regional groupings with Aw- and blueback 
herring regional groupings with Bb-. For example, the Mid Atlantic 
regional groupings of these two species would be referred to as Aw-Mid 
Atlantic and Bb-Mid Atlantic. We refer the reader to Figures 1 and 2 
below for maps distinguishing the boundaries between stock complexes.
    Self-assignment tests to these regional groups ranged from 86-92 
percent for alewives and 76-95 percent for blueback herring (Reid et 
al. 2018). However, self-assignment to individual rivers was low. These 
results indicate that at larger spatial scales, there are regions of 
restricted gene flow within the range-wide populations; Reid et al. 
(2018) noted that this could be driven by environmental and habitat 
differences. However, the results also indicate that the extent of gene 
flow across regional groupings was higher than previously reported by 
Palkovacs et al. (2014), especially at the borders, and that proximate 
rivers are usually not demographically independent due to straying 
behaviors. Reid et al. (2018) noted transitional populations present 
between regions, with rivers such as the Hudson and the Connecticut 
Rivers

[[Page 28634]]

acting as transition zones for alewife and blueback herring, 
respectively.
    Genetic studies also demonstrate that stocking practices influence 
genetic differentiation among populations (McBride et al. 2014, McBride 
et al. 2015). McBride et al. (2015) used 12 microsatellite loci to 
evaluate the genetic structure of 16 alewife populations in Maine to 
determine whether past stocking influenced current populations and the 
genetic composition of alewives. Results showed a highly significant 
relationship between genetic differentiation and geographic distance 
among non-stocked populations, but a non-significant relationship among 
stocked populations (McBride et al. 2015).
    The unusual genetic groupings of river herring in Maine are likely 
a result of Maine's complex stocking history. Alewife populations in 
Maine have been subject to considerable within-basin and out-of-basin 
stocking for the purpose of enhancement, recolonization of extirpated 
populations, and stock introduction. Alewife stocking in Maine dates 
back at least to 1803 when alewives were reportedly moved from the 
Pemaquid and St. George Rivers to create a run of alewives in the 
Damariscotta River (Atkins and Goode 1887). These efforts were largely 
responsive to considerable declines in alewife populations following 
the construction of dams, over exploitation, and pollution. Although 
there has been considerable alewife stocking and relocation throughout 
Maine, there are very few records documenting these efforts. In 
contrast, considerably less stocking of alewives has occurred in 
Maritime Canada. This information further demonstrates that past 
stocking patterns influence contemporary genetic diversity, and 
stocking history should be taken into account when interpreting genetic 
groupings (Atkins and Goode 1887, McBride et al. 2014, McBride et al. 
2015).
    In summary, the best available genetic data suggest that alewife 
and blueback herring may be distinguished by regional groupings. Recent 
studies show a minimum of four stock complexes of alewife and five 
stock complexes of blueback herring. Transfer of river herring within-
basin and out-of-basin has likely altered the genetic diversity of 
alewife and blueback herring observed today in several ways. First, 
stocked areas are most likely to have had already low populations (or 
local extirpation), and second, this reduced population is then stocked 
with a likely different genetic stock, further masking the previous 
population's genetics.
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Straying

    River herring conform to a metapopulation paradigm (i.e., a group 
of spatially separated populations of the same species that interact at 
some level) with adults frequently returning to their natal rivers for 
spawning with straying occurring between rivers (Jones 2006; ASMFC 
2009a). There have been very few studies to quantify straying rates, 
despite evidence of straying in the literature (Jessop 1994, Palkovacs 
et al. 2014, McBride et al. 2014, Turner and Limburg 2014, McBride et 
al. 2015, Ogburn et al. 2017). Jessop (1994) reported straying rates of 
3-37 percent in the St. John River, New Brunswick. McBride et al. 
(2014) and Palkovacs et al. (2014) reported greater isolation by 
distance for alewives than for blueback herring, suggesting higher 
overall straying rates for blueback herring. Additionally, isolation by 
distance evidence from Palkovacs et al. (2014) and McBride et al. 
(2015), suggest that genetic exchange (straying) is more likely to 
happen with nearest-neighbor rivers over such distances as 100-200 
kilometers (km) (62-124 miles (mi)). Straying has also been reported in 
other anadromous fishes, such as American shad (Jolly et al. 2012) and 
striped bass (Gauthier et al. 2013). Pess et al. (2014) reviewed basic 
life history traits of diadromous fish and hypothesized recolonization 
rates. Alewife and blueback herring were considered to have a moderate 
to strong tendency to colonize new streams (Pess et al. 2014). Both 
species were considered to have the highest tendencies to colonize new 
streams of all the east coast diadromous fish, with blueback herring 
scoring slightly higher than alewife. Alewife and blueback herring were 
also considered to have strong tendencies to expand into habitat within 
existing streams; scoring higher than all other diadromous fish, except 
for sea lamprey.

Abundance and Trends

United States Waters
    A 2017 alewife and blueback herring stock assessment update was 
prepared and compiled by the River Herring Stock Assessment 
Subcommittee, hereafter referred to as the `subcommittee,' of the ASMFC 
Shad and River Herring Technical Committee. Data and reports used for 
this assessment were obtained from Federal and state resource agencies, 
power generating companies, and universities.
    The 2017 stock assessment followed the same methods and analyses 
outlined in the 2012 benchmark report (ASMFC 2012a) and updated the 
existing time series by adding data when available for the years 2011-
2015. The subcommittee assessed the coastal stocks of alewife and 
blueback herring by individual rivers as well as coast-wide based on 
available data. As this assessment provides the most up-to-date 
abundance and trends data of river herring, the Status Review Report 
includes many excerpts from the 2017 ASMFC stock

[[Page 28636]]

assessment (see sections on Commercial Catch Per Unit Effort (CPUE), 
Run Counts, Young[hyphen]Of[hyphen]The[hyphen]Year Seine Surveys, 
Juvenile[hyphen]Adult Fisheries[hyphen]Independent Seine, Gillnet and 
Electrofishing Surveys, Juvenile and Adult Trawl Surveys, Mean Length, 
Maximum Age, Mean Length[hyphen]at[hyphen]Age, Repeat Spawner 
Frequency, Total Mortality (Z) Estimates, and Exploitation Rates) (NMFS 
2019). For the full ASMFC stock assessment (including additional tables 
and figures), see River Herring Stock Assessment Update Volume I 
(www.asmfc.org/uploads/file/59b1b81bRiverHerringStockAssessmentUpdate_Aug2017.pdf). Of the 54 in-
river stocks of river herring for which data were available, the 2017 
ASMFC Stock Assessment indicates that from 2006 through 2015, 16 
experienced increasing trends, two experienced decreasing trends, eight 
were identified as stable by the ASMFC working group, 10 experienced no 
discernible trend/high variability, and 18 did not have enough data to 
assess recent trends, including one that had no returning fish (see 
Table 2 in NMFS 2019; ASMFC 2017a). The coastwide meta-complex of river 
herring stocks on the U.S. Atlantic coast remains depleted to near 
historic lows. A depleted status indicates that there was evidence for 
declines in abundance due to a number of factors, but the relative 
importance of these factors in reducing river herring stocks could not 
be determined.
    Commercial landings of river herring peaked in the late 1960s, 
declined rapidly through the 1970s and 1980s, and have remained at 
levels less than 3 percent of the peak over the past decade. Fisheries-
independent surveys did not show consistent trends and were quite 
variable both within and among surveys. Those surveys that showed 
declines tended to be from areas south of Long Island. A problem with 
the majority of fisheries-independent surveys is that the length of 
their time series did not overlap with the period of peak commercial 
landings (i.e., prior to 1970); therefore, there is no accurate way of 
comparing historical landings to fisheries-independent surveys. There 
appears to be a consensus among various assessment methodologies that 
exploitation has decreased. The decline in exploitation over the past 
decade is not surprising because river herring populations are at low 
levels and more restrictive regulations or moratoria have been enacted 
by states (See Directed Commercial Harvest below and State Regulations 
in the Status Review Report, NMFS 2019, for further detail).
Canadian Waters
    The Department of Fisheries and Oceans (DFO) monitors and manages 
river herring runs in Canada. River herring monitoring in the Maritime 
region falls into two categories, rivers where abundances can be 
directly estimated (e.g., monitoring at fishways), and rivers where 
information is available from the commercial fishery (Gibson et al. 
2017). River herring runs in the Miramichi River in New Brunswick and 
the Margaree River in Cape Breton, Nova Scotia were monitored 
intensively from 1983 to 2000 (DFO 2001). More recently (1997 to 2017), 
the Gaspereau River alewife run and harvest has been intensively 
monitored and managed partially in response to a 2002 fisheries 
management plan that had a goal of increasing spawning escapement to 
400,000 adults (DFO 2007). During the period of 1970 to 2017, Billard 
(2017) estimated run size of alewife in the Gaspereau from 265,000 to 
1.2 million. The exploitation rate for this same period ranged from 33 
percent to 89 percent. Billard (2017) classified the most recent years 
2015 and 2016 as having healthy escapement rates, but overexploited as 
a fishery. Elsewhere, river herring runs have been monitored less 
intensively, though harvest rates are monitored throughout Atlantic 
Canada through license sales, reporting requirements, and a logbook 
system that was enacted in 1992 (DFO 2001). At the time DFO conducted 
their last stock assessment in 2001, they identified river herring 
harvest levels as being low (relative to historical levels) and stable 
to low and decreasing across most rivers where data were available (DFO 
2001).
    With respect to the commercial harvest of river herring, reported 
landings of river herring peaked in 1980 at slightly less than 25.5 
million lbs (11,600 metric tons (mt) and declined to less than 11 
million lbs (5,000 mt) in 1996. Landings data reported through DFO 
indicate that river herring harvests have continued to decline through 
2010.

Species Finding

    Based on the best available scientific and commercial data 
summarized above, we find that the alewife and blueback herring are 
currently considered as two taxonomically-distinct species (see 
Taxonomy and Distinctive Characteristics of NMFS 2019) and, therefore, 
meet the definition of ``species'' pursuant to section 3 of the ESA. 
Below, we evaluate whether each species warrants listing as endangered 
or threatened under the ESA throughout all or a significant portion of 
its range.

Distinct Population Segment Determination

    In addition to evaluating whether each species is at risk of 
extinction, the SRT was asked to identify any DPSs of these species and 
evaluate whether such DPSs may be at risk of extinction throughout all 
or a significant portion of its range. As described above, the ESA's 
definition of ``species'' includes ``any subspecies of fish or wildlife 
or plants, and any distinct population segment of any species of 
vertebrate fish or wildlife which interbreeds when mature.'' The DPS 
Policy requires the consideration of two elements: (1) The discreteness 
of the population segment in relation to the remainder of the species 
to which it belongs, and (2) the significance of the population segment 
to the species to which it belongs.
    A population segment of a vertebrate species may be considered 
discrete if it satisfies either one of the following two conditions. 
The first condition is if the species is markedly separated from other 
populations of the same taxon as a consequence of physical, 
physiological, ecological, or behavioral factors. Quantitative measures 
of genetic or morphological discontinuity may provide evidence of this 
separation. The second condition is if the species is delimited by 
international governmental boundaries within which differences in 
control of exploitation, management of habitat, conservation status, or 
regulatory mechanisms exist that are significant in light of section 
4(a)(1)(D) of the ESA. If a population segment is found to be discrete 
under one or both of the above conditions, its biological and 
ecological significance to the taxon to which it belongs is evaluated. 
Factors that can be considered in evaluating significance may include, 
but are not limited to: (1) Persistence of the discrete population 
segment in an ecological setting unusual or unique for the taxon; (2) 
evidence that the loss of the discrete population segment would result 
in a significant gap in the range of a taxon; (3) evidence that the 
discrete population segment represents the only surviving natural 
occurrence of a taxon that may be more abundant elsewhere as an 
introduced population outside its historic range; or (4) evidence that 
the discrete population segment differs markedly from other populations 
of the species in its genetic characteristics.

Evaluation of Discreteness

    The SRT evaluated whether any alewife or blueback herring DPSs, 
including those identified by the petitioner in 2011, exist. The Status 
Review Report, in particular the section

[[Page 28637]]

on Population Structure, provides a summary of information they 
reviewed, including tagging and genetics data, as well as fisheries 
management information (NMFS 2019). As highlighted in the DPS Policy, 
quantitative measures of morphological discontinuity or differentiation 
can serve as evidence of marked separation of populations. After review 
of the best available information, the SRT found that genetic studies 
provide evidence of regional differentiation in both alewife and 
blueback herring by demonstrating discrete groupings at a large 
geographic scale. In particular, the SRT found that the study by Reid 
et al. (2018), which includes a large number of rivers across the 
species' ranges, provides the most comprehensive evidence of regional 
differentiation for these species, because STRUCTURE analyses 
demonstrate support for regional groupings, and because the self-
assignment tests to regional groupings have high values ranging from 
86-92 percent for alewife and 76-95 percent for blueback herring. The 
SRT found the following regional stock complexes for alewife represent 
discrete groupings: (1) Aw-Canada (Garnish River, Newfoundland to Saint 
John River, New Brunswick); (2) Aw-Northern New England (St. Croix 
River, ME to Merrimack River, NH); (3) Aw-Southern New England (Parker 
River, MA to Carlls River, NY) and; (4) Aw-Mid Atlantic (Hudson River, 
NY to Alligator River, NC). These four discrete groupings correspond to 
the stock complexes in Figure 1. In addition the SRT found the 
following regional stock complexes for blueback represent discrete 
groupings: (1) Bb-Canada/Northern New England (Margaree River, Nova 
Scotia to Kennebec River, ME); (2) Bb-Mid New England (Oyster River, NH 
to Parker River, MA); (3) Bb-Southern New England (Mystic River, MA to 
Gilbert-Stuart Pond, RI); (4) Bb-Mid Atlantic (Connecticut River, CT to 
Neuse River, NC), and; (5) Bb-Southern Atlantic (Cape Fear River, NC to 
St. Johns River, FL). These five discrete groupings correspond to the 
stock complexes shown in Figure 2.
    While the SRT found that genetic information provides evidence for 
regional population separation and discreteness for these stock 
complexes (depicted in Figures 1 and 2), especially at a large spatial 
scale, the SRT noted some uncertainty associated with the level of 
discreteness of these groupings. Specifically, the high degree of 
admixture (mixture of two or more genetically differentiated 
populations) at the boundaries of each of these stock complexes, 
referred to earlier as transitions zones, makes separation between 
stocks unclear at finer spatial scales. Also spatial gaps exist where 
samples were not obtained or tested (e.g., between the Aw-Southern New 
England and Aw-Mid Atlantic stock complexes, and between the Bb-
Southern New England and Bb-Atlantic stock complexes) making the 
accuracy of these boundaries uncertain.
    Additionally, the SRT noted that there is some uncertainty 
surrounding these groupings due to the methodology used by Reid et al. 
(2018) in the rangewide analysis where STRUCTURE was run on collection 
sites without binning into larger spawning habitats. For example, Black 
Creek, a tributary of the Hudson, was considered separate from the 
Hudson in the analysis even though these rivers share an estuary. 
Additionally, a number of small tributaries of the Connecticut River 
(e.g., Wethersfield Cove, Mill Creek, and Mill Brook) were considered 
as separate independent populations.
    Overall, the SRT relied upon the best available genetic information 
(see NMFS 2019 for complete discussion) to determine discreteness for 
the alewife and blueback herring. The SRT discussed but did not find 
evidence of physiological, ecological, behavioral factors or life 
history differences that would aid in further delineating discrete 
populations. In addition, the SRT discussed combining and/or further 
separating the genetic groupings outlined above, but did not find 
evidence to support modifying the genetic groups, despite the study 
limitations discussed (see above).

Evaluation of Significance

    As noted above, the DPS Policy instructs that significance is 
evaluated in terms of the ecological and biological importance of the 
population segment to the species. The SRT considered the significance 
of each of the regional groupings (i.e., stock complexes) found to be 
discrete. In reviewing the factors that support a finding of 
significance outlined above, the SRT found that the discrete groupings 
identified for both species are not found in areas that appear to have 
unique or unusual ecological settings. Although the petitioner 
suggested that the terrestrial ecoregions identified by The Nature 
Conservancy (Anderson 2003) may represent unique or unusual ecological 
settings for the species, the SRT found several ecoregions were not 
unique or unusual because they could be found within the range of more 
than one discrete group. For example, the Northern Appalachian/Acadian 
terrestrial ecoregion extends throughout both the Aw-Northern New 
England and Aw-Canada stock complexes. Additionally, the Northern 
Piedmont and North Atlantic Coastal ecoregions extended through the Bb-
Mid-New England, Bb-Southern New England and into the Bb-Mid-Atlantic 
stock complexes. For ecoregions that existed entirely within one stock 
complex, the SRT found that the ecoregions appeared to have no unique 
or unusual bearing on the discrete grouping's biology, as the range of 
the group included more than one ecoregion. For example, the Chesapeake 
Bay Lowlands exist entirely within the range of the Aw-Mid-Atlantic 
stock complex; however, this range also contains a portion of the North 
Atlantic coast ecoregion (which spans three stock complexes). The SRT 
also considered whether other ecological factors, such as ocean 
currents or thermal regimes, existed within the boundaries of these 
complexes, and might point to persistence in a unique ecological 
setting. However, the SRT did not find that any of these stock 
complexes persist in a unique terrestrial ecoregions or other 
``ecological settings,'' instead they noted that some of these stock 
complexes may share marine environments where oceanic features appear 
unique, and that terrestrial ecoregions do not align with the 
identified discrete stock complex boundaries.
    Next, the SRT considered whether the loss of the population 
segments would result in significant gaps in the range of the taxa. The 
SRT agreed that the length of coastline or overall size of the habitat 
that the discrete grouping inhabited would be the greatest factor in 
determining whether a gap, or loss in the range, was significant to a 
taxon as a whole. Specifically, large gaps in the range across 
widespread watersheds might be difficult for either species to refill 
naturally (i.e., through straying) and would be extremely difficult to 
fill through management efforts (e.g., stocking).
    Large gaps in the range may interfere with connectivity between 
populations, resulting in isolated populations that are more vulnerable 
to the impacts of large threats or catastrophic events (e.g., storms, 
regional drought). Connectivity, population resilience and diversity 
are important when determining what constitutes a significant portion 
of the species' range (Waples et al. 2007). Maintaining connectivity 
between genetic groups supports proper metapopulation function, in this 
case, anadromy. Ensuring that river herring populations are well 
represented across diverse habitats helps to maintain and enhance 
genetic variability and

[[Page 28638]]

population resilience (McElhany et al. 2000). Additionally, ensuring 
wide geographic distribution across diverse climate and geographic 
regions helps to minimize risk from catastrophes (e.g., droughts, 
floods, hurricanes, etc.; McElhany et al. 2000). Furthermore, 
preventing isolation of genetic groups protects against population 
divergence (Allendorf and Luikart, 2007). Further, a large gap on the 
periphery of the range would limit the distribution of the species, 
similarly reducing resiliency. For example, wide distributions may 
provide a diversity of habitats and buffer species against widespread 
threats such as changing temperatures by providing more opportunities 
for habitat refugia. Although there is no evidence currently available 
to suggest that genetic differences between these stock complexes 
represent adaptive traits (only neutral genetic markers have been used 
in the current population structure analyses), the SRT also noted that 
significant gaps could represent a loss of genetic adaptation if these 
regional groupings are also linked to adaptive traits (NMFS 2019).
    As noted in the Status Review Report river herring discrete stock 
complexes could re-colonize spatial gaps in the range. Genetic studies 
provide evidence of straying (see Straying above) and suggest 
transition zones between populations (NMFS 2019). The SRT noted that 
gaps in the population would most likely be filled in a step-wise 
fashion with fish moving in from the borders of the nearest stock 
complexes, but that some straying may occur mid-range as well. Because 
river herring exhibit straying both from nearby rivers and over larger 
distances (Gardner et al. 2011, Hogg 2012, sensu Reid et al. 2018), the 
SRT noted that the significance of any particular gap will be primarily 
a factor of the geographic scope (or size of the gap).
    The SRT noted that the life history, fecundity, and straying 
behavior of these species could lead to having river herring within 
individual rivers once occupied by the ``lost'' stock (i.e., fish 
recolonizing the gap in the range) rather quickly, but perhaps at low 
or less than sustainable levels. For the purposes of considering the 
loss of each discrete stock complex, the SRT defined a significant gap 
to be a large geographic area of the range (considering the length of 
coastline or size of the watershed) that was unlikely to be recolonized 
with self-sustaining populations within at least 10 generations (40-60 
years); the upper limit of time the SRT believed that the taxon could 
sustain without detrimental effects from loss of connectivity.
    There is debate in the literature regarding the application of 
assigning a general number to represent when populations are 
sufficiently large enough to maintain genetic variation (Allendorf and 
Luikart 2007). The SRT settled on a self-sustaining population of 
around 1,000 spawning fish annually in currently occupied rivers within 
the area; a number close to the population of some smaller river 
systems where populations are able to maintain returns (e.g., Little 
River, MA). This metric of 1,000 fish is close to, but greater than the 
``500 rule'' introduced by Franklin (1980) for indicating when a 
population may be at risk of losing genetic variability.
    The SRT reviewed each of the discrete stock complexes for both 
species and considered the overall size of the gap that would exist as 
well as the likelihood that the area would be filled in by neighboring 
stock complexes. The SRT noted that the nearest neighboring stock 
complex would be most likely to colonize in a step-wise fashion at the 
borders of any gap. The SRT also acknowledged that strays may colonize 
from any stock complex, as isolation by distance evidence from 
Palkovacs et al. (2014) and McBride et al. (2015) suggests that genetic 
exchange (straying) currently happens over such distances as 100-200 km 
(62-124 mi). However, while this is possible, this scenario was less 
likely than strays colonizing from the closest stock complex.
    The loss of discrete stock complexes that were large in geographic 
scope and, therefore, unlikely to be filled in by neighboring stock 
complexes were considered likely to leave a significant gap in the 
species' range. These findings are summarized below in Table 1.

