Endangered and Threatened Wildlife; Determination on Whether To List the Harbor Seals in Iliamna Lake, Alaska as a Threatened or Endangered Species, 81074-81086 [2016-27690]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 81, Number 222 (Thursday, November 17, 2016)]
[Notices]
[Pages 81074-81086]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-27690]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[Docket No. 121120640-6943-02]
RIN 0648-XC365


Endangered and Threatened Wildlife; Determination on Whether To 
List the Harbor Seals in Iliamna Lake, Alaska as a Threatened or 
Endangered Species

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

ACTION: Notice of a listing determination.

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SUMMARY: We, NMFS, have completed our review of the status of eastern 
North Pacific harbor seals (Phoca vitulina richardii) in Iliamna Lake, 
Alaska. Our review was in response to a petition to list these seals as 
threatened or endangered under the Endangered Species Act (ESA). Based 
on the best scientific and commercial information available, we 
conclude that the seals in Iliamna Lake do not constitute a species, 
subspecies, or distinct population segment (DPS) under the ESA. As a 
result, we conclude that listing the harbor seals in Iliamna Lake, 
Alaska is not warranted.

DATES: This listing determination is made as of November 17, 2016.

ADDRESSES: This finding and supporting information are available on our 
Web page at: https://alaskafisheries.noaa.gov/pr/harbor-seals. 
Supporting documentation used in preparing this listing determination 
is available for public inspection, by appointment, during normal 
business hours at the office of NMFS Alaska Region, Protected Resources 
Division, 709 West 9th Street, Room 461, Juneau, AK 99801. This 
documentation includes the petition, the Biological Review Team's DPS 
report, information provided by the public and interested parties, and 
scientific and commercial data gathered for the review.

FOR FURTHER INFORMATION CONTACT: Mandy Migura, NMFS Alaska Region, 
(907) 271-1332; Jon Kurland, NMFS Alaska Region, (907) 586-7638; or 
Lisa Manning, NMFS Office of Protected Resources, (301) 427-8466.

SUPPLEMENTARY INFORMATION:

Background

    On November 19, 2012, we received a petition submitted by the 
Center for Biological Diversity (CBD) to list the harbor seals in 
Iliamna Lake, Alaska as a threatened or endangered species under the 
ESA, and to designate critical habitat concurrent with listing. CBD 
asserted that the harbor seals found in Iliamna Lake constitute a DPS 
of Pacific harbor seals and contended that the seals in Iliamna Lake 
face threats warranting protection as a listed species under the ESA. 
Iliamna Lake is the largest freshwater lake in Alaska and is connected 
to the Bristol Bay region of the Bering Sea by the Kvichak River.
    On May 17, 2013 (78 FR 29098), we found that the petition presented 
substantial information indicating that listing the seals in Iliamna 
Lake under the ESA may be warranted, and we requested comments from the 
public to inform our status review, and to help us determine whether 
these seals should be listed as threatened or endangered. To assist 
with our status review, we convened a Biological Review Team (BRT), 
composed of federal scientists with expertise in marine mammal biology 
and marine mammal genetics, to review the available information about 
the status of the species, and provide an assessment regarding the 
seals in Iliamna Lake. The BRT compiled information about the harbor 
seals in Iliamna Lake in a DPS Report (Boveng et al., 2016).
    In this notice, we announce our finding that the petitioned action 
to list harbor seals in Iliamna Lake under the ESA as either threatened 
or endangered is not warranted because the seals do not constitute a 
distinct population segment (DPS) and thus are not a separate 
``species,'' as the ESA defines that term. Speficically, while we 
conclude that the seals are a discrete population, the best scientific 
and commercial data available suggest that they are not significant to 
the greater taxon to which they belong, i.e., the eastern North Pacific 
harbor seal subspecies (Phoca vitulina richardii).

ESA Statutory, Regulatory, and Policy Considerations

    Section 3 of the ESA defines a ``species'' as ``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.'' 
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).
    Under section 4(a)(1) of the ESA, we must determine whether a 
species is threatened or endangered because of any one or a combination 
of the following factors: (A) The present or threatened destruction, 
modification, or curtailment of its habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) inadequacy of 
existing regulatory mechanisms; or (E) other natural or human-made 
factors affecting its continued existence. We must make this 
determination 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 being made by states or foreign 
governments to protect the species.
    The first step in determining whether the harbor seals in Iliamna 
Lake warrant listing under the ESA is to assess if they meet the ESA's 
definition of ``species.'' Although there has been speculation

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regarding the taxonomy of the seals in Iliamna Lake (i.e., whether they 
are harbor seals, spotted seals, or hybrids), recent genetic analyses 
(O'Corry-Crowe 2013) provide a high degree of confidence these seals 
are harbor seals (Phoca vitulina). The data available are insufficient 
to suggest the seals in Iliamna Lake, Alaska are a separate subspecies 
of harbor seal apart from the subspecies P. v. richardii (Boveng et 
al., 2016), which ranges from Mexico to Alaska. Therefore, we assessed 
whether the harbor seals in Iliamna Lake constitute a distinct 
population segment of P. v. richardii.
    The U.S. Fish and Wildlife Service (USFWS) and NMFS (the 
``Services'') adopted the Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments under the ESA (the DPS Policy, 61 FR 
4722; February 7, 1996) to clarify the Services' interpretation of the 
term ``distinct population segment'' for the purposes of listing, 
delisting, and reclassifying vertebrates under the ESA. The DPS Policy 
establishes two criteria that must be met for a population or group of 
populations to be considered a DPS: (1) The population segment must be 
discrete in relation to the remainder of the species (or subspecies) to 
which it belongs; and (2) the population segment must be significant to 
the remainder of the species (or subspecies) to which it belongs. In 
this case, harbor seals in Iliamna Lake would need to be both discrete 
from and significant to the eastern North Pacific subspecies of harbor 
seals (P. v. richardii), to be designated as a DPS.
    If the seals in Iliamna Lake were found to meet the DPS criteria, 
we would then conduct a status review and determine whether they are 
threatened or endangered because of any one or a combination of the 
factors from section 4(a)(1) of the ESA. Such a determination would be 
based solely on the best scientific and commercial data available. 
Here, because we concluded that the seal population in Iliamna Lake is 
not a DPS, we did not conduct a status review of the population under 
section 4(a)(1) of the ESA.

Harbor Seal Biology and Life History

Physical Description

    Harbor seals (Phoca vitulina) range in length and size from 1.5-1.9 
meters (m) and 75-180 kilograms (kg) for males, and 1.4-1.7 m and 60-
145 kg for females, with weights varying seasonally (Sease 1992). At 
birth, harbor seal pups are approximately 0.75-1.0 m in length and 
weigh 10-20 kg (Sease 1992). There is a large amount of natural 
variation in harbor seal coats with coloration ranging from tan/brown 
to light gray/black with patterns of spots, rings, and blotches that 
vary between individuals (Shaughnessy and Fay 1977; Kelly 1981). 
Variable patterns in seal coats have been well documented and may be a 
result of the age or sex of the animal, season, location, or the 
environment they inhabit (Shaughnessy and Fay 1977; Kelly 1981; Moss 
1992; Caro et al., 2012). The stage of molting also has an impact on 
the appearance of their coats.

Life History

    On average, harbor seals reach sexual maturity at the age of five 
for both females and males; however, females exhibit a larger range of 
age at maturity (Calkins and Pitcher 1979). The variation depends on 
population size and trend, body condition, and prey resources (Pitcher 
and Calkin 1979; Mclaren and Smith 1985; Atkinson 1997). Harbor seals 
in the eastern North Pacific subspecies also exhibit natural variation 
in the timing of pupping, ranging from March to September (Bigg 1969; 
Temte et al., 1991; Searse 1992), depending in part on general 
geographic location. Aerial surveys of harbor seals in Iliamna Lake 
since 2010 have documented that pupping occurs in the lake, with pups 
observed during aerial surveys in June, July, and August (Burns et al., 
2012; Burns et al., 2013; Boveng et al., 2016; NMML unpubl. data).
    Harbor seals molt annually following pupping (Pitcher and Calkins 
1979). Molting usually lasts 1-2 months, during which time seals spend 
a large amount of time hauled-out (Pitcher and Calkins 1979; Daniel et 
al., 2003). Molting occurs in stages across the body, affecting 
coloration and pattern of the coat throughout the molt.
    Harbor seals are considered opportunistic foragers and feed on a 
wide variety of prey found in marine, estuarine, and fresh waters 
(Carretta et al., 2015). Since they inhabit coastal waters, harbor seal 
dives are often less than 50 m and last 2-5 minutes (Bowen et al., 
1999; Frost et al., 2001, 2006) which influences the prey species 
available for foraging. Alaskan harbor seals have been documented to 
forage on pollock, Pacific cod, Pacific sand lance, sculpins, Pacific 
salmon, trout, char, graylings, flatfishes, capelin, eulachon, smelt, 
and Pacific herring (Hobson et al., 1997; Iverson et al., 1997; Houser 
et al., 2008; Geiger et al., 2013). Power and Gregoire (1978) report 
harbor seal diet in Lower Seal Lake, Quebec being dominated by lake and 
brook trout. Harbor seals have also been documented to follow salmon 
and other anadromous fish up rivers and into freshwater lakes where 
they may remain for extended periods (e.g. Bigg 1969a, 1981, and Hoover 
1988 as cited in Sease 1992; Middlemas et al., 2006). One of the 
largest sockeye salmon populations in the world run up the Kvichak 
River into Iliamna Lake annually in June and July. Harbor seals have 
been observed to follow these fish runs seasonally from Bristol Bay, 
although whether those seals enter Iliamna Lake has not been 
documented.

