PEBBLE WATCH FACT SHEET

Key terms Population — In general, scientists use the term population to refer to a component or subgroup of individuals within a species or subspecies that share a common geographic region during one or more periods of their life cycle. For instance, marine mammal biologists might refer to the population of harbor seals, or the discrete population of Iliamna Lake seals. (Dave Withrow / NOAA Fisheries) Stock — The Marine Mammal Protection Act (MMPA) defines a marine mammal stock as a group of Iliamna Lake Harbor Seals individuals “of the same species or smaller taxon in a common spatial When we think of harbor seals, we picture them in the shifting tides and arrangement that interbreed when seaweed covered rocks of saltwater coastal zones. But imagine walking mature.” The Iliamna Lake seal is a along a lakeshore and finding a population of seals in the lake. subgroup of the stock of harbor seals. This is the case of the rare Iliamna Lake seal, which scientists consider to be a discrete QUICK READ Substock — A portion of a stock. This population of the Bristol Bay stock of the eastern portion may or may not be discrete. • There are about 400 Pacific harbor sealsubspecies (Phoca vitulina Iliamna Lake seals. Species — A biological ranking below richardii). The eastern Pacific harbor seal is one genus of a population potentially of six species of true seals in Alaska. • They are the only freshwater harbor capable of interbreeding. Of the true seals, Lake Iliamna seals are unique seal population in the Subspecies — A population of a in that they likely spend their entire life cycle United States. particular geographic region within isolated in the freshwater of Lake Iliamna. In • Scientists believe the a species. A biological ranking below fact, Iliamna Lake seals are one of only five seals stay in Iliamna species. populations of freshwater seals of the world. Two, Lake for their entire lifecycle. Endemic — Organisms that exist including Iliamna Lake seals, are members of the only in one geographic region. harbor seal species. The other three are of the • Some proposed Usually an area that contains genus Pusa and occur in arctic Eurasia, including components of the include a endemic species is isolated in the Baikal Seal which is endemic to Lake Baikal. some way, so that species have ferry transport across Iliamna Lake. difficulty spreading to other areas, Some freshwater seal populations resulted from or it has unusual environmental land rising after ice retreated 9,000 to 11,000 • There is concern for the characteristics to which the endemic years ago. However, Iliamna Lake seals were welfare of the seals if species is uniquely adapted. likely established 200 to 5,000 years ago by their habitat is used as a transportation corridor. marine seals swimming up the , and See page 5 for a list of references used to develop this fact sheet. currently comprise about 400 individuals. near the

Iliamna Lake

Iliamna Lake, Alaska's largest freshwater lake, is situated in the Bristol Bay region. The islands on the east end of the lake are the seals’ primary habitat. Credit: Jason Ching/University of Washington

Habitat and Movements 2019, scientists compared isotope ratios in teeth between Iliamna Lake Iliamna Lake seals inhabit Alaska’s The Iliamna Lake seals and Bristol Bay harbor seals to largest freshwater lake, which covers Monster Mystery determine if seals consumed prey an area great than 1,000 square from salt water or freshwater. Their People have reported miles and measures up to 1,000 results support the hypothesis that seeing glimpses of a large feet deep. During winter, the lake is Iliamna Lake seals are lifelong lake sea creature in Lake Iliamna typically covered in ice, but seals use residents and rely principally on since the late 1940s. Village cracks, leads, and polynyas to find resources produced in the lake. residents consistently tell air pockets and other areas of open of huge aquatic creatures water. They are difficult to detect, Importance for Subsistence in the lake. The Anchorage because they stay hidden, utilizing Several native villages surround Lake Daily News once offered subnivean habitat under the snow- Iliamna, including Newhalen, Iliamna, a reward for proof of the and ice-covered lake. In summer, Pedro Bay, Igiugig and Kokhanok. “monster’s” existence. In the seals use island haulouts in the These communities have relied on 2019 researchers Bruce northeastern end of the lake. Iliamna Lake seals as a subsistence Wright and Charlotte Iliamna Lake seals prey upon lake resource for generations. Annually Levy used a two-pronged fish such as lamprey, smelt, sculpin, the harvest is about 24 seals, and the approach to further research whitefish, and sticklebacks, as well as meat, blubber and hide are prized. the mystery: they employed taking advantage of the seasonally deep water video cameras abundant anadromous sockeye. In Hunters and elders report that the and collected water seals in the lake are larger and fatter samples to be analyzed for KEY TERMS than nearby marine harbor seals. The DNA. Some say it’s a large coats of lake seals are considered to sleeper shark. Others bet Polynya – a stretch of open water be softer than those in salt water. This on a sturgeon. For now, it surrounded by ice, especially in Arctic seas observation is consistent with those remains a mystery. Subnivean – Spaces below snow above reported for the freshwater harbor frozen lakes seal population in eastern Canada.

2 near the

(Dave Withrow / What kind of seal NOAA Fisheries) is that?