         Table 1--Summary of Significant Gap Discussion for Alewife and Blueback Herring Stock Complexes
----------------------------------------------------------------------------------------------------------------
                                         Estimates of
                                     geographic scope of
                                      the stock complex
                                       (watershed size
                                      (square kilometers                             Loss of the stock complex
      Discrete stock complex        (km\2\) (square miles      Likelihood of       would result in a significant
                                      mi\2\)); coastline       recolonization             gap (yes or no)
                                     distance (km) (mi);
                                      degrees latitude;
                                     percent of rangewide
                                       watershed area)
----------------------------------------------------------------------------------------------------------------
Alewife Canada....................  169,000 km\2\ (65,251  Recolonization is      Yes.
                                     mi\2\); 15,200 km      unlikely due to the
                                     (9,444 mi); 7.5        large size of the
                                     degrees latitude; 35   gap and with only
                                     percent.               one neighboring
                                                            complex to the south.
Alewife Northern New England......  74,000 km\2\ (28,572   Recolonization across  Yes.
                                     mi\2\); 5,800 km       this range is
                                     (3,604 mi); 2.5        unlikely due to the
                                     degrees latitude,15    large size of the
                                     percent.               gap despite having
                                                            neighboring
                                                            complexes to the
                                                            south and north
                                                            beginning to
                                                            recolonize bordering
                                                            areas.
Alewife Southern New England......  35,500 km\2\ (13,707   Recolonization is      Yes.
                                     mi\2\); 7400 km        unlikely due to the
                                     (4,598 mi); 2.5        large size of the
                                     degrees latitude; 7    gap and with only
                                     percent.               one neighboring
                                                            complex to the north.
Alewife Mid-Atlantic..............  211,500 km\2\ (81,661  Recolonization is      Yes.
                                     mi\2\); 19,600 km      unlikely due to the
                                     (12,179 mi); 9         large size of the
                                     degrees latitude; 43   gap and with only
                                     percent.               one neighboring
                                                            complex to the north.
Blueback Herring Canada/Northern    137,000 km\2\ (52,896  Recolonization is      Yes.
 New England.                        mi\2\); 11,100 km      unlikely due to the
                                     (6,897 mi); 4          large size of the
                                     degrees of latitude;   gap and with only
                                     26 percent.            one neighboring
                                                            complex to the south.
Blueback Herring Mid New England..  12,000 km\2\ (4,633    Recolonization across  No.
                                     mi\2\); 311 km (193    this range is likely
                                     mi); 0.5 degrees of    given the small size
                                     latitude; <3 percent.  of the gap and
                                                            because neighboring
                                                            complexes can
                                                            recolonize step-wise
                                                            from the south and
                                                            north.
Blueback Herring Southern New       9,000 km\2\ (3,475     Recolonization across  No.
 England.                            mi\2\); 2,900 km       this range is likely
                                     (1,802 mi); 1.5        given the small size
                                     degrees of latitude;   of the gap and
                                     <2 percent.            because neighboring
                                                            complexes can
                                                            recolonize step-wise
                                                            from the south and
                                                            north. Additionally,
                                                            proximity to known
                                                            river herring
                                                            overwintering
                                                            grounds might
                                                            support further
                                                            recolonization.
Blueback Herring Mid Atlantic.....  211,000 km\2\ (81,468  Recolonization across  Yes.
                                     mi\2\); 24,800 km      this range is
                                     (15,410 mi); 9         unlikely due to the
                                     degrees of latitude;   large size of the
                                     40 percent.            gap despite
                                                            neighboring
                                                            complexes to the
                                                            south and north
                                                            beginning to
                                                            recolonize bordering
                                                            areas.

[[Page 28639]]

 
Blueback Herring Southern Atlantic  140,000 km\2\ (54,054  Recolonization is      Yes.
                                     mi\2\); 18,300 km      unlikely due to the
                                     (11,371 mi); 7         large size of the
                                     degrees of latitude,   gap and with only
                                     26 percent.            one neighboring
                                                            complex to the north.
----------------------------------------------------------------------------------------------------------------

    The SRT did not find evidence that discrete population segments 
outlined previously represent the only surviving natural occurrence of 
a taxon that may be more abundant elsewhere as an introduced population 
outside its historic range. The SRT identified four alewife DPSs and 
three blueback herring DPSs. Therefore, none of the DPSs represent the 
only surviving natural occurrence of either alewife or blueback 
herring.
    Finally, the SRT considered evidence to determine whether any of 
the discrete population segments differ markedly from other populations 
of the species (i.e., the other identified stock complexes) in its 
genetic characteristics. The SRT discussed the methodology in the Reid 
et al. (2018) paper and inquired with one of the lead authors about 
information on the genetic diversity (e.g. heterozygosity among stock 
complexes) results from the study. The SNP markers in the Reid et al. 
(2018) paper used neutral genetic markers which do not convey adaptive 
traits, so the SRT was unable to find evidence that the discrete stock 
complexes differ markedly from other populations of the species in its 
genetic characteristics. The SRT also considered spawning timing, which 
has been shown to be heritable in steelhead and presumably could be 
heritable in other anadromous fish, including alewife or blueback 
herring. The SRT examined rangewide spawning strategies, and was not 
aware of differing life history strategies, such as winter and fall 
spawning timing in the species (as exhibited in steelhead). Alewives 
and blueback herring use thermal cues for spawning timing; however, 
this appears to be due to clinal patterns, with rivers in the southern 
portion of the range beginning spawning earliest in the year and the 
rivers at highest latitudes spawning latest in the year. Overall, the 
SRT did not find existing evidence to support heritable spawning timing 
in alewife or blueback herring.
    After reviewing the significance criteria, the SRT did not find 
evidence to demonstrate these discrete stock complexes persist in a 
unique ecological setting or that they differ markedly from one another 
in their genetic characteristics. The SRT did find evidence that loss 
of the population segment would result in a significant gap in the 
range of the taxon for all four discrete stock complexes of alewife: 
Aw-Canada; Aw-Northern New England; Aw-Southern New England, and; Aw-
Mid-Atlantic. In addition, the SRT also found evidence that loss of the 
population segment would result in a significant gap in the range of 
the taxon for three of the five discrete stock complexes of blueback 
herring: Bb-Canada/Northern New England, Bb-Mid-Atlantic, and bb-
Southern Atlantic. However, due to the small size of the Bb-Mid-New 
England and Bb-Southern New England stock complexes and because this 
habitat is likely to be recolonized by blueback herring stock complexes 
to the north and to the south, the loss of one of these two discrete 
stock complexes did not represent a significant gap in the range of the 
taxon (which includes five discrete stock complexes across the range).
    While the SRT applied the ``10 generations for recolonization'' 
formula (described above), we do not find that the use of such a 
formula is necessary given the large geographic scope (see Table 1 
column 2) of the potential gaps caused by the loss of the Aw-Canada; 
Aw-Northern New England; Aw-Southern New England, or; Aw-Mid-Atlantic 
stock complex or the Bb-Canada/Northern New England, Bb-Mid-Atlantic, 
or Bb-Southern Atlantic stock complex. The potential loss of any of 
these stock complexes would create a large gap in the range of these 
species creating issues with connectivity between populations, lowering 
the diversity of habitats that these species span, and reducing the 
species' ability to overcome large threats or catastrophic events. In 
contrast, a small gap in the range, such as either the potential loss 
of the Bb-Mid New England or Bb-Southern New England stock complex, may 
be less important to these species because their straying behavior and 
fecundity may allow them to regain or even maintain connectivity 
between neighboring stock complexes. Accordingly, based on these 
considerations, we agree with the SRT's findings that the loss of the 
Aw Canada; Aw-Northern New England; Aw-Southern New England, or; Aw-
Mid-Atlantic stock complex or the Bb-Canada/Northern New England, Bb-
Mid-Atlantic, or Bb-Southern Atlantic stock complex would create a 
significant gap in the range of these species.
    The SRT relied on the best available information throughout this 
analysis, but noted that future information on behavior, ecology, and 
genetic characteristics may reveal differences significant enough to 
show fish to be uniquely adapted to each stock complex.
    Because the following stock complexes meet both the discreteness 
and significance prongs, the SRT identified, and we agree with, the 
following DPSs for alewife (Figure 3):
     Aw-Canada DPS the range includes Garnish River, 
Newfoundland to Saint John River, New Brunswick;
     Aw-Northern New England DPS--the range includes St. Croix 
River, ME to Merrimack River, NH;
     Aw-Southern New England DPS--the range includes Parker 
River, MA to Carll's River, NY; and
     Aw-Mid Atlantic DPS--the range includes Hudson River, NY 
to Alligator River, NC.
    Because the three blueback herring stock complexes meet both the 
discreteness and significance prongs, the SRT recommends, and we agree, 
with the following DPSs for blueback herring (Figure 4):
     Bb-Canada-Northern New England DPS--the range includes 
Margaree River, Nova Scotia to Kennebec River, ME;
     Bb-Mid Atlantic DPS--the range includes Connecticut River, 
CT to Neuse River, NC; and
     Bb-Southern Atlantic DPS--the range includes Cape Fear 
River, NC.
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Assessment of Extinction Risk

Foreseeable Future

    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 any species which is likely to become 
an endangered species within the foreseeable future throughout all or a 
significant portion of its range (16 U.S.C. 1532(6) and (20)). The term 
``foreseeable future'' is not further defined or described within the 
ESA. However, consistent with our past practice, we describe the 
``foreseeable future'' on a case-by-case basis, using the best 
available data for the particular species, and taking into 
consideration factors such as the species' life history 
characteristics, threat projection time frames, and environmental 
variability. We interpret the foreseeable future as extending only so 
far into the future as we can reasonably determine that both the 
threats and the particular species' responses to those threats are 
likely. 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 is not necessarily 
reducible to a particular number of years.
    Highly productive species with short generation times (e.g., river 
herring) are more resilient than less productive, long-lived species, 
as they are quickly able to take advantage of available habitats for 
reproduction (Mace et al. 2002). Species with shorter generation times, 
such as river herring (4 to 6 years), experience greater population 
variability than species with long generation times, because they 
maintain the capacity to replenish themselves more quickly following a 
period of low survival (Mace et al. 2002). Consequently, given the high 
population variability among clupeids, projecting out further than a 
few generations could lead to considerable uncertainty in predicting 
the response to threats for each species.
    As described below, the SRT determined that dams, water withdrawal, 
poor water quality, incidental catch, inadequacy of regulations, and 
climate change vulnerability are the main threats to both species. The 
SRT determined, and we agree, the foreseeable future is best defined by 
a 12 to 18 year time frame (i.e., out to 2030-2036), or a three-
generation time period, for each species for both alewife and blueback 
herring. This is a period in which impacts of present threats to the 
species could be realized in the form of noticeable population 
declines, as demonstrated in the available survey and fisheries data. 
This timeframe would allow for reliable predictions regarding the 
impact of current levels of mortality on the biological status of the 
two species.

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Evaluation of Demographic Risks

    In determining the extinction risk of a species, it is important to 
consider both the demographic risks facing the species as well as 
current and potential threats that may affect the species' status. To 
this end, a qualitative demographic analysis was conducted for the 
alewife and blueback herring. A demographic risk analysis is an 
assessment of the manifestation of past threats that have contributed 
to the species' current status, and it informs the consideration of the 
biological response of the species to present and future threats.
    The approach of considering demographic risk factors to help frame 
the consideration of extinction risk has been used in many of our 
status reviews (see https://www.nmfs.noaa.gov/pr/species for links to 
these reviews). In this approach, the collective condition of 
individual populations is considered at the species level according to 
four demographic viability factors: Abundance, growth rate/
productivity, spatial structure/connectivity, and diversity. These 
viability factors reflect concepts that are well founded in 
conservation biology and that individually and collectively provide 
strong indicators of extinction risk.
    Using these concepts, the SRT evaluated demographic risks by 
individually assigning a risk score to each of the four demographic 
criteria (abundance, growth rate/productivity, spatial structure/
connectivity, diversity). Qualitative reference levels with ranking 
scores of whole numbers from 1-5 of ``very low,'' ``low,'' 
``moderate,'' ``high,'' and ``very high'' were used to describe the 
risk of demographic criteria. A factor (or viable population 
descriptor) was ranked (1) very low if it was unlikely that this 
descriptor contributed significantly to risk of extinction, either by 
itself or in combination with other viable population descriptors. A 
factor was ranked (2) low risk if it was unlikely that this descriptor 
contributed significantly to long-term or near future risk of 
extinction by itself, but there was some concern that it may, in 
combination with other viable population descriptors. A factor was 
ranked (3) moderate risk if this descriptor contributed significantly 
to long-term risk of extinction, but did not in itself constitute a 
danger of extinction in the near future. A factor was ranked (4) high 
risk if this descriptor contributed significantly to long-term risk of 
extinction and was likely to contribute to short-term risk of 
extinction in the near future, and a factor was ranked (5) very high 
risk if this descriptor by itself indicated danger of extinction in the 
near future.
    Each SRT member scored each demographic factor individually. Each 
SRT member identified other demographic factors and/or threats that 
would work in combination with factors ranked in the higher categories 
to increase risk to the species. SRT members provided their expert 
opinions for each of the demographic risks, including considerations 
outlined in McElhany et al. (2000) and the supporting data on which it 
was based, and discussed their opinions with the other SRT members. SRT 
members were then given the opportunity to adjust their individual 
scores, if desired. These adjusted scores were tallied, reviewed, and 
then combined for an overall extinction risk determination (see below). 
This scoring was carried out for both species rangewide and for each 
DPS, and the demographic scoring summary is presented below. Here the 
SRT's qualitative ranking for each demographic factor is identified by 
rounding the mean ranking score, which is provided in parentheses. For 
example, a demographic factor falling between the low (2) and moderate 
(3) risk rankings with a mean ranking score of 2.1 will be identified 
as low (2.1), while a factor with a mean ranking score of 2.5 will be 
identified as moderate (2.5). As noted throughout this section and in 
the Threats Assessments section and in the corresponding sections of 
the Status Review Report, many of the mean ranking scores fall between 
low (2), and moderate (3). Only a few scores were found to be 3 or 
higher. As more fully explained in the Status Review Report, the SRT 
used a scale of whole numbers from 1 to 5 (NMFS, 2019).
Alewife
Abundance
    The SRT members individually evaluated the available alewife 
abundance information, which is summarized in the Abundance and Trends 
section of this listing determination and additional detail can be 
found in the Status Review Report (NMFS 2019). Alewife abundance has 
declined significantly from historical levels throughout its range 
(ASMFC 2017a, ASMFC 2012a, Limburg and Waldman (2009).
    While abundance is at or near historical lows, the recent stock 
assessment update reported few declining abundance trends by dataset in 
recent years (ASMFC 2017a). The ASMFC River Herring Stock Assessment 
assessed data from the last ten years (2006-2015) and reported that no 
run counts reflect declining trends with 11 of 29 showing increasing 
trends, 14 showing no trend, and four not being updated (two due to 
discontinuation and two due to agency recommendation to remove the 
rivers based on data discrepancies between observed river herring 
presences and fishway counts) (ASMFC 2017a and b). Because abundance is 
known to be highly variable from year to year for these species, in 
addition to the trend information, the SRT reviewed annual run count 
numbers and escapement information, when available, as part of its 
consideration of information that may inform the abundance estimates of 
these populations. Given the substantial number of runs with increasing 
trends and relatively large run counts reported in various portions of 
the range in recent years (in the hundreds of thousands throughout 
various regions) (ASMFC 2017a), there do not appear to be depensatory 
processes rangewide that result in low abundances such that the 
populations may be insufficient to support mate choice, sex-ratios, 
fertilization and recruitment success, reproductive or courting 
behaviors, foraging success, and predator avoidance behaviors. The SRT 
reviewed available abundance indices for each DPS (see NMFS 2019 for 
complete summary). The mean score calculated based on the SRT's scores 
for alewife rangewide (2.0), the Aw-Canada (2.0) DPS, the Aw-Northern 
New England (2.0) DPS, and the Aw-Southern New England DPS (2.1) all 
correspond to a low ranking, because the SRT found this factor is 
unlikely to contribute significantly to the risk of alewife extinction.
    While abundance information is limited for alewife in the Aw-Canada 
DPS, data provide some indicators of population size in several rivers. 
Examples of data reviewed by the SRT included (but were not limited 
to): Gaspereau River, Nova Scotia time series (1970 to 2017) estimates 
that ranged from a low of 265,208 (1983) to 1.2 million (2016), 
(Billard 2017); St. John River, New Brunswick fixed escapement policy 
of 800,000 alewife released above the dam annually; and Tusket River in 
Nova Scotia estimated escapement for this stock in 2014-1015 in the 
range of 1.6 million to 2.3 million alewife.
    For populations in the United States, comprehensive summaries of 
data that inform abundance reviewed by the SRT are available in the 
ASMFC State-Specific Reports (2017b).
    The ASMFC Stock Assessment reports trends from select rivers along 
the

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Atlantic Coast (see Table 1 of ASMFC 2017a); depending on sampling 
methods, these may be reported by species or in combination (i.e., 
reported as just river herring). Within the Aw-Northern New England 
DPS, updated recent trends (2006-2015) for alewife were reported as 
increasing for the Androscoggin, Damariscotta, and Cocheco rivers. The 
ASMFC reported increasing trends for river herring as a whole from the 
Kennebec, Sebasticook, and Lamprey Rivers. The ASMFC also reported no 
trend for alewife in the Union River, stable river herring trends in 
the Exeter River, decreasing alewife trends in the Oyster River, no 
returns of river herring in the Taylor River, and unknown trends for 
the Winnicut River throughout this period (ASMFC 2017a).
    Within the Aw-Southern New England DPS, updated recent trends 
(2006-2015) for alewife were reported as increasing for the 
Mattapoisett, Monument, Nemasket, Buckeye, and Bride Brook Rivers. The 
ASMFC reported stable river herring trends in the Parker and Gilbert 
Rivers; decreasing alewife trends in the Stony Brook and Nonquit 
Rivers; and no trends for alewife in the Mianus and Shetucket Rivers; 
and unknown trends in the Farmington and Naugatuck Rivers (ASMFC 
2017a).
    The Aw-Mid-Atlantic DPS abundance risk mean score corresponded to a 
moderate (2.7) ranking. Within the Aw-Mid-Atlantic DPS, updated recent 
trends (2006-2015) for alewife were reported as increasing for river 
herring in the Hudson River, no tend for alewife in the Delaware and 
Rappahannock Rivers, stable for alewife in the Nanticoke and Potomac 
Rivers, and unknown for alewife in the James, York, and Alligator 
Rivers (ASMFC 2017a). SRT members noted uncertainty about abundance in 
the Mid-Atlantic DPS, due to minimal available abundance information 
(with the exception of the Hudson, several rivers in Chesapeake Bay, 
and a few ASMFC time series). However, preliminary results from the 
Chesapeake Bay (Ogburn unpublished data) appear favorable, with 
abundance estimates in surveyed rivers in the 100,000s of fish. Recent 
estimates of alewife absolute abundance using hydroacoustics for the 
Roanoke River during 2008-2015 have ranged from 32,000 to 419,000 
(Waine 2010, Hughes and Hightower 2015; McCargo 2018).
Growth Rate/Productivity
    The SRT evaluated the available information on life history traits 
for alewife as they relate to this factor, as summarized in the 
Reproduction, Growth, and Demography section in the Status Review 
Report (NMFS 2019). Data are limited on growth rate/productivity, and 
there is little effort to systematically collect and standardize this 
type of data in most of the range of the species. The SRT considered 
previously discussed trends in abundance and reviewed trends in maximum 
age, average size-at-age, repeat spawners, and modeling results for the 
qualitative ranking of growth rate and productivity. ASMFC (2017a) 
reported alewife maximum age data indicate most runs had stable ages, 
and no trends appear reversed relative to the 2012 benchmark. 
Specifically, maximum age results showed no trends in the Androscoggin, 
Exeter, Cocheco, Monument, and Gilbert-Stuart Rivers; increasing trends 
in the Lamprey River (NH); and decreasing tends in the Nanticoke River 
(MD) and Chowan River (NC). Size at age results showed no trend in the 
Androscoggin, Cocheco (female), Lamprey, Winnicut, and Hudson Rivers; 
and decreasing trends in the Exeter (male), Monument, and Nanticoke 
Rivers. Additionally, for the Status Review Report, a population growth 
model (MARSS) was used for alewife rangewide. The MARSS model results 
show a population growth rate point estimate of 0.038, with the 
associated 95 percent confidence interval ranging from (0.005-0.071) 
(NMFS 2019).
    The mean score calculated for this demographic factor based on SRT 
members' scores corresponds to a low ranking rangewide (2.1), and in 
each DPS (Aw-Canada DPS (2.0), Aw-Northern New England DPS (2.0), Aw-
Southern New England DPS (2.1), and the Aw-Mid-Atlantic DPS (2.3)), as 
this factor is unlikely to contribute significantly to the risk of 
extinction for alewife. SRT members noted that rates of population 
growth for many rivers have shown growth in the past 5-10 years. Where 
mean age has been reduced, it is often in conjunction with recruitment 
of strong year classes as the populations rebuild. Some systems are 
beginning to have increases in age structure as older individuals 
persist. The SRT noted some runs in the southernmost portion of the 
range have not shown as strong or consistent improvement; this was 
reflected in the slightly higher numeric score and variability of the 
qualitative ranking for the growth rate of the Mid-Atlantic DPS (NMFS 
2019).
Spatial Structure/Connectivity
    The SRT evaluated the available information on alewife spatial 
structure (tagging and genetics information) summarized in the 
Population Structure section in the Status Review Report (NMFS 2019). 
Alewife range from North Carolina to Newfoundland, Canada. While the 
species exhibits homing, rates of straying and therefore dispersal help 
to buffer the species from threats related to loss of habitat and loss 
of spatial connectivity. The mean score calculated based on SRT 
members' scores corresponds to a moderate (2.6) ranking rangewide and 
for all DPSs (2.7-2.9), as this factor contributes significantly to 
long-term risk of extinction, but does not in itself constitute a 
danger of extinction in the near future. SRT members noted that habitat 
degradation and destruction threats related to human population growth 
will presumably continue to increase, and the cumulative effects will 
influence the species range wide. Reduced, restricted, and impacted 
spawning and nursery habitat will likely remain a limiting factor to 
population growth in many river systems.
Diversity
    The SRT evaluated the available information on alewife diversity 
summarized in the Population Structure section in the Status Review 
Report (NMFS 2019). The available genetics studies indicate that there 
are a minimum of four genetic stock complexes rangewide and there is 
reproductive connectivity along a continuum rangewide. SRT members 
noted that, due to declines in abundance over the last several hundred 
years, the species has likely lost some genetic diversity, and 
therefore has lost some adaptive potential. This loss of diversity 
affects resilience, especially in the face of climate change. 
Additionally, SRT members determined that human activities of stocking 
and propagation have also contributed to reduced genetic diversity. 
Further, the SRT noted that stocking activities, coupled with habitat 
alterations (e.g., in-river obstructions like dams), and reduced access 
to spawning and nursery habitat, may even result in the selection of 
characteristics in these fish that are conducive to survival in 
modified and dammed river systems.
    The mean score calculated based on SRT members' scores corresponds 
to a moderate ranking rangewide (2.6) and in each of the DPSs (Aw-
Canada (2.7), Aw-Northern New England (2.7), Aw-Southern New England 
(2.9) and Aw-Mid-Atlantic (2.9) DPS), as this descriptor contributes 
significantly to long-term risk of extinction, but does not in itself 
constitute a danger of extinction in the near future. Although still 
receiving a moderate ranking, SRT members noted that the Aw-Canada DPS