Distribution and Abundance

    Harbor seals are one of the most widespread pinniped species and 
are found throughout the northern hemisphere, ranging from temperate to 
polar regions. As of 2008, the worldwide harbor seal population was 
estimated between 350,000 and 500,000 mature individuals (Thompson and 
H[auml]rk[ouml]nen 2008). Currently, there are five recognized 
subspecies of harbor seals: P. v. vitulina in the eastern Atlantic; P. 
v. concolor in the western Atlantic; P. v. mellonae in some lakes and 
rivers draining into eastern Hudson Bay; P. v. richardii in the eastern 
North Pacific; and P. v. stejnegeri (also known as P. v. kurilensis) in 
the western North Pacific (Rice 1998; Berta and Churchill 2012).
    The harbor seals found in Iliamna Lake are classified as part of 
the subspecies P. v. richardii, also commonly referred to as eastern 
North Pacific harbor seals. Eastern North Pacific harbor seals range 
from Mexico to Alaska (Carretta et al., 2015), with an estimated 
abundance of 360,000 individuals (DFO 2010). More than 205,000 harbor 
seals occur in Alaska (Muto and Angliss 2015).
    Eastern North Pacific harbor seals in Alaska are divided into 12 
separate stocks under the Marine Mammal Protection Act; however, these 
stocks do not represent taxonomic delineations, and all 12 stocks are 
part of the subspecies P. v. richardii. Harbor seals in Iliamna Lake 
are part of the Bristol Bay stock, which was estimated at approximately 
32,350 individuals based on a 2011 survey (Muto and Angliss 2015), an 
increase from the estimated 18,577 seals in 2005 (Allen and Angliss 
2014).
    Aerial surveys of harbor seals in Iliamna Lake have primarily been 
conducted in the summer and have consistently documented fewer than 350 
animals (Mathisen and Kline 1992; Small 2001; Withrow and Yano 2009; 
Burns et al., 2012; Burns et al., 2013; NMML unpubl. data). The 
standard protocol for harbor seal aerial surveys is that only seals on 
land are counted and

[[Page 81076]]

seals in the water are not counted (Burns et al., 2011; Burns et al., 
2013). It is likely that not all seals haul-out at the same time and 
some seals present in the water were not counted during the surveys of 
Iliamna Lake. Thus, the actual number of seals in Iliamna Lake at the 
time of these surveys may have been greater than the number of seals 
reported during the aerial surveys. To estimate abundance and trends in 
seal numbers in Iliamna Lake, a simple demographic model was developed 
(Boveng et al., in prep as reported in Boveng et al., 2016). That model 
indicates that the number of seals in the lake, about 400, has been 
relatively stable from 1984-2013 with little to no evidence of a trend 
over the past 5,10, and 15-year horizons. In 2011, household surveys of 
local residents from six communities in the Iliamna Lake region were 
conducted. Based upon a synthesis of the information provided by this 
local traditional knowledge (LTK) of Iliamna Lake residents, the 
population size of seals in the lake was believed to be approximately 
329 individuals, with a general belief that the population was 
increasing (Burns et al., 2013).

Habitat Use and Movements

    Harbor seals typically inhabit near-shore coastal waters, but are 
well known for their use of estuaries and rivers, and have been 
recorded over 200 kilometers (km) upstream (see review in COSEWIC 
2007). Harbor seals are known to haul-out on a variety of natural and 
manmade substrates which include beaches, sandbars, rocks, islands, 
ice, docks, piers, and boats. Their varied haul-out substrates are an 
example of the behavioral plasticity of harbor seals to adapt to a 
range of environmental settings and conditions (Komers 1997; Vincent et 
al., 2010).
    Harbor seals are often described as a sedentary, non-migratory 
species, with considerable site fidelity to one or a few haul-outs, 
with large scale movements being rare. Traditional thinking is that 
harbor seals generally stay within 50 km of a primary haul-out site 
(e.g., see Peterson et al., 2012). However, Burns (2002) states this is 
a ``gross oversimplification'' and instead states that harbor seals 
move quite extensively in some cases, including movements characterized 
as ``migrations, juvenile dispersal, seasonal shifts, shifts related to 
breeding activity, responses to seals habitat exclusion, responses to 
acute or chronic disturbance, and immigration/emigration, occasionally 
on a relatively large scale.'' Satellite tagging studies document that 
harbor seals have large home ranges with haul-out sites that vary 
seasonally and by individual, with some seals migrating hundreds of km 
between breeding and post-breeding habitats (e.g., Lowry et al., 2001; 
Lesage et al., 2004; Peterson et al., 2012; Womble and Gende 2013). 
These studies also report strong evidence of site fidelity by harbor 
seals to their breeding or locations where they were tagged during 
summer. In the St. Lawrence estuary in Canada, over half of the 
satellite tagged harbor seals left their summer haul-out areas once 
solid ice formed within the bays of the estuary, and migrated between 
65 km and 520 km to over-wintering sites (Lesage et al., 2004). In the 
Pacific Northwest region of the United States, Hardee (2008) reported 
that harbor seal movements up to 100 km from the tagging site occurred 
most frequently outside of the breeding season, and that some adult 
males made trips in excess of 200 km roundtrip that lasted 1-8 weeks 
between April and August. Hardee (2008) observed long-distance and 
long-duration movements by harbor seals throughout the study period, 
with males making multiple roundtrip movements greater than 200 km that 
were not associated with a migratory over-wintering behavior. Hardee's 
(2008) study, as well as a study of harbor seals from the Wadden Sea, 
Denmark (Tougaard et al., 2003 as cited in Hardee 2008), contradict the 
traditional view that harbor seals reside in a limited geographic area 
and do not leave that home area for extended periods of time. Peterson 
et al. (2012) documented adult male harbor seals in the Pacific 
Northwest moving rapidly between haul-outs, at times traveling over 100 
km in about two days. That study also concluded that some adult male 
harbor seals had secondary haul-out sites greater than 100 km from the 
primary haul-out site; that the locations of, and distances between, 
primary and secondary haul-outs varied by seal; and that seasonal 
migrations over 100 km by adult male seals were more common than 
previously believed. In Alaska, Lowry et al. (2001) reported juvenile 
harbor seal movements of 300-500 km, and Womble and Gende (2013) 
documented extensive migrations of harbor seals from Glacier Bay during 
the post-breeding season, with some females traveling to Prince William 
Sound, a distance up to 900 km one way. A harbor seal tagged in the 
Egegik and Ugashik region of eastern Bristol Bay traveled in excess of 
470 km, and 8 of 14 tagged harbor seals traveled in excess of 100 km 
from a major haul-out site (ADF&G unpubl. data).
    There is also variation in individual movements of harbor seals 
within a population, with some seals traveling great distances 
seasonally while others stay within a smaller area year-round. Womble 
and Gende (2013) noted that some harbor seals in Glacier Bay, Alaska, 
were residents year-round whereas others were migratory. For the 
migrating harbor seals, there was a high degree of site fidelity back 
to Glacier Bay the following pupping/breeding season despite the 
extensive migration away from the breeding area during the post-
breeding season (Womble and Gende 2013). Lesage et al. (2004) 
documented that half of the tagged harbor seals in the St. Lawrence 
estuary in Canada left their summer haul-out areas and migrated up to 
520 km to over-wintering sites, whereas the other half stayed year-
round. Peterson et al. (2012) concluded that some harbor seals in the 
Pacific Northwest had spatially separated primary and secondary haul-
outs, while other seals stayed relatively close to a primary haul-out 
year-round. Sharples et al. (2012) documented highly variable 
individual harbor seal movements for seals tagged in the British Isles. 
This study also concluded that region and season better explained the 
variation in foraging movements than the individual seal's sex, size, 
and body condition (Sharples et al. 2012), suggesting the local habitat 
conditions and distance to profitable feeding grounds may influence the 
foraging movements of the seals.
    No harbor seals in Iliamna Lake have been satellite tagged, thus 
there are no data available about harbor seals movements in Iliamna 
Lake comparable to those discussed in the preceding paragraphs. Data on 
habitat use and movements of harbor seals in Iliamna Lake are from 
aerial surveys documenting locations where harbor seals were hauled-out 
(e.g., Mathisen and Kline 1992; Small 2001; Withrow and Yano 2009; 
Burns et al., 2012; Burns et al., 2013), and the LTK of residents, 
including Alaska Native subsistence hunters around Iliamna Lake (e.g., 
Burns et al., 2013; Van Lanen et al., 2013). In Iliamna Lake, hauled-
out harbor seals are observed primarily in the northeastern portion of 
the lake, but some local residents report seeing seals in the 
southwestern portion of the lake, especially near the Kvichak River and 
Igiugig (Burns et al., 2013). The majority of aerial surveys of Iliamna 
Lake were conducted during the summer/ice-free season, with a small 
number of recent (2010-2013) surveys also flown during the winter/ice-
present season. The recent aerial surveys documented

