Harbor porpoise bycatch near Point Barrow contributes to larger study on Bering Sea population

When James Judkins began pulling up his fishing nets out near Point Barrow this month, the weight of the catch pulled back at him.

“Man, this is a really big fish,” Judkins thought. Then, he glimpsed the dorsal fin. Then another. “Dolphins?” he wondered.

Close. Harbor porpoises, a marine mammal resembling dolphins, but in the same family as whales, have made several appearances in Utqiaġvik recently.

In recent weeks, local fishermen have caught at least four porpoises in subsistence fishing nets near Point Barrow. Judkins recovered two, along with a seal, on Aug. 12 in Elson Lagoon. The other two were bycatches in Christian Stein and Charlie Sikvaguyak’s separate nets set in the same area. For some fishermen, it was their first time seeing the mammal.

“I went to Sea World when I was real little and I saw stuff in aquariums, but never in real life,” said Judkins, 33.

Dorcas Stein and her husband have been setting nets in the same area for more than 25 years, and had never heard of anyone getting a porpoise until they caught one themselves. They called North Slope Borough Wildlife Department, who came out to sample the animal. Stein said she gifted the meat to family. Judkins and his partner Jaime Patkotak, after gifting some meat to community members, are smoking their remaining porpoise, which is rumored to taste similar to beluga whale.

In Alaska, harbor porpoises are divided into three stocks: Bering Sea, Gulf of Alaska and Southeast Alaska. The estimated population size of the Bering Sea stock is 66,076 animals, with about 41,854 in the Gulf of Alaska and 17,076 animals in the Southeast, according to the Alaska Department of Fish and Game.

Raphaela Stimmelmayr, North Slope Borough wildlife veterinarian and research biologist, collected tissue samples from three of the recovered porpoises (plus another found dead on shore) to submit to the University of Alaska Museum of the North. The samples will contribute to research on the Bering Sea stock.

Stimmelmayr says there isn’t a lot of information on the species in Alaska because of their small size and shy nature, making them easy to miss in aerial surveys. “We don’t know much about them,” she said. “They are better described in more populated coastal areas (such as) Washington coast, British Columbia (and) California.”

She also noted a distinction between bycatch in Utqiaġvik, versus other regions and states where subsistence marine mammal consumption is less common. All of the recovered animals were consumed by community members.

Stimmelmayr, who last saw a porpoise in 2013, said that the two adult females and one adult male porpoises she sampled all looked relatively healthy, based on her initial assessment. They measured between 125 and 130 centimeters (about 50 inches), according to her records.

“I haven’t seen a harbor porpoise for a couple of years,” Stimmelmayr said. “Though it could’ve happened that some were caught in years passed, but people just didn’t contact us.”

Community Elder Johnny Adams, 75, echoes Stimmelmayr’s suspicion that it’s not that the harbor porpoises aren’t there, it’s that they haven’t been caught or reported.

Adams remembers his grandfather getting porpoises in the lagoon, and another time his granduncle got one in the ocean.

“It’s not really uncommon for them to be up here nowadays,” Adams said. “My guess is that they’re following up on the food chain (and the) other smaller fish that we have ... like candle fish.”

Both Judkins and Stein saw a large run of small fish just before the porpoises showed up.

“The capelin (paŋmaksraqs) and the rainbow smelts (ilhuaġniqs) were running, and a lot of pink salmon,” Stein wrote to The Sounder.

Some of the limited information about harbor porpoises, especially the Bering Sea stock, has come from Utqiaġvik’s local whale biologist, Craig George. George co-published a paper on harbor porpoise sightings near Point Barrow in 1993, along with author Robert Suydam.

George and Suydam looked at records of harbor porpoises found near Point Barrow between 1985 and 1991. The records included live sightings, animals found dead on the beach and animals entangled in fishing nets.

In 1991, six harbor porpoises were caught in subsistence fishing gear in Elson Lagoon, the most at any one time within the period of study.

“Subsistence fishermen in Barrow state this it is not uncommon for one or two porpoises to be caught each summer,” the paper says, noting that 1991 was an anomaly. Some speculative reasons for why high numbers are caught certain years include changes in sea ice and prey movement.

In 1991, the pack ice that is typically about 16 miles north of Point Barrow was against the coast for most of July and August, the paper said, which could have forced more porpoises into the lagoon that year. This summer, the pack is much further out and currently over 100 miles north of Point Barrow, George said.

George also speculated that the abundance of fish in the coastal arctic lagoons may have attracted harbor porpoises north.

According to George’s research, harbor porpoises regularly visit the North Pacific Ocean, the Bering Sea and occasionally the Chukchi Sea during ice-free months. Point Barrow is the northernmost limit where the animal is typically found.

Elsewhere in the state and country, researchers are working to understand more about harbor porpoises, including the Bering Sea stock.

Kim Parsons, National Oceanic and Atmospheric Administration research geneticist at Northwest Fisheries Science Center in Seattle, surveyed harbor porpoises in Southeast Alaska in 2016 and 2019. She said she’s working on analyzing the current samples, along with archived tissue samples collected from bycatch over the past 30 years.

“There’s certainly lots of questions about the biology and physiology of harbor porpoise that are still unanswered,” Parsons said. “The pieces that we know little about are pieces like: how far individuals are moving, how many calves they’re having each year and things like that you’d get from doing long-term study.”

That data will help paint a clear picture of global long-term patterns of change, Parsons said.

“If environmental changes affect the distribution and abundance of prey, then marine mammals will follow that prey,” she said.