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may have a slightly lower risk in comparison to other areas, as this 
DPS has a very large range and access to a wide variety of stream size 
and temperature regimes. Additionally, the SRT noted the Aw-Canada DPS 
likely experiences less active stocking (which has been suggested to 
negatively affect genetic diversity); therefore, the risk to genetic 
diversity in this DPS was ranked slightly lower.
Blueback Herring
Abundance
    The SRT individually evaluated the available blueback herring 
abundance information, which is summarized in the Description of 
Population Abundance and Trends section of the Status Review Report 
(NMFS 2019). SRT members noted that the available information indicated 
blueback herring abundance had declined significantly from historical 
levels throughout its range. The SRT reviewed the recent ASMFC stock 
assessment update and available abundance indices for each DPS (NMFS 
2019; ASMFC 2017a). Blueback herring abundance estimates were lower 
than available estimates for alewife, but recent run count estimates 
documented hundreds of thousands of fish in the Chowan River, 
Chesapeake Bay (Ogburn unpublished data), Connecticut River, various 
Massachusetts rivers, and rivers in Maine (ASMFC 2017b) and New 
Brunswick (Gibson et al. 2017). The mean score calculated based on the 
SRT's scores corresponds to a moderate ranking rangewide (3.0) and in 
each DPS (Bb-Canada/Northern New England (3.0), Bb-Mid-Atlantic (3.0), 
and Bb-Southern Atlantic (3.0) DPSs), as this factor is contributing 
significantly to the blueback herring's risk of extinction, but does 
not in itself constitute a danger of extinction in the near future.
    The SRT reviewed the best available data on blueback herring 
abundance in the Bb-Canada/Northern New England DPS. The SRT noted that 
blueback herring in the St. John River, New Brunswick are managed using 
a fixed escapement policy of 200,000 blueback herring moved above the 
dam each year; this number is not indicative of abundance, but can be 
viewed as a minimum when escapement targets are met. The Mactaquac time 
series (1999 to 2017) ranged from 192,000 to 515,000, with over 489,000 
blueback herring passed upstream in 2017. Escapement estimates for the 
Tusket River in Nova Scotia during the period of 2014 to 2015 ranged 
from 200,000 to 600,000 blueback herring. As noted above for alewife, 
the ASMFC Stock Assessment reports trends from select rivers along the 
Atlantic Coast (see Table 1 of ASMFC 2017a); depending on sampling 
methods these may be reported by species or in combination (i.e., 
reported as just river herring). There is little stock specific 
information on blueback herring in Maine. Within the U.S portion of the 
Bb-Canada/Northern New England DPS, the ASMFC (2017a) reported trends 
over 2006-2015 as increasing for river herring in the Kennebec and 
Sebasticook Rivers. Data reported from rivers throughout this range 
were also reviewed, and numbers varied widely from year to year, as 
expected for this species. According to the most recent stock 
assessment report (ASMFC 2017b), blueback herring estimates for the 
Kennebec and Sebasticook Rivers in Maine were over 1 million fish 
(reported as combined species). The state of Maine conducts an annual 
young-of-the-year survey for six Maine rivers (1979 to 2015). Relative 
abundance was near zero from 1979 to 1991, and increased gradually 
through 2004 before declining in recent years (ASMFC 2017a).
    The SRT reviewed available abundance data for the Bb-Mid-Atlantic 
DPS, which ranges from Connecticut to North Carolina. The ASMFC (2017a) 
reported increasing blueback herring trends for the Mianus and 
Rappahannock Rivers; stable trends for the Connecticut River, Shetucket 
River, and Chowan River; no trends for the Delaware and Nanticoke 
Rivers; and unknown trends for the Farmington, Naugatuck, Potomac, 
James, York, Alligator, Scuppernog, and St. Johns Rivers. Additionally, 
trends for river herring were reported as increasing in the Hudson 
(ASMFC 2017a). Data reported from rivers throughout this range were 
also reviewed, and numbers varied widely from year to year as expected 
for this species. The SRT noted blueback herring abundance estimates 
ranging from 500,000-700,000 during 2013-2016 in the Choptank River; 
18,000-54,000 during 2016-2017 in the Patapsco River; and 500,000-
950,000 during 2013-2014 in the Marshyhope River (Ogburn unpublished 
data). Additionally, absolute abundance estimates of blueback herring 
in the Roanoake River using hydroacoustics ranged from 100,000-478,000 
(Waine 2010, Hughes and Hightower 2015, McCargo 2018) across studies 
conducted in 2008, 2009, 2010, 2011, and 2015, with the high reported 
in 2015. Total blueback herring population estimates (for age 3+) in 
the Chowan River time series (1972 to 2015) ranged from a high of 157 
million (1976) to a low of 593,693 (2007; ASMFC 2017b). The most recent 
estimate of blueback herring abundance in the Chowan River was 
5,160,983 (2015). Commercial CPUE estimates for blueback herring in the 
Chowan River have declined since the 1980s.
    The ASMFC (2017a) reported no trend for blueback herring in the 
Santee Cooper River and unknown trends for the St. Johns River. Due to 
limited trend information, the SRT reviewed available abundance data 
for the Bb-Southern Atlantic DPS, including young-of-the-year push 
trawl estimates from Florida (2007 to 2016); CPUE estimates from 
Santee-Cooper River (1969 to 2015), and minimum population size 
estimates from the Santee-Cooper River (1990 to 2015) (ASMFC 2017b). 
Minimum population size estimates from the Santee Cooper River ranged 
from 8,503 (1990) to 3.4 million (1996); the minimum population size 
was estimated at 410,000 in 2015. The SRT noted increased uncertainty 
for Bb-Southern Atlantic abundance risk due to the small number of 
available indices.
Growth Rate/Productivity
    The SRT evaluated the available data for blueback herring as they 
relate to this factor, as summarized in the Reproduction, Growth, and 
Demography section in the Status Review Report (NMFS 2019). Data are 
limited on growth rate/productivity, and there has been limited effort 
to systematically collect and standardize this type of data in most of 
the range of the species. SRT members noted that in some populations 
the maximum age appears to be trending upward, and blueback herring 
maximum age data indicate most runs had stable ages (ASMFC 2017a). On a 
rangewide basis, the MARSS model (NMFS 2019) showed blueback herring 
population growth rates of 0.05 with a 95 percent confidence interval 
(-0.03 to 0.13). Also, while recent abundance trends have indicated 
positive growth rates, trends in demographic (maximum age) and 
reproductive rates (repeat spawners) are largely negative or stable; 
the combination of these two trends is an indicator of a potentially 
declining growth rate, given the paucity of high accuracy abundance 
data for blueback herring.
    The mean score calculated based on SRT member's scores corresponds 
to a moderate ranking rangewide (2.75) and in all DPSs (Bb-Canada/
Northern New England DPS (2.75), Bb-Mid-Atlantic DPS (2.88) and Bb-
Southern Atlantic DPS (3.0)) as this factor is contributing 
significantly to the blueback herring's risk of extinction, but does 
not in itself constitute a danger of extinction in the

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near future. The lack of available data contributed to higher 
uncertainty around the growth rate for blueback herring.
Spatial Structure/Connectivity
    The SRT evaluated the available information on blueback herring 
spatial structure (tagging and genetics information), summarized in the 
Population Structure section in the Status Review Report (NMFS 2019). 
Blueback herring range from Florida to Nova Scotia, spanning 20 degrees 
latitude and ranging thousands of kilometers along the Atlantic Coast. 
While the species exhibits homing, rates of straying and the resulting 
dispersal help to buffer the species from threats related to loss of 
habitat and loss of spatial connectivity. The SRT noted, however, that 
blueback herring likely have longer distances between populations in 
comparison to alewife populations (AMFC 2017a,b), which could result in 
less resiliency in comparison to alewife. Additionally, depending on 
natal river, some blueback herring have longer migratory distances from 
overwintering areas, thereby exposing them to a longer duration of 
threats in the marine environment in comparison to alewife.
    Maintaining connectivity between genetic groups supports proper 
metapopulation function. Ensuring that populations are well represented 
across a variety of river systems help to maintain and enhance 
population resilience and genetic variability (McElhany et al. 2000). 
Blueback herring appear to have connected populations and genetic 
exchange with bordering populations. However, Reid et al. (2018) noted 
that the Bb-Southern Atlantic population appears to be the most 
distinct genetically from other populations, suggesting that gene flow 
and connectivity may be more limited in this DPS compared to other 
DPSs. Still the range of the Bb-Southern Atlantic population stretches 
over a wide area, and the SRT noted obstructions were more likely found 
farther up river in this region, providing more accessible habitat for 
the species.
    The mean score calculated based on SRT member's scores rangewide 
(2.87) and in each DPS (Bb-Canada/Northern New England DPS (2.86), Bb-
Mid-Atlantic DPS (2.88), and Bb-Southern Atlantic DPS (2.71)) 
corresponds to a moderate ranking rangewide, as this factor is 
contributing significantly to the blueback herring's risk of 
extinction, but does not in itself constitute a danger of extinction in 
the near future.
Diversity
    The SRT evaluated the available information on blueback herring 
diversity summarized in the Population Structure section in the Status 
Review Report (NMFS 2019). The available genetics studies indicate that 
there are a minimum of five genetic stock complexes rangewide and there 
is evidence of reproductive connectivity along a continuum rangewide. 
However, blueback herring exhibit larger distances between populations 
when compared to alewives (ASMFC 2017a,b), thus in comparison, alewife 
may be better positioned to maintain genetic diversity (through mixing 
with bordering populations). The SRT noted that due to declines in 
abundance over the last several hundred years, the species has likely 
lost genetic diversity and therefore has lost some amount of adaptive 
potential. This loss of diversity affects resiliency, especially in the 
face of climate change. Additionally, SRT members felt that human 
activities of stocking and propagation have also contributed to reduced 
genetic diversity. The mean score calculated based on SRT member's 
scores correspond to a moderate ranking rangewide (3.1) and in each DPS 
(Bb-Canada/Northern New England DPS (3.14), Bb-Mid-Atlantic DPS (3.0), 
and Bb-Southern Atlantic DPS (3.14)), as this descriptor contributes 
significantly to long-term risk of extinction, but does not in itself 
constitute a danger of extinction in the near future.

Evaluation of Threats

    Next the SRT considered whether any of the five factors (specified 
in section 4(a)(1) of the ESA) are contributing to the extinction risk 
of alewife or blueback herring. Threats considered included habitat 
destruction, modification, or curtailment; overutilization; disease or 
predation; inadequacy of existing regulatory mechanisms; and other 
natural or manmade threats, because these are the five factors 
identified in section 4(a)(1) of the ESA.
    The SRT identified the following threats falling under the five 
factors reviewed for listing determinations (see section 4 of the 
Status Review Report, NMFS 2019): Climate change and variability, 
climate change and vulnerability, dams and other barriers, dredging/
channelization, water quality, water withdrawal, directed commercial 
harvest, retained and discarded incidental catch (including slippage), 
recreational harvest, scientific research, educational use, disease, 
predation, inadequacy of existing regulations (international, Federal 
and state), competition, artificial propagation, hybrids, and 
landlocked populations. The SRT conducted a qualitative ranking of the 
severity of each of these threats to alewife and blueback herring 
rangewide and for each identified DPS. SRT members ranked the threats 
for the alewife and blueback herring at a rangewide scale and then by 
each DPS.
    The SRT members used the ``likelihood point'' (Forest Ecosystem 
Management Assessment Team or FEMAT) method to allow individuals to 
express uncertainty in determining the contribution to extinction risk 
of each threat to the species (see Status Review Report, NMFS 2019). 
Each SRT member was allotted five likelihood points to rank each 
threat. SRT members individually ranked the severity of each threat 
through the allocation of these five likelihood points across five 
ranking criteria ranging from a score of ``very low contribution'' to 
``very high contribution.'' A threat was given a rank of very low if it 
is unlikely that the threat contributes significantly to risk of 
extinction, either by itself or in combination with other threats. That 
is, it is unlikely that the threat will have population-level impacts 
that reduce the viability of the species. A threat was ranked as low 
contribution if it is unlikely that the threat contributes 
significantly to long-term or near future risk of extinction by itself, 
but there is some concern that it may do so, in combination with other 
threats. A threat was ranked as medium contribution if the threat 
contributes significantly to long-term risk of extinction, but does not 
in itself constitute a danger of extinction in the near future. A 
threat was ranked high contribution if the threat contributes 
significantly to long-term risk of extinction and is likely to 
contribute to short-term risk of extinction in the near future. 
Finally, a threat was ranked very high contribution if the threat by 
itself indicates a danger of extinction in the near future. Detailed 
definitions of the risk scores can be found in the Status Review Report 
(NMFS 2019).
    The SRT also considered the ranking with respect to the 
interactions with other factors and threats. For example, the SRT found 
that threats due to the inadequacy of existing regulatory mechanisms 
may interact with the threat of overutilization and slow population 
growth rates (a demographic factor) to increase the risk extinction.
    SRT members were asked to rank the effect that the threat was 
currently having on the extinction risk of the species. Each SRT member 
could allocate all five likelihood points to one

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ranking criterion or distribute the likelihood points across several 
ranking criteria to account for any uncertainty. Each individual SRT 
member distributed the likelihood points as she/he deemed appropriate, 
with the condition that all five likelihood points had to be used for 
each threat. SRT members also had the option of ranking the threat as 
``0'' to indicate that, in their opinion, there was insufficient data 
to assign a score, or ``N/A'' if in their opinion the threat was not 
relevant to the species either throughout its range or for individual 
stock complexes. When a SRT member chose either N/A (Not Applicable) or 
0 (Unknown) for a threat, all five likelihood points had to be assigned 
to that category only.
    During the group discussion, the SRT members were asked to identify 
other threat(s) or demographic factor(s) that were interacting with the 
threats or demographic factors to increase the species' extinction 
risk. As scores were provided by individual SRT members, each 
individual stated his or her expert opinion regarding each of the 
threats, and the supporting data on which it was based.
    We summarize the threats to alewife and blueback herring below. The 
SRT's qualitative ranking is identified by rounding the mean ranking 
score, which is provided in parentheses. For example, a threat falling 
between the low (2) and medium (3) rankings with a mean ranking score 
of 2.1 will be identified as low (2.1), while a threat with a mean 
score of 2.5 will be identified as medium (2.5). As noted throughout 
this section and in the Threats Assessments sections of the Status 
Review Report, many of the mean ranking scores fall between very low 
(1), low (2), and medium (3); only a few scores were found to be 3 or 
higher. A detailed account of the rankings is provided in section 6 of 
the Status Review Report (NMFS 2019).

A. Habitat Destruction, Modification, or Curtailment

    The SRT assessed six different factors that may contribute to 
destruction, modification or curtailment of habitat: Climate change and 
variability, climate change and vulnerability, dams and other barriers, 
dredging/channelization, water quality, and water withdrawal. All 
threats listed in this category scored in the low or medium 
contribution to extinction risk categories. Dams and other barriers and 
water withdrawal were the highest ranked alewife threats in this 
category. Dams and other barriers, water quality, and water withdrawal 
were the highest ranked blueback herring threats in this category.
Climate Change and Variability
    Climate change and variability are discussed in section 4.1.1 of 
the Status Review Report (NMFS 2019); below we provide a summary. The 
SRT evaluated the available information on climate change and climate 
variability as summarized in the status review (NMFS 2019). River 
herring range from Canada through Florida in both marine and freshwater 
environments, and, in many of these areas, there has been reported 
environmental change. For example, the climate of the Northeast U.S. 
continental shelf (U.S. Northeast Shelf) is changing both as a result 
of anthropogenic climate change and natural climate variability (Hare 
et al. 2016a, Hare et al. 2016b). Ocean temperature over the last 
decade in the U.S. Northeast Shelf and surrounding Northwest Atlantic 
waters have warmed faster than the global average (Pershing et al. 
2015). New projections also suggest that this region will warm two to 
three times faster than the global average from a predicted northward 
shift in the Gulf Stream (Saba et al. 2016). Hare et al. (2016a) 
provides a literature summary of how the climate system is changing on 
the U.S. Northeast Shelf; changes include a high rate of sea-level 
rise, as well as increases in annual precipitation and river flow, 
magnitude of extreme precipitation events, and magnitude and frequency 
of floods. NMFS (2017a) provides a literature summary of climate change 
drivers in the South Atlantic, which include warming ocean temperatures 
and sea level rise. The combination of increases in water temperature, 
coupled with associated changes in water composition, is believed to be 
one of the most significant risk drivers in the oceans and freshwater 
habitats in Canada (DFO 2012). Both natural climate variability and 
anthropogenic-forced climate change will affect river herring. For 
example, the species is likely to be impacted by climate change through 
changes in the amount of preferred marine habitat (Lynch et al. 2015).
    Changes to riverine flows and habitat due to extreme events will 
impact both spawning and early life stages of fish (Tommasi et al. 
2015), while migratory patterns and food availability will be two of 
many impacts of a changing climate on the ocean stages. As water 
temperatures continue to increase, river herring's coastal ranges may 
shrink and shift northward. A contraction of their range could result 
in natural or anthropogenic catastrophic events having a larger impact 
on the species' extinction risk.
Alewife
    The SRT ranked climate change variability as low (2.4) rangewide 
and medium (2.5-2.7) in each DPS. The SRT noted uncertainty makes it 
difficult to determine the degree to which current limitations in 
predicting the specific changes that will occur within river herring 
habitat across the range may impact river herring in the foreseeable 
future. While mean rankings scores were close rangewide and across the 
DPSs, the SRT ranked the Aw-Southern New England (medium, 2.6) and the 
Aw-Mid-Atlantic (medium, 2.7) DPSs threat score for climate variability 
slightly higher. The SRT noted the large estuary ecosystems within the 
Aw-Southern New England DPS could be severely impacted by river/ocean 
warming and sea level rise. Additionally, rivers in this DPS are 
situated in areas with high population densities and with predicted 
population growth, which will likely decrease the amount of water 
available for river herring and lead to juveniles being unable to 
emigrate from nursery habitats. Increased impervious surfaces, as well 
as anthropogenic responses to rising sea levels are likely to increase 
flow variability in this DPS. The Aw-Mid-Atlantic DPS constitutes the 
southern edge of the range. It will likely be the first to see extreme 
riverine temperatures during spawning and juvenile phases. In addition, 
many of the known runs in this DPS are in larger river systems, and 
spawning success will likely be negatively impacted by the extreme 
spring flows as well as the increased summertime salt intrusions 
predicted to occur due to climate change.
Blueback Herring
    The overall mean blueback herring rangewide score for climate 
change variability corresponded to a low (2.1) ranking rangewide and in 
the Bb-Canada/Northern New England DPS (low, 2.2) and Bb-Mid-Atlantic 
DPS (low, 2.1). The Bb-Southern Atlantic DPS score for climate change 
and variability corresponded to a medium (2.6) ranking. The Bb-Southern 
Atlantic DPS constitutes the southern edge of the range and will be the 
first to experience extreme riverine temperatures during spawning and 
juvenile phases. In addition, many of the known runs in this DPS are in 
larger river systems, and spawning success will likely be negatively 
impacted by the extreme spring flows as well as the increased 
summertime salt intrusions predicted to

[[Page 28647]]

occur due to climate change. The interacting effects of climate change 
with anthropogenic changes, especially in relation to temperature and 
flow, carry a potentially significant threat.
Climate Change and Vulnerability
    Climate change and vulnerability is discussed in section 4.1.2 of 
the Status Review (NMFS 2019), and below we provide a summary.
Alewife
    The mean scores for climate change and vulnerability for alewife 
rangewide corresponded to a medium (2.6) ranking rangewide and in each 
DPS (2.7-2.8). While mean ranking scores were close rangewide and 
across the DPSs, the SRT predicted that alewives in more southern 
portions of the range were at a slightly higher risk from climate 
change and vulnerability due to the reduced timeline of predicted 
impacts from this threat.
    Alewife in the Aw-Mid-Atlantic DPS (medium, 2.8) will likely be the 
first to see extreme riverine temperatures during spawning and juvenile 
phases. Additionally, fish at the edges of the range will be most 
impacted by changes in ocean currents due to climate change, as these 
fish have the longest ocean migrations to known overwintering areas. 
Alewife populations could expand northward, however it is unknown if 
expansion could occur fast enough to preserve genetic integrity of this 
DPS. This threat is magnified because there will be minimal opportunity 
to control negative climatic effects as they become more apparent.
Blueback Herring
    The overall mean score for climate change and vulnerability 
corresponded to a medium (2.5) ranking rangewide and in each DPS (2.5-
2.9). The SRT noted that blueback herring currently persist in warmer 
habitats than alewives and therefore may be more resilient to warmer 
temperatures. However, the largest populations of blueback herring 
appear to be concentrated farther south (Mid-Atlantic) than alewives, 
therefore the SRT expected the threats from climate change 
vulnerability to be greater for blueback herring than that experienced 
by alewives. Early life stage growth/survival and successful spawning 
events are temperature dependent. Increasing and irregular water 
temperature regimes will have large impacts at these stages. While mean 
ranking scores were close rangewide and across the DPSs, the SRT 
predicted that climate change and vulnerability threats would be 
greatest in the Bb-Southern Atlantic DPS (medium, 2.9) because this 
region will be the first to experience extreme temperatures during 
spawning and juvenile phases. Numerous shifts in range and other signs 
of thermal stress have been observed in fish species in this region, 
and the same can be expected for blueback herring. Being at the 
southern end of the species' range, one would expect that they are 
already at the maximum tolerance for temperature effects. Additionally, 
anthropogenic responses to climate change may include construction of 
floodgates, berms around cities, and changes in water structures, which 
may further reduce access to spawning habitat. This threat is magnified 
because there will be minimal opportunity to control negative climatic 
effects as they become more apparent.
Dams and Other Barriers
    Dams and other barriers are discussed in section 4.1.3 of the 
Status Review Report (NMFS 2019), and below we provide a summary. Dams 
and other barriers to upstream and downstream passage (e.g., culverts, 
tidal and amenity barrages) can block or impede access to habitats 
necessary for spawning and rearing; can cause direct and indirect 
mortality from injuries incurred while passing over dams, through 
downstream passage facilities, or through hydropower turbines; and can 
degrade habitat features necessary to support essential river herring 
life history functions. As described in more detail in the Status 
Review Report (NMFS 2019), dams are also known to impact river herring 
through various mechanisms, such as habitat alteration, fish passage 
delays, and entrainment (injury from transport along with the flow of 
water) and impingement (injury related to colliding with any part of a 
dam; Ruggles 1980, NRC 2004). River herring can experience delayed 
mortality from injuries such as scale loss, lacerations, bruising, eye 
or fin damage, or internal hemorrhaging when passing through turbines, 
over spillways, and through bypasses (Amaral et al. 2012). Man-made 
barriers that block or impede access to rivers throughout the entire 
historical range of river herring have resulted in significant losses 
of historical spawning habitat for river herring.
    Dams and other man-made barriers have contributed to the historical 
and current declines in abundance of both blueback herring and alewife 
populations. While estimates of habitat loss over the entire range of 
river herring are not available, estimates from studies in Maine show 
that less than 5 percent of lake spawning habitat and 20 percent of 
river habitat remains accessible for river herring (Hall et al. 2010). 
Mattocks et al. (2017) estimated that, due to damming, only 6.7 percent 
and 7.9 percent of stream habitat in the Connecticut and Merrimack 
Rivers, respectively, is accessible. The Merrimack and Thames-Pawtucket 
watersheds had the greatest losses in lake habitat due to damming, with 
2.8 percent and 6.4 percent, respectively, of available habitat in 
1900. Total biomass lost due to damming from 1630 to 2014 was estimated 
to be 7 million mt (freshwater) and 2.4 million mt (marine; Mattocks et 
al. 2017).
    Dams prevent access to historical spawning habitat (e.g., Hall et 
al. 2012, Mattocks et al. 2016), and also alter stream continuity and 
impair water quality on a number of levels. Dams and other barriers 
often affect migration rates, influencing both upstream and downstream 
migration of adults and downstream migration of juveniles. Delayed 
migration can have serious impacts at both life stages, including 
impacts on the timing of forage (zooplankton availability) as well as 
on predator avoidance for juveniles, and preferred spawning 
temperatures for adults (McCord 2005). Finally, dams often have 
detrimental nutrient and temperature impacts on downstream river 
communities affecting both adult and early life stages (MEOEA 2005).
    The passage solutions to get fish above dams can have a wide range 
of efficacy, and in some instances can be quite ineffective. 
Constructed fish passage also does not restore full riverine continuity 
or address water quality concerns. Further, both nature-like and 
technical fishways are engineered and built to function on flows 
modeled from historical records. Deviations in future flow patterns due 
to climate change could greatly reduce fishway efficacy.
Alewife
    Because dams and other man-made barriers may result in a variety of 
impacts (discussed above), the overall mean score corresponded to a 
medium (2.9) threat for alewife rangewide ranking and in each of the 
DPSs (3.1-3.4). While the SRT noted that risks to the two species are 
similar in nature, there is some evidence, that, of the two river 
herring species, alewife are better adapted to navigating fishways (K. 
Sullivan, pers. comm; B.Gahagan, unpublished). Specific barriers vary 
across the range, and threats related to the Aw- Canada DPS include (1) 
head-of-tide dams that block access to freshwater habitat and (2) 
increased prevalence of dams and tidal barrages in