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seasonal variations in seal presence and abundance in the lake, with 
significantly greater numbers of seals observed hauled-out during the 
summer pupping and molting periods (e.g., 237 seals observed August 4, 
2013) than during the winter (e.g., 9 seals observed April 4, 2013) 
(Burns et al., 2011; Withrow et al., 2012; Burns et al., 2012; Burns et 
al., 2013; NMML unpubl. data).
    While harbor seals are known to haul-out on ice, recent aerial 
surveys have documented few seals hauled-out during winter surveys in 
Iliamna Lake. For example, an aerial survey flown in April 2010, when 
the lake was almost completely frozen-over, documented only 11 seals; 
observers reported they ``did not see any areas that could support the 
several hundred seals that have been documented in the summer'' 
(Withrow et al., 2011). Another aerial survey in April 2013 observed 
only nine hauled-out seals (NMML unpubl. data). Although fewer seals 
are documented during winter months, there has been some speculation, 
primarily by some local residents (Burns et al., 2013; Van Lanen et 
al., 2013), that all the seals remain in the lake year-round and are 
undetectable during winter aerial surveys. It is possible seals present 
in the lake in winter are not observed because they are either in the 
water or they are under the ice in areas with air pockets, which may 
become accessible along shorelines when the lake's water level drops 
after a heavy layer of ice has formed at the surface. The particular 
environmental condition of under-ice air pockets has been 
scientifically documented in the Lacs des Loups Marins in Canada 
(Twomey 1939 as cited in Smith and Horonowitsch 1987; Smith and 
Horonowitsch 1987). The Lacs des Loups Marins are home to harbor seals 
in subspecies P. v. mellonae, who reside in freshwater lakes year-round 
and are believed to use under ice haul-outs when the lakes are iced-
over (Smith and Horonowitsch 1987; Smith 1997; DFO 2016). While neither 
this environmental condition nor the use of under-ice air pockets by 
harbor seals have been scientifically assessed in Iliamna Lake, the use 
of under ice air pockets or chambers could explain why fewer seals are 
observed in Iliamna Lake when it is frozen compared to when it is not. 
However, this theory does not explain why only eight seals were counted 
in November 2010 (Burns et al., 2011) when the lake was not iced-over. 
There currently is no scientific evidence available to determine 
whether air chambers or haul-outs are used by seals under the ice in 
Iliamna Lake during the winter; however, local residents have reported 
hearing seals under the ice in such spaces (Burns et al., 2013). 
Regardless of the number of seals present in winter, the aerial surveys 
provide scientific evidence of some level of year-round presence of 
harbor seals in Iliamna Lake.
    Conclusions drawn from recent aerial surveys suggest that some 
harbor seals may be year-round residents of Iliamna Lake whereas other 
harbor seals may seasonally migrate to and from the lake (Burns et al., 
2011; Withrow et al., 2011; Burns et al., 2012; Burns et al., 2013). 
Some of the LTK regarding the migration patterns of seals in Iliamna 
Lake are inconsistent, and collectively they do not provide clarity 
(see Burns et al., 2013). Some LTK reports indicate harbor seals 
migrate between Iliamna Lake and Bristol Bay and are frequently seen 
traversing the Kvichak River (e.g., Alvarez 2013; Burns et al., 2013; 
Igiugig Tribal Village Council 2013; Mohr 2013; Wilson 2013), while 
other reports indicate that the seals do not migrate and are present in 
the lake year-round (e.g., Burns et al., 2013; Jacko 2013; Mohr 2013). 
Local residents around Iliamna Lake indicate that observations of 
harbor seals in the Kvichak River are typically made beginning in 
spring, peak during mid-summer, and decline to zero in the winter 
months; however, some residents of Levelock on the Kvichak River have 
observed seals in the river in the winter (Burns et al., 2013). This 
suggests that the Kvichak River may be used seasonally as a migration 
route between Iliamna Lake and Bristol Bay.
    No scientific data are available to determine whether enough fish 
remain in Iliamna Lake to support hundreds of seals during winter. Some 
LTK indicates that the lake may not have sufficient food available to 
support the number of seals observed in summer months on a year-round 
basis. A local seal hunter recently noted that two seals harvested 
during two consecutive winters in the lake had not ``one drop of food 
in the stomach or intestines'' (Burns et al., 2013). Another seal 
hunter recollected shooting a seal in March one year that was very 
skinny and had no fat on it, and speculated that during cold winters 
there was inadequate food for the seals (Burns et al., 2013). However, 
the hunter also mentioned that it was very rare to find a skinny seal 
in Iliamna Lake. During our public comment period we received a comment 
that provided calculations of the abundance of non-salmonid freshwater 
fish available during the overwinter period and indicated that a 
population of approximately 300 seals could not be sustained on the 
levels of freshwater fish available in the winter. We have no 
information to support or refute the calculations provided by the 
commenter.
    Alternatively, there may be adequate abundance of prey available in 
the lake year-round, but some seals could leave the lake in winter for 
other reasons. In the St. Lawrence estuary, a study of satellite-tagged 
harbor seals found that seals left summer haul-out areas when solid ice 
formed within the bays of the estuary despite ``evidence of high 
abundance of potential prey for harbor seals in the estuary during 
winter'' (Lesage et al., 2004). This study concluded that availability 
of prey in winter ``is not the primary factor which influences the 
movement and distribution patterns of harbor seals'' (Lesage et al., 
2004). As discussed earlier, harbor seals have been documented to have 
spatially separated home ranges which vary seasonally (e.g. Lowry et 
al., 2001; Lesage et al., 2004; Peterson et al., 2012; Womble and Gende 
2013), but also high site fidelity to breeding locations. Thus, it is 
plausible that some harbor seals from Bristol Bay seasonally follow the 
salmon to Iliamna Lake and return to Bristol Bay for winter, but there 
are no data available either to support or refute this scenario.
    Whether seals migrate seasonally between Iliamna Lake and Bristol 
Bay has not been scientifically investigated, with the exception of a 
few recent aerial surveys of Iliamna Lake and the Kvichak River. Aerial 
surveys of the Kvichak River (five complete or partial river surveys 
conducted from 2008-2013) have failed to document harbor seal presence 
in the river (Burns et al., 2013), but it is possible that seals in the 
river may have been missed during the surveys or that the surveys were 
conducted when seals were not using the river. For example, during an 
aerial survey in 2011, the survey crew received a report of seals in a 
tributary of the Kvichak River near Kastinak Flats, but the survey crew 
was unable to locate the seals when they flew over the area 
approximately 30 minutes later (Burns et al., 2013; D. Withrow, NMML, 
pers. comm.). Additionally, Burns et al., (2013) postulated that seals 
present in the Kvichak River may not be accounted for as a result of 
the survey methodology, which only counts seals hauled-out, not those 
in the water. Other reports suggest harbor seals are regularly seen 
throughout the Kvichak River (Burns et al., 2013; Van Lanen et al., 
2013; ADF&G unpubl. data). Of 14 harbor seals satellite tagged in 
Egegik and Ugashik Bays within eastern Bristol

[[Page 81078]]

Bay in 2000 and 2001, none were documented in the Kvichak River or 
Iliamna Lake (ADF&G unpubl. data). However, the sample size is too 
small to conclude that migration between Bristol Bay and Iliamna Lake 
does not occur. We did not find any scientific evidence to conclude the 
harbor seals in Iliamna Lake constitute a closed population with no 
migration between the lake and marine waters, and the documented LTK on 
this question was inconsistent. In the absence of persuasive evidence 
of a closed population, for purposes of our DPS assessment, we assumed 
that harbor seal migration between Iliamna Lake and Bristol Bay (or 
beyond) is possible.

Subsistence Harvest

    Harbor seals are an important resource for Alaska Native 
communities surrounding Iliamna Lake. Harbor seals are not only a food 
source, but also provide materials that can be used for clothing, 
handicrafts, and cultural traditions. Reports of harvesting harbor 
seals by indigenous people around Iliamna Lake date back to the early 
1800s and LTK suggests that seals have inhabited the lake for many 
centuries (Fall et al., 2006; Van Lanen 2012; Burns et al., 2013). The 
majority of hunting occurs during February and March; however, some 
animals have been harvested in summer and occasionally in winter (Burns 
et al., 2013). Seven communities around Iliamna Lake and along the 
Kvichak River were surveyed regarding their harvest of marine mammals: 
Pedro Bay, Pope-Vannoy Landing, Kokhanok, Newhalen, Igiugig, Iliamna, 
and Levelock (Burns et al., 2013). Between 1982 and 2011, approximately 
150 seals were harvested in Iliamna Lake; however, there is a marked 
difference in the number of seals harvested each of those years (Burns 
et al., 2013). For instance, there were no reported harvests of seals 
in 1982 and 1996, yet 33 were harvested in 1991. The most recent survey 
in 2011 reported that 44 percent of households surveyed from these 
seven communities used ``freshwater'' harbor seal products and 13 
percent used ``saltwater'' harbor seal products in some capacity, 
resulting from an estimated harvest of 29 seals (five ``saltwater'' and 
24 ``freshwater'') (Burns et al., 2013).

Distinct Population Segment (DPS) Assessment

    As described above, only species, subspecies, and DPSs are eligible 
for listing as a threatened or endangered species under the ESA. A DPS 
is a population or group of populations of a vertebrate species that 
meet both the ``discreteness'' and ``significance'' criteria of our DPS 
policy (61 FR 4722; February 7, 1996). If a population segment is found 
to be discrete and significant, it is a DPS and is considered a 
``species'' under the ESA. If the population is not both discrete and 
significant, it does not meet the criteria for designation as a DPS and 
does not qualify as a ``species'' as defined by the ESA; thus, we need 
not evaluate its status relative to the factors in section 4(a)(1) of 
the ESA because it cannot be listed as a threatened or endangered 
species. Our assessment first addresses the discreteness of the harbor 
seals found in Iliamna Lake, and then addresses whether these seals are 
significant to P. v. richardii, as these terms are defined in our DPS 
policy (61 FR 4722; February 7, 1996).
    As discussed above, we know from formal scientific studies and LTK 
that at least some harbor seals are present in the lake year-round; 
i.e. are residents of Iliamna Lake. What is not clear from the science 
or LTK is whether harbor seals from Bristol Bay migrate to Iliamna 
Lake. The BRT considered four scenarios: (1) The population of seals in 
Iliamna Lake is self-sustaining with seals being year-round residents 
of the lake, and no migration of seals from Bristol Bay into the lake 
occurs; (2) there are resident seals in the lake, and some seals from 
Bristol Bay migrate to the lake during the summer, but there is no 
interbreeding of seals from the two regions and the Bristol Bay seals 
do not stay in the lake during winter; (3) Iliamna Lake contains a mix 
of seals born in the lake and those born in the marine environment but 
who migrated to the lake (either temporarily or permanently), and these 
seals are interbreeding; or (4) there is no self-sustaining population 
of seals in the lake and migration is necessary to sustain the 
population of seals in the lake. The BRT found three of the four 
scenarios to be plausible, favoring explanations 1 and 2, but not 
ruling out 3. None of the BRT members considered the forth scenario 
likely (Boveng et al., 2016). For our DPS analyses, we recognize that 
questions remain regarding whether there is migration, and references 
below to seals in or from Iliamna Lake are not meant to imply that 
their birth location (either in Iliamna Lake or the marine environment) 
is known, but rather are an indication of the seals' location in 
Iliamna Lake at time of observation or sampling.

