Published Feb 26, 2024 by Yereth Rosen For the first time, the underwater calls made by the endangered beluga whales in Southcentral Alaska’s Cook Inlet have been recorded, identified and cataloged.
To accomplish that, University of Washington Ph.D. student Arial Brewer spent thousands of hours listening to the noises captured from audio devices planted on the seafloor. The result was a catalog of 18 distinct calls used by the belugas, which were a mixture of whistles and pulsed calls.
And, importantly for the belugas’ conservation, there is now evidence that those calls might be getting drowned out by noises from the commercial ships that ply the marine waters of Alaska’s most populous region, according to a study led by Brewer that details the findings.
Beyond the question of permitted takes, there is another way to reduce noise impacts to belugas and other whales: slower speed limits.
Brewer pointed to Washington’s Puget Sound as an example. There, in habitat for an endangered killer whale population, shippers are experimenting with slower vessel speeds. It is, for now, a voluntary program.
Additionally, a new state law that goes into effect next year creates a mandatory 1,000-yard vessel buffer there to protect the whales.
Noise disturbances have been at the center of concerns elsewhere in Alaska, including their potential effect on whales swimming in Arctic waters. There, climate change has reduced sea ice and expanded shipping opportunities.
A 2021 study by Canadian and U.S. scientists, including some from the University of Alaska Fairbanks and Alaska Department of Fish and Game, found that belugas and bowhead whales in the Chukchi and Beaufort seas are swimming in the same places where ship traffic is expected to increase. “Without proactive vessel management and effective mitigation measures, acoustic disturbance of whales is expected to increase, and eventually expand to more months of the year, as ship traffic continues to increase in step with increases in the length of the open water season,” the study said.
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