Climate change is today smiling on the commercial salmon fishermen and salmon processors of Alaska’s Bristol Bay in a big way with daily harvests of sockeye salmon exceeding the annual catches of the fabled Copper River or Cook Inlet combined.

As of Thursday, fishermen had pulled about 51 million of the fish out of the big bay cupped into the state’s far Southwest coast just north of the Aleutian Island chain, and another 14 million had been counted making their way up the rivers that drain the region’s many lake-filled watersheds.

The graph of harvests since 2000 looks more than a little like the famous “hockey stick” graph of global temperatures over the last 2,000 years.

Alaska Department of Fish and Game biologists are expecting the final count of sockeye at season’s end to meet or exceed their preseason forecast of an unprecedented and once unimagined, total return of 75.3 million – near twice the 20-year, average return of 41.3 million.

The Bay’s commercial salmon fishery dating back to 1884 began an upward climb after Alaska statehood in 1959, but it has exploded over the course of the last two decades.

The largest harvest on record during Alaska’s territorial days was 24.5 million in 1917, according to the records, and in only 10 of the 75 years between the fishery’s beginning and statehood did the harvest top 20 million.

“During the 118 years between 1895 and 2012, Bristol Bay fishermen harvested more than 1.7 billion sockeye salmon, with an annual average harvest of 15 million sockeye salmon,” economists at the University of Alaska’s Institute of Social and Economic Research (ISER) observed in 2014.

The 15 million standard

“Harvests have been particularly strong since 1980,” the ISER researchers added, “with an annual average harvest of 24.6 million sockeye salmon during the period 1980-2012.”

Since then, anything less than 20 million has come to be considered a ‘bad’ year.

The 10-year average harvest from 2010 to 2019 was 31.5 million sockeye with the last five years of that period averaging 39.6 million.

The 2020 harvest matched that average and “was the third largest since 2000 and the fifth largest sockeye salmon harvest recorded in Bristol Bay since 1893,” according to Fish and Game.

Last year brought a new record return that overwhelmed the fishery’s harvest capacity, in part because of bad weather during the always fast and furious flood of fish in July.

“The (total) 2021 inshore sockeye salmon run of approximately 67.7 million fish was the largest run on record and 35 percent above the preseason forecast of 50.0 million,” according to Fish and Game, but the harvest reached only 42.0 million, “the second largest since 2001 and the third largest sockeye salmon
harvest recorded in Bristol Bay since 1893.

Weather got the blame.

“Between June 22 and July 1, (2021), a series of storms moved through the Bristol Bay region that brought strong easterly winds and heavy inshore seas,” according to state reports. “This likely affected harvest power as some vessels elected not to fish at times, and for those that did, gillnet gear can become less effective in rough sea conditions.”

Area rivers ended up plugged with salmon as result. Twice the 2 million desired spawners escaped the fishery to enter the Naknek River. The Egegik River went 300,000 sockeye over its upper goal of 2 million.  The Kvichak River was near double its minimum goal of 2 million.

Warming waters

Most of this increase in productivity, scientists agree, has been driven by warming waters.

“Since the early 1960s, there have been changes in both freshwater and ocean environmental conditions with the potential to influence life-history transitions in sockeye salmon.” according to University of Washington scientists who’ve spent decades studying the Bay’s sockeye. “Southwest Alaska has been warming rapidly during this time period. Spring ice break-up dates on lakes in Bristol Bay have occurred much earlier, and summer lake temperatures have increased.

“Ice break-up on Lake Aleknagik, an intensively studied lake in the Wood River system, has occurred on average 2.5 days per decade earlier and summer lake temperatures have increased by 0.5 °C (almost 1 degree Fahrenheit) per decade, both leading to longer and more productive growing seasons.

“Earlier ice-off and warmer lake conditions are positively correlated with Daphnia (plankton)…a primary food source for juvenile sockeye and juvenile salmon growth. In the North Pacific Ocean, the primary rearing area for sockeye, there have been changes in surface temperature as well as upwelling and productivity. The Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO) are inter-decadal shifts in sea surface temperatures and upwelling that are strongly correlated with sockeye productivity in Alaska.”

Their conclusions, with which other fishery biologists agree, were published in Nature Ecology and Evolution in 2019.

Though some environmental activists and journalists find these conclusions speculative and hard to accept, they are what they are. There is no ignoring them just because the official narrative says all global warming is bad.

The reality is that all environmental shifts bring changes both good and bad. While Bristol Bay sockeye are clear winners, and Gulf of Alaska pink salmon appear to be likewise, Gulf of Alaska sockeye, Chinook salmon Pacific-wide, coho salmon appear to be losers.

The North Pacific was in 2018 reported to be supporting more salmon than at any time in recorded history, but two out of every three were pinks with the American Fisheries Society noting that “Chinook and coho salmon and steelhead trout are depressed throughout much of their range.”

Meanwhile, the human species is facing a threat from warming because its population is concentrated near the equator and steadily thins to the north and south.

Only 7.1 million people inhabit the planet north of Anchorage at 61 degrees latitude, This is 1.8 million fewer than live in New York City, the largest city in the U.S.

Only 33 million people occupy the planet north of Bristol Bay at about 58 degrees latitude. There are about 4.5 million more than that living in Tokyo, now the world’s largest city. 

