AFSC/MML: Marine Mammal Aerial Surveys in the Bering, Chukchi, and Beaufort Seas, and Amundsen Gulf, 1979-2021

The Bureau of Ocean Energy Management (BOEM), formerly the Minerals Management Service (MMS), and its precursor, the Bureau of Land Management, funded aerial surveys in the Beaufort, Chukchi, and Bering seas from 1979 to 2019. In 2008, through an Interagency Agreement between MMS and the Alaska Fisheries Science Center (AFSC, National Marine Fisheries Service, National Oceanic and Atmospheric Administration [NOAA]), the Marine Mammal Laboratory (MML, a division of AFSC), formerly the National Marine Mammal Laboratory assumed co-management responsibilities for these surveys. Throughout the history of the surveys, they were referred to as the Bowhead Whale Aerial Survey Project (BWASP) and the Chukchi Offshore Monitoring in Drilling Area (COMIDA) marine mammal aerial surveys, both of which are described in more detail below. In 2011, a new Interagency Agreement between BOEM and NMML was established to authorize NMML to continue the BWASP and COMIDA studies under the auspices of a single study, Aerial Surveys of Arctic Marine Mammals (ASAMM). In 2020 and 2021, aerial line-transect surveys for bowhead whales and other marine mammals were funded and co-managed by the North Slope Borough (NSB) through contract 2021-069 with the Cooperative Institute for Climate, Ocean, and Ecosystem Studies (CICOES), a part of the University of Washington, with collaboration from AFSC, NOAA Fisheries. Consistent survey protocol has been in effect on surveys conducted since 1982. Data collected from 1979 to 1981 were not vetted as carefully as data from 1982 to 2021, and should generally not be used for most analyses. WESTERN BEAUFORT SEA Aerial surveys in the western Beaufort Sea (south of 72 degrees N, 140-157 degrees W) have been conducted each year since 1979. MMS personnel and contractors conducted the surveys from 1979 to 2007. From 2008 to 2019, the surveys were conducted by MML. In 2020 and 2021, surveys were conducted by NSB. The primary goal of the project, also known as BWASP through 2010, ASAMM from 2011 to 2019, and NSB Autumn Aerial Surveys  in 2020 and 2021, was to document bowhead whales (Balaena mysticetus) during their fall migration through the western Beaufort Sea, although data were also collected for all other marine mammals that were sighted during the surveys. The surveys were typically conducted during the months of September and October, when offshore drilling and geophysical exploration were feasible and when the fall subsistence hunt for bowhead whales takes place near Kaktovik, Cross Island (village of Nuiqsut), and Utqiagvik (formerly Barrow), Alaska. Additional surveys were conducted in the western Beaufort Sea during spring and summer 1979-1986, during summer 2011-2019, and from approximately 15 September to 15 October in 2020 and 2021. The emphasis of surveys in the Beaufort Sea was to conduct broad-scale surveys to assess shifts in the migration pathway of bowhead whales, and to coordinate effort and manage data necessary to support seasonal offshore drilling and seismic exploration regulations. The selection of survey blocks to be flown on a given day was nonrandom, based primarily on criteria such as observed and predicted weather conditions over the study area and offshore oil industry activities. From 2016 to 2019, to incorporate the area near Liberty prospect, all transects in survey block 1 were extended inshore of the barrier islands to the shoreline. From 19 July through 20 August 2016, transects extended north beyond the usual BWASP study area into study blocks 8, 9, and 10, and north of blocks 11 and 12 (beyond 72 degrees N) to survey Eastern Chukchi Sea (ECS) beluga habitat. In 2017, a coastal transect 1 km offshore between Point Barrow and Demarcation Bay in the Beaufort Sea was added. Otherwise, the project attempted to distribute effort evenly east-to-west across the entire study area. Aerial coverage favored inshore survey blocks because bowhead whales were rarely sighted north of blocks 2, 6, and 7 during surveys conducted from 1979 to 1986. EASTERN CHUKCHI SEA Aerial surveys in the eastern Chukchi Sea (68-73 degrees N, 157-169 degrees W) were conducted by MMS contractors from 1982 to 1991. From 2008 to 2019, the surveys were conducted by MML. In 2020 and 2021, the surveys were conducted by NSB in collaboration with CICOES and MML and used a similar methodology to the surveys conducted in previous years. In 2009, a coastal transect 1 km offshore extending from Point Barrow to Point Hope was added. Starting in 2014, surveys expanded south to 67 degrees N. In July and August 2018, surveys were expanded north to 73 degrees N, 157-160 degrees W to assess potential bowhead whale use of this area in July and August. The goal of the surveys, also known as COMIDA through 2010, ASAMM from 2011 to 2019, and NSB Autumn Aerial Surveys in 2020 and 2021, was to investigate the distribution and relative abundance of marine mammals in the Chukchi Sea Planning Area (CSPA) during the open water (i.e., ice-free) months of June to October, when various species are undertaking seasonal migrations through the area. However, from 1979 to 1984, surveys were also conducted during spring. In 2020 and 2021, NSB Autumn Aerial Surveys in the Chukchi Sea from approximately 15 September to 15 October, were prioritized only when weather conditions were not conducive to surveying the western Beaufort Sea. NORTHERN BERING AND SOUTHERN CHUKCHI SEAS Aerial surveys in the northern Bering and southern Chukchi seas (63-68 degrees N, east of the International Date Line) were conducted by MMS contractors from 1979 to 1985. The goal of these surveys was to investigate the distribution, abundance, migration timing, habitat relationships and behavior of endangered whales during the spring migration. Surveys were conducted from April to July. EASTERN BEAUFORT SEA AND AMUNDSEN GULF Aerial surveys in the eastern Beaufort Sea and Amundsen Gulf (67-73 degrees N, 118-140 degrees W), were conducted by MML from 5 to 27 August 2019, in collaboration with BOEM, NSB, Department of Fisheries and Oceans Canada, Inuvialuit Game Council, and Fisheries Joint Management Committee. The goal of these surveys, known as the ASAMM Bowhead Abundance (ABA) project, was to collect aerial survey data specific to estimating the abundance of the Bering-Chukchi-Beaufort Seas bowhead whale population. The primary ABA study area in its entirety includes the Beaufort Sea shelf and Amundsen Gulf (118-158 degrees W). This database contains aerial survey data from the surveys described above.

Tags: abundance, aerial, alaska, alaska fisheries science center, amundsen gulf, arctic, beaufort sea, bering sea, canada, cetacean assessment and ecology program, chukchi sea, distribution, doc/noaa/nmfs/afsc, fall, habitat, line-transect survey, national marine fisheries service, noaa, northwest territories, spring, summer, u.s. department of commerce
Organization: National Oceanic and Atmospheric Administration, Department of Commerce