Discreteness

    We first sought to determine whether the harbor seal population in 
Iliamna Lake is discrete in relation to the remainder of the taxon to 
which it belongs (i.e., the eastern North Pacific harbor seal 
subspecies, P. v. richardii). A population segment of a vertebrate 
species may be considered discrete if it satisfies either one of the 
following conditions specified in our DPS policy: ``(1) it 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; or (2) it 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.'' Because Iliamna Lake is entirely within the 
United States, the second discreteness criterion identified above is 
not relevant. Thus, we focused our assessment of discreteness on 
whether the harbor seals in Iliamna Lake are markedly separated from 
other harbor seals in the subspecies P. v. richardii, with emphasis on 
the nearest harbor seal stock in adjacent Bristol Bay. In addition to 
examining four categories of factors (i.e., physical, physiological, 
ecological, or behavioral factors) as mechanisms with the potential for 
providing marked separation by limiting the dispersal of breeders 
between populations, the BRT recognized that dispersal rates often 
cannot be directly measured in natural populations. As such, the BRT 
also decided to separately review the available genetic information for 
evidence of separation.
    Physical Factors: Iliamna Lake is located at the base of the Alaska 
Peninsula, where it drains through the Kvichak River into Bristol Bay. 
Thus, harbor seal habitat in Iliamna Lake is separated from the nearest 
habitat commonly used by harbor seals in Bristol Bay by the Kvichak 
River. Reports regarding the length of the Kvichak River vary, with 
some older documents reporting the river is approximately 80 km (50 mi) 
in length (e.g., Orth 1971; BLM 2004), whereas more recent reports 
suggest it is closer to 115-120 km (71-75 mi) (e.g., Withrow and Yano 
2009; Boveng et al., 2016; validated by a measurement of the river path 
between Kogging and Iliamna Lake using a high resolution topographic 
map). The discrepancy in reported distances of the river could be 
explained by changes in the river itself over time, variances in the 
starting and ending measurement points, or by using

[[Page 81079]]

straight-line measurements on a map versus tracing the path of the 
river.
    Although seals are found predominantly in the northeast region of 
Iliamna Lake, the most recent studies indicate harbor seals are found 
throughout Iliamna Lake, in rivers draining into the lake (Iliamna, 
Newhalen, and Gilbralter rivers), and throughout the Kvichak River 
(Alvarez 2013; Burns et al., 2011; Burns et al., 2012; Burns et al., 
2013; Igiugig Tribal Village Council 2013; Mohr 2013; Van Lanen et al., 
2013; Wilson 2013). The distance that seals would have to travel from 
the lake to Bristol Bay is well within the known distances that harbor 
seals travel (see previous discussion in ``Habitat Use and 
Movements''). Thus, the evidence available does not indicate that the 
length of the Kvichak River nor the distance to the northeast region of 
Iliamna Lake (approximately 180 km from Bristol Bay) would be a 
physical barrier separating seals in Iliamna Lake from those in Bristol 
Bay.
    Physical factors that could impede harbor seal passage in the 
Kvichak River include shallow braided sandbars and ice cover during 
winter. Although poorly adapted for travel on land, harbor seals in 
other areas have been suspected to cross land up to 0.15 km long and on 
inclines as steep as 25 degrees to get from one body of water to 
another (COSEWIC 2007), so it is reasonable to assume harbor seals have 
the capability to cross shallow braided sandbars in the Kvichak River.
    Millions of sockeye salmon enter Iliamna Lake from marine waters 
annually via the Kvichak River along with other species of anadromous 
salmon. Also, another marine mammal species has been reported to travel 
to Iliamna Lake via the Kvichak River. Beluga whales, which are less 
agile and much larger than harbor seals, have been documented in the 
Kvichak River (Frost et al., 1983; Quakenbush 2002) in the spring, 
summer, and fall (Chythlook and Coiley 1994) and have been observed 
near Igiugig (Burns et al., 2013; Wilson 2013) and in Iliamna Lake 
(Mohr 2013). Thus, the available evidence suggests the Kvichak River is 
passable for harbor seals, at least part of the year when the river is 
not frozen over.
    Individual BRT members were not in agreement regarding the 
scientific support for discreteness due to physical factors, but 
concluded ``no strong evidence was found either for or against marked 
separation by physical barriers between harbor seals in Iliamna Lake 
and those in Bristol Bay'' (Boveng et al., 2016). When we considered 
the best available information indicating that there is access between 
Iliamna Lake and Bristol Bay via the Kvichak River, which is passable 
at least part of the year, and that the distance between the two 
locations is within documented migration distances of harbor seals, 
along with with the opinion of the BRT, we concluded that the best 
available information does not support a conclusion that there is 
separation due to physical factors. As such, we find that harbor seals 
in Iliamna Lake are not markedly separated from other harbor seals of 
the subspecies P. v. richardii as a consequence of physical factors.
    Physiological Factors: Unlike the Lacs des Loups Marins harbor 
seals in Canada, a landlocked population that lives exclusively in 
freshwater lakes and rivers and has documented physiological 
differences from the adjacent harbor seal population in marine waters 
(Smith et al., 1994), no studies exist suggesting there are 
statistically significant morphological or physiological differences 
between harbor seals in Iliamna Lake and other members of the 
subspecies P. v. richardii. Consequently, our discreteness analysis 
considered other types of evidence which may suggest physiological 
differences. Specifically, we considered observations obtained 
primarily from those with LTK of seals in Iliamna Lake having a 
different size, taste, pelage, and timing of pupping as compared to 
seals in Bristol Bay.
    The concentration and availability of salmon to seals in Iliamna 
Lake in the summer may account for perceived differences reported by 
LTK in size and taste of seals in Iliamna Lake compared to seals in 
Bristol Bay. For example, several respondents of a recent LTK survey 
indicated that the ``physical size of the seals grows every year 
following the salmon runs'' (Burns et al., 2013), suggesting high 
availability and consumption of energy-rich salmon results in growth of 
seals during the summer. While the well-fed seals may have experienced 
salmon-fueled growth, the flavor of the harvested seals has been 
reported to become less desirable after the salmon runs, which is 
reportedly why seals in Iliamna Lake are not normally hunted in fall 
(Burns et al., 2013). The LTK perception of differences in pelage 
pattern and coloration is conflicting (see Burns et al., 2013), and no 
formal studies have been conducted to determine if there are 
significant differences in pelage patterns for harbor seals in Iliamna 
Lake versus elsewhere. Burns et al., (2013) speculate that the timing 
of the harvest of harbor seals in relation to the timing of the annual 
molt may play a role in the perceptions of difference in pelage texture 
or coloration. The observed variances in taste, body size, and pelage 
traits are more likely a reflection of seasonal diet, normal phenotypic 
plasticity, and individual variation rather than an indication that the 
seals in Iliamna Lake are physiologically distinct from those in the 
adjacent marine environment.
    The timing of pupping for eastern North Pacific harbor seals ranges 
from March to September (Bigg 1969; Temte et al., 1991; Sease 1992). In 
Iliamna Lake, LTK reports about the timing of pupping are variable, 
with some reports of seal pups born on the lake ice during March and 
April, and other reports indicating pups are born during the first half 
of June (Burns et al., 2013). LTK observations of seal pup sightings in 
Iliamna Lake ranged from February to September, with the majority of 
pup sightings between April and August (Burns et al., 2013). Between 
2009 and 2013, aerial surveys of Iliamna Lake documented newborn pups 
in June, July, and August (Burns et al., 2013). Both aerial survey 
observations and local resident observations of newborn seal pups in 
Iliamna Lake are within the normal range of pupping dates for the 
eastern North Pacific harbor seal subspecies.
    Jemison and Kelly (2001) and Reijnders et al. (2010) showed that 
the timing of harbor seal pupping in the same location can shift by as 
much as several weeks over the course of a few decades. A review of 
data from 1975-2006 for harbor seals in Nanvek Bay, Alaska, (which is 
the main location within Bristol Bay for which harbor seal pupping data 
are available) indicates that the average peak pupping date can vary by 
a couple of weeks over just a few years (e.g., June 18 in 2002 vs. July 
3 in 2006; see Table 1 in Boveng et al., 2016). This observed natural 
variation in timing of harbor seal pupping, along with scarcity of 
available data, may account for seemingly conflicting information in 
the scientific literature about the timing of pupping in Iliamna Lake 
relative to other harbor seals in Alaska (e.g., Burns et al., 2013 
states ``when compared to Bristol Bay seals only, the timing of pupping 
in Iliamna does not appear to be substantially delayed'' versus Withrow 
et al. (2011) which states ``Elsewhere in Alaska we observe harbor 
seals pupping much earlier, in May and June''). According to the BRT 
report (Boveng et al., 2016), the latest peak pupping date estimated 
for the Nanvek Bay region of Bristol Bay was July 5 (1990). Iliamna 
Lake aerial surveys flown in 2010, 2011, and 2013 indicate that the 
earliest peak pupping date was July 9 (2010). Sparse data

[[Page 81080]]