[[Page 28648]]

the Bay of Fundy, Minas Basin, and the St. Croix River. The SRT noted 
that there were limited data on barriers in this region to be able to 
assess the threat on alewife. A majority of SRT members spread their 
ranking scores to reflect greater uncertainty regarding the severity of 
this threat across this region.
    The SRT determined that threats to alewife posed by dams and other 
barriers within the range of the Aw-Northern New England (medium, 3.3) 
and the Aw-Southern New England (medium, 3.4) DPS are more severe 
compared to those on a rangewide scale. The SRT took into account that 
these regions were the epicenters of colonial and industrial era dam 
building, and many of these structures remain in this area.
    In the Aw-Northern New England DPS, the ASFMC (2017b) reports dam 
construction in Maine during the last century isolated many of the 
inland waters currently stocked with alewives. The historical 
significance of anadromous fish to these waters was eventually lost, 
and freshwater fish communities, especially recreationally important 
game fish, began dominating these habitats. Access to much of the river 
herring habitat in Maine is still blocked by dams (without upstream 
fish passage) and other impediments (ASFMC 2017b).
    According to ASFMC (2017b), resource agencies in Maine are making 
progress by installing upstream and downstream fish passage facilities, 
especially in the Sebasticook River watershed and smaller coastal 
watersheds. In recent years, rock-ramp or nature-like fishways have 
become increasingly popular for passing river herring in Maine. In New 
Hampshire, restoration of diadromous fish populations began with 
construction of fishways in the late 1950s and continued through the 
early 1970s by the New Hampshire Fish and Game Department (NHFGD) in 
the Exeter, Lamprey, Winnicut, Oyster, and Cocheco Rivers in the Great 
Bay Estuary and the Taylor River in the Hampton-Seabrook Estuary. These 
fishways re-opened acres of freshwater spawning and nursery habitat for 
river herring (ASFMC 2017b).
    The SRT determined that threats posed by dams and other barriers 
within the range of the Aw-Southern New England DPS are more severe 
compared to those on a rangewide scale. According to ASMFC (2017b), 
there are over 500 dams within the historic range of river herring in 
Connecticut. Access to habitat previously blocked has been restored 
through construction of fishways and dam removal, providing more 
spawning habitat to increase production. Since 1990, 11 dams have been 
removed and 53 fishways have been constructed throughout the state, 
with more projects being completed each year.
    In Rhode Island, the Division of Fish and Wildlife is partnering 
with government agencies, NGOs, and private entities on a variety of 
anadromous habitat restoration projects throughout the state. Projects 
include constructing new fishways, culvert modifications, and dam 
removals to enhance spawning and nursery habitat (ASFMC 2017b). Gilbert 
Stuart and Nonquit Rivers river herring stocks are predominantly 
alewives. At Gilbert Stuart River, the Alaskan steeppass has been the 
primary survey site for monitoring adult river herring since 1981. 
Edwards (2015) reported that the fishway passed over 290,000 fish in 
2000, and in recent years estimates of one thousand fish per hour have 
been observed. The Denil fishway at Nonquit River has been the primary 
survey site for monitoring adult river herring since 1999. In 1999, the 
fishway passed over 230,000 fish (Edwards 2015). Buckeye Brook (RI) is 
a free[hyphen]flowing system, and river herring migrate to Warwick Pond 
without obstruction (ASFMC 2017b).
    Despite the aforementioned state-run fish passage solutions, the 
SRT determined that dams and other barriers are a more pertinent threat 
to the species in this DPS because alewife are typically more reliant 
on habitats upstream of dams for reproductive success. The SRT noted 
that the Aw-Southern New England DPS, like the Aw-Northern New England 
DPS, has many more dams located closer to the head of tide compared to 
the other DPSs. As a result, there is limited spawning habitat below 
these dams, and spawning runs are heavily influenced by management 
practices (e.g. truck and transport, fish lifts, fishway maintenance).
    The average score for dams and other barriers in the Aw-Mid-
Atlantic DPS (medium, 3.1) was slightly lower than the two northern 
DPSs' scores. Specific barrier threats related to this DPS include the 
presence of man-made barriers within the historic range of river 
herring. While dams and other barriers to fish migration are widely 
distributed throughout this DPS, the SRT noted that the existing dams 
are generally further upstream, leaving relatively more habitat below 
the dams. As such, the SRT determined that barrier threats related to 
the Aw-Mid-Atlantic DPS are similar (and possibly less severe) compared 
to those considered in the rangewide analysis.
    In New Jersey, restoration programs for river herring have been 
limited to the installation of fish ladders and occasional minor trap 
and transport programs or dam removal. Fish ladders have also been 
installed in Delaware to restore river herring runs. Twelve tidal 
streams located within the Delaware River/Bay watershed have fish 
ladders installed (eight in Delaware and four in New Jersey) at the 
first upstream dam to allow for river herring passage into the non-
tidal impoundments above the dams.
    In addition to fish passage installations, dam removal has been the 
focus of restoration effort is some states. In May 2016, the first dam 
upstream of the confluence with the Hudson River was removed from the 
Wynants Kill, a relatively small tributary in Troy, NY, downstream of 
the Federal Dam. According to ASMFC (2017b) within days of the removal, 
hundreds of river herring moved past the former dam location into 
upstream habitat. Subsequent sampling efforts yielded river herring 
eggs, providing evidence that river herring were actively spawning in 
the newly available habitat. This dam removal will provide an 
additional half km (0.3 mi) of spawning habitat for river herring that 
has not been available for 85 years (ASMFC 2017b). Similarly, Maryland 
DNR's Fish Passage program has completed 79 projects, reopening a total 
735.5 km (457 mi) of upstream spawning habitat in Maryland since 2005.
    In Pennsylvania, dam removals along with installation of fish 
passage have opened up 100 river miles to migratory fish. In 2000 and 
2001, river herring were transported to the Conestoga River, a 
tributary of the Susquehanna River in Pennsylvania. The transported 
river herring left the Conestoga River, moved up the mainstem 
Susquehanna River, and were observed at the Safe Harbor Dam. Transports 
to the Conestoga River included 1,820 alewives in 2000.
    Several states within the range of this DPS have implemented 
restoration programs focused on a range of solutions to fish passage. 
These solutions include fish passage installation, dam removal, and 
trap-and-transport initiatives. An abundance of available coastal and 
estuarine habitat and the presence of long undammed sections of major 
rivers within the range of this DPS led the SRT to determine that the 
threat of dams was slightly reduced in this region compared to other 
DPSs.
Blueback Herring
    The overall mean score for dams and other barriers corresponded to 
a

[[Page 28649]]

medium (3.1) threat ranking rangewide and in each DPS (2.6-3.3).
    The SRT ranked the Bb-Canada/Northern New England slightly elevated 
(medium, 3.3) compared to the rangewide score. Specific barrier threats 
related to the Bb-Canada/Northern New England DPS include (1) head-of-
tide dams that block access to freshwater habitat, and (2) increased 
prevalence of dams and tidal barrages in the Bay of Fundy, Minas Basin, 
and St. Croix River. The SRT took into account that the region was one 
of the epicenters of colonial and industrial era dam building and that 
many of these structures remain in this area. According to ASFMC 
(2017a), dam construction in Maine during the last century isolated 
many of the inland waters. The historical significance of anadromous 
fish to these waters was eventually lost, and freshwater fish 
communities, especially recreationally important game fish, began 
dominating these habitats.
    Access to much of river herring habitat in Maine is still blocked 
by dams without upstream fish passage and other impediments (ASFMC 
2017a). The SRT took into account high mortality associated with the 
tidal barrages present in the Canadian portion of the range. The SRT 
noted that, compared to other DPSs, there are many more dams closer to 
the head of tide in this region. As a result, there is limited spawning 
habitat below these dams, and spawning runs are heavily influenced by 
management practices (e.g., truck and transport, fish lifts, fishway 
maintenance).
    According to ASFMC (2017a), resource agencies in Maine are making 
progress by installing upstream and downstream fish passage facilities, 
especially in the Sebasticook River watershed and smaller coastal 
watersheds. In recent years, rock[hyphen]ramp or nature[hyphen]like 
fishways have become increasingly popular for passing river herring in 
Maine. In Maine, blueback herring populations appear to be increasing 
in the upper regions of the state's watersheds (ASFMC 2017a).
    The overall mean score for dams and other barriers corresponded to 
a medium (3.0) threat ranking in the Bb-Mid-Atlantic DPS, slightly 
lower than the rangewide score. Specific barrier threats related to 
this DPS include the presence of man-made barriers within the historic 
range of river herring. While dams and other barriers to fish migration 
continue to be present in states within the range of this DPS, the SRT 
noted that the dams that do exist in the region are further upriver, 
leaving a lot of blueback herring habitat below the dams. As such, the 
SRT determined that barrier threats related to the Bb-Mid-Atlantic DPS 
are similar (and possibly less severe) compared to those considered in 
the rangewide analysis.
    Several states within the range of this DPS have implemented 
restoration programs focused on a range of solutions to fish passage. 
These solutions include fish passage installation, dam removal, and 
trap-and-transport initiatives.
    In Connecticut, the largest blueback herring run has historically 
been found in the Connecticut River. Between 1849 and 1955, anadromous 
fish had no access above the Holyoke Dam, in Holyoke, Massachusetts. 
Today, the Connecticut River blueback herring population size below the 
Holyoke Dam is unknown, and there are insufficient historical data to 
make an estimate. However, according to ASFMC (2017a), there continues 
to be stable juvenile blueback herring production in recent years with 
index values comparable to values produced with passage of several 
hundred thousand of fish at the lift despite the lack of adults passed 
at the Holyoke Dam. It is unknown as to whether or not the peak values 
of passage at the Holyoke Dam are a sustainable population for the 
Connecticut River above the Holyoke Dam, since there is not enough 
historical population data.
    The SRT ranked the threat of dams in Bb-Southern Atlantic DPS as a 
medium (2.6), with a slightly lower score than the rangewide and other 
DPS scores. An abundance of available coastal and estuarine habitat and 
the presence of long undammed sections of major rivers within the range 
of this DPS led the SRT to rank the mean score lower. Specific barrier 
threats related to this DPS include habitat loss and alterations 
occurring in tributaries of Winyah Bay, the Santee-Cooper River system, 
and the Savannah River. The SRT noted that dams in this region are 
often very high in river systems and in many cases are not likely to 
block an abundance of blueback herring habitat. The SRT also considered 
this threat somewhat mitigated in this DPS by the ability of blueback 
herring to use successfully lotic spawning habitats such as those found 
below dams. The SRT added that alterations to flow regimes and thermal 
effects of dams are still of concern, and these concerns may grow in 
importance with climate change.
    Documented impacts of past flow manipulations support the SRT's 
assessment. In 1938, a large diversion project to move water from the 
Santee River to the Cooper River was initiated. The project resulted in 
the construction of the Wilson Dam for flood control on Santee River at 
km 143, which created Lake Marion, and the construction of Pinopolis 
Dam at km 77 on the Cooper River, which is a hydroelectric facility 
with a navigation lock. According to Cooke and Coale (1996), large 
numbers of blueback herring that utilized the Cooper River before 
rediversion, switched to the Santee River after rediversion.
Dredging and Habitat Alteration
    Dredging and habitat alteration are discussed in section 4.1.4 of 
the Status Review Report (NMFS 2019), and below we provide a summary.
    Wetlands provide migratory corridors and spawning habitat for river 
herring. The combination of incremental losses of wetland habitat, 
changes in hydrology, and inputs of nutrients and chemicals over time, 
can be extremely harmful, resulting in diseases and declines in the 
abundance and quality of habitat. Wetland loss is a cumulative impact 
that results from activities related to dredging/dredge spoil 
placement, port development, marinas, solid waste disposal, ocean 
disposal, and marine mining. In the late 1970s and early 1980s, the 
United States was losing wetlands at an estimated rate of 300,000 acres 
(1,214 square kilometer (km\2\)) per year. The Clean Water Act and 
state wetland protection programs helped decrease wetland losses to 
117,000 acres (473 km\2\) per year between 1985 and 1995. Estimates of 
total wetland loss vary according to the different agencies. The U.S. 
Department of Agriculture attributes 57 percent of wetland loss to 
development, 20 percent to agriculture, 13 percent to creation of 
deepwater habitat, and 10 percent to forest land, rangeland, and other 
uses. Of the wetlands lost between 1985 and 1995, the USFWS estimates 
that 79 percent of wetlands were lost to upland agriculture. Urban 
development and other types of land use activities were responsible for 
6 percent and 15 percent of wetland loss, respectively.
    Similar to dams, dredging has affected historical spawning and 
nursery habitats. Maintenance dredging continues to reduce available 
habitat, negatively affect water quality, and s change river flows. 
Although regulated through Federal and state permitting, dredging and 
shoreline hardening associated with estuary/coastline development are 
not likely to decrease in spatial extent or scope through the next 
century. Both practices reduce wetland and nearshore habitats, 
impacting nursery habitats for river herring, including the macrophytes 
and

[[Page 28650]]

natural streamflow important to nearshore ecosystem health.
Alewife
    The SRT ranked the threat of dredging/channelization rangewide and 
in each DPS as low (1.5-1.7). The SRT ranked the threat of dredging in 
the Aw-Mid-Atlantic DPS (low, 1.7) to be at slightly higher risk 
compared to other DPSs. The increased volume of industrial activity and 
growing number of dredge projects in the Aw-Mid-Atlantic DPS may pose a 
greater risk to alewife compared to other regions. This DPS encompasses 
several hundred miles of dredged river channels, as well as the ports 
of New York and New Jersey, Baltimore Harbor, the Hudson and Delaware 
Rivers, and the Chesapeake Bay, all of which are subject to regular 
dredging.
Blueback Herring
    The SRT ranked the threat of dredging/channelization as low (2.0-
2.3) rangewide and in each DPS. For the same reasons stated above for 
the Aw-Mid-Atlantic DPS, the SRT ranked the threat of dredging slightly 
higher in the Bb-Mid-Atlantic DPS (low, 2.3) compared to the blueback 
herring rangewide and other DPS scores.
Water Quality
    Risks associated with changes to water quality are discussed in 
section 4.1.5 of the Status Review (NMFS 2019), and below we provide a 
summary.
    Nutrient enrichment has become a major cumulative problem for many 
coastal waters. Nutrient loading results from the individual activities 
of coastal development, marinas and recreational boating, sewage 
treatment and disposal, industrial wastewater and solid waste disposal, 
ocean disposal, agriculture, and aquaculture. Excess nutrients from 
land-based activities accumulate in the soil, pollute the atmosphere, 
and groundwater, and move into streams and coastal waters. Nutrient 
inputs have a direct effect on water quality. For example, nutrient 
enrichment can stimulate growth of phytoplankton that consumes oxygen 
when they decay, which can lead to low dissolved oxygen that may result 
in fish kills (Correll 1987, Tuttle et al.1987, Klauda et al. 1991b); 
this condition is known as eutrophication.
    From the 1950s to the present, increased nutrient loading has made 
hypoxic conditions more prevalent (Officer et al. 1984, Mackiernan 
1987, Jordan et al. 1992, Kemp et al. 1992, Cooper and Brush 1993, 
Secor and Gunderson 1998). Hypoxia is most likely caused by 
eutrophication, due mostly to non-point source pollution (e.g., 
industrial fertilizers used in agriculture) and point source pollution 
(e.g., urban sewage). In addition to the direct cumulative effects 
incurred by development activities, inshore and coastal habitats are 
also threatened by persistent increases in certain chemical discharges. 
The combination of incremental losses of wetland habitat, changes in 
hydrology from dams and other barriers, and nutrient and chemical 
inputs produced over time can be extremely harmful to marine and 
estuarine biota, including river herring, and can result in diseases 
and declines in the abundance and quality of the affected resources.
    Poor water quality is an important threat in some parts of the 
species' range. While the large scale acute water quality issues that 
fueled the creation of the EPA and enactment Clean Water Act have, in 
many areas, been remedied, the wide impacts of increasing urbanization 
on the eastern coast of the United States has led to widespread 
deleterious conditions (e.g., perennial hypoxic and anoxic areas in 
estuaries and nurseries, eutrophication of freshwater systems, invasive 
plants and eutrophication altering spawning habitat). Siltation--
resulting from erosional land use practices as well as natural 
disturbances such as hurricanes and/or flood events reduces survival of 
aquatic vegetation and impacts streamflow. Additionally, climate 
variability may increase sedimentation in natal rivers, contributing to 
poorer water quality. These types of effects, often from non-point 
sources, occur over entire landscapes and are often more difficult to 
detect, measure, test, and remedy.
Alewife
    The overall mean score for water quality corresponded to a medium 
(2.8) ranking rangewide and in each DPS (2.7-3.2). The threat from poor 
water quality was slightly elevated in the Aw-Mid-Atlantic DPS (medium 
3.2) compared to the rangewide ranking. Many of the major estuaries in 
the Aw-Mid-Atlantic DPS have documented water quality issues. This DPS 
also has many growing population centers, and anthropogenic threats are 
predicted to increase in the foreseeable future. Similar to climate 
change and variability, the interactions between anthropogenic change 
and climate change are likely to have severe detrimental effects on 
water quality, especially water temperature, in regions at the edge of 
the species' tolerance.
Blueback Herring
    The overall mean score for water quality corresponded to a medium 
(2.9) ranking rangewide and in each DPS (2.9-3.2). For the same reasons 
stated above for the Aw-Mid-Atlantic DPS, the threat of water quality 
was slightly elevated in the Bb-Mid-Atlantic DPS (medium, 3.2) compared 
to the rangewide ranking.
Water Withdrawal/Outfall (Physical)
    Water withdrawal facilities and toxic and thermal discharges have 
also been identified as a threat that is impacting river herring. This 
threat is discussed in section 4.1.6 of the Status Review Report (NMFS 
2019), and below we provide a summary of impacts to river herring.
    Water withdrawal facilities impact natural streamflow and result in 
impingement/entrainment mortality of river herring. Disrupting 
streamflow can influence migratory timing as well as water quality 
downstream of the facility. Additionally, water withdrawal (for 
agriculture or other human activities) degrades or destroys habitat for 
river herring and poses a significant threat to their survival, 
especially when coupled with other threats. The threat is likely to 
increase alongside coastal population growth, which, in conjunction 
with climate change effects, will likely result in reduced base flows. 
Water withdrawals and reduced flows can disrupt connectivity between 
habitats and cause ontogenetic shifts in life history. For alewives and 
blueback herring to be successful, adults must be able to immigrate to 
nursery areas, spawn, and then emigrate. Juveniles should have adequate 
flow to emigrate volitionally. In this way, withdrawals act much like 
dams and other barriers, even though their effects are less obviously 
visible.
Alewife
    The overall mean score for water withdrawal corresponded to a 
medium (3.2) ranking for alewife rangewide and in each DPS (2.8-3.3). 
The threat of water withdrawal was slightly reduced in the Aw-Canada 
DPS (medium, 2.8) compared to the rangewide ranking. Human population 
density and the resulting anthropogenic effects on water quality 
(including animal husbandry and agriculture) and the demands for water 
withdrawals/diversions are likely less of a threat to the species in 
this DPS compared to rangewide average.
    Because of the lower human population density in the Aw-Northern 
New England DPS (medium, 3.0) and corresponding demands on water

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resources, there is a diminished risk related to water withdrawals for 
the species in this region compared to the rangewide average. However, 
the presence of numerous head-of-tide-dams, where emigration is related 
to fall flows/water levels from head ponds, remains a threat.
    The threat of water withdrawal was slightly elevated in the Aw-
Southern New England (medium, 3.3) DPS compared to the rangewide 
ranking. Water withdrawal may be higher in the Aw-Southern New England 
DPS than in other areas due to high population density. Water 
withdrawal can lead to reduced stream flow, and the water storage 
capacities of impoundments can further affect temporal variability of 
stream flow. Similar to populations further north, populations here 
face an increased risk from artificially manipulated water levels in 
head ponds, where summer and fall emigration is dependent on adequate 
stream flows. As water transfers/withdrawals increase in the future, 
this threat will increase.
    The threat of water withdrawal in the Aw-Mid-Atlantic DPS (medium, 
3.2) was similar to the rangewide score for alewife. The SRT noted 
predicted high population growth rate in this region. Demand for water 
and anthropogenic pressures will likely increase, resulting in reduced 
stream flows, which affect juvenile emigration and survival.
Blueback Herring
    The overall mean score for water quality corresponded to a medium 
(2.9) ranking for blueback herring rangewide and in each DPS (2.8-2.9). 
Because of the lower human population density in the Bb-Canada/Northern 
New England DPS (medium, 2.8) and corresponding demands on water 
resources, there is a diminished risk to the species as compared to the 
rangewide average. Human population density and the resulting 
anthropogenic effects on water quality (including animal husbandry and 
agriculture) and the demands and for water withdrawals/diversions are 
likely less of a threat to the species in this DPS compared to the 
rangewide average. The threat ranking for water withdrawal in the Bb-
Mid-Atlantic DPS (medium, 2.9) was similar to the rangewide score. The 
SRT noted that predicted population growth rate in this region will 
drive future demand for water. As anthropogenic pressures increase, it 
will negatively affect water quality (hypoxia, eutrophication) in most 
major estuaries. Further, the interactions between anthropogenic change 
and climate change are likely to severely affect water quality in 
portions of the species' range where water quality is already impaired. 
The threat ranking for water withdrawal in the Bb-Southern DPS (medium, 
2.9) was similar to the rangewide score. The SRT noted that utility 
water intake may be a larger issue in the Bb-Southern Atlantic DPS 
compared to water withdrawals rangewide.

