Alaska’s Bristol Bay sees record return of sockeye salmon. The warming climate may have helped.

SEATTLE — Amid a fierce June storm that whipped up 8-foot waves, Robin Samuelsen told his four young crew members to let out the gillnets behind his 32-foot boat in the Nushagak district of Bristol Bay.

For the 70-year-old, a veteran of more than a half-century of fishing, this was a tough day to start the 2021 sockeye salmon harvest. But soon the crew, all of them his grandsons, were dancing on the back deck as they spotted splash after splash made by sockeye hitting the net’s mesh in a surprisingly strong display of abundance so early in the season.

In the weeks that followed, storms often returned to make fishing miserable, and at times dangerous. Through it all, the salmon kept surging back from their ocean feeding grounds in what — by this week — developed into a record return of more than 65.5 million sockeye to the Bristol Bay region.

“It was pretty rough out there. It was really rough out there,” Samuelsen said. “But it was a fabulous year here in the Nushagak.”

The massive return once again demonstrated Bristol Bay’s stunning sockeye productivity at a time when these fish are struggling in other parts of North America, in part due to climate change, which can increase the temperature of the rivers adults must navigate to their spawning grounds. It can also reduce food for them in the ocean.

Scientists still are trying to unravel the factors influencing the big Bristol Bay sockeye runs of the past decade. At least so far, climate change in this more northern realm appears to have not undermined their productivity, and some research indicates that warming could be working in the fish’s favor by improving food supplies when they are very young.

Climate and behavior

This summer’s bountiful harvest, which peaked in earlier this month, has generated a surge of deep-red sockeye fillets at the seafood counters of the Pacific Northwest and other U.S. and international markets. These fish were caught by some 2,500 fishermen and crews, and the permit holders include some 650 Washington-based gillnetters. Buoyed by strong consumer demand, processors have offered a price of $1.25 per pound for the whole fish — up from 70 cents per pound last year.

The record season, however, comes with some notable asterisks.

The average size of fish are typically small during a big run. These sockeye have been really small. They averaged 4.5 pounds, down from 5.2 pounds just two years ago, according to the Alaska Department of Fish and Game.

The record run also was not accompanied by a record harvest, which as of July 23 had tallied more than 39 million sockeye compared with the 1995 all-time record catch of 44 million. The rest of the fish swam upstream to spawning grounds in numbers well above the levels needed to sustain the next generation of salmon, according to fishery managers. This resulted, in part, from the rough weather that on occasion kept some fishing boats from putting out nets.

The adult salmon traverse Bristol Bay as they return from the ocean to freshwater spawning grounds, where the females lay eggs and the males release sperm just before they die.

Historically, most sockeyes that hatched from the spawning grounds spent two years in fresh water. But as the weather warms, these drainages have become warmer and ice-free for longer periods of time, offering more nourishment for juvenile salmon. And many of these fish spend only one year in fresh water and then head out to sea, where they stay from one to three years, according to a study published in 2019 in Nature Ecology & Evolution by Daniel Schindler, a professor in the University of Washington School of Aquatic and Fisheries Sciences. and two colleagues, Timothy Cline and Jan Ohlberger.

“Climate change is literally speeding up the early part of their life cycle across the whole region,” Schindler said.

Tim Sands, an Alaska Fish and Game biologist who helps manage the Bristol Bay runs, thinks the Nushagak District sockeye have benefited from the warming trend. With improved feeding in fresh water, more fish may have gone out to sea better able to survive to adulthood.

Sands said that the average run of fish to the district’s drainages, up to 2017, was around 8 to 9 million sockeye. Then that year, some 20 million sockeye returned to the district, and 33 million in 2018. This year, the run tops 27 million, and ranks as the biggest producer in the five Bristol Bay fishing districts.

“It just broke the mold. Something happened that just amped up the productivity. My personal belief is it was the warmer winters,” Sands said.