about pupping dates in both Bristol Bay and Iliamna Lake lead us to 
conclude that while we do not know the precise timing of peak pupping 
of harbor seals in either region, we do know that timing of peak 
pupping can vary by a couple of weeks among years within a given 
location. Therefore, an overlap of the timing of pupping between seals 
in Bristol Bay and Iliamna Lake is possible, even though there may be a 
15-day delay in the average peak pupping date in Iliamna Lake (July 12) 
versus the average peak pupping date in Nanvek Bay (June 27) (see 
Boveng et al., 2016). Burns et al. (2013) also concluded that compared 
to Bristol Bay, the timing of pupping in Iliamna Lake does not appear 
to be substantially delayed. A model developed to estimate the 
abundance and trend of harbor seals in Iliamna Lake (Boveng et al., in 
prep as cited in Boveng et al., 2016) predicted a peak pupping date of 
July 20 (versus the July 12 peak pupping date suggested by a simple 
average of the dates of maximum pup counts presented in Table 1 of the 
BRT Report); however, there was substantial imprecision in the model's 
estimate for the peak of pup counts in the lake.
    Individual BRT members were not all in agreement regarding the 
degree of scientific support for discreteness based upon marked 
separation due to physiological factors. Regarding differences in 
physiological traits such as pelage coloration or texture and seal size 
and taste, the BRT report stated ``whether any of these differences 
truly reflect physiological differences or separation is not clear, and 
the BRT was unaware of any documentation that these traits are 
heritable and would indicate separation or novel genetic diversity'' 
(Boveng et al., 2016). Regarding physiological separation based on the 
notion that pupping in Iliamna Lake is potentially delayed by two to 
six weeks when compared to nearby populations, the BRT stated, ``The 
sparsity of information currently available for Iliamna Lake, 
imprecision in determining the timing for any of the comparison 
populations, and the length of the harbor seal pupping period 
(approximately 6-10 weeks), reduce the confidence that can be placed on 
the apparent difference'' (Boveng et al., 2016).
    When we considered all the evidence currently available to us, 
including the lack of direct measures of physiological factors, the 
possibility that perceived differences in seals' appearance may be the 
result of natural individual variation, the imprecision of estimating 
pupping dates due to limited data, the potential overlap of pupping 
seasons between Iliamna Lake and Bristol Bay, and the large timeframe 
(March to September) for typical pupping times across the eastern North 
Pacific harbor seal taxon, we concluded that the available information 
is too weak for us to make a determination that there is separation 
based on physiological factors. As such, based on the available 
evidence, we find that harbor seals in Iliamna Lake are not markedly 
separated from other harbor seals of the subspecies P. v. richardii as 
a consequence of physiological factors.
    Ecological Factors: Harbor seals are known to pursue and aggregate 
around concentrations of anadromous prey, particularly salmon (e.g., 
London et al., 2001, Orr et al., 2004, and Wright et al., 2007, as 
cited in Peterson et al., 2012; Middlemas et al., 2006; Hauser et al., 
2008). Changes in distribution of seasonally abundant prey in the 
Pacific Northwest have been suggested as a possible explanation for 
seasonal movements of harbor seals in that area (Peterson et al., 
2012), as harbor seals may move deliberately to exploit regions of 
higher prey availability (Hardee 2008). In Alaska, movements of 125 km 
by adult female harbor seals have coincided with seasonal eulachon runs 
in the Copper River Delta (Lowry et al., 2001). Savarese and Burns 
(2010) documented peak harbor seal numbers coincident with peaks in 
regional salmon abundance in the Bering Glacier region, and contended 
the salmon attracted large numbers of harbor seals to the region. 
Peterson et al. (2012) speculated that the observations of harbor seals 
using spatially separated haul-out sites on a seasonal basis may be 
related to seasonal changes in prey distribution and foraging 
opportunities.
    Hauser et al. (2008) examined foraging by harbor seals in Iliamna 
Lake during July and August, when salmon are very abundant in the lake, 
and reported that the seals predominately fed on large salmonids 
(salmon, trout, char, and graylings) during the summer months. In 
addition to salmonids, Hauser et al. (2008) documented lampreys, 
smelts, sculpins, whitefishes, sticklebacks, and other unidentified 
prey items in the scat samples of harbor seals in Iliamna Lake. Thus, 
harbor seals in Iliamna Lake appear to be opportunistic feeders, 
consistent with the general pattern of harbor seals foraging on a wide 
variety of fish and invertebrate prey across their range, with regional 
differences in diet diversity (Jemison 2001; COSEWIC 2007). The prey 
items and seasonal concentration of salmon in the diet of seals in 
Iliamna Lake are consistent with those documented for harbor seals in 
other freshwater systems. For example, Middlemas et al. (2006) 
documented a summer peak in the contribution of salmonid prey to the 
diet of harbor seals observed in a Scottish river system; Beck et al. 
(1970) documented a seal in Edehon Lake, Canada with both trout and 
whitefish in its stomach; and Power and Gregoire (1978) reported that 
harbor seals in lakes ate various freshwater fish present in the lakes, 
including trout. Smith et al. (1996) examined stomachs of four harbor 
seals from the Lacs des Loups Marins which contained in large part lake 
whitefish, lake trout, and brook trout. Scat collected in the Nanvak 
Bay region of Bristol Bay also showed that harbor seals have a diverse 
diet, including some of the same types of prey species consumed in 
Iliamna Lake (e.g., salmon, smelts, sculpins) as well as other prey 
species (e.g., codfishes, herring, squid/octopus) (Jemison 2001).
    Stable isotope analyses of whiskers and muscle tissue can provide 
some insights about harbor seal diets from several months prior to the 
date the samples were collected. Samples collected from a small number 
of subsistence harvested harbor seals from Iliamna Lake provide 
preliminary evidence that those specific seals consumed freshwater fish 
during the previous winter (Burns et al., 2013). These preliminary data 
and the typical timing of ice melt in the Kvichak River and Iliamna 
Lake (May-June) suggest that these samples were most likely collected 
from seals which had overwintered in the lake. However, these 
preliminary stable isotope data are not especially revealing due to the 
lack of data on whisker growth rates, tissue turnover times, and direct 
measures of the isotopic signature of potential prey resources (Burns 
et al., 2013).
    If ecological factors prevented harbor seals in Iliamna Lake from 
mixing with other harbors seals during mating season, then there could 
be marked separation as a result of lack of opportunities for 
interbreeding. However, when considering the timing of the annual ice 
melt in the Kvichak River and Iliamna Lake, the sockeye salmon runs 
into Iliamna Lake, and the presumed mating seasons of seals in Bristol 
Bay and in Iliamna Lake, the BRT concluded that the timing of these 
events would not preclude opportunities for interbreeding by seals 
migrating from Bristol Bay to Iliamna Lake (Boveng et al., 2016).
    The BRT members were in general agreement regarding the degree of 
scientific support for discreteness based upon marked separation due to 
ecological factors, and concluded there

[[Page 81081]]

was ``no strong evidence for separation'' as a result of any of the 
ecological factors considered. Based on the available evidence, we find 
that harbor seals in Iliamna Lake are not markedly separated from other 
harbor seals of the subspecies P. v. richardii as a result of 
ecological factors.
    Behavioral Factors: There are no scientific or LTK data available 
to assess whether mating behaviors (e.g., vocalizations or mate 
attraction displays) differ for seals in Iliamna Lake relative to those 
in Bristol Bay or other areas of the eastern North Pacific harbor seal 
range. Absent data available regarding mating behaviors of harbor seals 
in Iliamna Lake, the BRT construed the selection of relatively remote 
pupping sites in the northeastern region of Iliamna Lake (nearly 200 km 
from pupping sites in Bristol Bay) to be a behavior, and suggested the 
selection of the unusual location was evidence of some degree of 
separation, especially given harbor seals' site fidelity to breeding 
locations. The selection of distant pupping sites could be interpreted 
to mean that harbor seals in Iliamna Lake are not freely breeding with 
harbor seals in Bristol Bay, and lead to a conclusion there is marked 
separation. However, even a small amount of breeding dispersal from 
marine populations of harbor seals into Iliamna Lake could render the 
degree of genetic differentiation insignificant (Boveng et al., 2016), 
suggesting there may not be marked separation. The available LTK does 
not resolve this question, as opinions vary regarding whether seals in 
the lake are residents, migrants, or a mix of both (see Burns et al., 
2013).
    Previously we mentioned that harbor seals commonly follow 
anadromous prey into freshwater environments, such as rivers and lakes. 
Thus, we do not consider the mere presence of harbor seals in Iliamna 
Lake to be a behavioral adaptation suggestive of marked separation from 
harbor seals in the marine environment. However, some Alaska Natives in 
the Iliamna Lake region, including subsistence hunters, have postulated 
that the seals overwinter in the lake by using under-ice air gaps and 
haul-outs (Burns et al., 2013), although such winter habitats have not 
been documented in Iliamna Lake. Lack of data complicates a 
determination of whether use of under-ice shelters would be a special, 
learned behavioral adaptation that is unique to harbor seals over-
wintering in freshwater environments, or if this behavior would be one 
that any harbor seal in a similar environment may adopt. Similar under-
ice habitats in the Lacs des Loups Marins in Canada have been suggested 
as potential harbor seal lairs or breathing chambers (e.g., Smith and 
Horonowitsch 1987; COSEWIC 2007). This, in turn, suggests that use of 
such under-ice habitats may be an example of the behavioral plasticity 
that results in harbor seals using a range of behaviors and habitats in 
response to environmental conditions (Komers 1997; Vincent et al., 
2010).
    The Lacs des Loups Marins harbor seal population has shown evidence 
of modifying typical harbor seal behavior and adapting to its 
environment. It is postulated that, because no pups have been observed 
being born on the ice during that species' pupping time period (April, 
when the lakes are frozen), the Lacs des Loups Marins harbor seals have 
learned and adapted to their situation by whelping in under-ice 
shelters similar to subnivean birth lairs (snow caves) used by ringed 
seals (Consortium Gilles Shooner & Associes et al., 1991 as cited in 
Smith 1997). On the contrary, Burns et al. (2013) include information 
from local residents near Iliamna Lake who suggest some harbor seal 
pups may be born in Iliamna Lake in March and April, when the lake is 
still frozen, but pup on the ice, not under it. Due to this reported 
on-ice pupping, even if the harbor seals in Iliamna Lake utilize under-
ice habitats as shelters or breathing chambers, such behavior would not 
be an adaptation necessary for successful pupping by seals that use the 
lake. Thus, unlike the Lacs des Loups Marins harbor seals, the evidence 
suggests that harbor seals in Iliamna Lake have not developed novel 
behaviors to facilitate pupping in a lake environment.
    The BRT members were in general agreement regarding the degree of 
scientific support for discreteness based upon marked separation due to 
behavioral factors, as determined by selection of pupping locations far 
from those in Bristol Bay, and the ambiguity regarding the degree of 
migration and breeding dispersal (if any). Their judgment suggests 
behavioral separation is possible, but the available evidence is not 
strong, or is contradicted by other evidence. Our review of behavioral 
factors indicates that the observed harbor seal behaviors in Iliamna 
Lake are not uncommon; harbor seals in Iliamna Lake have not been 
documented to display behaviors outside the range of normal harbor seal 
behaviors (e.g., no unique mating, pupping, or foraging behaviors 
reported), although there are unresolved questions about migration and 
use of under ice shelters. There is no information available to suggest 
that harbor seals living in ice conditions year-round in a freshwater 
system would require different behavioral adaptations from harbor seals 
living in ice conditions in a saltwater or estuarine system. Despite 
the lack of these obvious indications of potential behavioral 
separation, we recognize the possibility that the selection of pupping 
locations distant from other known pupping locations could be construed 
as a behavior and indicate marked separation as a result of the 
selection of pupping sites limiting the potential for interbreeding. 
Therefore, we find that the best available evidence is not conclusive 
but indicates that harbor seals in Iliamna Lake may be markedly 
separated from other harbor seals of the subspecies P. v. richardii as 
a consequence of behavioral factors.
    Genetics: To further consider whether harbor seals in Iliamna Lake 
are markedly separated from other populations of eastern North Pacific 
harbor seals as a consequence of physical, physiological, ecological, 
or behavioral factors, we examined available genetic evidence which may 
be indicative of separation. Genetic samples available from harbor 
seals in Iliamna Lake were compared to genetic samples available from 
harbor seals in the Egegik and Ugashik regions of eastern Bristol Bay. 
Bristol Bay has the nearest concentration of seals to Iliamna Lake, and 
the BRT determined ``the seals in eastern Bristol Bay would be expected 
to be the most similar to the Iliamna Lake seals if there is breeding 
dispersal between the two areas, and therefore would be expected to 
pose the most stringent test for demonstrating discreteness'' (Boveng 
et al., 2016).
    Genetic samples have been collected and analyzed from 13 harbor 
seals in Iliamna Lake collected in six years from 1996 through 2012. 
The mitochondrial DNA (mtDNA) analysis revealed that 11 of 13 seals 
sampled from Iliamna Lake exhibited the same mtDNA haplotype (O'Corry-
Crowe 2013), meaning all 11 seals had the same group of genes inherited 
from their female parent. The remaining two DNA samples did not yield 
results for this test. This specific mtDNA haplotype (Pvit-Hap#7) is 
the most common haplotype found in harbor seals sampled from Bristol 
Bay and is observed in roughly 21 percent of harbor seals from the 
Egegik and Ugashik regions of Bristol Bay (Burns et al., 2013; O'Corry-
Crowe 2013). Thus, this haplotype is not unique to harbor seals in 
Iliamna Lake.
    The identification of only one mtDNA haplotype in harbor seals from 
Iliamna Lake appears to suggest unusually low genetic diversity. For 
comparison, 76 harbor seals sampled from the Egegik