B. Overutilization

    The SRT assessed five different factors that may contribute to the 
overutilization of alewife: Directed commercial harvest, retained and 
discarded incidental catch (including slippage), recreational harvest, 
scientific research and educational harvest. Although ranked 
separately, the SRT's assessments for scientific research and 
educational harvest are discussed in combination below due to the 
limited information and similarity in overall rankings for these 
factors.
Directed Commercial Harvest
    This threat is discussed in sections 4.2.1 of the Status Review 
Report (NMFS 2019). Below, we provide a summary of impacts on river 
herring.
    Information on river herring fisheries in the United States was 
gathered largely from the ASMFC's benchmark assessment of river herring 
stocks of the U.S. Atlantic Coast from Maine through Florida (ASMFC 
2012) and the River Herring Stock Assessment update (ASMFC 2017a). The 
ASMFC (2017a) report provides an update to the 2012 benchmark 
assessment of river herring. Both documents were prepared by the River 
Herring Stock Assessment Subcommittee (SAS) of the ASMFC's Shad and 
Herring Technical Committee (TC).
    Domestic commercial landings of river herring were presented in the 
stock assessment update by state and by gear from 1887 to 2015 where 
available (ASMFC 2017a). Landings of alewife and blueback herring were 
collectively classified as ``river herring'' by most states. Only a few 
states had species-specific information recorded for a limited range of 
years. Commercial landings records were available for each state since 
1887, except for Florida and the Potomac River Fisheries Commission 
(PRFC), which began recording landings in 1929 and 1960, respectively. 
It is important to note that historical landings presented in the stock 
assessment do not include all landings for all states over the entire 
period and are likely underestimates, particularly for the first third 
of the time series, because not all river landings were reported (ASMFC 
2012, ASMFC 2017a).
    During 1887 to 1938, reported commercial landings of river herring 
along the Atlantic Coast averaged approximately 30.5 million lbs 
(13,835 mt) per year. The majority of river herring landed by 
commercial fisheries in these early years are attributed to the mid-
Atlantic region (NY to VA). The dominance of the mid-Atlantic region 
is, in part, due to the apparent bias in the spatial coverage of the 
reported landings. During this early period, landings were 
predominately from Maryland, North Carolina, Virginia, and 
Massachusetts (overall, harvest is likely underestimated because 
landings were not recorded consistently during this time.) Virginia 
made up approximately half of the commercial landings from 1929 until 
the 1970s, and the majority of Virginia's landings came from the 
Chesapeake Bay, the Potomac River, the York River, and offshore 
harvest.
    Severe declines in landings began coast-wide in the early 1970s 
and, where still allowed, domestic landings are now a fraction of what 
they were at their peak, having remained at persistently low levels 
since the mid-1990s. Moratoria were enacted in Massachusetts 
(commercial and recreational in 2005), Rhode Island (commercial and 
recreational in 2006), Connecticut (commercial and recreational in 
2002), Virginia (for waters flowing into North Carolina in 2007), and 
North Carolina (commercial and recreational in 2007). As of January 1, 
2012, river herring fisheries in states or jurisdictions without an 
approved sustainable fisheries management plan, as required under ASMFC 
Amendment 2 to the Shad and River Herring Fishery Management Plan, were 
closed. (Note as anadromous alosines of the east coast, shad, alewife, 
and blueback herring are managed under the same Fisheries Management 
Plan; ASMFC 1987). As a result, prohibitions on harvest (commercial or 
recreational) were extended to New Jersey, Delaware, Pennsylvania, 
Maryland, DC, Virginia, Georgia and Florida (ASMFC 2012, ASMFC 
2017a,b).
    The ASMFC stock assessment committee calculated in-river 
exploitation rates of the spawning runs for five rivers (Damariscotta 
River (ME--alewife), Union River (ME--alewife), Monument River (MA--
both species combined), Mattapoisett River (MA--alewife), and Nemasket 
River (MA--alewife)) by dividing in-river harvest by total run size 
(escapement plus harvest) for a given year (ASMFC 2012). Exploitation 
rates were highest (range: 0.53 to 0.98) in the Damariscotta River and 
Union River prior to 1985, while the exploitation was lowest (range: 
0.26

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to 0.68) in the Monument River. In Massachusetts, exploitation rates of 
both species in the Monument River and of alewives in the Mattapoisett 
River and Nemasket River were variable (average = 0.16) and, except for 
the Nemasket River, declined generally through 2005 until the 
moratorium was imposed. Exploitation rates of alewives in the 
Damariscotta River were low (<0.05) during the period from 1993 to 
2000, but they increased steadily through 2004 and remained greater 
than 0.34 through 2008. Exploitation in the Damariscotta River dropped 
to 0.15 in 2009 to 2010. In-river exploitation of alewives has 
continued to decline in the Damariscotta River, with the lowest levels 
occurring in the last five years (2011-2015), with the exception of 
very low values that occurred in the 1990s (due to lack of harvest) 
(ASMFC 2017a). Exploitation rates of alewives in the Union River 
declined through 2005 but have remained above 0.50 since 2007 (ASMFC 
2012). In-river exploitation of alewives has remained relatively stable 
in the Union River, but it did decline to the lowest level of the time 
series (2010-2015) in the terminal year of the update. Exploitation has 
essentially ceased on other rivers assessed during the benchmark due to 
moratoria (MA rivers) (ASMFC 2017a).
    The coastwide index of relative exploitation also declined 
following a peak in the late 1980s and has remained fairly stable over 
the past decade. In all model runs except for one, exploitation rates 
coastwide declined. Exploitation rates estimated from the statistical 
catch-at-age model for blueback herring in the Chowan River (see Status 
of River Herring in North Carolina in the ASMFC 2017b stock assessment) 
also showed a slight declining trend from 1999 to 2007, at which time a 
moratorium was instituted.
    There appears to be a consensus that exploitation has decreased in 
recent times. The stock assessment indicates that the decline in 
exploitation over the past decade is not surprising because river 
herring populations are at low levels and more restrictive regulations 
or moratoria have been enacted by states (ASMFC 2017a).
    Fisheries in Canada for river herring are regulated through limited 
seasons, gears, and licenses. Licenses may cover different gear types; 
however, few new licenses have been issued since 1993 (DFO 2001). 
River-specific management plans include closures and restrictions. 
River herring used locally for bait in other fisheries are not 
accounted for in river-specific management plans (DFO 2001). DFO 
estimated river herring landings at just under 25.5 million lbs (11,577 
mt) in 1980, 23.1 million lbs (10,487 mt) in 1988, and 11 million lbs 
(4,994 mt) in 1996 (DFO 2001). The largest river herring fisheries in 
Canadian waters occur in the Bay of Fundy, southern Gulf of Maine, New 
Brunswick, and in the Saint John and Miramichi Rivers where annual 
harvest estimates often exceed 2.2 million lbs (1,000 mt) (DFO 2001).
    There is little directed effort on river herring across the 
Northwest Atlantic. Foreign fleet landings of river herring (reported 
as alewife and blueback shad) are available through the Northwest 
Atlantic Fisheries Organization (NAFO). Offshore exploitation of river 
herring and shad (generally <190 millimeters (mm) (7.5 inches) in 
length) by foreign fleets began in the late 1960s and landings peaked 
at about 80 million lbs (36,320 mt) in 1969 (ASMFC 2017a). After the 
Fishery Conservation and Management Act of 1976 (16 U.S.C. 1801 et 
seq.), later retitled the Magnuson Fishery and Conservation and 
Management Act, and the formation of the Fishery Conservation Zone in 
1977, foreign allocation of river herring (to both foreign vessels and 
joint venture vessels) between 1977 and 1980 was 1.1 million lbs (499 
mt). The foreign allocation was reduced to 220,000 lbs (100 mt) in 1981 
because of the condition of the river herring resource. In 1985, a 
bycatch cap of no more than 0.25 percent of total catch was enacted for 
the foreign fishery. The cap was exceeded once in 1987, and this shut 
down the foreign mackerel fishery. In 1991, amendment 4 to the Atlantic 
Mackerel, squid and butterfish fisheries management plan added area 
restrictions to exclude foreign vessels from within 20 miles (32.2 km) 
of shore for two reasons: (1) In response to the increased occurrence 
of river herring bycatch closer to shore and (2) to promote increased 
fishing opportunities for the domestic mackerel fleet (50 CFR part 
611.50; ASMFC 2012). There have been no reported landings by foreign 
fleets since 1990 (ASMFC 2012, ASMFC 2017). From 1991 to 2015, the only 
reported catch in Areas 5 and 6 was from the United States.
Alewife
    The overall mean score for alewife directed harvest corresponded to 
a low (1.7) ranking rangewide and for all DPS (1.2-2.1). 
Overutilization for commercial purposes was once considered one of the 
primary threats to alewife and blueback herring populations. 
Significant declines have been documented throughout much of the range 
for both species due to historic fishing pressure and other threats. 
Directed harvest does still occur in several states (see State 
Regulations in the Status Review Report for Maine, New Hampshire, New 
York, the Potomac River Fisheries Commission/District of Columbia, 
North Carolina, and South Carolina (NMFS 2019), and the fishing occurs 
during migration to spawning grounds. Amendment 2 to the ASMFC Shad and 
River Herring Interstate Fishery Management Plan requires states to 
have a sustainable fishery management plan (SFMP) for each river with a 
river herring fishery (beginning in 2012). SFMPs must be reviewed by 
the ASMFC Shad and River Herring Technical Committee for adequate 
sustainability measures and approved by the ASMFC Management Board. 
Monitoring is required on all harvested runs in the U.S. Overall, SRT 
members found that the current directed harvest was well regulated and 
occurred only on stocks that have demonstrated sustainability.
    The threat ranking for directed commercial harvest was higher in 
the Aw-Canada DPS (low, 2.1) compared to the rangewide ranking and 
other DPSs (1.2-1.7). SRT members noted increased uncertainty related 
to directed harvest levels within Canada. Gibson et al. (2017) 
indicated high annual removal rates where recorded or reported. 
Additionally, Gibson et al. (2017) indicated that previous reporting 
and collection methods do not provide consistent and accurate 
information, increasing concern and uncertainty for this threat. 
Finally, the Department of Fisheries and Oceans still allows some 
fishing on mixed stocks in Canadian waters, which makes managing 
impacts to individual populations more difficult.
    The threat ranking for directed commercial harvest was slightly 
higher in the Aw-Northern New England DPS (low, 1.7) compared to the 
rangewide ranking. Maine and New Hampshire currently have approved 
ASMFC sustainable fishing management plans within this DPS. The SRT 
noted uncertainty related to lack of publicly available commercial 
harvest data for Maine due to confidentiality; therefore, the total 
removals and removal rates by river system are largely unknown.
    The threat ranking for directed commercial harvest was lower in the 
Aw-Southern New England DPS (low, 1.2) compared to the rangewide 
ranking. There is currently no directed commercial harvest conducted 
within the Aw-Southern New England DPS. The Nemasket River, in southern 
Massachusetts, has an ASMFC approved SFMP, but no harvest has occurred 
to date, largely due to variability in run strength. SRT members noted

[[Page 28653]]

uncertainty related to whether further directed harvest of alewife 
would be permitted within the Aw-Southern New England DPS in the 
foreseeable future.
    The threat ranking for directed commercial harvest was lower in the 
Aw-Mid-Atlantic DPS (low, 1.6) compared to the rangewide ranking. New 
York is the only state to have an approved ASMFC sustainable fishing 
management plan within this DPS.
Blueback Herring
    For the same reasons stated above for alewife, the overall mean 
score for blueback herring directed harvest corresponded to a low (1.8) 
ranking rangewide and for all DPS (1.5-1.9). The threat ranking for 
directed commercial harvest was slightly higher in the Bb-Canada/
Northern New England DPS (low, 1.9) compared to the rangewide ranking, 
for the same reasons stated above for the Aw-Canada and the Aw-Northern 
New England DPSs including the lack of publicly available commercial 
harvest data for Maine. Likewise, for the same reason stated above for 
the Aw-Mid-Atlantic DPS ranking, this threat ranked in the low (1.6) 
category for the Bb-Mid-Atlantic DPS.
Retained and Discarded Incidental Catch (Including Slippage)
    River herring are caught incidentally at sea in Federal fisheries 
targeting other species such as Atlantic herring, squid, and mackerel. 
In this section, we refer to several terms: Retained incidental catch, 
discarded incidental catch, slippage and bycatch. Retained incidental 
catch is the capture and mortality of a non-targeted species. Discarded 
incidental catch is the portion of the non-targeted catch brought on 
board and then returned to sea. Slippage is a term used to describe a 
process in which a boat does not bring the entire catch on board and 
releases part of the catch into the water, thereby potentially biasing 
estimates of retained and discarded incidental catch. Bycatch, under 
National Standard 9, refers to fish that are harvested in a fishery, 
but that are not sold or kept for personal use (50 CFR part 600).
    The magnitude of this ocean catch is highly uncertain because of 
the short time series of incidental data, underreporting, and a lack of 
observer coverage. In addition, there are limited data on the stock 
composition of the incidentally caught fish and, thus, no way to 
partition estimates of bycatch among river systems. With no estimates 
of coastwide or regional stock complex abundances, it is also difficult 
to assess the significance of these removals on the overall population 
or segments of it (ASMFC 2017a).
    Because bycatch occurs in marine waters, and alewife and blueback 
herring stock complexes overlap in their distribution in the ocean, the 
retained and discarded incidental catch occurs on a mixed stock complex 
fishery (that is, there is no ``oceanic'' stock of alewife or blueback 
herring, the alewife and blueback herring in the ocean come from all of 
the stock complexes described herein). Recent studies have also shown 
that alewife and blueback herring incidentally caught in a number of 
statistical areas were from several genetic stock complexes (Hasselman 
et al. 2016, Palkovacs unpublished). This finding increases the 
probability that alewife and blueback herring are being exploited from 
populations that do not meet sustainable harvest requirements approved 
through the ASMFC.
    Several studies estimated river herring retained and discarded 
incidental catch (Cieri et al. 2008, Wigley et al. 2009, Lessard and 
Bryan 2011). The discard and incidental catch estimates from these 
studies cannot be directly compared, as they used different ratio 
estimators based on data from the Northeast Fishery Observer Program 
(NEFOP), as well as different information to quantity total catch 
estimates. Cieri et al. (2008) estimated the kept (i.e., landed) 
portion of river herring incidental catch in the Atlantic herring 
fishery with an estimated average annual landed river herring catch of 
approximately 71,290 lbs (32.4 mt) for 2005-2007, and the corresponding 
coefficient of variation (CV) was 0.56. Cournane et al. (2012) extended 
this analysis with additional years of data. Further work is needed to 
elucidate how the incidental catch of river herring in the directed 
Atlantic herring fishery compares to total incidental catch across all 
fisheries. Since this analysis only quantified kept river herring in 
the Atlantic herring fishery, it underestimates the total catch (kept 
and discarded) of river herring across all fishing fleets. Wigley et 
al. (2009) quantified river herring discards across fishing fleets that 
had sufficient observer coverage from July 2007-August 2008 with an 
estimated approximately 105,820 lbs (48 mt) discarded during the 12 
months (July 2007 to August 2008); the estimated precision was low (149 
percent CV). This analysis estimated only river herring discards (in 
contrast to total incidental catch), and noted that midwater trawl 
fleets generally retained river herring while otter trawls typically 
discarded river herring.
    Lessard and Bryan (2011) estimated an average incidental catch of 
river herring and American shad of 3.3 million lbs (1,498 mt)/yr from 
2000-2008. Lessard and Bryan (2011) analyzed NEFOP data at the haul 
level; however, the sampling unit for the NEFOP database is at the trip 
level. Within each gear and region, all data, including those from high 
volume fisheries, appeared to be aggregated across years from 2000 
through 2008. However, substantial changes in NEFOP sampling 
methodology for high volume fisheries were implemented in 2005, 
limiting the interpretability of estimates from these fleets in prior 
years. The total number of tows from the fishing vessel trip report 
(VTR) database was used as the raising factor to estimate total 
incidental catch. The use of effort without standardization makes the 
implicit assumption that effort is constant across all tows within a 
gear type, potentially resulting in a biased effort metric. In 
contrast, the total kept weight of all species is used as the raising 
factor in standardized bycatch reporting methodology (SBRM). SBRM is a 
methodology to assess the amount and type of bycatch in a fishery. When 
quantifying incidental catch across multiple fleets, total kept weight 
of all species is an appropriate surrogate for effective fishing power 
because it is likely that no trips will exhibit the same attributes. 
Lessard and Bryan (2011) also did not provide precision estimates, 
which are imperative for estimation of incidental catch.
    The stock assessment update (ASMFC 2017a, b) presents the total 
incidental catch of river herring updated through 2015 following 
methods described in the benchmark assessment. These methods were 
developed during Amendment 14 to the Atlantic Mackerel, Squid and 
Butterfish (MSB) Fishery Management Plan, which includes measures to 
address incidental catch of river herring and shads (ASMFC 2017a). The 
stock assessment update presents the total incidental catch estimates 
by species.
    From 2005 to 2015, the total annual incidental catch of alewife 
ranged from 36.5-531.7 m (80,469-1,172,198 lbs) in New England and 
10.9-295.0 mt (24,030-650,364 lbs) in the Mid-Atlantic region (ASMFC 
2017a). The dominant gear varied across years between paired midwater 
trawls and bottom trawls (ASMFC 2017a). Corresponding estimates of 
precision exhibited substantial inter-annual variation and ranged from 
0-10.6 across gears and regions. Between 2005 and 2015, total annual 
blueback herring incidental catch ranged from 8.2-186.6 mt

[[Page 28654]]

(18,078-411,383 lbs) in New England and 1.4-388.3 mt (3,086-856,055 
lbs) in the Mid-Atlantic region (ASMFC 2017a). Across years, paired and 
single midwater trawls exhibited the greatest blueback herring 
incidental catches (ASMFC 2017a). Corresponding precision estimates 
ranged from 0-3.6.
    The temporal distribution of incidental catch was summarized by 
quarter and fishing region for the most recent 10-year period (2005 to 
2015). River herring catches occurred primarily in midwater trawls (62 
percent, of which 48 percent were from paired midwater trawls and the 
rest from single midwater trawls), followed by small mesh bottom trawls 
(24 percent). Catches of river herring in gillnets were negligible. 
Across gear types, catches of river herring were greater in New England 
(56 percent) than in the Mid-Atlantic (37 percent). The percentages of 
midwater trawl catches of river herring were similar between New 
England (31.3 percent) and the Mid-Atlantic region (30.5 percent). 
However, catches in New England small mesh bottom trawls were almost 
three times higher (27 percent) than those from the Mid-Atlantic (10 
percent). Overall, the highest quarterly catches of river herring 
occurred in midwater trawls during Quarter 1 in the Mid-Atlantic (28 
percent), followed by catches in New England during Quarter 4 (12 
percent) (ASMFC 2017). Quarterly catches in small mesh bottom trawls 
were highest in New England during Quarter 1 (9 percent) and totaled 5 
to 7 percent during each of the other three quarters (ASMFC 2017a). The 
New England and Mid-Atlantic Fishery Management Councils have adopted 
measures for the Atlantic herring and mackerel fisheries intended to 
decrease incidental catch and bycatch of alewife and blueback herring.
    Partitioning incidental bycatch in U.S. waters to river of origin 
or proposed stock complex is an ongoing area of research. Using the 15 
microsatellites previously identified (Palkovacs et al. 2014), 
Hasselman et al. (2016) applied genetic stock identification (GSI) to 
determine potential regional stock composition of river herring bycatch 
from the New England Atlantic herring fishery (2012-2013). GSI is a 
biological tool to determine the composition of mixed stocks and the 
origin of individual fish. Results showed assignment of over 70 percent 
to the Aw-Southern New England stock complex for alewife and 78 percent 
assignment to the Bb-Mid-Atlantic stock complex for blueback herring. 
The study also gives a marine spatial snapshot of stock complexes in 
the NOAA statistical areas sampled during 2012-2013, though the authors 
noted extreme inter-annual variability in both the magnitude and 
composition of incidental catch, demonstrating that marine 
distributions for both species are highly dynamic from year to year.
    Retained and discarded incidental catch (including slippage) is 
likely negatively affecting some river herring populations. Slippage 
was defined as catch that is discarded prior to it being brought aboard 
a vessel and/or prior to making it available for sampling and 
inspection by a NOAA-approved observer. The SRT noted that historical 
declines in river herring abundance were not likely driven by 
incidental catch, but because of current depleted abundances, 
incidental catch may impede population growth. As with all of the 
threats, the true magnitude of incidental catch remains largely unknown 
because there is no estimate of rangewide abundance. While some 
monitoring of incidental catch does occur in the Atlantic herring and 
mackerel fisheries, it has been estimated that monitored fisheries may 
only constitute half the discards in a given year (Wigley 2009). 
Further, the contribution of slippage also remains unknown because it 
is not currently reported.
Alewife
    Based on the best available information, noted above, the SRT 
concluded that the threat from incidental catch corresponded to a 
medium (2.5) contribution to extinction risk to alewife rangewide and 
in the Aw-Canada DPS (2.7), the Aw-Northern New England DPS (2.4), the 
Aw-Southern New England DPS (2.7), and the Aw-Mid-Atlantic DPS (2.5). 
However, the SRT noted the highest uncertainty around the contribution 
of incidental catch to extinction (expressed in variability and range 
of scores; see NMFS 2019), due to uncertainties around the estimates of 
exploitation, future monitoring coverage, and future use of bycatch 
avoidance programs.
    Incidental catch data available from the herring and mackerel 
fisheries for the years 2012-2015 (Palkovacs, unpublished) showed large 
proportions of Aw-Mid-Atlantic and Aw-Southern New England alewife 
captured by mid-water trawl and small mesh bottom trawl in the Atlantic 
herring/mackerel fisheries compared to other DPSs. Aw-Northern New 
England alewife made up a minimal amount of indirect catch (Palkovacs, 
unpublished). Much of the incidental catch from these fisheries was 
concentrated around Block Island Sound, which is located closest to the 
Aw-Mid-Atlantic DPS. SRT members noted that the results presented by 
Palkovacs are representative of the bycatch samples in the Atlantic 
herring and mackerel fisheries, which are concentrated generally in the 
Mid-Atlantic and Northeast.
    Hasselman et al. (2016) estimated that incidental catch from rivers 
south of the Hudson River ranged from 400,000 in 2012 to 1.3 million in 
2013. However, these previous estimates assumed that the Hudson River 
grouped with the Aw-Southern New England DPS, rather than the Aw-Mid-
Atlantic DPS, where it is now grouped. Therefore, if the analysis were 
rerun with the new boundaries, the estimates of incidental catch would 
be greater for this DPS. The study did not collect samples from other 
small-mesh coastal fisheries in this DPS, which may also catch alewife.
Blueback Herring
    Based on the best available information, as noted above, the SRT 
concluded that the threat from incidental catch rangewide (2.4) and for 
the Bb-Southern Atlantic DPS (1.7) corresponded to a low ranking. The 
mean score for the Bb-Canada/Northern New England DPS and the Bb-Mid-
Atlantic DPS corresponded to medium (2.6 for each). Again, the SRT 
noted uncertainty in assessing incidental catch because of the 
uncertainty in estimating exploitation, future monitoring coverage, and 
future use of bycatch avoidance programs.
    Limited information is available to estimate the impacts of 
incidental catch in the Bb-Canada/Northern New England DPS. Though 
fewer fish from this Bb-Canada/Northern New England DPS are reported in 
the Atlantic herring/mackerel fisheries (Palkovacs, unpublished data), 
other small mesh fisheries in this region may incidentally catch river 
herring.
    Data available from the herring and mackerel fisheries for the 
years 2012-2015 (Palkovacs, unpublished) suggest that blueback herring 
from the Bb-Mid-Atlantic DPS are also caught as bycatch in the Atlantic 
herring fishery. SRT members noted uncertainty due to limited 
information regarding the magnitude of small mesh coastal fisheries. 
Additional uncertainty comes from the limited sample area (Atlantic 
Herring Management Area 2 fisheries). Numerous small mesh fisheries 
exist in Atlantic Herring Management Areas 1 and 2, and new information 
regarding bycatch in those fisheries would be very beneficial to 
understanding the level of impact on river herring populations in this 
DPS.