Schindler, in an interview this week from a Bristol Bay fish camp, says the warmer weather also may have made the coastal waters of the Bering Sea more hospitable to these young fish and improved their early survival rates as they first enter salt water.

“We don’t have a lot of data on this but it is certainly a plausible hypothesis,” Schindler said.

Wild salmon runs rise and fall over time, and no one can be sure just how long the Bristol Bay sockeye runs will continue to be gangbusters.

In the ocean, the sockeye face increasing competition for food from other wild salmon and huge numbers of salmon reared in hatcheries that are released into the North Pacific. And long-term warming trends may work against the Bristol Bay sockeye.

In 2019, foreshadowing a more difficult future, one Bristol Bay river — the Igushik — heated up to the point where some adult fish died before they reached the spawning grounds.

Runs suffer elsewhere

In Alaska, outside of Bristol Bay, many sockeye runs, as well as Chinook runs, have been declining. The diminished runs include the heavily promoted Copper River reds, which this year was forecast to be more than a third below its 10-year average, and is unlikely to even reach that mark.

In British Columbia and the Lower 48, warm freshwater rivers have frequently become obstacles for adult salmon trying to reach spawning grounds. And warmer ocean temperatures already have made life more difficult in some areas where they feed.

The Lake Washington sockeye run, which is sustained by Cedar River spawning grounds, hit a record low return last year despite millions of dollars spent in hatchery and other efforts to revive the numbers.

In the Columbia River Basin, sockeye runs have improved in recent years but remain below historical peaks, which were reached before dams created obstacles to freshwater passage and slow-moving stretches of the river, where water is prone to heat up.

In 2015, most of the basin sockeye run was lost as water temperatures climbed in the Columbia and its tributaries. This summer, more than 142,000 sockeye passed the Bonneville Dam but have again faced warmer water.

In a July 16 video released this week by the Columbia Riverkeeper, sockeye with fungus and lesions are shown lingering in a tributary, far from their upstream spawning grounds.

Michele DeHart, manager of the Fish Passage Center, said that water temperatures above Bonneville Dam are not as bad as 2015. But sockeye survival rates decrease above 68 degrees. This year, as of Tuesday, the temperature topped 70 degrees in the waters below McNary Dam on the Columbia.

“With these temperatures, we would expect that migration upstream will be slower, and survival rates lower,” DeHart said.

Weathering the storm

The 2021 Bristol Bay season came on the heels of a tense 2020 harvest when concerns about COVID-19 prompted strict quarantines of processing workers and other measures to limit the spread of the coronavirus in Bristol Bay communities.

This year, the unusually stormy weather emerged as a serious challenge to fishermen. On July 1, one boat got stuck on a sandbar, then took on water as it was buffeted by waves. The crew ended up in the water, and one man, later identified as Lance Eric Norby, did not survive.

“It was very unsafe,” said Michael Sather, a Marysville-based gillnetter, who said he worked through some “horrendous weather.”

In the Nushagak District, Samuelsen said the nets, which would be left in the water for up to 45 minutes, sometimes brought in more than 10,000 pounds of sockeye.

Samuelsen is a prominent Native leader in the Bristol Bay region who began fishing as a boy with setnets strung out from shore. He has emerged as a high-profile critic of the Pebble Mine, an open-pit mine proposed in a portion of the Bristol Bay headwaters that has generated fierce opposition.

A key permit was rejected last fall by the U.S. Army Corps of Engineers. And President Joe Biden has said he is opposed to this development. Samuelsen hopes Biden’s words will be followed up by federal action that offers permanent protection to the watershed.

Through the July peak of the Bristol Bay season, Samuelsen and his grandsons bunked each night in the cramped quarters of their boat as they awaited news of when they could put out their nets.

Their galley fare included plenty of fresh-caught sockeye salmon, a meal that Samuelsen said never grows old.

“We barbecue it. We fry it. We’re fish eaters,” Samuelsen said.