[[Page 81082]]

and Ugashik regions of eastern Bristol Bay exhibited 33 different mtDNA 
haplotypes (O'Corry-Crowe 2013; Burns et al., 2013). If seals from the 
Egegik and Ugashik regions were immigrating into the lake and staying 
year-round, there would be almost an 80 percent likelihood that one of 
the other mtDNA haplotypes, not Pvit-Hap#7, would be seen in samples 
collected from Iliamna Lake (O'Corry-Crowe 2013). However, because 
mtDNA is inherited from the mother, mtDNA diversity analysis cannot 
determine if male seals are migrating to and from the lake and breeding 
with resident female seals. Hardee (2008) recognized similar 
limitations of mtDNA given observations of male harbor seals in the 
Pacific Northwest traveling larger distances than previously believed, 
possibly to mate in a separate geographic region before returning to 
their home site. Therefore, conclusive results about the level of 
genetic diversity require analyses using nuclear DNA (nDNA; which also 
provides information from the male parent), and more formal analyses of 
mtDNA with statistical comparisons to harbor seals sampled from other 
regions within the range of the taxon (O'Corry-Crowe 2013). These more 
stringent data regarding genetic diversity do not exist.
    In addition to examining the existing genetic diversity of the 
samples, analyses were conducted to examine the extent of genetic 
differentiation between harbor seals sampled in Iliamna Lake from those 
sampled in the Egegik and Ugashik regions of eastern Bristol Bay. The 
results of analyses examining genetic differentiation using both mtDNA 
and nDNA suggest that the harbor seals sampled in Iliamna Lake were 
genetically differentiated from harbor seals sampled in the Egegik and 
Ugashik regions of eastern Bristol Bay (Burns et al., 2013; O'Corry-
Crowe 2013). The results of these analyses also suggest that male and 
female-mediated dispersal between the Egegik and Ugashik regions of 
eastern Bristol Bay and Iliamna Lake was restricted (Burns et al., 
2013; O'Corry-Crowe 2013). Although no directed comparisons were 
conducted between Iliamna Lake samples and genetic samples collected 
from harbor seals in other areas of Bristol Bay or other portions of 
the range of the taxon, the measure of mtDNA genetic differentiation 
between seals in Iliamna Lake and those in eastern Bristol Bay yielded 
results showing substantially greater genetic differentiation than all 
previous pairwise comparisons between the other major centers of harbor 
seal abundance in Alaska (O'Corry-Crowe 2012; Boveng et al., 2016). 
These genetic differentiation results are suggestive of the presence of 
a small, isolated population of harbor seals in Iliamna Lake.
    O'Corry-Crowe (2013) identifies several limitations of the findings 
for the Iliamna Lake samples. He cautions that the sample size is 
extremely small and that questions regarding the patterns of kinship 
among the collected samples remain unresolved (i.e., if some of the 
samples were from related individuals, then the data could be skewed 
and not representative of a random sampling of the population), and 
indicates that genetic differentiation may be enhanced in small 
populations when there is a rapid rate of genetic drift, even when 
there is continued gene flow. Although the 13 genetic samples from 
seals in Iliamna Lake were collected between 1996 and 2012, most 
samples were collected during months when seasonal migrants would not 
be expected to be in the lake, thus the power to detect seasonal 
migrants may be low. Conversely, the timing of the samples may be 
benficial for considering if the resident seals in the lake are 
discrete from their marine counterparts because for most samples 
seasonal migrants would not be expected to be present in the lake. 
O'Corry-Crowe (2013) also provides recommendations for future genetic 
research to resolve lingering issues, including analyzing 20 
microsatellite loci (only 9-11 loci were analyzed) and updating the 
techniques used for the analyses to newer technologies, which would 
increase the power to resolve genetic questions. We also note that the 
tests for genetic differentiation compared the Iliamna Lake samples 
solely against samples collected from the Egegik and Ugashik regions of 
eastern Bristol Bay. Thus, the samples used for the comparison group 
may not be representative of all the seals that could migrate to 
Iliamna Lake.
    The genetic data available suggest the harbor seals sampled in 
Iliamna Lake have low mtDNA diversity, possess the most common mtDNA 
haplotype found in Bristol Bay harbor seals, and are genetically 
differentiated from harbor seals sampled in the Egegik and Ugashik 
regions of eastern Bristol Bay. Given the concerns about the limited 
nature of the available genetic information previously discussed here 
and by O'Corry-Crowe (2013), ambiguity remains regarding the degree of 
separation, and hence discreteness, of harbor seals in Iliamna Lake. 
However, in the absence of more samples collected from a greater number 
of seals in Iliamna Lake and the Kvichak River, to include the 
potential migration season, and/or completion of additional tests such 
as those recommended by O'Corry-Crowe (2013), we consider the existing 
genetic results to be the best available data upon which to base our 
determination. These genetic results support a decision that harbor 
seals in Iliamna Lake are markedly separated from harbor seals in 
eastern Bristol Bay, and by assumption, from the remainder of the 
taxon.

Discreteness Conclusion

    We find the available evidence for discreteness based on physical, 
physiological, or ecological factors to be unconvincing. The available 
evidence based on behavioral factors is not conclusive, but the 
selection of pupping locations distant from other known pupping 
locations could be construed as a behavior and indicate marked 
separation as a result of the selection of pupping sites limiting the 
potential for interbreeding. The strongest evidence for discreteness 
derives from 13 genetic samples collected from seals in Iliamna Lake. 
Analyses of these samples strongly indicate the seals from Iliamna Lake 
are genetically differentiated from seals sampled in two locations 
within Bristol Bay (Ugashik and Egegik), the nearest concentration of 
seals to Iliamna Lake with genetic data available. Genetic comparisons 
of samples for the entire taxon do not exist, but this region within 
Bristol Bay was expected to provide the most stringent comparison for 
discreteness if there is breeding dispersal between the two regions. 
The BRT was in strong agreement that the genetic data reflect marked 
separation, although the BRT acknowledged that the mechanism of such 
separation is unknown and the data are limited. It is possible that the 
limited available genetic data may accurately represent the situation 
in both Iliamna Lake and all of Bristol Bay, or that additional genetic 
analysis from P. v. richardii animals sampled from elsewhere in their 
range or from additional seals in Iliamna Lake, could result in a 
different conclusion. Nonetheless, the best available genetic 
information leads us to conclude that some portion, and perhaps all, of 
the harbor seals in Iliamna Lake likely constitute a resident 
population that is genetically differentiated from harbor seals in 
eastern Bristol Bay, and thus meet the criteria for consideration as a 
discrete entity per our DPS policy (61 FR 4722; February 7, 1996).

Significance

    Having determined that resident seals from Iliamna Lake are likely 
discrete, at

[[Page 81083]]

least from harbor seals in the Egegik and Ugashik regions of nearby 
Bristol Bay, we next sought to determine whether they are significant 
to the P. v. richardii subspecies.
    In carrying out the significance examination per our DPS policy (61 
FR 4722; February 7, 1996), we are to consider available scientific 
evidence of the population's importance to the taxon to which it 
belongs. This consideration may include, but is not limited to, the 
following: (1) Persistence of the discrete population segment in an 
ecological setting unusual or unique for the taxon; (2) evidence that 
loss of the discrete population segment would result in a significant 
gap in the range of the 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.
    This determination, however, is highly fact specific and may 
consider factors besides those enumerated above. Further, significance 
of the discrete population segment is not necessarily determined by 
existence of one of these classes of information standing alone. 
Information analyzed under these and any other applicable 
considerations is evaluated relative to the biological and ecological 
importance of the discrete population to the taxon as a whole. 
Accordingly, all relevant and available biological and ecological 
information is analyzed. As we explained in the DPS policy, ``the 
principal significance to be considered in a potential DPS will be the 
significance to the taxon to which it belongs'' (61 FR 4722, 4724; 
February 7, 1996). Finally,we assessed the biological and ecological 
significance of the seals in Iliamna Lake to the P. v. richardii (the 
eastern North Pacific harbor seal) taxon in light of Congressional 
guidance that the authority to list DPSs be used ``sparingly'' while 
conserving the genetic diversity of the species (see Senate Report 151, 
96th Congress, 1st Session).
    Persistence in an Unusual or Unique Ecological Setting: In 
assessing the ``persistence of the discrete population segment in an 
ecological setting unusual or unique for the taxon,'' we considered 
whether specific characteristics of the Iliamna Lake environment are 
unusual or unique; whether persistence in the Iliamna Lake environment 
is unusual or unique; and whether there are adaptations as a result of 
persistence in an unusual or unique environment which would result in 
the discrete population being biologically or ecologically significant 
to the taxon P. v. richardii.
    The diet of harbor seals in Iliamna Lake is consistent with what we 
would expect for the species occupying a freshwater system dominated by 
anadromous salmon. Hauser et al. (2008) indicate that harbor seals in 
Iliamna Lake consumed large amounts of sockeye salmon when they were 
seasonally abundant, and also fed on trout, char, graylings, lampreys, 
smelts, sculpins, whitefishes, sticklebacks, and other unidentified 
prey items. Burns et al. (2013) examined eight harbor seal stomachs 
collected from seals harvested from Iliamna Lake in 2011 and 2012; only 
three had identifiable prey items and the remaining five stomach were 
either empty, only had worms, or had unidentifiable contents. An 
examination of the identifiable prey items found that these seals had 
consumed small or young salmonids (salmon and/or trout), threespine 
stickleback, and Arctic grayling or lake whitefish (Burns et al., 
2013). The variety and types of prey items in the diet of these sampled 
seals in Iliamna Lake reflects harbor seals being opportunistic feeders 
(Carretta et al., 2015), and the available data suggest no unusual or 
unique prey for the habitat occupied.
    We also considered whether the habitat available for use by seals 
in Iliamna Lake is unusual or unique. Harbor seals commonly use reefs, 
sand and gravel beaches, sand and mud bars, island beaches, and ice 
(glacial ice, pan ice, sea ice, or icebergs) as haul-out sites. Harbor 
seals in Iliamna Lake are known to haul-out on rocky and sandy 
substrates, sand bars, small islands, and ice near pressure cracks or 
polynas (Burns et al., 2011; Burns et al., 2012). None of these haul-
out substrates are unique or unusual for harbor seals. Harbor seals in 
Iliamna Lake are reported to pup both on ice (Burns et al. 2013) and 
other haul-outs in the absence of ice. There is no evidence of seals in 
Iliamna Lake pupping in air pockets beneath the ice, which would be 
unusual. Such use has been hypothesized for the harbor seals in the 
Lacs des Loups Marins (Consortium Gilles Shooner & Associes et al. 1991 
as cited in Smith 1997; DFO 2016). According to LTK, pupping in Iliamna 
Lake likely occurs at island beaches or sandbars in the northeastern 
portion of the lake, which is consistent with the types of substrates 
upon which aerial surveys documented pups (i.e., on low-lying islands 
and sand spits; Burns et al., 2013). Nothing suggests that harbor seals 
in Iliamna Lake display unusual or unique pupping behaviors (including 
habitat usage).
    Smith and Horonowitsch (1987) studied the ice at one location 
within the Lacs des Loups Marins and documented what they refer to as 
``shoreline ice-steps'' which they speculated could be used as 
breathing chambers for over-wintering seals in the lake. LTK suggests 
the presence and use of similar under-ice haul-outs in Iliamna Lake 
(Burns et al., 2013). While this would represent unusual habitat use 
for harbor seals in general, and unique habitat for harbor seals of P. 
v. richardii, it would be consistent with the general observation that 
harbor seals exhibit wide variation in habitat use, rather than being 
indicative of an adaptation by seals in Iliamna Lake that would be 
significant to the P. v. richardii taxon as a whole (see further 
discussion of habitat adaptation below).
    Harbor seals have the broadest distribution and occur in more 
different habitats than any other pinniped species (Burns 2002; COSEWIC 
2007), and are frequently and commonly observed in freshwater systems 
(Burns 2002). Mansfield (1967) provides information about sightings of 
harbor seals in rivers and lakes in Arctic Canada (referencing Doutt 
1942 and Harper 1961 for detailed summaries of Arctic harbor seals' 
freshwater distribution), indicating that harbor seals have ``a strong 
liking for fresh water'' and are often found in estuaries and 
freshwater habitats ``far from the sea.'' Beck et al., (1970) report 
harbor seals in the Thlewiaza River system and associated lakes west of 
Hudson Bay. Smith et al. (1994) and Smith (1997) provide an extensive 
list of reports of harbor seals documented in freshwater systems. Smith 
et al. (1996) conducted analyses involving both the Lacs des Loups 
Marins harbor seals as well as a second group of ``lacustrine'' harbor 
seals from Kasegalik Lake in Canada's Northwest Territory. Middlemas et 
al. (2006) provide documentation of harbor seals in a Scottish river 
system. The Committee on the Status of Endangered Wildlife in Canada 
(COSEWIC) reports that harbor seals occasionally ascend the St. 
Lawrence River to the Great Lakes (COSEWIC 2007). In the Bristol Bay 
region, harbor seals have been observed in other lakes in addition to 
Iliamna Lake, such as Lake Becharof and Naknek Lake (Mathisen and Kline 
1992). Thus, the presence of harbor seals in freshwater systems or 
lakes, including Iliamna Lake, is not unusual or unique for the 
species.
    Year-round persistence of harbor seals in a lake is less common. 
Besides the unknown number of harbor seals