[[Page 28655]]

Recreational Harvest
    Section 4.2.3 of the Status Review Report provides a state-by-state 
summary of recreational landing information for river herring. 
Recreational fishing in Canada for river herring is limited by 
regulations providing for area, gear, and seasonal closures, and limits 
on the number of fish that can be harvested per day. However, 
information on recreational catch is limited. Licenses and reporting 
are not required by Canadian regulations for recreational fisheries, 
and harvest is not well documented.
Alewife
    The SRT noted recreational harvest has largely been eliminated in 
the U.S. range, and where it does exist, it is well regulated. 
Amendment 2 to the ASMFC Shad and River Herring Interstate Fishery 
Management Plan requires states to have a sustainable fishery 
management plan for each river with a river herring fishery (beginning 
in 2012). Plans must be reviewed by the ASMFC Shad and River Herring 
technical committee for adequate sustainability measures and must be 
approved by the ASMFC management board (see Directed Commercial Harvest 
above). Historical rangewide recreational catch is largely unknown, and 
the recent ASMFC assessment (2017a) deemed recreational catch estimates 
unreliable.
    Based on the best available information, the SRT concluded that the 
threat from recreational harvest corresponded to a low (1.5) 
contribution to extinction risk rangewide and in all DPSs (1.3-2.1). 
However, the SRT noted that illegal and unmonitored recreational 
harvest could have significant local impacts for individual rivers with 
extremely low abundance. The SRT also noted higher uncertainty in the 
Aw-Canada DPS in comparison to the rangewide score due to uncertainty 
surrounding monitoring and reporting of recreational fisheries in 
Canada.
Blueback Herring
    For the same reasons stated above for alewife rangewide, the SRT 
concluded that the threat from recreational harvest corresponded to a 
low (1.5) contribution to extinction risk rangewide and in all DPSs 
(1.3-1.8) for blueback herring. However, as noted above, the SRT noted 
that illegal and unmonitored recreational harvest could have 
significant local impacts for individual rivers with extremely low 
abundance. The SRT noted increased uncertainty in the Bb-Canada/
Northern New England DPS due to uncertainties surrounding monitoring 
and reporting of recreational fisheries in Canada.
Scientific Research and Educational Harvest
    The states of Maine, New Hampshire, Massachusetts, and Rhode Island 
estimate run sizes using electronic counters or visual methods. In 
Massachusetts, various counting methods are used at the Holyoke Dam 
fish lift and fish ways on the Connecticut River. Young-of-the-Year 
(YOY) surveys are conducted through fixed seine surveys capturing YOY 
alewife and blueback herring generally during the summer and fall in 
Maine, Rhode Island, Connecticut, New York, New Jersey, Maryland, 
District of Columbia, Virginia, and North Carolina. Rhode Island 
conducts surveys for juvenile and adult river herring at large fixed 
seine stations. Virginia samples river herring using a multi-panel gill 
net survey and electroshocking surveys. Florida conducts 
electroshocking surveys to sample river herring. Maine, New Hampshire, 
Massachusetts, Rhode Island, Maryland, and North Carolina collect age 
data from both commercial and fisheries-independent sampling programs, 
and length-at-age data. All of these scientific monitoring efforts are 
believed to have minimal impacts on river herring populations.
    As noted previously, there is insufficient information available on 
river herring in many areas. Research needs were recently identified in 
the ASMFC River Herring Stock Assessment Reports (ASMFC 2012, 2017); 
NMFS Stock Structure, Climate Change and Extinction Risk Workshop/
Working Group Reports (NMFS a, b, c 2012) and associated peer reviews; 
and New England and Mid-Atlantic Fishery Management Council documents 
(NEFMC 2012, MAFMC 2012).
Alewife and Blueback Herring Rangewide and All DPSs
    There is little information linking scientific and educational use 
to declines in alewife or blueback herring populations. Therefore, 
based on the best available information, the SRT concluded that neither 
scientific use nor educational use is contributing to the species' risk 
of extinction. Both threats ranked in the very low (1.0) category.

C. Disease or Predation

    The SRT (section 4.3.2) assessed the available information on 
disease and predation of alewife and blueback herring summarized in the 
Status Review Report (NMFS 2019).
Disease
    Little information exists on diseases that may affect river 
herring; however, there are reports of a variety of parasites that have 
been found in both alewife and blueback herring. The most comprehensive 
report is that of Landry et al. (1992) in which 13 species of parasites 
were identified in blueback herring and 12 species in alewives from the 
Miramichi River, New Brunswick, Canada. The parasites found included 
one monogenetic trematode, four digenetic trematodes, one cestode, 
three nematodes, one acanthocephalan, one annelid, one copepod and one 
mollusk. The same species were found in both alewife and blueback 
herring with the exception of the acanthocephalan, which was absent 
from alewives.
    In other studies, Sherburne (1977) reported piscine erythrocytic 
necrosis (PEN) in the blood of 56 percent of pre-spawning and 10 
percent of post-spawning alewives in Maine coastal streams. PEN was not 
found in juvenile alewives from the same locations. Coccidian parasites 
were found in the livers of alewives and other finfish off the coast of 
Nova Scotia (Morrison and Marryatt 1990). Marcogliese and Compagna 
(1999) reported that most fish species, including alewife, in the St. 
Lawrence River become infected with trematode metacercariae during the 
first years of life. Examination of Great Lakes fishes in Canadian 
waters showed larval Diplostomum (trematode) commonly in the eyes of 
alewife in Lake Superior (Dechtiar and Lawrie 1988) and Lake Ontario 
(Dechtiar and Christie, 1988), though intensity of infections was low 
(<9/host).
    Heavy infections of Saprolegnia, a fresh and brackish water fungus, 
were found in 25 percent of Lake Superior alewife examined, and light 
infections were found in 33 percent of Lake Ontario alewife (Dechtiar 
and Lawrie 1988). Larval acanthocephala were also found in the guts of 
alewife from both lakes. Saprolegnia typically is a secondary 
infection, invading open sores and wounds, and eggs in poor 
environmental conditions, but under the right conditions, it can become 
a primary pathogen. Saprolegnia infections usually are lethal to the 
host.
    More recently, alewives were found positive for Cryptosporidium for 
the first time on record by Ziegler et al. (2007). Mycobacteria, which 
can result in ulcers, emaciation, and sometimes death, have been found 
in many Chesapeake Bay fish, including blueback herring (Stine et al. 
2010). Lovy and Friend (2015) characterized two intestinal coccidians, 
Goussia

[[Page 28656]]

ameliae and G. alosii in alewives of the Maurice River, New Jersey. G. 
ameliae infected both landlocked and anadromous alewives. The parasites 
were prevalent in both juveniles and adult fish. While significant 
mortality seemed not to occur, researchers suggest that the energetic 
costs of these parasites should be considered when estimating impacts 
of climate change and habitat loss.
    Another parasite recently discovered in New Jersey, Myxobolus 
mauriensis, attacks the ribs of juvenile river herring and can spread 
to other tissues (Lovy and Hutcheson 2016). This new species of 
Myxobolus was found mostly in the Maurice River (20 percent), but was 
also present in two other New Jersey river systems.
Alewife and Blueback Herring Rangewide and all DPSs
    The overall mean score for disease corresponded to a low (alewife 
1.5, blueback 1.7) ranking rangewide and in all DPSs for both alewife 
and blueback herring. The SRT could find little information linking 
disease to declines in alewife and blueback herring populations in any 
specific areas of the range. SRT members noted disease is of biggest 
concern at low population levels; however, warmer summer temperatures, 
changing fish communities, and changing migratory patterns due to 
climate change may make alewife and blueback herring populations more 
susceptible to disease in the future.
Predation
    While alewife and blueback herring are an important forage species, 
predators on the Northeast U.S. shelf are generally opportunistic 
(versus specialized) and will consume prey species in relation to their 
abundance in the environment. At high population levels, predation is 
likely not an issue; however, as populations decline predation can 
become a larger threat, especially locally. Recent papers focus on the 
predation impacts of striped bass; however, the predatory impact by 
striped bass is likely localized to areas and times of overlap (Davis 
et al. 2012, Ferry and Mather 2012, Overton et al. 2008).
    Two recent papers with contradictory conclusions discussed striped 
bass predation on river herring in Massachusetts and Connecticut 
estuaries and rivers, showing temporal and spatial patterns in 
predation (Davis et al. 2012; Ferry and Mather 2012). Davis et al. 
(2012) estimated that approximately 400,000 blueback herring are 
consumed annually by striped bass in the Connecticut River spring 
migration. In this study, striped bass were found in the rivers during 
the spring spawning migrations of blueback herring and had generally 
left the system by mid-June (Davis et al. 2012). Ferry and Mather 
(2012) discuss the results of a study conducted in Massachusetts 
watersheds with drastically different findings for striped bass 
predation. Striped bass were collected and stomach contents analyzed 
during three seasons from May through October (Ferry and Mather, 2012). 
The stomach contents of striped bass from the survey were examined and 
less than 5 percent of the clupeid category (from 12 categories 
identified to summarize prey) consisted of anadromous alosines (Ferry 
and Mather 2012). Overall, the Ferry and Mather (2012) study observed 
few anadromous alosines in the striped bass stomach contents during the 
study period. The contradictory findings of these two 2012 studies echo 
the findings of previous studies showing a wide variation in predation 
by striped bass with spatial and temporal effects.
    The diets of other predators, including other fish (e.g., bluefish, 
spiny dogfish), along with marine mammals (e.g., seals) and birds 
(e.g., double-crested cormorant), have not been quantified as 
extensively, making it more difficult to assess the importance of river 
herring in both the freshwater and marine food webs. As a result, some 
models found a significant negative effect from predation (Hartman 
2003, Heimbuch 2008), while other studies did not find an effect 
(Tuomikoski et al. 2008, Dalton et al. 2009).
    In addition to predators native to the Atlantic coast, river 
herring are vulnerable to invasive species such as the blue catfish 
(Ictalurus furcatus) and the flathead catfish (Pylodictis olivaris). 
These catfish are large, opportunistic predators native to the 
Mississippi River drainage system that were introduced into rivers on 
the Atlantic coast. They consume a wide range of species, including 
alosines, and ecological modeling on flathead catfish suggests they may 
have a large impact on their prey species (Pine 2003, Schloesser et al. 
2011). In August 2011, ASMFC approved a resolution calling for efforts 
to reduce the population size and ecological impacts of invasive 
species, and named blue and flathead catfish as species of concern due 
to their increasing abundance and potential impacts on native 
anadromous species. Non-native species are a particular concern because 
of the lack of native predators, parasites, and competitors to keep 
their populations in check.
Alewife and Blueback Herring Rangewide and All DPSs
    While alewife and blueback herring are important forage species, 
predators on the Northeast U.S. shelf are generally opportunistic 
(versus specialized) and will consume prey species in relation to their 
abundance in the environment. At high population levels, predation is 
likely not an issue; however, as populations decline, predation can 
become a larger threat, especially locally. Recent papers focus on the 
predation impacts of striped bass; however, the predatory impact by 
striped bass is likely localized to areas/times of overlap (Davis et 
al. 2012, Ferry and Mather 2012, Overton et al. 2008).
    The overall mean score for predation corresponded to a low ranking 
for both species rangewide and in all DPSs. The SRT noted uncertainty 
surrounding introduced or invasive piscivores such as snakeheads or 
blue catfish, which could have larger impacts if they dramatically 
expand their ranges. Alterations to fish behavior were also noted as 
components of predation that have not been well described in the 
literature to date. For example, little is known about how increased 
predator abundance (including an abundance of introduced predators) may 
influence anadromous fish species' ability to access fish passage. 
Additionally, the effects of predation can be highly localized, as 
noted in the striped bass predation examples provided above (Davis et 
al. 2012, Ferry and Mather 2012, Overton et al. 2008); therefore, while 
the SRT characterized the rangewide and DPS threat risk as low (alewife 
1.7-1.8, blueback herring 1.8-2.0), individual river populations may 
experience greatly increased threat levels.

D. Inadequacy of Existing Regulatory Mechanisms

    The ESA requires an evaluation of existing regulatory mechanisms to 
determine whether they may be inadequate to address threats to river 
herring. Numerous Federal (U.S. and Canadian), state and provincial, 
tribal, and inter-jurisdictional laws, regulations, and agency 
activities regulate impacts to alewife and blueback herring as wide-
ranging anadromous species. The status review SRT assessed the adequacy 
of regulatory mechanisms by examining regulations at three different 
governmental levels: international regulations, Federal regulations, 
and state regulations. Section 4.4 of the Status Review Report provides 
a summary of how these regulatory mechanisms--international

[[Page 28657]]

regulations, Federal regulations, and state regulations--may provide 
protections for river herring populations (NMFS 2019).
International Regulations
    The Canadian Department of Fisheries and Oceans (DFO) manages 
alewife and blueback herring fisheries that occur in the rivers of the 
Canadian Maritimes under the Fisheries Act (R.S.C., 1985, c. F-14). The 
Maritime Provinces Fishery Regulations include requirements when 
fishing for or catching and retaining river herring in recreational and 
commercial fisheries (DFO, 2006; https://laws-lois.justice.gc.ca).
    Commercial and recreational river herring fisheries in the Canadian 
Maritimes are regulated by license, fishing gear, season, and/or other 
measures (DFO 2001). Since 1993, DFO has issued few new licenses for 
river herring (DFO 2001). River herring are harvested by various gear 
types (e.g., gillnet, dip nets, trap), and the regulations depend upon 
the river and associated location (DFO 2001). The primary management 
measures are weekly closed periods and limitations on the total number 
of licenses (DFO 2001). Logbooks are issued to commercial anglers in 
some areas as a condition of the license, and pilot programs are being 
considered in other areas (DFO 2001). The management objective is to 
maintain harvest near long-term mean levels when no specific biological 
and fisheries information is available (DFO 2001).
    DFO stated that additional management measures may be required if 
increased effort occurs in response to stock conditions or favorable 
markets, and noted that fishery exploitation rates have been above 
reference levels, while fewer licenses are fished than have been issued 
(DFO 2001). In 2001, DFO reported that in some rivers river herring 
were being harvested at or above reference levels (e.g., Miramichi), 
while in other rivers river herring were being harvested at or below 
the reference point (e.g., St. John River at Mactaquac Dam). The DFO 
(2001) believed precautionary management involving no increase or 
decrease in exploitation was important for Maritime river herring 
fisheries, given that biological and harvest data were not widely 
available. DFO (2001) added that river-specific management plans based 
on stock assessments should be prioritized over general management 
initiatives.
    Eastern New Brunswick appeared to be the only area in the Canadian 
Maritimes with a river herring integrated fishery management plan (DFO 
2012). The DFO used Integrated Fisheries Management Plans (IFMPs) to 
guide the conservation and sustainable use of marine resources (DFO 
2010). An IFMP managed a fishery in a given region by combining the 
best available science on the species with industry data on capacity 
and methods for harvesting (DFO 2010). The 6-year management plan 
(2007-2012) for river herring for Eastern New Brunswick was implemented 
in conjunction with annual updates to specific fishery management 
measures (e.g., seasons). It is unclear if this management plan has 
been updated or discontinued.
Alewife and Blueback Herring Rangewide and All DPSs
    The inadequacy of regulatory mechanisms to control the harvests of 
alewife and blueback herring was once considered a significant threat 
to their populations. The best available information indicates limited 
fishing is permitted in Canada, though uncertainties remain about the 
efficacy of international fishing regulations. The inadequacy of 
international regulations was ranked rangewide as low (alewife 2.1, 
blueback herring 2.0) contribution to extinction risk category. The 
threat was also ranked as low for the Aw-Northern New England (2.3), 
Aw-Southern New England (2.1), Aw-Mid Atlantic (2.0), Bb-Canada/
Northern New England (2.3), and Bb-Mid Atlantic (2.0). SRT members 
ranked the threat of international regulations as a slightly higher 
risk with a medium ranking (2.7) within the Aw-Canada DPS. This DPS is 
located entirely within Canada; therefore, international regulations 
are predicted to directly affect this DPS more than the other DPSs. 
Canada does not routinely separate river herring species and less 
reported monitoring compared to the United States.
Federal Regulations
    River herring stocks are managed under the authority of section 
803(b) of the Atlantic Coastal Fisheries Cooperative Management Act 
(Atlantic Coastal Act, 16 U.S.C 5101 et seq.), which states that, in 
the absence of an approved and implemented Fishery Management Plan 
(FMP) under the Magnuson-Stevens Fishery Conservation and Management 
Act (MSA, 16 U.S.C. 1801 et seq.) and, after consultation with the 
appropriate Fishery Management Council(s), the Secretary of Commerce 
may implement regulations to govern fishing in the EEZ, i.e., from 3 to 
200 nautical mi (nm) (~5.6-370 km) offshore. The regulations must be: 
(1) Compatible with the effective implementation of an American Shad 
and River Herring Interstate Fisheries Management Program (ISFMP) by 
the ASMFC; and (2) consistent with the national standards set forth in 
section 301 of the MSA.
    The MSA is the primary law governing marine fisheries management in 
Federal waters. The MSA was first enacted in 1976 and amended in 1996 
and 2007. Most notably, the MSA aided in the development of the 
domestic fishing industry by phasing out foreign fishing. To manage the 
fisheries and promote conservation, the MSA created eight regional 
fishery management councils. The 1996 amendment focused on rebuilding 
overfished fisheries, protecting essential fish habitat, and reducing 
bycatch. The 2007 amendment mandated the use of annual catch limits and 
accountability measures to end overfishing, provided for widespread 
market-based fishery management through limited access privilege 
programs, and called for increased international cooperation.
    The MSA requires that Federal FMPs contain conservation and 
management measures that are consistent with the ten National 
Standards. National Standard 9 states that conservation and management 
measures shall, to the extent practicable, (A) minimize bycatch and (B) 
to the extent bycatch cannot be avoided, minimize the mortality of such 
bycatch. The MSA defines bycatch as fish that are harvested in a 
fishery, but which are not sold or kept for personal use. This includes 
economic discards and regulatory discards. Alewife and blueback herring 
are encountered as both bycatch and incidental catch in Federal 
fisheries. While there is no directed fishery for alewife or blueback 
herring in Federal waters, they co-occur with other species that have 
directed fisheries (Atlantic mackerel, Atlantic herring, whiting) and 
are either discarded or retained in those fisheries.
    Commercial fisheries that incidentally catch river herring in 
Federal waters are managed by the New England Fisheries Management 
Council (NEFMC), the Mid-Atlantic Fishery Management Council (MAFMC), 
and NMFS. Several management measures intended to reduce commercial 
fisheries interactions with river herring and shad in Federal waters 
are currently in place. These management measures have been developed 
by the NEFMC, the MAFMC, the Greater Atlantic Regional Fisheries 
Office, and the Northeast Fisheries Science Center (NEFSC) and 
promulgated through Federal fishery management plans (FMP) for Atlantic 
Herring and Atlantic Mackerel, Squid, and Butterfish.
    The types of management measures currently in place or being 
considered

[[Page 28658]]

fall into several general categories: Limitations on total river 
herring and shad catch; improvements to at-sea sampling by fisheries 
observers; river herring avoidance program; increased monitoring of the 
Atlantic herring fishery; and including river herring in a Federal FMP.
    Vessels fishing for Atlantic mackerel and Atlantic herring can 
encounter river herring and shad. The MAFMC and NEFMC recommended river 
herring and shad catch caps for these fisheries, and NMFS implemented 
catch caps for these fisheries beginning in 2014 to minimize bycatch 
and incidental catch. Managers do not currently have enough data to 
determine biologically based river herring and shad catch caps or to 
assess the potential effects of such catch caps on river herring and 
shad populations coastwide. However, the Councils and NMFS find that 
river herring and shad catch caps provide a strong incentive for the 
mackerel and herring fleets to continue avoiding river herring and 
shad. These catch caps are intended to allow for the full harvest of 
the mackerel and herring annual catch limits while reducing river 
herring and shad incidental catch and bycatch.
    In December 2014, NMFS implemented river herring and shad catch 
caps for the Atlantic herring fishery for 2014-2015, and allowed the 
NEFMC to set river herring and shad catch caps and associated measures 
in future years though specifications or frameworks, as appropriate (79 
FR 71960, December 4, 2014). Catch of river herring and shad on fishing 
trips that landed more than 6,600 lbs (3 mt) of Atlantic herring 
counted towards the caps. Caps were area- and gear-specific. Upon a 
NMFS determination that 95 percent of a river herring and shad cap has 
been harvested, a 2,000-lb Atlantic herring possession limit for that 
area and gear would become effective for the remainder of the fishing 
year. This possession limit has been imposed twice due to achieving the 
river herring and shad catch caps (both for midwater trawl vessels in 
2018) since the catch caps were implemented in 2014. The river herring 
and shad catch caps for the Atlantic herring fishery for 2019 (set in 
the 2019 Adjustment to the Atlantic Herring Specifications; 84 FR 2760, 
February 8, 2019) are as follows:
    A midwater trawl cap for the Gulf of Maine Catch Cap Area (76.7 mt) 
(169,094 lbs);
    A midwater trawl cap for Cape Cod Catch Cap Area (32.4 mt) (71,430 
lbs);
    A midwater trawl cap for Southern New England Mid-Atlantic Catch 
Cap Area (129.6 mt) (285,719 lbs); and
    A bottom trawl cap for Southern New England Catch Cap Area (122.3 
mt) (269,625 lbs).
    The river herring and shad catch cap for the mackerel fishery is 
set through annual specifications. NMFS set the 2018 river herring and 
shad cap for the mackerel fishery at 82 mt (180,779 lbs) as part of a 
final rule to implement the 2016 through 2018 Atlantic mackerel 
specifications (81 FR 24504, April 4, 2016). The 2018 Atlantic mackerel 
specifications, including the river herring and shad catch cap, apply 
to 2019 until Framework 13 to the Atlantic mackerel, squid, and 
butterfish FMP is finalized (84 FR 26634, June 7, 2019). Catch of river 
herring and shad on fishing trips that land greater than 20,000 lbs of 
mackerel count towards the cap. If NMFS determines that 95 percent of 
the river herring and shad cap has been harvested, a 20,000-lb mackerel 
possession limit will become effective for the remainder of the fishing 
year. In 2019, the river herring and shad cap was met in March, and the 
Atlantic mackerel possession limit was reduced starting on March 12, 
2019 (84 FR 8999; March 13, 2019). The 2019 river herring and shad 
catch cap will be adjusted in the final rule implementing Framework 
Adjustment 13 to the Atlantic Mackerel, Squid, and Butterfish Fishery 
Management Plan. Framework 13 proposes an initial 89-mt (196,211 lbs) 
catch cap. The cap could be increased to 129 mt (284,396 lbs) if 
commercial mackerel landings exceed 10,000 mt (22,046,200 lbs). The 
increased cap reflects a proportional increase to the proposed increase 
in the Atlantic mackerel commercial landings limit. Framework 13 will 
be in place by fall of 2019.
    Under the MSA, there is a requirement to describe and identify 
Essential Fish Habitat (EFH) in each Federal FMP. EFH is defined as 
those waters and substrate necessary to fish for spawning, breeding, 
feeding, or growth to maturity. The rules promulgated by the NMFS in 
1997 and 2002 further clarify EFH with the following definitions: (1) 
Waters--aquatic areas and their associated physical, chemical, and 
biological properties that are used by fish and may include aquatic 
areas historically used by fish where appropriate; (2) substrate--
sediment, hard bottom, structures underlying the waters, and associated 
biological communities; (3) necessary--the habitat required to support 
a sustainable fishery and the managed species' contribution to a 
healthy ecosystem; and (4) spawning, breeding, feeding, or growth to 
maturity--stages representing a species' full life cycle (62 FR 19723; 
April 23, 1997 and 67 FR 2343; January 17, 2002).
    EFH has not been designated for alewife or blueback herring, though 
EFH has been designated for numerous other species in the Northwest 
Atlantic. Measures to improve habitats and reduce impacts resulting 
from those EFH designations may benefit river herring either directly 
or indirectly. Conservation measures implemented in response to the 
designation of Atlantic salmon EFH and Atlantic herring EFH likely 
provide the most conservation benefit to river herring over any other 
EFH designation. Habitat features used for spawning, breeding, feeding, 
growth, and maturity by these two species encompasses many of the 
habitat features necessary for river herring throughout their life 
history. The geographic range in which river herring may benefit from 
the designation of Atlantic salmon EFH extends from Connecticut to the 
Maine/Canada border. The geographic range in which river herring may 
benefit from the designation of Atlantic herring EFH designation 
extends from the Maine/Canada border to Cape Hatteras.
    The Atlantic salmon EFH includes most freshwater, estuary and bay 
habitats historically accessible to Atlantic salmon from Connecticut to 
the Maine/Canada border (NEFMC 2006). Many of the estuary, bay and 
freshwater habitats within the current and historical range of Atlantic 
salmon incorporate habitats used by river herring for spawning, 
migration, and juvenile rearing. Among Atlantic herring EFHs are the 
pelagic waters in the Gulf of Maine, Georges Bank, Southern New 
England, and mid-Atlantic south to Cape Hatteras out to the offshore 
U.S. boundary of the EEZ (NEFMC 1998). These areas incorporate nearly 
all of the U.S. marine areas most frequently used by river herring for 
growth and maturity. Accordingly, conservation measures aimed at 
improving or minimizing impacts to habitats in these areas for the 
benefit of Atlantic salmon or Atlantic herring may provide similar 
benefits to river herring.
    A number of other Federal laws provide habitat-related protections 
that may benefit river herring. Further information on the protections 
associated with these laws is summarized in section 4.4.2 of the Status 
Review Report (NMFS 2019).
Alewife and Blueback Herring Rangewide and All DPSs
    The inadequacy of regulatory mechanisms to control the harvests of 
alewife and blueback herring was once considered a significant threat 
to their

