Hanna Shoal is a shallow, natural

shoal In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. It ...

located off the coast of northwest Alaska in the

Chukchi Sea Chukchi Sea ( rus, Чуко́тское мо́ре, r=Chukotskoye more, p=tɕʊˈkotskəjə ˈmorʲɪ), sometimes referred to as the Chuuk Sea, Chukotsk Sea or the Sea of Chukotsk, is a marginal sea of the Arctic Ocean. It is bounded on the west b ...

. The region around Hanna Shoal is one of the Chukchi Sea’s most biologically productive areas. As a biologically important region for marine mammals and seabirds, Hanna Shoal is an important hunting area for local people.Kuletz, K., M. Ferguson, B. Hurley, A. Gall, E. Labunski, and T. Morgan
"Seasonal spatial patterns in seabird and marine mammal distribution in the Pacific Arctic: Identifying biologically important pelagic areas"
"Progress in Oceanography", May 2015. Retrieved 2016-08-16. The Chukchi Sea is thought to contain significant oil and gas reserves, and the greater Hanna Shoal region has long been part of a public conversation about conservation and extraction.

Geography

This shallow underwater shoal diverts warm water masses flowing northward from the

Bering Sea The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...

and holds colder water long into the summer season, which in turn allows sea ice to persist longer in this area. While the shoal is no longer covered by continuous pack ice all year as it historically was, it still has the most reliable ice present on the entire Chukchi shelf.

Fauna

Due to the region’s high primary productivity, rich seafloor, and late summer sea ice, Hanna Shoal is a significant hot spot for wildlife. Pack ice and

ice floes An ice floe () is a large pack ice, pack of Drift ice, floating ice often defined as a flat piece at least 20 m across at its widest point, and up to more than 10 km across. Drift ice is a floating field of sea ice composed of several ice fl ...

are highly important haulout and resting areas for species like the

pacific walrus The walrus (''Odobenus rosmarus'') is a large flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the fa ...

polar bear The polar bear (''Ursus maritimus'') is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear specie ...

bearded seal The bearded seal (''Erignathus barbatus''), also called the square flipper seal, is a medium-sized pinniped that is found in and near to the Arctic Ocean. It gets its generic name from two Greek words (''eri'' and ''gnathos'') that refer to its h ...

, and

ringed seal The ringed seal (''Pusa hispida'') is an earless seal inhabiting the Arctic and sub-Arctic regions. The ringed seal is a relatively small seal, rarely greater than 1.5 m in length, with a distinctive patterning of dark spots surrounded by light g ...

. Hanna Shoal is also an important foraging area for many bird species. Species that have been identified in this region are

black-legged kittiwake The black-legged kittiwake (''Rissa tridactyla'') is a seabird species in the gull family Laridae. This species was first described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae'' as ''Larus tridactylus''. The English ...

black guillemot The black guillemot or tystie (''Cepphus grylle'') is a medium-sized seabird of the Alcidae family, native throughout northern Atlantic coasts and eastern North American coasts. It is resident in much of its range, but large populations from the ...

, crested auklet,

glaucous gull The glaucous gull (''Larus hyperboreus'') is a large gull, the second-largest gull in the world. It breeds in Arctic regions of the Northern Hemisphere and winters south to shores of the Holarctic. The genus name is from Latin ''larus'', which a ...

ivory gull The ivory gull (''Pagophila eburnea'') is a small gull, the only species in the genus ''Pagophila''. It breeds in the high Arctic and has a circumpolar distribution through Greenland, northernmost North America, and Eurasia. Taxonomy The ivory ...

northern fulmar The northern fulmar (''Fulmarus glacialis''), fulmar, or Arctic fulmar is a highly abundant seabird found primarily in subarctic regions of the North Atlantic and North Pacific oceans. There has been one confirmed sighting in the Southern Hemis ...

pomarine jaeger The pomarine jaeger (''Stercorarius pomarinus''), pomarine skua, or pomatorhine skua, is a seabird in the skua family Stercorariidae. It is a migrant, wintering at sea in the tropical oceans. Taxonomy Its relationships are not fully resolved; i ...

, and Ross’s gull.Drew, G., Piatt, J., and Renner, M
"User’s guide to the North Pacific Pelagic Seabird Database 2.0"
U.S. Geological Survey Open-File Report, July 2015. Retrieved 2016-08-18. A major migration corridor for several species crosses the Hanna Shoal region.

Bowhead whales The bowhead whale (''Balaena mysticetus'') is a species of baleen whale belonging to the family Balaenidae and the only living representative of the genus ''Balaena''. They are the only baleen whale endemic to the Arctic and subarctic waters, an ...

traveling past Barrow Canyon cross the region in autumn to access habitats in Russian waters, as do

beluga whales The beluga whale () (''Delphinapterus leucas'') is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus ''Delphinapterus''. It is also known as the whi ...

. Marine birds also migrate through this corridor, including Steller’s eider,

king eider The king eider (pronounced ) (''Somateria spectabilis'') is a large sea duck that breeds along Northern Hemisphere Arctic coasts of northeast Europe, North America and Asia. The birds spend most of the year in coastal marine ecosystems at high l ...

s, ivory gulls, and Ross’s gulls.

Importance

Hanna Shoal is likely to provide ecosystem resilience to climate change due to the stable physical features of the region that divert water masses and encourage lingering sea ice floes; these dynamics influence the rich seafloor and the local wildlife diversity. The unique combination of characteristics that distinguish Hanna Shoal as a key feature of the Chukchi Sea are likely to persist in future decades, making this area a priority for conservation over the long-term. As part of a

Bureau of Ocean Energy Management The Bureau of Ocean Energy Management (BOEM) is an agency within the United States Department of the Interior, established in 2010 by Secretarial Order. The Outer Continental Shelf Lands Act (OCSLA) states: "...the outer Continental Shelf is a vi ...

(BOEM) environmental stewardship program, the Hanna Shoal Ecosystem Study was launched. The Hanna Shoal Ecosystem Study is currently working to further reveal why the area is so highly productive. In 2008, the

Minerals Management Service The Minerals Management Service (MMS) was an agency of the United States Department of the Interior that managed the nation's natural gas, oil and other mineral resources on the outer continental shelf (OCS). Due to perceived conflict of intere ...

, the predecessor agency to BOEM, sold oil and gas leases in the Chukchi Sea, including in the Hanna Shoal region, for $2.67 billion. Companies, led by

Shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard ou ...

, pushed to drill exploration wells in the area. Hanna Shoal and the surrounding region influenced by its productivity were identified by conservation groups as an Important Ecological Areas of the U.S. Arctic Ocean. In 2015, one million acres of the Hanna Shoal region (defined by the 40-meter depth contour line) were removed from consideration for future oil and gas leasing activities. In addition, the 2017–2022 Outer Continental Shelf (OCS) Oil and Gas Leasing Program Draft Programmatic Environmental Impact Statement (DPEIS) recognized the Hanna Shoal Walrus Foraging Area and Walrus Movement Corridor as Environmentally Important Areas So far, attempted oil and gas development near the shoal has been unproductive. In 2015, one well was completed at the Burger prospect, roughly 10 miles from the Hanna Shoal important area. That well was unsuccessful, and as of July 2016, oil companies have relinquished all but one lease in the Chukchi Sea.

Geography

Fauna

Importance

References

Further reading