Survey report for Gulf of Alaska

Posted on April 18, 2014

The U.S. Navy periodically uses a Temporary Maritime Activities Area (TMAA) in the central Gulf of Alaska (GoA), east of Kodiak Island. Current scientific data on affected biological and environmental resources are necessary to conduct analyses required for Navy training, exercise, and technology-acquisition activities. In 2009, the Navy funded a vessel-based line-transect survey that provided density estimates for fin (Balaenoptera physalus) and humpback (Megaptera novaeangliae) whales in the TMAA. However, additional data on marine mammal species were necessary to obtain the regionalized population-density data that Navy and other participating Federal agencies like the Bureau of Ocean Energy Management need to meet their environmental stewardship obligations. In the summer of 2013, the Navy funded a second survey to fill in the gaps of knowledge on distribution, movements, and densities of marine mammals within this training area.

During this survey, the visual team surveyed 4,504 kilometers (km) of ‘full-effort,’ which included 349 km of ‘transit-effort.’ There was an additional 375 km of ‘fog-effort’ (transect and transit). Based on total effort, there were 802 sightings (1,998 individuals) of 13 confirmed marine mammal species, with an additional 162 sightings (228 individuals) of unidentified cetaceans and pinnipeds (including those recorded on transit and during off-effort mode).