North Slope Borough, NOAA, UW collaborate on whale study

Autumn survey found high density of bowhead whales in Arctic waters

An aerial survey of bowhead whales just north of Point Barrow in the autumn of 2020 is being cited by biologists with the Alaska Fisheries Science Center as one of the highest densities of bowhead whales ever seen.

The survey was a collaborative effort of the North Slope Borough, NOAA Fisheries, the University of Washington’s Cooperative Institute for Climate, Ocean and Ecosystem Studies and others, in the wake of climate change factors which resulted in the whales arriving two to three months later in 2019.

A report released by NOAA on Monday, Nov. 9, noted that in 2019, Alaska’s hottest year on record, sea surface temperatures were significantly warmer than average, and the timing of the bowhead whale migration was also different. By late October, Utqiagvik had seen few whales, which are critical to the subsistence culture of North Slope communities.

“We were really worried that this might become the new normal,” said Robert Suydam, senior Wildlife biologist with the North Slope Borough.

Whale surveys were funded by the federal Bureau of Ocean Energy Management from 1979 to 2019, but then they ended. The North Slope Borough then opted to support an aerial survey in 2020 to collect data on the bowhead whale migration timing density, distribution, and activities in the western Beaufort Sea. The data collection was important because changes in the bowhead migration in 2019 meant that Utqiagvik hunters were only able to harvest one bowhead very late in the season, in mid-November. The whale harvest is more typically from mid-September through mid-October.

Megan Ferguson, a research biologist with the Alaska Fisheries Science Center, said the aerial survey offered a great opportunity to work with their co-management partners at the Alaska Eskimo Whaling Commission and colleagues at the North Slope Borough. This year, while different than 2019, was still an unusual year, she said. During their last flight, just north of Point Barrow, they saw what may turn out to be the highest or the second highest densities of bowhead whales ever seen.

During the month-long survey from Sept. 17 to Oct. 15, the survey team covered 8,905 miles primarily between Prudhoe Bay and Point Barrow. They encountered 770 bowhead whales, including 24 calves. Almost half of these whales were observed in concentrated feeding aggregations between Point Barrow and Dease Inlet on the last day of the survey. The whales were skim feeding — swimming with their mouths open to collect and filter their prey, in this case krill, Ferguson said.

Throughout the survey, small numbers of gray, humpback and fin whales and clusters of beluga whales were observed, along with a few harbor porpoises, walruses, seals and a polar bear mother and her cub who were feeding on a large whale carcass on a barrier island.

Due to the pandemic, strict protocols were observed for the safety of residents of Utqiagvik, where the survey team, observers and pilots were housed. Overall, it was a really successful survey on all counts, NOAA officials said.