[[Page 81084]]

occupying Iliamna Lake through the winter, the Lacs des Loups Marins 
harbor seals are the only other documented instance of harbor seals 
persisting in freshwater systems year-round. However, a review of 
available literature suggests the possibility this scenario may be more 
prevalent than just these two groups of harbor seals. For example, 
Mansfield (1967) states that the population of freshwater harbor seals 
in the Upper and Lower Seal Lakes east of Hudson Bay (a.k.a. the Lacs 
des Loups Marins) is not unique given reports of harbor seals found in 
other freshwater systems of Canada. Beck et al. (1970) postulated that 
harbor seals may live in the Thlewiaza River and associated lakes year-
round, and documented a pup in the Edehon Lake, leading them to 
conclude that harbor seal reproduction is successful in that freshwater 
habitat. Beck et al. (1970) also concluded that individual seals in 
those lakes may be born and spend most or all of their lives in 
freshwater, but there was no reason to believe they were an isolated 
population. In Alaska, winter aerial surveys led Savarese and Burns 
(2010) to suggest that harbor seals are present year-round in Vitus 
Lake, a tidally-influenced lake near the Bering Glacier. No pups were 
documented during that study and diet and genetic data indicated seals 
from various stocks moved into Vitus Lake to take advantage of local 
salmon runs (Savarese and Burns 2010). These reports of potential year-
round presence of harbor seals in various freshwater systems are 
sporadic, and do not confirm self-sustaining populations exist in those 
other freshwater systems. Therefore, it is reasonable to conclude that 
the year-round persistence of a discrete population of harbor seals in 
the freshwater environment of Iliamna Lake is at least unusual, if not 
unique, to the P. v. richardii harbor seal taxon.
    The BRT considered whether the persistence of the population of 
harbor seals in this setting is important to the taxon as a whole (see 
discussion in Boveng et al., 2016). Specifically, the BRT considered 
whether harbor seals in Iliamna Lake exhibit any adaptations to the 
environment which would be biologically or ecologically significant to 
the P. v. richardii harbor seal taxon. The evidence of such adaptations 
is not necessarily required to demonstrate significance; however, the 
BRT examined such evidence here in light of harbor seals' widespread 
and diverse habitat and diet. The BRT considered the physiology of the 
seals in Iliamna Lake as well as their over-wintering strategy as 
possible indicators of adaptations of potential importance for the 
taxon.
    As previously discussed, some local residents of the Iliamna Lake 
region have suggested they think the harbor seals harvested from 
Iliamna Lake taste, look, or feel different (e.g., seals are fatter; 
pelage is softer) from those harvested in the marine environment (Burns 
et al., 2013). There was, however, a lack of consensus regarding the 
perceived differences (e.g., some say seals from Iliamna Lake are 
darker than marine counterparts, others say the seals are lighter) 
among the local residents interviewed. Moreover, attributes such as 
fatness and softness of the coat, or the way the seals taste when 
consumed, are not necessarily inherited traits and could be acquired 
during time spent in the lake. Unlike other lake seal species, there 
are no data available to document whether morphological (e.g., 
craniometric) differences exist; if such morphological differences are 
present, they are not distinct enough to be generally recognized in 
traditional knowledge of Alaska Native residents in the area (see 
discussion in Boveng et al., 2016). There is no evidence to suggest 
these reported physical differences in fatness, softness, or taste are 
adaptations that would convey significance of these seals to the taxon.
    The use of air gaps under the ice in winter is a potential 
adaptation to freshwater life in sub-Arctic regions, and is only 
documented among harbor seals in one location (P. v. mellonae of Lacs 
des Loups Marins). Whether the use of under-ice shelters would be a 
true adaptation to a freshwater environment which freezes over, or 
would simply be a response to habitat conditions that may be used by 
any harbor seal exposed to those conditions, remains uncertain. On the 
importance of this particular behavior relative to significance of 
seals in Iliamna Lake to the P. v. richardii subspecies, the BRT 
concluded any assessment would ``be in the realm of judgment or even 
speculation'' (Boveng et al.,2016). Even though harbor seals in Iliamna 
Lake cope with the extensive ice cover in winter, there is no 
indication they have adapted or modified their breeding, whelping, or 
pup-rearing behaviors in a manner unusual for, or of significance to, 
the taxon.
    The BRT members were in strong agreement that harbor seals 
persisting year-round and breeding in a freshwater lake that freezes 
over almost completely nearly every year is unique for the subspecies 
P. v. richardii, and unusual for the harbor seal species. However, 
there was a lack of consensus amongst BRT members whether the available 
evidence reflects physical, life-history, or other adaptations as a 
result of persisting in an unusual or unique ecological setting which 
would make the harbor seal population in Iliamna Lake biologically or 
ecologically significant to the broader taxon. The discrepancies in 
opinion stemmed from ``differences in assessing the weights of several 
lines of qualitative and indirect evidence'' (Boveng et al., 2016). The 
BRT also concluded (1) seals from the marine population would be able 
to persist in the Iliamna Lake setting, and (2) even if seals from the 
marine population were unable to persist in Iliamna Lake, the ``lack of 
`ecological exchangeability' is not important to the persistence of the 
taxon as a whole'' (Boveng et al., 2016). Ultimately, the BRT's 
assessment favored ``a conclusion that the evidence does not support 
significance'' (Boveng et al., 2016). We agree that persistence of a 
population of harbor seals in the unusual or unique ecological setting 
of Iliamna Lake in and of itself does not confer significance of that 
population to the taxon. The absence of evidence suggesting the harbor 
seals in Iliamna Lake have adaptations to their environment which would 
benefit the taxon to which they belong leads us to determine that the 
persistence of a population of harbor seals in Iliamna Lake is not 
significant to the subspecies P. v. richardii.
    Evidence That Loss Would Result in Significant Gap in Range: 
Eastern North Pacific harbor seals range from Mexico northward along 
the coastlines of the continental U.S. and Canada and much of Alaska. 
In Alaska, harbor seals of this subspecies are distributed almost 
continuously throughout the southern coastal waters in the region 
surrounding Iliamna Lake. In assessing whether the loss of harbor seals 
in Iliamna Lake would result in a significant gap in the range, we 
considered a scenario whereby all the seals in the lake were extirpated 
and there was no migration into the lake, either because there is no 
migration currently occurring or because a future physical barrier 
prevents migration. Given the extensive and continuous range of the 
eastern North Pacific harbor seals, the loss of the small proportion of 
habitat in Iliamna Lake would not result in a significant gap in the 
range. Furthermore, the evidence indicating possible seasonal movement 
of some harbor seals from Bristol Bay to Iliamna Lake suggests that the 
habitat in this portion of the range could be reoccupied.
    The loss of harbor seals in Iliamna Lake would not have a 
detrimental impact to other harbor seal populations

