Saving Seafood

Beluga Whale Sounds Aid Scientific Understanding of When Whales are Hunting Prey

December 1, 2021 — When listening to beluga whales, the sound of a crunch or a clapped jaw may be a reliable indication that a beluga whale just successfully captured or missed a fish. In a new published paper on beluga whales in Alaska, scientists analyzed sound data, collected over several years, to monitor beluga whale calls and other data. With these data they are gaining new insights into belugas’ diet, feeding behavior, and feeding habitats.

“Our goal is to collect data to help understand and recover Cook Inlet beluga whales, an endangered species and NOAA Fisheries,” said Manuel Castellote, NOAA Affiliate and lead author for the study from the Cooperative Institute for Climate and Ocean and Ecosystem Studies, University of Washington. “There is a paucity of basic ecological knowledge, such as prey preference, about this population of whales. This impedes our efforts to help recover the population. The population is estimated to be only 279 animals, and was in decline during the 10-year period from 2008-2018, the most recent time period for which we have data.”

Given the endangered status of the Cook Inlet belugas, there are limited studies that are permitted on this population. So scientists conducted research using tagging technology and other methods on a comparable surrogate—an abundant population of beluga whales in Bristol Bay, Alaska. The Bristol Bay beluga population is estimated to be between 2,000 and 3,000 animals.

Read the full story at NOAA Fisheries

 

First Long Term Acoustic Study Tunes Into Cook Inlet Beluga Whale Foraging Ecology

February 19, 2020 — The following was released by NOAA Fisheries:

The first continuous multiyear acoustic monitoring effort across Cook Inlet provides the most comprehensive description of beluga whale seasonal distribution and feeding behavior to date.

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.”

Read the full release here