Want to quickly impress your friends on your next sealife cruise or visit to the aquarium? Look closely at a seal’s ears and flippers. True Seals lack external ear flaps and are classified in the family Phocidae. Their flippers point backward and don’t rotate, making movement in water graceful and movements on land cumbersome. Eared Seals have external ear flaps and are classified in the family Otariidae. Flippers can rotate forward, allowing them to walk on all Could the Pebble project impact Iliamna Lake seals? fours. (Think of sea lions, which are considered eared seals.) The Pebble project, currently in permitting, includes three alternatives that envision a ferry crossing of Iliamna Lake, as well as a natural gas pipeline built under the lake. Pebble Limited Partnership (PLP) prefers an alternative that bisects the lake from north to south. PLP Population Surveys contends that developing a ferry system across Iliamna Lake would not Iliamna Lake seals were first present a threat to seals, but concerns from the public, environmental documented by Russian explorers organizations, native communities and scientists abound. in 1819. In modern times, The Center for Biological Diversity has petitioned NOAA Fisheries to list information from Local Traditional Iliamna Lake seals under the Endangered Species Act, stating that “Mine Knowledge (LTK) and aerial operations would include year-round use of an icebreaker ferry, which surveys (private, local, state and would destroy lake ice relied upon by seals during the winter and run federal) are used to describe immediately adjacent to critical haul-out, pupping and fishing areas.” distribution and abundance of (read more on page 4). these unique seals. Additionally, Native communities are concerned that disturbance of Following a period of growth seals due to increased traffic would impact their way of life. This concern in the 1980s, the lake’s seal led local citizens to conduct their own aerial surveys and to participate population has stabilized to about with scientists to better understand the biology of Iliamna Lake seals. 400 individuals. The production rate (seals produced annually) Scientific studies point towards impacts. Endemics species are more estimate was about 5% per year, suspectable to cumulative effects of disturbance and climate change. similar to the harvest rate. In other regions of Alaska, NOAA Fisheries scientists found the risk of flushing harbor seals in glacial fjords increased when cruise ships In a recent study, scientists approached within 500-m. They argue that their findings indicate the determined that, in the absence need to develop regulations to maintain a 500-m separation between of a catastrophic event, there is a ships and seals in all Alaska glacial fjords. 1% to 3% risk of quasi-extinction (defined as a population of less Another NOAA Fisheries study found high potential for broad-scale than 50 animals in the next 100 disturbance by a single vessel, and underscores the need to develop years) of Iliamna Lake seals. conservation measures to reduce seal-ship overlap in an Alaska glacial fjord. The authors emphasize that results should be applied cautiously due to the limitations of their risk model.

www.pebblewatch.com - Impartial, educational, fact-based 3 Scientific Classification: Current Status and Jurisdictions related to Pebble Iliamna Lake harbor seal The Marine Mammal Protection the eastern North Pacific, and thus Kingdom Animalia Act gives the authority to conserve were not listed under the ESA. Phylum Chordata and manage seals and other Class Mammalia NOAA Fisheries acknowledged marine mammals to the National Order Carnivora that Iliamna Lake is a unique Marine Fisheries Service of the Family Phocidae ecological setting for seals, but National Oceanic and Atmospheric Genius Phoca concluded loss of seals at that Species Phoca vitulina Administration, often referred to site would not create a gap in the Subspecies Phoca vitulina richardii as NOAA Fisheries. The Alaska taxon’s range. Stock Bristol Bay Department of Fish and Game also Discrete Lake Iliamna seals maintains a strong presence in In February 2020 the Center Population marine mammal conservation due for Biological Diversity again to the great importance of these petitioned to list the seal under species to Alaska. the ESA. As of May 2020, NOAA are reliant on salmon from a Fisheries is determining if the Endangered Species? single basin (e.g. Iliamna Lake), current petition warrants another constraining their access to food A species, subspecies or a Distinct review. if local salmon are depleted. Population Segment (DPS) can be considered for protection under New study points to How could an ESA listing the US Endangered Species Act susceptibilities impact the Pebble project? of 1973 (ESA). In 2012 the Center In a 2019 scientific study, The U.S. Army Corps of for Biological Diversity petitioned researchers used stable isotopes Engineers is analyzing the Pebble NOAA Fisheries to list the Iliamna to determine that Iliamna Lake project to determine the Least Lake seal under the ESA. seal food sources are acquired Environmentally Damaging Iliamna Lake seals are not exclusively from the lake. This Practicable Alternative (LEDPA). scientifically recognized by indicates a lack of migratory NOAA Fisheries as a species or a connectivity to the Bristol Bay If Iliamna Lake seals were to subspecies, so must qualify as a harbor seal population, and thus be listed as endangered or DPS to be considered for listing provides support to the argument threatened under the ESA, (much like the Beluga that this population is endemic the lake and its resident fishes Whale). to Iliamna Lake. Researchers could be considered critical note that Iliamna Lake seals have habitat. This would decrease the The primary attributes of a DPS a unique foraging ecology that likelihood that a ferry crossing are a population’s discreteness makes them more susceptible to would be permitted. and significance. In 2016, NOAA declines in marine food availability. Fisheries ruled that while the seals The researchers argue that while are a discrete population, they marine seals can take advantage are not ecologically significant to of salmon stocks from many the subspecies of harbor seals in river basins, Iliamna Lake seals

Distinct Population Segments (DPS) that is markedly separated from other About Pebble Watch populations of the same taxon as a Pebble Watch is an impartial, Under the Endangered Species Act, a consequence of physical, physiological, educational and fact-based resource for discrete DPS of a vertebrate population is ecological or behavioral factors. sharing information about the proposed from other populations of the species and Pebble project. It is a program of the significant in relation to the entire species. Significant– A population is significant if Bristol Bay Native Corporation Land it is important to the overall welfare of the Department. Questions? Write info@ Discrete pebblewatch.com. – A discrete population is one entire species.