[[Page 28659]]

populations. However, the best available information indicates an 
adequate regulatory framework now exists within ASMFC to effectively 
manage alewife and blueback herring directed harvest, and there are 
multiple forms of habitat-related regulatory protections for these 
fish. The SRT ranked Federal regulations in the medium category 
rangewide (2.6) and for most DPSs (2.7-2.8). The Aw-Canada DPS was 
ranked as low (2.3), because this DPS fell entirely within Canada where 
U.S. Federal regulations may have slightly less influence in comparison 
to other areas overlapping or within the United States.
    SRT members noted that in the framework of inter-jurisdictional 
management, these fish may not receive as much protection as more 
commercially valuable species. The SRT noted uncertainty around future 
catch caps (catch caps are scheduled to be recalculated in 2019) 
monitoring coverage, and the use of bycatch avoidance programs.
    The SRT also considered other Federal non-fishery regulations such 
as the Clean Water Act and the Federal Power Act. Despite current 
regulations, habitat alterations, such as dams and culverts, excess 
nutrient loading and sedimentation due to poor land use practices, 
dredging, and coastal development, continue to affect both marine and 
freshwater habitats, potentially limiting population growth. The SRT 
also noted that habitat improvements related to long-term regulatory 
processes, such as relicensing of hydropower facilities through the 
Federal Energy Regulatory Commission that may result in dam removal or 
fish passage facilities, would not be immediately realized.
    In tandem with the predicted effects of climate change, such as 
increased precipitation and warming ocean temperatures, the importance 
of Federal regulations to alewife and blueback herring sustainability 
will likely increase in the future.
State Regulations
    A historical review of state regulations was compiled and published 
in Volume I of the stock assessment (ASMFC 2012, 2017b); an excerpt has 
been added to section 4.4.3 of the Status Review Report, which provides 
an overview of state regulations that may provide protections to river 
herring (NMFS 2019).
Alewife and Blueback Herring Rangewide and All DPSs
    SRT members noted that, as with Federal regulations, existing state 
regulations related to fisheries provide structure for protection of 
river herring through ASMFC. However, like Federal regulations 
(discussed above), state regulations related to habitat loss remain a 
large concern for the future of the species with the predicted effects 
of climate change, especially since spawning and nursery habitats are 
found in state waters.
    The SRT expressed uncertainty about the effectiveness of state 
regulations related to the reliability of enforcement of existing state 
laws and concerns for non-fishing regulations that authorize 
modifications to coastal and riverine habitat in the face of increasing 
populations and coastal development. State regulations were ranked in 
the medium (alewife, 1.6-2.7; blueback herring 2.5-2.7) contribution to 
extinction risk category, with state regulations having the lowest 
impact on the Aw-Canada DPS (1.6).

E. Other Natural or Manmade Factors Affecting the Species' Continued 
Existence

    The Status Review identifies four different threats that may 
contribute to other natural or manmade factors affecting the alewife 
and blueback herring continued existence: artificial propagation/
stocking, competition, hybrids, and landlocked populations.
Artificial Propagation
    Genetics data have shown that stocking alewife and blueback herring 
within and out of basin in Maine has had an impact on the genetic 
groupings within Maine (McBride et al. 2014); however, the extent to 
which this poses a threat to river herring locally or coast-wide is 
unknown. Stocking river herring directly affects a specific river/
watershed system for river herring in that it can result in passing 
fish above barriers into suitable and new spawning and rearing habitat 
and in expanding populations into other watersheds.
    The alewife restoration program in Maine focuses primarily on 
stocking in Androscoggin and Kennebec watersheds. The highest number of 
stocked fish was 2,211,658 in 2009 in the Sebasticook River and 93,775 
in 2008 in the Kennebec River. In 2017, the majority of fish were 
stocked in the Kennebec (150,121), Androscoggin (97,083), and 
Sebasticook (50,450) watersheds. An additional 23,784 adult fish were 
stocked into locations out of basin, using fish collected from the 
Androscoggin (16,584) or Kennebec (7,200) Rivers. The Union River 
fishery in Ellsworth, Maine, is sustained through the stocking of adult 
alewives above the hydropower dam at the head-of-tide. Fish passage is 
not currently required at this dam, but fish are transported around the 
dam to spawning habitat in two lakes. Since 2015, the annual adult 
stocking rate has been 315,000 fish. Adult river herring are trapped at 
commercial harvest sites below the dam and trucked to waters upstream 
of the dam. The highest number of stocked fish in the Union River was 
1,238,790 in 1986. In the Penobscot River watershed, over 48,000 adult 
fish were stocked into lakes in 2012 using fish collected from the 
Kennebec (39,650) and Union Rivers (8,998).
    In New Hampshire, from 1984 to 2015, approximately 55,600 adult 
river herring have been stocked in coastal rivers (Cocheco, Winnicut, 
Exeter, Lamprey, and Salmon Falls) (ASMFC 2017b). The transfers that 
occurred were either in[hyphen]basin transfers to previously unoccupied 
habitat or out[hyphen]of[hyphen]basin transfers to help supplement 
spawning runs in rivers with lower return numbers. Fish were stocked 
from various rivers including the Connecticut, Cocheco, Lamprey, 
Kennebec, and Androscoggin Rivers.
    The Massachusetts Division of Marine Fisheries (DMF) conducts a 
trap and transport-stocking program for alewife and blueback herring in 
Massachusetts. The three major objectives are to: (1) Maintain and 
enhance existing populations, (2) restore historically important 
populations and (3) create new populations where feasible. Stocking of 
gravid river herring where river access has been provided or improved 
is generally conducted for three or more consecutive years per system. 
Prior to the moratorium in 2012, the program transported between 30,000 
and 50,000 fish per year into 10-15 different systems. Since the 
moratorium, a DMF stocking protocol was developed and implemented in 
2013 that provided criteria for stocking decisions and a focus to allow 
remnant populations present at restoration sites to naturally 
recolonize habitat prior to the introduction of donor stock genetics. 
The protocol has reduced stocking activity, with most recent efforts 
occurring within drainage, moving fish upstream past multiple 
obstructions to the headwater-spawning habitat (ASMFC 2017b).
    Rhode Island's Department of Environmental Management (DEM) 
conducts trap and transport utilizing out[hyphen]of[hyphen]state and 
in[hyphen]state broodstock sources to supplement existing runs or 
restore extirpated systems where habitats have been restored. Gilbert 
Stuart River was Rhode Island's only broodstock source for river 
herring between 1966 and 1972, and today it is

[[Page 28660]]

still an important source. Nonquit River has not been utilized as a 
broodstock source, but was considered in 2001, prior to the drastic 
decrease in spawning stock size. Between 1990 and 1993, both Gilbert 
Stuart and Nonquit Rivers received supplemental stockings from the 
Agwam and Bourne rivers located in Massachusetts. Since 2001, it has 
become increasingly difficult to obtain available out-of-state and in-
state broodstock sources, due to the declines in river herring run 
sizes. In 2015, the following locations were stocked: Kickemuit, Turner 
Reservoir, Woonsquatucket, Potowamut, and Watchaug with 1,000 fish 
each, and Pawtucket with 2,000 fish.
    The Edenton National Fish Hatchery (NFH) in North Carolina and the 
Harrison Lake NFH in Virginia have propagated blueback herring for 
restoration purposes. Edenton NFH is currently rearing blueback herring 
for stocking in Indian Creek and Bennett's Creek in the Chowan River 
watershed in Virginia.
Alewife and Blueback Herring Rangewide and DPSs
    Artificial propagation ranked as a very low threat to alewife and 
blueback rangewide (alewife, 1.2; blueback herring, 1.3) and in all 
DPSs (alewife, 1.2-1.3; blueback herring, 1.2), except for the Aw-
Northern New England DPS (1.7) and Bb-Canada/Northern New England DPS 
(1.8) where artificial propagation was ranked as a low threat.
    SRT members noted that artificial propagation/stocking has 
detrimental effects on river herring populations. First, hatchery 
efforts often take focus and importance away from on-the-ground issues 
with a fish and its habitat, which would be harmful in the long term. 
Second, artificial propagation would almost certainly lead to a 
significant loss of genetic diversity, which is already likely 
substantially lower than most times in the past.
    The SRT ranked the threat of artificial propagation/stocking 
slightly higher in the alewife Aw-Northern New England DPS and the Bb-
Canada/Northern New England DPS compared to the rangewide and other 
DPS' risk scores. As noted in the abundance discussion of the 
Extinction Risk Assessment within the Status Review Report (NMFS 2019), 
the persistence of many populations in Maine are reliant on active 
management strategies (e.g. truck and transport, fish lifts, fishway 
maintenance) rather than on volitional passage. Therefore, a change in 
management strategy, especially related to stocking/truck and transport 
would have dramatic impacts on these runs, and therefore raises 
uncertainty associated with this area. However, there is no information 
to suggest that these stocking efforts would be discontinued, as these 
efforts are economically and recreationally important to these areas. 
The intensive stocking in this region has likely reduced genetic 
variability in the U.S. portion of this DPS.
Competition
    Intra- and inter-specific competition were considered as potential 
natural threats to alewife and blueback herring. The earlier spawning 
time of alewife may lead to differences from blueback herring in prey 
selection, given that these fish become more omnivorous with increasing 
size (Klauda et al. 1991a). This could lead to differences in prey 
selection given that juvenile alewife would achieve a greater age and 
size earlier than blueback herring. Juvenile American shad are reported 
to focus on different prey than blueback herring (Klauda et al. 1991b). 
However, Smith and Link (2010) found few differences between American 
shad and blueback herring diets across geographic areas and size 
categories; therefore, competition between these two species may be 
occurring. Cannibalism has been observed (rarely) in landlocked systems 
with alewife. Additionally, evidence of hybridization exists between 
alewife and blueback herring, but the implications of this are unknown. 
Competition for habitat or resources has not been documented with 
alewife/blueback herring hybrids, as there is little documentation of 
hybridization in published literature, but given the unknowns about 
their life history, it is possible that competition between non-hybrids 
and hybrids could be occurring.
Alewife and Blueback Herring Rangewide and All DPSs
    Competition among fish species is difficult to determine because it 
requires demonstration of a limiting resource(s). Given the diet and 
generalist nature of alewife and blueback herring, prey are likely not 
limiting. However, there is some possibility that space could be 
limiting for these species (e.g. dams, poor fish passage, etc.). 
Competition ranking fell between very low to low rangewide and for all 
DPSs (alewife, 1.4-1.5; blueback herring, 1.4-1.6).
Hybrids
    Genetic studies indicate that interbreeding, or hybridization, 
between alewife and blueback herring may be occurring in some instances 
where populations overlap (see for example, NMFS 2012a). Though 
interbreeding among closely related species is relatively uncommon, it 
does occasionally occur (Levin 2002) and has been reported at rates of 
1.8 to 2.4 percent (Hasselman et al. 2014, Hasselman et al. 2016). Most 
often, different reproductive strategies, home ranges, and habitat 
differences of closely related species prevent interbreeding or keep 
interbreeding at very low levels. In circumstances where interbreeding 
does occur, natural selection often keeps hybrids in check because 
hybrids are typically less fit in terms of survival or their ability to 
breed successfully (Levin 2002). Other times, environmental conditions 
can provide an environment where hybrids can thrive. Though available 
evidence indicates that some alewife and blueback herring hybrids are 
found in the wild (Hasselman et al. 2014, Hasselman et al. 2016) there 
is not enough evidence to conclude whether or not hybridization poses a 
threat to one or both species of river herring.
Alewife and Blueback Herring Rangewide and All DPSs
    Hybrids have likely been a natural occurrence throughout the 
history of alewife and blueback herring. In most cases, they occur at 
low to very low rates in natural and impacted systems (McBride et al. 
2014, Hasselman et al. 2014). The SRT ranked hybrids in the very low 
category rangewide and for all DPSs (1.0-1.1).
Landlocked Populations
    Alewives and blueback herring maintain two life history variants: 
anadromous and landlocked. It is thought that they diverged relatively 
recently (300 to 5,000 years ago) and are now discrete from each other. 
Landlocked alewife populations occur in many freshwater lakes and ponds 
from Canada to North Carolina as well as the Great Lakes (Rothschild 
1966, Boaze and Lackey 1974). Landlocked blueback herring occur mostly 
in the southeastern United States and the Hudson River drainage. At 
this time, there is no substantive information that would suggest that 
landlocked populations can or would revert to an anadromous life 
history if they had the opportunity to do so.
    The discrete life history and morphological differences between the 
two life history variants provide substantial evidence that upon 
becoming landlocked, landlocked herring populations become largely 
independent and separate from anadromous populations. Landlocked 
populations and anadromous populations occupy largely separate 
ecological niches, especially as related to their contribution to 
freshwater,

[[Page 28661]]

estuary and marine food webs (Palkovacs and Post 2008). Thus, the 
existence of landlocked life forms does not appear to pose a 
significant threat to the anadromous forms.
Alewife and Blueback Herring Rangewide and All DPSs
    Landlocked populations are discrete from anadromous blueback 
herring, occupy different ecological niches, and have differing 
morphological features. The SRT ranked landlocked populations as a very 
low contribution to extinction risk rangewide and for all DPSs.

Overall Risk Summary

    Guided by the results from the demographics risk analysis as well 
as threats assessment, the SRT members used their informed professional 
judgment to make an overall extinction risk determination for each 
species, now and in the foreseeable future. The SRT used a ``likelihood 
analysis'' to evaluate the overall risk of extinction. Each SRT member 
had 10 likelihood points to distribute among the following overall 
extinction risk categories: low risk, moderate risk, or high risk. 
These categories are described in Section 6.1.4 Overall Level of 
Extinction Risk Analysis of the Status Review Report (NMFS 2019). As 
noted earlier, the team was asked to review the demographic risks and 
threats to the species, and to consider and discuss how these threats, 
acting in combination, may increase risk to the species. For example, 
the SRT noted how climate variability may enhance sedimentation in 
river systems, increasing the threat associated with poor water 
quality, and how climate change effects may enhance the threat of water 
withdrawal in regions. The SRT noted higher uncertainty around how the 
combination of such threats may impact the two species, and this 
uncertainty is reflected in a wider range in their distribution of 
likelihood points for these threats (largely those associated with 
habitat-related threats). The SRT's uncertainty about how the 
demographic risks and the combination of threats may impact the species 
(or DPSs) is also reflected in a wider distribution of likelihood 
points for the overall risk to the species.
    We have independently reviewed the best available scientific and 
commercial information, including the status review report (NMFS 2019), 
and other published and unpublished information reviewed by the SRT. As 
described earlier, an endangered species is ``any species which is in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species is one ``which is likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range.'' We reviewed the results of the SRT 
and concurred with the SRT's findings regarding extinction risk. We 
then applied the statutory definitions of ``threatened species'' and 
``endangered species'' to the SRT findings and other available 
information to determine if listing alewife or blueback herring 
rangewide or in any of their respective DPSs was warranted.

Alewife

    The mean scores based on the SRT members' individual scores 
indicate that the level of extinction risk to the alewife rangewide is 
low, with 75 percent of the SRT members' likelihood points allocated to 
the low risk category. The SRT allocated 22 percent of their likelihood 
points to the moderate extinction risk category. The SRT allocated 3 
percent of their likelihood points to the high extinction risk 
category. SRT members attributed the high extinction risk points to 
concerns associated with the species' complex anadromous fish life 
history, uncertainty in climate change and vulnerability, incidental 
catch, potential habitat modification (e.g. increased coastal 
development and water use), and concern about the adequacy of current 
and future regulatory mechanisms, including fisheries rangewide. As 
noted throughout the Extinction Risk Analysis section, the SRT 
expressed considerable uncertainty about the demographics risk to the 
species and the threats, with a majority of the mean scores for ranking 
threats falling between the very low (1) to medium (3) categories. 
Overall the SRT acknowledged that alewife are at historical low levels, 
but noted that improved fisheries management efforts in recent years 
have reduced fishing mortality rates in alewife stocks and that 
hundreds of habitat improvement projects have been completed in the 
past 20 years. Many relatively robust populations of alewife exist, and 
genetic data show connectivity among populations (genetic continuum 
along the coastline) despite regional groupings.
    Given this level of extinction risk, which is based on an 
evaluation of the contribution of alewife's demographic parameters and 
threats to extinction risk, we have determined that the alewife 
rangewide does not meet the definition of an endangered or threatened 
species and, as such, listing under the ESA is not warranted at this 
time.
    SRT members also applied the same likelihood point method to each 
alewife DPS. The mean overall risk scores for alewife in the Aw-Canada 
DPS correspond to a 77 percent likelihood of a low risk and 23 percent 
moderate risk of extinction. The mean overall risk scores for alewife 
in the Aw-Northern New England DPS correspond to a 74 percent 
likelihood of a low risk and 26 percent moderate risk of extinction. 
The mean overall risk scores for alewife in the Aw-Southern New England 
DPS correspond to a 69 percent likelihood of a low risk and 31 percent 
moderate risk of extinction. The mean overall risk scores for alewife 
in the Aw-Mid-Atlantic DPS correspond to a 70 percent likelihood of a 
low risk and 30 percent moderate risk of extinction.
    Given this level of extinction risk for all alewife DPSs, which is 
based on an evaluation of the contribution of demographic parameters 
and threats to extinction risk, we have determined that the Canada, Aw-
Northern New England, Aw-Southern New England and Aw-Mid-Atlantic DPSs 
do not meet the definition of an endangered or threatened species and, 
as such, listing under the ESA is not warranted at this time.

Blueback Herring

    For blueback herring rangewide, SRT members indicated that there 
was a 66 percent low risk of extinction, a 30 percent moderate risk of 
extinction, and a 4 percent high risk of extinction. SRT members 
attributed the high extinction points to concerns associated with the 
complex anadromous fish life history, uncertainty in climate change and 
vulnerability, incidental catch, potential habitat modification (e.g. 
increased coastal development and water use), and concern about the 
adequacy of current and future regulatory mechanisms, including 
fisheries rangewide. As noted throughout the Extinction Risk Analysis 
section, the SRT expressed considerable uncertainty about the 
demographics risk to the species and the threats, with a majority of 
the mean scores for ranking threats falling between the very low (1) to 
medium (3) categories. The SRT noted blueback herring have been 
subjected to habitat impacts for centuries and to considerable fishing 
pressure for many decades. The SRT also acknowledged that blueback 
herring are at historically low levels, but noted that improved 
fisheries management efforts in recent years have reduced fishing 
mortality rates for blueback herring stocks and that hundreds of 
habitat improvement projects have been completed in the past 20 years. 
While over one third of

[[Page 28662]]

the SRT's allocation points were in the moderate/high categories, 
indicating that blueback herring are at a greater risk of extinction 
compared to alewives due to lower overall abundances, increased 
vulnerability to anthropogenic disturbances in combination with climate 
change, greater distances between populations, poorer performance at 
fishways, and uncertainties surrounding accurate distribution 
information rangewide, a majority of the points were still allocated to 
the low risk category based on resilient life history traits and 
current abundance information.
    Given this level of extinction risk, which is based on an 
evaluation of the contribution of blueback herring's demographic 
parameters and threats to extinction risk, we have determined that the 
blueback herring rangewide does not meet the definition of an 
endangered or threatened species and, as such, listing under the ESA is 
not warranted at this time.
    SRT members also applied the same likelihood point method to each 
blueback herring DPS. The mean overall risk scores for blueback herring 
in the Bb-Canada/Northern New England DPS correspond to a 67 percent 
low risk of extinction, a 30 percent moderate risk of extinction, and a 
3 percent high risk of extinction. The mean overall risk scores for 
blueback herring in the Bb-Mid-Atlantic DPS correspond to a 69 percent 
low risk of extinction, a 30 percent moderate risk of extinction, and a 
1 percent high risk of extinction. The mean overall risk scores for 
blueback herring in the Bb-Southern Atlantic DPS correspond to a 69 
percent low risk of extinction, a 30 percent moderate risk of 
extinction, and a 1 percent high risk of extinction.
    Given this level of extinction risk for all blueback herring DPSs, 
which is based on an evaluation of the contribution of blueback 
herring's demographic parameters and threats to extinction risk, we 
have determined that the Bb-Canada/Northern New England, Bb-Mid-
Atlantic and Bb-Southern Atlantic DPSs do not meet the definition of an 
endangered or threatened species and, as such, listing under the ESA is 
not warranted at this time.

