North pacific right whale surveys conducted in the Bering Sea and North Pacific Ocean by Alaska Fisheries Science Center, National Marine Mammal Laboratory from 2007-08-01 to 2011-09-10 (NCEI Accession 0133935)

Protection was supposedly afforded by international treaties in the 1930s and 1940s, but the illegal capture of hundreds of individuals by the Soviet Union, primarily in the 1960s drastically impacted the recovery of the species. Currently, only a small remnant of this population (estimated at approximately 30 individuals) inhabits the southeastern Bering Sea (SEBS).

There is an increasing body of evidence suggesting that the middle shelf domain constitutes the primary habitat of NPRWs in the SEBS during the summer. Despite substantial observation effort from various sources in some other areas, the only region in the Bering Sea where NPRWs have been consistently seen is the middle shelf. Vessel surveys were conducted in the summers of 2007 - 2011 in the EBS mostly within the NPRW critical habitat boundary (located on the middle shelf of the SEBS).