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Groundfish Assessment Program

Habitat Research Team Ventures Into the Northern Bering Sea (continued, pg.2)

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Figure 4. Walruses peeking through ice holes. Photo courtesy of Andrew Trites, University of British Columbia.
 
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Figure 5. Members of the the walrus tagging team. Photo courtesy of Andrew Trites, University of British Columbia.
 
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Figure 6. A benthic grab deployment aboard the U.S. Coast Guard icebreaker Healy. Photo courtesy of Tom Van Pelt, North Pacific Research Board.

Four days’ sailing from Kodiak, Alaska, led the Healy to thick ice near St. Lawrence Island. Forty-three benthic sampling stations were located mainly to the south of the island. Many of these stations were ice-bound and required the icebreaking capabilities of the Healy. A van Veen grab was deployed at each station to collect multiple infauna and sediment samples. The infauna samples were sieved on deck, and the animals were preserved. Sediment samples were taken for grainsize, chlorophyll, and nutrients analyses. On-station activities also include the deployment of conductivity-temperature-depth (CTD) and optical instruments to characterize the biochemical and physical properties of the water column, bongo nets for collecting zooplankton, and a HAPS corer to obtain undisturbed sediments for incubation experiments. With temperatures colder than -20°C in the first week, keeping instruments functional on deck was a major challenge. Sieve boxes, sediment samples, and even hot water hoses were frozen—a testament to the difficulty of Arctic research and the tenacity of the researchers.

The region’s featured megafauna are seabirds and marine mammals, particularly the spectacled eiders and walruses (Fig. 4). These keystone species are dependent on the benthic communities of mollusks, crustaceans, and polychaetes for food and are vulnerable to climate and anthropogenic changes affecting the ecosystem. The Healy’s onboard helicopter transported scientists studying walrus (Fig. 5) and eider to search for their subjects on the ice. Scientists also went on the ice to collect cores and sample the communities and conditions underneath the ice. At those ice stations, an armed watch was set against polar bears, and a Coast Guard rescue diver stood by. Net, core, and grab sampling (Fig. 6), and laboratory experiments were conducted around the clock. In addition to all this, a series of evening talks provided topics ranging from arctic ecology to climbing Mt. McKinley. The commander of the Healy, Captain Frederick Sommer, gave a tantalizing talk on Coast Guard history, highlighting an overland rescue expedition from Cape Vancouver to Barrow, Alaska, in 1897.

The BEST/BSIERP programs showcase exciting and innovative research and render it accessible to all who are concerned about the Bering Sea ecosystem. On the Healy, dedicated researchers from diverse disciplines conferred to seek a comprehensive knowledge of how climate change may affect nature and society. With the benthic grab and impressed with the significance of the benthic community in the Bering Sea ecosystem, the AFSC Habitat Research Group will turn its focus this summer on cruises to the southeastern Bering Sea, where benthic sampling will be integrated into our studies of the habitats and ecology of managed species.

By Cynthia Yeung
 

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