Beluga whales absent from Kenai River during poeak fishing season

Published 10:32 am Friday, July 31, 2026

Endangered Cook Inlet beluga whales have been absent during times of high human activity in a recent two-year period, according to recent data — a time in which they have traditionally fed in the salmon-rich Kenai River.

Sonia Kumar, a PhD student at the College of Fisheries and Ocean Sciences at the University of Alaska Fairbanks (UAF) led a team that spent two years tracking belugas in the Kenai and Kasilof rivers using underwater microphones. The team also included researchers with the college and the National Oceanic and Atmospheric Administration.

Belugas have historically fed in throughout the summer, from April to November, but the hydrophone data Kumar and her team collected found that the whales were much less likely to be present throughout the summer fishing seasons, when people arrive each year in search of salmon.

“Commercial fishing, personal-use dipnetting, sport fisheries, seafood-processing companies — there’s just a ton of activity going on,” Kumar said.

Based on the data from 2021 and 2022, researchers determined that belugas were skipping the peak of the sockeye salmon run on the Kenai River, and were more likely to feed in the Kenai during the fall, when human activity was low. Belugas were not detected in the Kasilof River at any time.

The data also followed a decade-long trend which showed a decline in the beluga’s genetically distinct population. An estimated 331 belugas lived in the inlet year-round during the most-recent 2022 survey — roughly a quarter of the number that were present during the late 1980s.

While the population has stabilized in recent years, researchers are still working to learn more about beluga behavior in the Cook Inlet and to better understand the causes behind the population drop.

“We have a population that has room to expand and recover, and they’re not,” said Lara Horstmann, a UAF marine biology professor who participated in the study. “There’s certainly room to understand what’s impeding their recovery.”

Researchers also cautioned that the findings do not necessarily point to human-caused activity as the reason for the beluga population decline in the two rivers during the summer.

The low numbers also mean there is less competition among Cook Inlet belugas in the past, and the remaining whales may bypass the Kenai River because they can feed in areas where prey abundance may be higher, according to UAF.

Kumar added that it is not a black-and-white issue.

”Because their population is small, belugas may have their pick of where the most optimal foraging location is,” she said. “There’s a happy middle ground where we can all be in this ecosystem together, and we need to figure out what that is.”