And while Alaska was this month registering monster sockeye salmon runs thanks to warming, the BMJ – the journal of the British Medical Association – was warning of “the rising public health dangers of extreme heat.”

“In 2021, the UK Met Office estimated that a 2°C rise (3.6 degrees Fahrenheit) in global temperatures would lead to a billion people living in extreme heat stress, up from 68 million people today.,” it was reported there Wednesday. “A June 2022 study found that a 1.0°C (1.8 degrees Fahrenheit) rise in global heat could be linked to a million deaths in Latin America. Many of the world’s people most affected are located on the populous Indian subcontinent, in Brazil, and in central Africa.”

But they are not the only ones at risk. A 2003 heatwave in Europe was blamed for 20,000 deaths in France alone.

While Alaska, Canada and Russia – where agriculture is projected to boom – look to be global-warming winners, most of the residents of the planet are expected to pay a price – not reap a reward – for climate change.

Smaller fish

And the fishery situation in Alaska isn’t quite as rosy as big harvests at first make it appear.

Pink salmon, the smallest and least valuable of the species, have been driving once unimagined annual harvests near or over 200 million fish while Bay sockeye have been shrinking in size.

The average, 4.89 pound weight of 2021 was about 17 percent less than the 20-year average of 5.7 pounds, according to Fish and Game  data. The shrinkage is especially problematic in a market now dominated by farmed salmon.

Farmed fish, which can be grown to any desired size, have created a peak market demand for fillets from salmon of 8.5 pounds and up. 

Bert Lewis, the state’s regional supervisor for commercial fisheries in the Bay, this week said that the fish are again this year “pretty small.

“They’re keeping up with the old age: big run, small fish,” he said.

On a more positive note, however, he added that fears of a lack of processing capacity given the size of the run have not materialized thanks in part to expansion of some Bay processing facilities and the addition of “long-haul tenders” outfitted with refrigerated sea water (RSW) systems to preserve the catch.

RSW tenders, he said, have allowed processors to haul salmon from the Bay to processing facilities as far away as Kodiak or Cordova, a port on the opposite side of the Gulf of Alaska more than 400 miles from the Bay,  with little if any loss of quality.

Processors, he said, have been “keeping up amazingly well,” but are getting close to “running out of containers to ship fish out.

“It’s been crazy to watch.”

How long this “new normal” of harvests of more than 30 million sockeye per year can last is an unknown. As the planet continues to warm, there is expected to come a point where the benefits of warming become the opposite.

But “we just don’t know where there’s a tipping point, especially as we fill the ocean with hatchery competitors,” Daniel Schindler, a UW fisheries professor and the lead author on the Nature study told the UW News.

“We know climate warming is making rivers more productive for the food juvenile salmon eat, meaning their growth rate is speeding up. That puts the salmon on a growth trajectory that moves them to the ocean faster.”

But that jump start in freshwater is offset by the fish spending an extra year in the ocean to grow or returning after two years at a much smaller size.

Complicated picture

Scientists are still trying to sort out how much of this is due to a marine ecosystem altered by warning and how much to competition from a new-found bounty of pink and chum salmon boosted by the 5 billion hatchery-raised salmon now released into the North Pacific each year.

Alaska is a world leader in hatchery production, pumping out 1.7 billion to 1.8 billion young fish every year, according to the North Pacific Anadromous Fish Commission.

That is eight to nine times the number of salmon produced by all the salmon hatcheries in the Lower 48, and about five times the number released by Canada.

With Canadian salmon runs struggling, the government there is planning a substantial increase in hatchery production, while U.S. hatcheries in the Pacific Northwest are under fire as costly failures and a possible threat to the survival of wild salmon.

How directly their bust is linked to Alaska’s boom is a subject of increasing scientific debate. Greg Ruggerone, a fisheries consultant in Seattle, and a group of fellow scientists made up primarily of Canadian and U.S. government researchers, have suggested the abundance of pinks in the Gulf and sockeye in the Bay is reducing the survival rates for Pacific Northwest Chinook and sockeye salmon that migrate north to use the same feeding grounds in the Bering Sea and along the rim of the Gulf of Alaska.

They note a 56 percent decline in Chinook stomach fullness in odd-numbered years when pinks, primarily of Russian origin, are at maximum abundance in the Bering Sea, and a notable decline in Chinook numbers from 1980 to 2019 as the hatchery program began by the state of Alaska and later turned over to commercial fishermen began pumping out increasing numbers of pinks. 

The joint explosions of pink and sockeye salmon in the Bering Sea might also help explain why Yukon River Chinook, which also feed there, are in as bad shape, or worse, than the Chinook of the much-dammed Columbia and Snake rivers in the Pacific Northwest.

“The Arctic-Yukon-Kuskokwim (AYK) Region experienced unprecedented salmon run failures during the 2021 season,” according to the National Oceanic and Atmospheric Administration (NOAA). “The cause of poor Chinook, chum, and coho salmon runs throughout the AYK Region are not known, but prevailing hypotheses are focused on sub-optimal conditions for growth and survival in the marine environment.”

Scientists are still trying to sort out this situation there, but a couple of things are clear.

1. Yukon Chinook have generally been in decline since the start of the new millennium while Bay sockeye and pink salmon everywhere, most particularly odd-year pink salmon, have generally been in a steady state of growth.
2. Environmental changes always produce winners and losers, and no matter the exact reasons as to why, Bay sockeye are now clearly one of the biggest winners.