Significant Portion of Its Range

    As the definitions of ``endangered species'' and ``threatened 
species'' make clear, the determination of extinction risk can be based 
on either assessment of the rangewide status of the species, or the 
status of the species in a ``significant portion of its range'' (SPR). 
Because the SRT determined that alewife and blueback herring are at a 
low risk of extinction rangewide and in each DPS, we asked the SRT to 
also consider whether a significant portion of the range may exist in 
either species and whether the species in those portions are in danger 
of extinction now or in the foreseeable future (79 FR 37578; July 1, 
2014).
    In 2014, the Services adopted a joint SPR Policy that outlines a 
step-wise analysis to be used to determine whether a portion of the 
range is ``significant.'' (79 FR 37578; July 1, 2014). The SRT followed 
the process outlined in the policy when it considered whether any 
portions of the ranges of alewife and blue back herring are 
significant.
    Consistent with the policy, when we conduct an SPR analysis, we 
first identify any portions of the range that warrant further 
consideration. The range of a species can theoretically be divided into 
portions in an infinite number of ways. However, as noted in the 
policy, there is no purpose to analyzing portions of the range that are 
not reasonably likely to be significant or in which a species may not 
be endangered or threatened. To identify only those portions that 
warrant further consideration we consider whether there is substantial 
information indicating that (1) the portions may be significant, and 
(2) the species may be in danger of extinction in those portions or is 
likely to become so within the foreseeable future. We emphasize that 
answering these questions in the affirmative is not a determination 
that the species is endangered or threatened throughout a significant 
portion of its range; rather, it is a step in determining whether a 
more detailed analysis of the issue is required (79 FR 37578; July 1, 
2014). Making this preliminary determination triggers a need for 
further review, but does not prejudge whether the portion actually 
meets these standards such that the species should be listed.
    If this preliminary determination identifies a particular portion 
or portions for potential listing, those portions are then fully 
evaluated under the ``significant portion of its range'' authority to 
determine whether the portion in question is biologically significant 
to the species and whether the species is endangered or threatened in 
that portion.
    The SPR Policy further provides that, depending on the particular 
facts of each situation, we may find it is more efficient to address 
the significance issue first, but in other cases, it will make more 
sense to examine the status of the species in the potentially 
significant portions first. Whichever question is asked first, an 
affirmative answer is required to proceed to the second question. (79 
FR 37587). If we determine that a portion of the range is not 
``significant,'' we will not need to determine whether the species is 
endangered or threatened there; if we determine that the species is not 
endangered or threatened in a portion of its range, we will not need to 
determine if that portion is ``significant.'' Thus, if the answer to 
the first question is negative--whether it addresses the significance 
question or the status question--then the analysis concludes, and 
listing is not warranted.
    In making a determination of ``significance,'' we consider the 
contribution of the individuals in that portion to the viability of the 
species. The SPR Policy established a threshold for ``significance'' 
(i.e., the portion's contribution to the viability is so important 
that, without the members in that portion, the species would be in 
danger of extinction or likely to become so in the foreseeable future). 
In two recent District Court cases challenging listing decisions made 
by the USFWS, the definition for ``significant'' in the SPR Policy was 
invalidated. The courts held that the threshold component of the 
definition was ``impermissible,'' because it set too high a standard. 
Specifically, the courts held that under the threshold in the policy, a 
species would never be listed based on the status of the portion, 
because in order for a portion to meet the threshold, the species would 
be threatened or endangered rangewide. 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). Accordingly, 
while the SRT used the threshold identified in the policy, which was 
effective at the time the SRT met, our analysis does not rely on the 
definition in the policy, but instead responds to the second Desert 
Survivors case (336 F. Supp. 3d 1131, 1134-1136; N.D. CA August, 2018), 
in which the Court stated that there is no geographic limitation to the 
holding that the definition of ``significant'' is impermissible. As 
such, our analysis independently construes and applies a biological 
significance standard, drawing from the record developed by the SRT 
with respect to viability characteristics (i.e., abundance, 
productivity, spatial distribution, and genetic diversity) of the 
members of the portions, in determining if a portion is a significant 
portion of a species' range.
    As described previously, based on abundance estimates in the recent 
stock assessment update (ASMFC 2017a) and the SRT's extinction risk 
results, the

[[Page 28663]]

SRT determined that alewife are at low risk of extinction rangewide and 
in each of the four DPSs. Applying the SPR Policy to the alewife, the 
SRT first evaluated whether there is substantial information indicating 
that any portions of the species' range are threatened or endangered. 
In light of the earlier findings that all four DPSs, which span the 
range of this species, are at low risk of extinction, and finding no 
other evidence of areas within the species range where there is a 
concentration of threats, the SRT did not identify portions of the 
alewife range that were at a high risk of extinction, nor could the SRT 
identify threats that significantly affected one portion of the range.
    The SRT then applied the SPR Policy to each alewife DPS. In other 
words, the SRT evaluated whether there is substantial information 
indicating that any portions of any singular DPS may have a 
concentration of threats and should be further evaluated under the SPR 
Policy. After reviewing the best available data, the SRT found no 
information to suggest that any portion of the Aw-Canada, Aw-Northern 
New England, Aw-Southern New England, or Aw-Mid-Atlantic DPSs stood out 
as having a heightened risk of extinction now or in the foreseeable 
future, and the SRT found no reason to further evaluate areas of any 
particular DPS under the SPR Policy.
    After reviewing the SRT's findings, we agree that there is no 
evidence to suggest that alewife are at heightened risk of extinction, 
now or in the foreseeable future, in any particular area rangewide or 
in a DPS. Thus, we find no evidence that a significant portion of this 
species or one the DPSs is threatened or endangered.
    As discussed in the Assessment of Extinction Risk section 
previously, the SRT determined that rangewide blueback herring have a 
66 percent low risk of extinction, a 30 percent moderate risk of 
extinction and a 4 percent high risk of extinction. Applying the SPR 
Policy to the blueback herring, the SRT first identified geographic 
areas where there may be a concentration of threats. The SRT then 
evaluated whether there is substantial information indicating that any 
of these portions of the species' range may be facing a risk of 
extinction now or in the foreseeable future.
    The SRT specifically considered whether recent information about 
the Bb-Mid-Atlantic stock complex of blueback herring suggested this 
region of the range may constitute an SPR. The SRT considered threats 
to this region (see previous Evaluation of Threats section). While some 
threats were ranked slightly higher numerically in the Mid-Atlantic 
compared to other areas (including, but not limited to water quality 
and water withdrawal), the scoring varied from other areas only by 
tenths of a point. Accordingly, the identified qualitative rankings 
(i.e., very low to medium) always matched at least one or more other 
areas for the particular threat category. Additionally, the SRT 
completed an overall extinction risk assessment for the Bb-Mid-Atlantic 
portion of the range (see previous Overall Risk Summary section). The 
SRT allocated a 69 percent low risk of extinction, a 30 percent 
moderate risk of extinction and a 1 percent high risk of extinction. 
Overall, the best available data indicate blueback herring in the Bb-
Mid-Atlantic stock complex are not at risk of extinction now or in the 
foreseeable future. Therefore, the SRT did not proceed to consider the 
biological significance of the Bb-Mid-Atlantic stock to the species.
    Additionally, because in 2011 the petitioner identified the Long 
Island Sound portion of the range as a potential DPS, the SRT 
considered if this portion of the Bb-Southern New England stock complex 
would be considered ``significant'' under the SPR Policy. The 
petitioners considered this area to consist of the Monument, Namasket, 
Mattapoiset, Gilbert-Stuart, Shetucket, Farmington, Connecticut, 
Naugatuck and Mianus Rivers.
    The SRT considered the threats affecting the Long Island Sound 
area, including habitat loss due to dams and other barriers, water 
withdrawal due to high population densities, and bycatch. Notably, this 
area is found within the Mid-Atlantic DPS (discussed above and reviewed 
in Evaluation of Threats), and much of the information that may differ 
in the Long Island portion of the range is expressed in the above 
descriptions with additional detail provided in the Status Review 
Report (NMFS 2019).
    The SRT analyzed the available run data for the time series for the 
Long Island trawl survey, Connecticut juvenile seine survey, and 
Monument River run counts. Overall blueback herring abundance for this 
portion is difficult to estimate accurately and managers have reported 
a mismatch of river wide trend in abundance in this region when 
comparing juvenile seine survey data from the Connecticut River and 
Holyoke fishway counts (ASMFC 2017b). While the Connecticut River 
watershed may act or has acted as a source for blueback herring in this 
region, many other rivers in this portion of the range are smaller 
coastal runs that drain directly into the ocean and are not expected to 
be large production rivers for blueback herring on the same scale. Over 
the full time series (2006-2015) in the most recent ASMFC assessment, 
run trends for blueback herring have decreased in the Monument River, 
were variable in the Connecticut River, and were stable in the 
Shetucket River and Mianus Rivers (ASMFC 2017a).
    When considering spatial distribution of blueback herring in this 
portion, the SRT noted that although the abundances are low, blueback 
herring were distributed through this entire portion and appear to be 
reasonably well connected with rivers to the south of the Connecticut 
and rivers to the north, which also have blueback herring populations. 
Recent genetic work by Reid et al. (2018) places river populations from 
this portion into at least two separate genetic groups. The Connecticut 
River and Mianus Rivers were assigned to the Mid Atlantic stock 
complex, and the Gilbert-Stuart and Monument Rivers were assigned to 
the Southern New England stock complex (Reid et al. 2018). The most 
recent genetic studies do not indicate that this portion is unique in 
its genetic diversity.
    Finally, the SRT completed an overall extinction risk assessment 
for the Long Island portion identified by the petitioners. Overall, the 
SRT concluded that there is a low risk of extinction in the Long Island 
Sound portion currently and in the foreseeable future. The Long Island 
Sound population is not threatened or endangered, nor is it likely to 
become so in the foreseeable future. Therefore, the SRT did not proceed 
to consider whether the portion may be biologically significant to the 
species rangewide.
    After reviewing the SRT's findings for the Bb-Mid-Atlantic stock 
and the Long Island Sound portion of the range, we agree that there is 
no evidence to suggest that blueback herring in these areas are at 
heightened risk of extinction. Thus, we find that the Mid-Atlantic 
stock and the Long Island Sound portion are not significant portions of 
the blueback herring range because they are not in danger of extinction 
or likely to become so in the foreseeable future.
    Next, the SRT considered the extinction risk of blueback herring in 
the Bb-Mid-New England stock complex (see Figure 2) due to recent 
concerns related to very low run counts in New Hampshire rivers. The 
SRT considered the best available information on abundance, growth 
rates/productivity, spatial distribution, and diversity contained in 
the recent stock assessment update (ASMFC 2017a, b). The SRT examined 
trends for the Oyster,

[[Page 28664]]

Winnicut, Taylor, Lamprey, and Cocheco Rivers in New Hampshire and 
discussed threats in this region. For a more detailed description of 
population trends see the Status Review Report (NMFS 2019). The SRT 
questioned whether the fisheries-independent surveys that are currently 
conducted by the state adequately target blueback herring, but the 
reported indices in the most recent stock assessment (ASMFC 2017b) are 
the best available information. The best available data show low 
blueback herring run count estimates for rivers in this portion, and 
the SRT noted that recent sampling in the Lamprey River resulted in 
zero blueback herring counted at the fishway. SRT members noted that 
there is likely some blueback herring spawning below the fishway, but 
the monitoring design only counts fish which ascend the fishway. 
However, this issue is not unique to this river system.
    The most recent genetic information classified blueback herring in 
this portion of the species' range as belonging to the Bb-Mid New 
England stock complex (Reid et al. 2018) (see Figure 2). The Bb-Mid New 
England portion is adjacent to stock complexes in the north (Bb-Canada/
Northern New England) and south (Bb-Mid Atlantic), though the precise 
boundaries and distribution of this stock complex are not fully 
understood due to the unsampled blueback herring populations located 
between the Oyster River and the Sebasticook River.
    The SRT considered the threats affecting the Bb-Mid New England 
area, including habitat loss due to dams and other barriers, threats to 
water quality, incidental catch, and inadequacies of state and Federal 
regulations. Notably, this area overlaps with the southern portion of 
the Aw-Northern New England (noted above and reviewed in Evaluation of 
Threats), and additional detail can be found in the Assessment of the 
ESA Section 4(a)(1) Factors of the Status Review Report, which reviews 
information for each threat along the coastline (NMFS 2019).
    The SRT completed an overall extinction risk estimate for the Bb-
Mid-New England stock complex of blueback herring and allocated 51 
percent of the likelihood points to the high risk of extinction, 39 
percent to moderate risk of extinction and 10 percent to low risk of 
extinction. The allocation of likelihood points in the high risk 
category was primarily due to declining run trends and poor population 
metrics.
    Because the SRT found the Bb-Mid-New England stock complex of 
blueback herring to be at a high risk of extinction, they considered 
the questions outlined in the Status Review Guidance (NMFS 2017) to 
determine if the Bb-Mid-New England stock complex might be considered 
biologically ``significant'' i.e., whether the portion's contribution 
to the viability of the species is so important that, without the 
members in that portion, the species would be in danger of extinction 
or likely to become so in the foreseeable future. Specifically, the SRT 
considered a number of questions that inform the viability 
characteristics: Abundance, productivity, spatial distribution, and 
genetic diversity. The SRT considered how the loss of the portion, 
given the current available information on abundance levels, would 
affect the species rangewide in a variety of ways. The SRT also 
considered how the loss of the portion would affect the spatial 
distribution of the species (i.e., would there be a loss of 
connectivity, would there be a loss of genetic diversity, or would 
there be an impact on the population growth rate of the remainder of 
the species).
    The SRT found that the Bb-Mid-New England portion of blueback 
herring was unlikely to contribute in such a way as to be considered 
significant to the blueback herring rangewide. More specifically, the 
Bb-Mid-New England portion is very small compared to the rest of the 
range, spanning approximately 311 km (193 mi) of coastline and 
encompassing less than 3 percent of the estimated watershed area of the 
species (see Table 1). Additionally, the current run sizes in this 
portion in the last decade have numbered in the 10,000s and more 
recently in the 1,000's and are estimated at less than 1 percent of 
overall rangewide abundance. The historical contribution of the Mid-New 
England portion to the rangewide abundance is assumed to be a similar 
proportion, as historical declines were noted across the blueback 
herring's range. However, the historical contribution may have been 
slightly higher than one percent due to the intense current and 
historic industrial development (e.g., dam construction near head of 
tide for mills) in this region (see Evaluation of Threats). Additional 
uncertainty exists as unsampled adjacent rivers may be attributed to 
this stock complex (see Figure 2). The SRT noted that due to the small 
abundance in the Bb-Mid-New England portion and its small contribution 
to the overall population size, they would not expect deleterious 
effects to the remainder of the species from its loss. The SRT also 
noted that the loss of the Bb-Mid-New England portion would not cause 
the species as a whole to be below replacement rate. Loss of the Bb-
Mid-New England portion could potentially disrupt connectivity in the 
very short term. However, the SRT noted that straying rates would allow 
for recolonization of the rivers in the foreseeable future and 
therefore maintain overall spatial diversity. Populations from the 
north (Bb-Canada/Northern New England DPS) and south (Bb-Mid-Atlantic 
DPS) contain hundreds of thousands of blueback herring and would likely 
be the first recolonizers of this 311 km (193 mi) stretch of coastline.
    If the Bb-Mid-New England portion was lost, blueback herring 
rangewide would lose one of five known regional stock complexes and 
potential genetic adaptation. However, four stock complexes would 
remain providing genetic diversity to the species as whole. Further, 
there is no evidence to indicate that the loss of genetic diversity 
from the Bb-Mid-New England stock complex would result in the remaining 
populations lacking enough genetic diversity to allow for adaptations 
to changing environmental conditions. In considering this portion of 
the range, the SRT was unaware of any particular habitat types that the 
species occupies that are found only in the Bb-Mid-New England portion 
(see Distinct Population Segment, significance discussion). In 
conclusion, the SRT determined that the Bb-Mid-New England stock is not 
a significant portion of the range because the loss of the members in 
the portion would not render the species in danger of extinction, nor 
make the species likely to become so in the foreseeable future.
    In light of these recent court decisions noted above that 
invalidated the threshold for ``significant'' in the SPR Policy that 
the SRT applied, we have independently reviewed and have considered the 
biological importance or value that this stock complex provides to the 
conservation of the species rangewide to determine if this portion may 
be ``significant'' as contemplated by the ``significant portion of its 
range'' phrase in the ESA. The foundation of the policy of defining 
``significant'' in terms of biological significance to the species has 
not been invalidated by any court, and we continue to rely on the 
principles of biological significance as the corner stone of this SPR 
analysis. Specifically, we consider how this portion contributes to the 
conservation of the species by analyzing the abundance, spatial 
distribution, genetic diversity and productivity of the members in the 
portion and the value these factors and other relevant factors

[[Page 28665]]

contribute to the conservation of the species overall.
    Regarding abundance estimates from this stock complex, while exact 
numbers of individuals are not available, the current indices show that 
this stock complex likely has a low level of biological importance to 
the rangewide abundance estimates. Due to the small geographic size of 
the area that it inhabits, this stock contributes a small proportion of 
the overall geographic distribution of the blueback herring rangewide. 
Specifically, this stock does not have the population numbers or 
habitat capacity to buffer surrounding stocks against environmental 
threats such as droughts, or flooding. We found only low abundance, and 
we did not find unique threats to this stock complex.
    We also examined spatial distribution and genetic diversity. This 
stock complex bridges connectivity between the Bb-Canada/Northern New 
England and Bb-Southern New England stock complexes by habitat between 
these two stocks. However, blueback herring have been observed to 
migrate this distance previously (e.g., Eakin 2017), and the importance 
of this bridge between stock complexes is likely low given the species' 
straying behavior. Overall, we find that the contribution that this 
stock makes to spatial distribution of the species is low because it 
inhabits a small area compared to other stock complexes of this species 
and to the rangewide distribution.
    According to the most recent genetic study (Reid et al. 2018), the 
Bb-Mid- New England stock complex represents one of five 
distinguishable groupings of genetic diversity for blueback herring. 
While it is likely that this unique genetic signature conveys some type 
of adaptive potential to the species rangewide, we do not currently 
have evidence of this. Because we do not know the adaptive potential of 
the genetic signature for the Bb-Mid-New England complex, we are not 
able to determine whether the genetic diversity contributes in a 
significant way to the persistence of the species rangewide. The 
available genetic research currently suggests that there is overlap in 
genetic signatures at the boundaries of all five stock complexes, such 
that we observe a coastwide continuum where each river is most similar 
to its nearest neighbors.
    Summarizing our analysis, we find that the Bb-Mid-New England stock 
complex contributes a low level of importance to the species rangewide 
in terms of abundance, productivity, and spatial distribution. As one 
of five of the stock complexes, we find that the Bb-Mid-New England 
stock complex contributes genetic diversity to the species; however, 
the importance of that diversity is unclear because there is no 
evidence at this time indicating that the genetic differences between 
stocks are linked to adaptive traits. Further, genetic mixing at the 
boundaries of these stock complexes obscures the importance of each 
group with regard to the genetic diversity for the species as a whole. 
Overall, we find that the Bb-Mid-New England stock complex's 
contribution to the population in terms of abundance and spatial 
distribution is of low biological importance and overall does not 
appear significant to blueback herring as a whole. Thus, we find that 
the Mid-New England stock complex does not represent a significant 
portion of the blueback herring range.
    In summary, we find that there is no portion of the blueback 
herring's range that is both significant to the species as a whole and 
endangered or threatened. Thus, we find no reason to list this species 
based on a significant portion of its range.

Protective Efforts

    In the Evaluation of Threats section, we describe ongoing efforts 
that provide for the conservation of alewife and blueback herring 
either indirectly or directly (see, specifically, discussions under A. 
Habitat Destruction, Modification, or Curtailment, and B. 
Overutilization). In these sections we describe efforts to restore 
alewife and blueback herring habitat (e.g., with connectivity projects 
such as dam removal and fish passage installation and improvements) and 
to manage threats associated with harvest. Protective efforts that are 
likely to be most effective in supporting the long-term growth of these 
species center on ensuring connectivity in spawning rivers. While 
hundreds of restoration projects have occurred over the last 20 years 
to improve access to alewife and blueback herring habitat across the 
range, these efforts often take many years to accomplish, and the 
likelihood of projects occurring (in the long term) are not easy to 
predict due to confounding factors associated with funding and 
political/community will. Further, once accomplished, the efforts may 
only have localized effects on independent rivers. While we have 
reviewed the states' efforts that may convey protections for these 
species into the future, we do not find that these future efforts are 
certain to significantly alter the extinction risk for alewife or 
blueback herring.

Final Determination

    Section 4(b)(1) of the ESA requires that listing determinations be 
based solely on the best scientific and commercial 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 information provided in the 
petition, information submitted in response to the request for comments 
(82 FR 38672; August 15, 2017), the status review report (NMFS 2019), 
and other published and unpublished information cited herein, and we 
have consulted with species experts and individuals familiar with the 
alewife and blueback herring. We identified four DPSs of the alewife 
and three DPSs of the blueback herring. We considered each of the 
section 4(a)(1) factors to determine whether any one of the factors 
contributed significantly to the extinction risk of the species. We 
also considered the combination of those factors to determine whether 
they collectively contributed significantly to extinction risk. As 
previously explained, we could not identify any portion of the species' 
range that met both criteria of the SPR Policy. Therefore, our 
determination set forth below is based on a synthesis and integration 
of the foregoing information, factors and considerations, and their 
effects on the status of the species throughout their ranges and within 
each DPS.
    Alewife and blueback herring have been subjected to habitat impacts 
for centuries and to considerable fishing pressure for many decades. We 
acknowledge that they are at historically low levels, but note that 
improved fisheries management efforts in recent years have reduced 
fishing mortality rates on alewife and blueback herring stocks.
    Many relatively robust populations of alewife exist, and genetic 
data show connectivity among populations (genetic continuum along the 
coastline) despite regional groupings. Demographic risks are low to 
moderate and significant threats have been reduced. Blueback herring 
are at a greater risk of extinction (as evidenced by over one third of 
the SRT likelihood points in the moderate/high categories), as 
indicated by lower overall abundances, increased vulnerability to 
anthropogenic disturbances in combination with climate change,

[[Page 28666]]

greater distances between populations, poorer performance at fishways, 
and uncertainties surrounding accurate distribution information 
rangewide. However, based upon the available information summarized 
here, blueback herring have an overall low risk of extinction rangewide 
and in each DPS, assuming the dominant threats to their populations 
continue to be managed.
    We conclude that the alewife and blueback herring are not in danger 
of extinction, nor likely to become so in the foreseeable future 
throughout all or a significant portion of their ranges or in any of 
the DPSs. We summarize the factors supporting this conclusion as 
follows: (1) The species are broadly distributed over a large 
geographic range within the Northwest Atlantic Ocean and along the U.S. 
and Canadian Atlantic coasts, with no marine barriers to dispersal; (2) 
genetic data indicate that populations are not isolated and that both 
species demonstrate a nearest neighbor genetic continuum along the 
coast; (3) while both the species possesses life history 
characteristics that increase vulnerability to overutilization, 
overfishing is not currently occurring within the range; (4) while the 
current population size has significantly declined from historical 
numbers, the population size is sufficient to maintain population 
viability into the foreseeable future and consists of at least millions 
of individuals in several DPSs and hundreds of thousands in other DPSs; 
(5) there is no evidence that disease or predation is contributing to 
increasing the risk of extinction; and (6) there is no evidence that 
the species is currently suffering from depensatory processes (such as 
reduced likelihood of finding a mate or mate choice or diminished 
fertilization and recruitment success) or is at risk of extinction due 
to environmental variation or anthropogenic perturbations.
    Since the alewife is not in danger of extinction throughout all or 
in a significant portion of its range, including DPSs, or likely to 
become so within the foreseeable future, it does not meet the 
definition of a threatened species or an endangered species. Therefore, 
the alewife does not warrant listing as threatened or endangered at 
this time.
    Additionally, since the blueback herring is not in danger of 
extinction throughout all or a significant portion of its range, 
including DPSs, or likely to become so within the foreseeable future, 
it does not meet the definition of a threatened species or an 
endangered species. Therefore, the blueback herring does not warrant 
listing as threatened or endangered at this time.

References

    A complete list of all references cited herein is available upon 
request (see FOR FURTHER INFORMATION CONTACT).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: June 13, 2019.
Christopher Wayne Oliver,
Assistant Administrator for Fisheries, National Marine Fisheries 
Service.
[FR Doc. 2019-12908 Filed 6-18-19; 8:45 am]
BILLING CODE 3510-22-P