4 References

ABR, Environmental Research and Burns, J. M., Van Lanen, J. M., Jansen, J. K., Boveng, P. L., Dahle, S. Service. 2011. Wildlife and habitat, Withrow, D., Holen, D., Askoak, P., & Bengtson, J. L. 2010. Reaction Bristol Bay drainages. In Pebble T., Aderman, H., … Jones, B. of Harbor Seals to Cruise Ships. The Project Environmental Baseline 2016. Integrating local traditional Journal of Wildlife Management, Document 2004-20008 (Chap. 16) knowledge and subsistence use 74(6), 1186–1194. doi: 10.1111/ Pebble Limited Partnership. patterns with aerial surveys to improve j.1937-2817.2010.tb01239.x scientific and local understanding ADFG 2012. Iliamna Lake Seals Local Jansen, J. K., Brady, G. M., Hoef, J. of the Iliamna Lake seals (Technical and Scientific Understanding. M. V., & Boveng, P. L. 2015. Spatially Paper No. 416). Juneau, AK: Alaska Estimating Disturbance of Harbor Boveng, P. L., Hoef, J. M. V., Withrow, Department of Fish and Game, Seals (Phoca vitulina). Plos One, 10(7). D. E., & London, J. M. 2018. A Division of Subsistence. doi: 10.1371/journal.pone.0129798 Bayesian Analysis of Abundance, Christman, C. L., and P. L. Boveng. Trend, and Population Viability for Mathisen, O. A., & Kline, T. C. 2019. Aerial surveys of freshwater Harbor Seals in Iliamna Lake, Alaska. 1992. Harbor seals in Iliamna Lake, harbor seals in Iliamna Lake, Alaska: Risk Analysis, 38(9), 1988–2009. doi: Bristol Bay, Alaska (final report on 2017–2018. AFSC Processed Rep. 10.1111/risa.12988 aerial census in 1991, jcdos 9203). 2019-03, 18 p. Alaska Fish. Sci. Cent., (Technical Report). Fairbanks, AK: Boveng, P. L., S. P. Dahle, J. K. Jansen, NOAA, Natl. Mar. Fish. Serv., 7600 Juneau Center for Fisheries and J. M. London, B. L. Taylor, and D. E. Sand Point Way NE, Seattle WA Ocean Sciences, University of Alaska Withrow. 2016. Scientific evaluation 98115. Fairbanks. of the distinctness of harbor seals COSEWIC. 2007. COSEWIC (Phoca vitulina) in Iliamna Lake. Small, R. J., Boveng, P. L., Byrd, G. V., assessment and update status report Report from the NOAA Alaska & Withrow, D. E. 2008. Harbor seal on the harbour seal Atlantic and Fisheries Science Center to the population decline in the Aleutian Eastern Arctic subspecies Phoca NOAA Fisheries Alaska Region Office. Archipelago. Marine Mammal vitulina concolor and Lacs des Loups Marine Mammal Laboratory, Alaska Science. doi: 10.1111/j.1748- Marins subspecies Phoca vitulina Fisheries Science Center, 7600 Sand 7692.2008.00225.x mellonae in Canada. Committee on Point Way NE, Seattle, WA 98115, the Status of Endangered Wildlife in Spafard, M. A., and J. A. Edmundson. U.S.A. 56 pp. Canada. 40 p. 2000. A morphometric atlas of Brennan, S. R., Fernandez, D. P., Alaskan lakes: Cook Inlet, Prince Hauser, D. D. W., Allen, C. S., Rich, Burns, J. M., Aswad, S., Schindler, William Sound, and Bristol Bay areas. H. B., & Quinn, T. P. 2008. Resident D. E., & Cerling, T. E. 2019. Isotopes Regional Information Report No. Harbor Seals (Phoca vitulina) in in teeth and a cryptic population of 2A00-23. Alaska Department of Fish Iliamna Lake, Alaska: Summer Diet coastal freshwater seals. Conservation and Game, Commercial Fisheries and Partial Consumption of Adult Biology, 33(6), 1415–1425. doi: Division, Anchorage, AK. Sockeye Salmon (Oncorhynchus 10.1111/cobi.13303 nerka). Aquatic Mammals, 34(3), 303– Russian Exploration in Southwest 309. doi: 10.1578/am.34.3.2008.303 Alaska: The Travel Journals of Petr Korsakovski (1818) and Ivan Ya, Vasilev (1829). Ed. James W. VanStone.

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