Science & Data

The North Pacific Ocean is a sentinel region for signs of ocean acidification. Approximately 30-50% of global anthropogenic carbon dioxide (CO2) emissions are absorbed by the world’s oceans. Dissolving CO2 increases the hydrogen ion (H+) concentration in the ocean, and thus reduces ocean pH. Corrosive waters reach shallower depths more so there than in other ocean basins, especially in Alaska, and so biological impacts will likely occur earlier than in many other places. Ocean acidification reduces the calcium carbonate (CaCO3) saturation point, which stresses calcifying organisms by making calcification more difficult. The Alaska Fisheries Science Center research plan will focus on commercially important fish and shellfish species, their prey (calcareous plankton) and shelter (corals). Ocean acidification will likely impact the ability of marine calcifiers, such as corals and shellfish, to make shells and skeletons from CaCO3. Ocean acidification may also affect fish, marine mammal and seabird species through reduced abundance of calcareous plankton at the base of the food web. Species-specific studies of shellfish, calcareous plankton, corals and fish will be conducted to understand physiological effects (growth and survival). The CaCO3 content of calcareous organisms is not well known and a survey of shellfish, calcareous plankton and corals will be conducted to assess species vulnerabilities to ocean acidification. The results of the species-specific studies will be incorporated into population and ecosystem models to forecast population and ecosystem impacts. Bioeconomic models of Alaskan crab fisheries will be used to forecast fishery performance for a range of climate and ocean acidification scenarios.

This report presents the summary views of Drs. Patrick Cordue, Cynthia Jones, and Robert Mohn on each of three terms of reference, as the reviewers were required to generate under the review statement of work. As such, the report only collates the summary views to generate a concise set of summaries, and it does not otherwise alter the reviewers’ text. For a more detailed discussion on each term, the reader should refer to the reviewers’ full reports.

Although chum salmon bycatch has historically remained at low levels relative to their biomass in the Bering Sea, recent increases in chum salmon bycatch have generated concern over bycatch impacts on Alaskan salmon stocks and the effectiveness of regulatory measures used to control bycatch in the groundfish fisheries. Member nations of the North Pacific Anadromous Fish Commission (Canada, Japan, Russia, South Korea, and the United States) developed the Bering-Aleutian Salmon International Survey (BASIS) in 2002 as an international cooperative research program designed to address concerns over the distribution, growth, and survival of salmon in the Bering Sea. By connecting information collected during BASIS research surveys to bycatch, we identify how size, foraging behavior, and foraging hotspots of chum salmon are important controlling factors of bycatch and bycatch potential in Bering Sea groundfish fisheries.

Pelagic fish and jellyfish were sampled using a trawl net towed in the upper 20 m of the eastern Bering Sea during the Alaska Fisheries Science Centers’ Bering Arctic Subarctic Integrated Surveys (BASIS) during late summer, 2002–2016. Stations were approximately 30 nautical miles apart and a trawl was towed for approximately 30 minutes. Area swept was estimated from horizontal net opening and distance towed.

Pelagic fish and jellyfish were sampled using a trawl net towed in the upper 20 m of the eastern Bering Sea during the Alaska Fisheries Science Centers’ Bering Arctic Subarctic Integrated Surveys (BASIS) during late summer, 2002–2016. Stations were approximately 30 nautical miles apart and a trawl was towed for approximately 30 minutes. Area swept was estimated from horizontal net opening and distance towed.

Pelagic fish and jellyfish were sampled using a trawl net towed in the upper 20 m of the eastern Bering Sea during the Alaska Fisheries Science Centers’ Bering Arctic Subarctic Integrated Surveys (BASIS) during late summer, 2002–2016. Stations were approximately 30 nautical miles apart and a trawl was towed for approximately 30 minutes. Area swept was estimated from horizontal net opening and distance towed.

This annual survey, conducted by the Southeast Coastal Monitoring (SECM) project, marks 20 consecutive years of systematically monitoring how juvenile salmon utilize marine ecosystems during a period of climate change.

This report describes field activities of the Aerial Surveys of Arctic Marine Mammals (ASAMM) project conducted during summer and fall (1 July–27 October) 2017, and data and analyses used to summarize field activities. Surveys were based in Utqiaġvik (formerly Barrow), Alaska, and Deadhorse, Alaska, and targeted the northeastern and southcentral Chukchi and western Beaufort seas, between 67°N and 72°N latitude, 140°W and 169°W longitude.

This report describes field activities of the Aerial Surveys of Arctic Marine Mammals (ASAMM) project conducted during summer and fall (1 July–31 October) 2016, and data and analyses used to summarize field activities. Surveys were based in Barrow, Alaska, and Deadhorse, Alaska, and targeted the northeastern and southcentral Chukchi and western Beaufort seas, between 67°N and 72N latitude and 140°W and 169°W longitude. Between 19 July and 20 August, surveys extended up to 111 km north of the usual ASAMM study area to collect information specific to the Eastern Chukchi Sea (ECS) stock of belugas.

The Hawaiian Islands Cetacean and Ecosystem Assessment Survey (HICEAS, pronounced "high-seas") is a large-scale ship survey for cetaceans (whales and dolphins) and seabirds within the U.S. waters of the Hawaiian Islands.