This knowledge is critical for understanding and managing potential threats impeding recovery of this endangered population.
“Cook Inlet belugas were listed as endangered in 2008. Despite protective measures, the population continued to decline,” said Manuel Castellote, NOAA Fisheries affiliate/University of Washington/Joint Institute for the Study of the Atmosphere and Ocean biologist who led the study. “We undertook this study to provide information that managers needed to develop an effective recovery strategy.”
Castellote worked in partnership with the Alaska Department of Fish and Game to develop a passive acoustic monitoring program. It recorded beluga movements and foraging behavior within their critical habitat year-round over five years.
“Summer beluga distribution has been well studied, especially in the upper inlet. But information on foraging behavior during the rest of the year was basically nonexistent,” Castellote said. “That knowledge is essential to identify threats impeding the whales’ recovery.”
An Unexplained Decline
Cook Inlet beluga whales are a distinct and isolated population that remains in Cook Inlet all year.
Between 1994 and 1998, the population plummeted by nearly 50 percent, due primarily to unregulated hunting. At that point, cooperative efforts between NOAA Fisheries and Alaska Native subsistence hunters dramatically reduced the harvest.
Despite protection after 1999, the beluga population continued to slowly decline.
In 2008, the Cook Inlet beluga whale population was listed as endangered. Now, more than two decades later, the population is still dropping.
There are an estimated 279 whales remaining as of 2018. Cook Inlet beluga whales are in danger of extinction unless the impediments to its recovery are identified and mitigated.