[[Page 81085]]

that comprise the subspecies P. v. richardii, as this is not an 
interstitial population of harbor seals whose loss would isolate 
another population from the main group. Additionally, there are only an 
estimated 400 harbor seals in Iliamna Lake (Boveng et al., 2016), so 
this population represents a minute fraction of the total population 
ofeastern North Pacific harbor seals, estimated at 360,000 (DFO 2010).
    The BRT was in strong agreement that the evidence is clear that the 
loss of the Iliamna Lake segment would not result in a significant gap 
in the range of the taxon, and we agree.
    Evidence of Only Surviving Natural Occurrence: Harbor seals in 
taxon P. v. richardii are currently found throughout their historic 
range along the coasts from Baja California, Mexico, northward to 
Alaska, and west through the Gulf of Alaska and Aleutian Islands, and 
in the Bering Sea north to Cape Newenham and the Pribilof Islands. 
There are no known introductions of this species to any place outside 
its historic range, thus it is naturally occurring wherever it occurs. 
The BRT was unanimous in its assessment that harbor seals in Iliamna 
Lake are not the only surviving natural occurrence of the taxon. We 
concur in that determination.
    Evidence of Marked Difference in Genetic Characteristics: As 
discussed above, the limited genetic data available from seals in 
Iliamna Lake indicate 11 of 13 (2 samples did not yield results) 
sampled seals had the same mtDNA haplotype, an indication of possible 
low genetic diversity (O'Corry-Crowe 2013). Unlike the Lacs des Loups 
Marins harbor seals, which exhibit mtDNA haplotypes that are only found 
in seals from the Lacs des Loups Marins (Smith 1997), the single mtDNA 
haplotype exhibited in the harbor seals in Iliamna Lake is not unique 
to Iliamna Lake. Rather, it is the most common mtDNA haplotype found in 
samples from harbor seals in Bristol Bay (O'Corry-Crowe 2013; Van Lanen 
et al., 2013). One plausible explanation for the single haplotype found 
in all the harbor seal samples from Iliamna Lake is that these seals 
are simply a genetic subset of seals from Bristol Bay, and have lost 
rather than gained substantial amounts of genetic diversity since 
isolation. An alternative explanation is the seals in Iliamna Lake have 
been isolated a long time, during which they may have accumulated 
genetic differences at other loci (not currently examined) via 
mutation, especially for loci under selective pressure (i.e., 
adaptation). However, as previously discussed, only a small number of 
genetic loci were tested and the sample size was small, so the reason 
for a single mtDNA haplotype is undeterminable at this time. We 
conclude that the best scientific and commercial data available, a 
single mtDNA haplotype which is commonly found in other populations of 
the taxon and the data used to assess discreteness of the population, 
do not indicate that harbor seals in Iliamna Lake have novel genes 
which could be significant to the taxon as a whole.
    There is no strong evidence to indicate the existence of phenotypic 
differences between harbor seals in Iliamna Lake and those in other 
portions of the taxon's range. Although there have been some LTK 
reports that the seals in Iliamna Lake may taste different or have 
pelage of varying appearance from seals in Bristol Bay, there have been 
no studies assessing whether these perceived differences are the result 
of significant differences in genetics. The BRT members did not reach 
consensus regarding this issue, with a slight preponderance of opinion 
favoring the conclusion that the genetic characteristics of seals in 
Iliamna Lake did not convey significance to these seals in regards to 
P. v. richardii. Some members considered the data available as mostly 
insufficient for drawing a conclusion regarding significance, and some 
considered the evidence against significance slightly more persuasive 
than the evidence for significance. Accordingly, we find that the 
genetic characteristics (i.e., mtDNA haplotype) found in seals from 
Iliamna Lake do not differ markedly from those found in Bristol Bay and 
therefore determine that the best available genetic data, albeit 
limited, supports a conclusion that harbor seals in Iliamna Lake do not 
have genetic characteristics that are significant to the taxon as a 
whole.
    Overall Significance to the Taxon: We considered several factors 
that could indicate whether harbor seals in Iliamna Lake may be 
biologically and ecologically significant to the taxon as a whole. Of 
the four factors delinated in the 1996 DPS policy, we conclude that 
there is evidence of only one: The population persists in an unusual or 
unique setting for the taxon. As we explained in our policy, 
``occurrence in an unusual ecological setting is potentially an 
indication that a population segment represents a significant resource 
of the kind sought to be conserved by the'' ESA and in ``any actual 
case of a DPS recognized in part on this basis, the Services will 
describe in detail the nature of this significance when accepting a 
petition or proposing a rule'' (61 FR at 4724). While year-round 
persistence in the freshwater environment of Iliamna Lake is unique to 
the taxon P. v. richardii and unusual for the entire species, we agree 
with the BRT (Boveng et al., 2016) that the best scientific and 
commercial data available are limited and suggest that the persistence 
of the seals in Iliamna Lake is not significant to the taxon as a 
whole. The loss of the Iliamna Lake segment would not result in a gap 
in the range of the taxon, and the harbor seals in Iliamna Lake are not 
the only surviving natural occurrence of the taxon; thus harbor seals 
in Iliamna Lake do not demonstrate significance to the taxon based on 
these factors. Further, available genetic data suggest that harbor 
seals in Iliamna Lake are not significant to the larger taxon. Although 
the best available genetic data indicate that at least some of the 
seals in Iliamna Lake are distinct from harbor seals in the eastern 
regions of nearby Bristol Bay, the genetic characteristics (e.g., the 
single mtDNA observed in samples from seals in Iliamna Lake is the most 
common haplotype found in seals frim Bristol Bay) do not appear to 
differ in ways that would convey significance to the P. v. richardii 
subspecies.
    Individual BRT members were not in agreement regarding the degree 
of scientific support overall for or against the significance of seals 
in Iliamna Lake to the P. v. richardii subspecies, but stated ``the 
slight majority judgment against significance of the population segment 
. . . summarized a diversity of views about how much weight to place on 
the various lines of mostly weak and qualitative evidence'' and that 
``the evidence itself must be characterized as mostly indirect, 
qualitative rather than quantitative, and equivocal for the purpose of 
demonstrating biological or ecological importance to the broader 
taxon'' (Boveng et al., 2016). Taking into consideration the totality 
of all the information discussed above regarding the possible 
significance of harbor seals in Iliamna Lake to the P. v. richardii 
taxon, including the qualitative and equivocal nature of the available 
information, along with the guidance from legislative history to 
identify DPSs ``sparingly,'' we find that the available evidence 
supports a conclusion that the harbor seals in Iliamna Lake are not 
significant to the remainder of the taxon.

DPS Conclusion

    Based on the best scientific and commercial data available, we find 
the evidence for marked separation of harbor seals in Iliamna Lake from 
the remainder of the taxon based on physical, physiological, ecological 
or behavioral factors to be unconvincing or

[[Page 81086]]

weak. The strongest support for marked separation comes from the best 
available genetic data which, although limited and preliminary, support 
a conclusion that at least some of the harbor seals in Iliamna Lake are 
likely isolated from harbor seals in the Egegik and Ugashik regions of 
eastern Bristol Bay. Thus, we conclude that the harbor seal population 
in Iliamna Lake is separated from other populations of the taxon and 
meet the discreteness criterion of our DPS policy (61 FR 4722; February 
7, 1996).
    Per the second component of our DPS Policy, we are to consider 
available scientific evidence of the discrete population's importance 
to the taxon to which it belongs (61 FR 4722; February 7, 1996). Our 
review of the best available information suggests the only 
characteristic which may make this population of harbor seals unique 
within its taxon is the fact that they persist year-round in a 
freshwater system which freezes over to some degree in most winters. 
While that characteristic is unique within the subspecies P. v. 
richardii, we determined such persistence is not biologically or 
ecologically important to the taxon as a whole. Furthermore, the 
information available supports a conclusion that loss of this 
population would not be detrimental to the persistence of the taxon or 
constitute a gap in the range of the taxon; this population is not the 
only natural surviving population; and there are no unique genetic 
characteristics conveying significance of this population to the taxon. 
After reviewing the best available data as they apply to the 
significance criterion, we conclude that the harbor seals in Iliamna 
Lake are not significant to the taxon P. v. richardii.
    Under our DPS Policy, both the discreteness and significance 
elements must be met to qualify as a DPS. Our review has determined 
that the seals persisting year-round in Iliamna Lake are discrete but 
not significant; therefore, the harbor seals in Iliamna Lake do not 
qualify as a DPS and are not a listable entity under the ESA.

Finding

    In assessing whether the actions in the petition are warranted, we 
reviewed the best available scientific and commercial information 
available, including the BRT report, the petition and literature cited 
in the petition, published and grey literature relevant to the topic, 
correspondence with experts in academic and government institutions, 
documentation of LTK, and public comments. On the basis of this review, 
we have determined that harbor seals in Iliamna Lake meet the criteria 
for discreteness but do not meet the criteria for significance. As 
such, the harbor seals in Iliamna Lake do not meet all the criteria 
necessary to constitute a DPS, and thus are not a listable entity under 
the ESA. Therefore, we find that the petitioned actions to list the 
harbor seals in Iliamna Lake as a threatened or endangered species 
under the ESA, and to designate critical habitat, are not warranted.
    In our 90-day finding (78 FR 29098; May 17, 2013), we indicated we 
were commencing a status review of the harbor seals in Iliamna Lake. To 
assist our evaluation of whether the seals in Iliamna Lake constitute a 
DPS, the BRT prepared a report which compiled background information 
about the harbor seals in Iliamna Lake and evaluated the scientific 
information relevant to the DPS criteria (Boveng et al., 2016). Upon 
our determination that the DPS criteria were not met and the seals in 
Iliamna Lake are not a ``species'' under the ESA, there is no need to 
complete the status review by conducting a threats assessment or 
extinction risk assessment in light of the factors in section 4(a)(1) 
of the ESA.
    In some instances, where we find a petitioned action is not 
warranted because the petitioned population does not constitute a 
``species'' under the ESA, we have initiated a status review of a 
related or larger population (e.g., the 12-month determination that the 
petitioned action to list Lynn Canal Pacific herring was not warranted, 
followed by a status review of the Southeast Alaska population of 
Pacific herring; 73 FR 19824; April 11, 2008). Here, the scope of the 
petition was limited to the seals in Iliamna Lake, and since the most 
recent abundance data for the Bristol Bay harbor seal stock (the stock 
that includes seals in Iliamna Lake) indicates this stock increased 
from an estimated 18,577 seals in 2005 to an estimated 32,350 seals in 
2011 (Allen and Angliss 2014; Muto and Angliss 2015), we are not 
initiating a status review of the Bristol Bay harbor seal stock at this 
time.

References

    A complete list of all references cited herein is available upon 
request (see ADDRESSES).

Authority

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

    Dated: November 10, 2016.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
[FR Doc. 2016-27690 Filed 11-16-16; 8:45 am]
 BILLING CODE 3510-22-P