The State of Circumpolar Walrus Populations

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activities are not well understood and require more thorough research and monitoring of these
animals. Lydersen et al. 2012:1555). A 15-mile exclusion zone on the development of onshore and
offshore infrastructure applying to the haulouts and surrounding water and shoreline, has been
recommended to protect walruses on the Vaigach (Lyamchin Peninsula), Matveyev, Britvin, and
Pukhovy islands (southern Novaya Zemlya); and on the Oranskiye islands, and Cape Konstantin
(northern Novaya Zemlya) which, as part of the National Park, already have a 12-mile protected
zone (Semyonova et al. 2015; M. Gavrilo pers. comm.).
Shelf regions of the Laptev Sea are polluted by a number of inland industries and activities
(Tsyban et al. 2005). River run-off and atmospheric transport play an important role in marine
pollution. Sources of pollution include oil and gas exploration and production, inland water and
sea transport, ore mining and processing, accidental oil spills and discharges, and effluent from
towns and settlements situated on the coast and along rivers such as the Lena River (Tsyban et al.
2005). With the extended ice navigation season ships tend to use polynias, which are vitally
important habitat for walruses that overwinter in the Laptev Sea (M. Gavrilo, pers.comm.).
Oil and gas exploration blocks in the Chukchi Sea overlap with shallow, productive, ice covered
habitat used by a significant proportion of the Pacific walrus population each summer (Garlich-
Miller et al. 2011). The waters of the eastern Chukchi Sea are considered particularly important
habitat for female walruses and their dependent young. In 2009, 2010, and 2011 a number of
seismic surveys were conducted in the lease sale area (USFWS 2014). The USFWS monitors and
mitigates potential impacts of oil and gas activities on walruses through incidental take
regulations (ITR) as authorized under the MMPA (USFWS 2014; Allen and Angliss 2015). These
regulations require measures to ensure that impacts to walruses remain negligible, minimize
habitat impacts, and eliminate adverse impacts on walrus availability for subsistence use. The
current ITRs were renewed in 2013 for another five years (USFWS 2014). The Hanna Shoal area
seems to be particularly attractive to walruses summering in the Chukchi Sea, and the current
ITRs also provide special considerations to limit potential impacts to walruses utilizing this area
(USFWS 2014). Current levels of oil and gas exploration are considered to pose a relatively minor
threat to the Pacific walrus population (USFWS 2011), but a large oil spill could significantly
impact the population depending on timing, location, amount and type of oil, efficacy of response
efforts, etc. (USFWS 2014).
Decreases in summer sea ice extent may lead to increased opportunities for commercial shipping
through the Arctic, leading to increased risk of disturbance, habitat modification (e.g., through
ice-breaking), and increased risk of spills and discharge of pollutants (Tynan and Demaster 1997;
Moore 2005; Laidre et al. 2008; Garlich-Miller et al. 2011). Transits through the Bering Strait
have increased significantly in recent years and are currently outpacing regulatory efforts to