Aerial Surveys of Arctic Marine Mammals

Alaska Fisheries Science Center's Cetacean Assessment & Ecology Program conduct aerial survey research in Alaska.

Alaska

Inter-agency Agreement

Inter-agency agreements were established between the Bureau of Ocean Energy Management (BOEM), Department of Interior and the Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA Fisheries, National Oceanic and Atmospheric Administration, Department of Commerce. The intent of these agreements was to provide funding to conduct surveys of bowhead whales (Balaena mysticetus) and other marine mammals in the Alaskan Arctic.

History

The Aerial Surveys of Arctic Marine Mammals (ASAMM) project was a continuation of the Bowhead Whale Aerial Survey Project (BWASP) and Chukchi Offshore Monitoring in Drilling Area (COMIDA) marine mammal aerial survey project. BWASP was conducted from 1979 to 2010 and targeted the autumn migration of bowhead whales through the western Beaufort Sea, although line transect data on all marine mammals sighted were collected. COMIDA surveys were conducted in the Chukchi Sea Planning Area in the northeastern Chukchi Sea from 1979 to 1991 and 2008 to 2010 to monitor marine mammal distribution, relative density, and behavior during the open-water (ice-free) months, from mid-June or early July to the end of October. BWASP and COMIDA surveys were funded or conducted by the Minerals Management Service (now BOEM) and the Bureau of Land Management, and starting in 2008, the Marine Mammal Laboratory began co-managing the projects with BOEM. In 2011, these projects were merged into ASAMM. Survey protocols remained consistent from1982-2019.

Purpose of Study

The goal of ASAMM was to document the distribution and relative abundance of bowhead, gray, fin, humpback, killer, minke, and right whales, belugas, and other marine mammals in areas of potential oil and natural gas exploration, development, and production activities in the Alaskan Beaufort and northeastern Chukchi seas.

Data from the ASAMM surveys provides important historic context to relate variation in marine mammal distribution or abundance to other variables, such as physical oceanographic conditions, indices of potential prey density, and anthropogenic activities if information on these variables is available.

ASAMM Survey Objectives

Monitor the spatial and temporal variability in the density, distribution, and behavior (including calving/pupping, feeding, hauling out) of marine mammals (cetaceans, ice seals, walruses, and polar bears) in the Alaskan Arctic, primarily through line-transect aerial survey data, with supplementary information from aerial photo-identification data.
Describe the annual migration of bowhead whales across the U.S. Arctic, including interannual variability or long-term trends in the spatial distribution and timing of the migration.
Provide near real-time data or derived products, such as graphical data summaries, on marine mammals and environmental conditions in the U.S. Arctic to BOEM and NMFS.
Provide information on marine mammal abundance and distribution to Alaska Natives for use in management of subsistence hunts and assessments of anthropogenic impacts on marine mammal resources.
Provide an objective wide-area context for understanding marine mammal ecology in the U.S. Arctic to help inform management decisions and interpret results of other small-scale studies.

ASAMM Bowhead Abundance (ABA)

ASAMM Bowhead Abundance (ABA)
ABA 2019 Study Area and Transects.

In 2019, the program conducted a bowhead whale abundance survey in the Alaskan and Canadian Beaufort Sea and Amundsen Gulf. This project, ASAMM Bowhead Abundance (ABA), is a collaboration between NOAA, BOEM, the North Slope Borough, and our Canadian colleagues in the Department of Fisheries and Oceans Canada, Inuvialuit Game Council, and Fisheries Joint Management Council.

Bering-Chukchi-Beaufort Bowhead Whales

The Bering-Chukchi-Beaufort (BCB) Sea bowhead whale stock is hunted for subsistence by Native groups in Alaska (and occasionally Russia).

The most recent population abundance estimate for this stock is approximately 17,000, derived from a 2011 survey. The International Whaling Commission (IWC) sets the aboriginal subsistence quota for BCB bowhead whales, requiring a new population abundance estimate every 10 years. Based on IWC rules, a new abundance estimate was required by spring 2021.

The objective of ABA was to apply ASAMM line-transect methodology to transects covering the Beaufort Sea shelf and Amundsen Gulf, with additional transects west of Pt. Barrow, east of Banks Island, and possibly in Viscount Melville Sound, within a three-week period in August. This area time period is when the majority of the population is typically within a relatively small area and can likely be surveyed using aerial line-transect methods.

The most recent abundance estimate for the Western Arctic bowhead stock, collected during spring 2019, indicates there are approximately 12,505 Western Arctic bowheads, with a 95 percent confidence interval ranging from 7,994 to 19,560 whales.