UPDATE: This story has been revised from the original to reflect the similar declines in wild Southeast Alaska chum masked by an increase in hatchery chum production.
As Southeast Alaska catches of chum salmon have steadily increased over the past 20 years due to hatchery farming of the sea, Canadian scientists are reporting that wild chum populations just to the south in British Columbia have been taking a beating.
“Our findings reveal major declines in the abundance of chum salmon returning to the Central Coast of British Columbia since 1960, with an average decline of more than 90 percent by 2020 across 25 populations with reliable long-term spawner escapement data over the last six decades,” they said.
Canadian chum returns appear to be almost the polar opposite of the bounty only a little further along the Alaska Current, an ocean river that pushes young salmon emerging from the rivers of the Pacific Northwest and British Columbia north toward the Panhandle of the 49th state.
The Canadians are now talking about boosting their production of hatchery salmon to mimic Alaska’s success in the business of farming the sea. And it is possible that the Canadians could find that free-range farming B.C. salmon is every bit as successful and profitable for them as it is now for Alaska.
But it could also be that Canada lost millions of wild chums because they were replaced by millions of Alaska hatchery chums, and recent research indicates that hatcheries might in that case make the wild chum survival worse, not better.
As the Canadian researchers observed, there have been “in recent years, a series of marine heatwaves (that) reduced food-web productivity in the North Pacific, increased metabolic demands on ectotherms like salmon and exacerbated competition between wild- and hatchery-origin salmon for limited food resources at sea.”
What is clear at this point is that wild chums are in a state of decline while hatchery chums are doing much better as Alaska Department of Fish and Game shows.
The state agency reports the catch of wild fish is now less than a quarter of what it was back in the old Alaska Territory, and that a rebound in chum numbers that followed the start of warming of the North Pacific Ocean in the early 1980s has now ended. Wild chums were climbing out of that depression just as major hatchery production began to come online in the mid-1980s.
Their numbers grew even as hatchery production skyrocketed into the 1990s, but peaked around the start of the new millennium and then fell rapidly. They appear to have settled into a new equilibrium since about 2010 with the annual harvest fluctuating around a mean of just below 1 million compared to the hatchery-free average of 4.5 million in territorial days.
The interactions between the wild fish and hatchery fish are not clear, but Alaska’s hatcheries appear to have given Southeast chums a big, competitive edge over their wild cousins, both Alaskan and Canadian, given that they start life bigger thanks to hatchery rearing and then, at least for the Alaska fish versus the Canadian fish, enter slightly cooler waters that produce better feed for salmon than warmer waters a little ways to the south.
Young hatchery chums are now regularly raised in net pens – just like farm-raised salmon in Norway – to grow them to the ideal weight for release.
At Crayfish Inlet 40 miles south of Sitka, the Northern Southeast Regional Aquaculture Association (NSRAA) has anchored 20 net pens where “all 14 million rearing (chum) fry are being grown to four grams, a strategy expected to maximize marine survival.”
The NSRAA is one of two Southeast aquaculture associations controlled by commercial fishermen. Both it and the Southern Southeast Regional Aquaculture Association (SSRA) have found significant success in farming the sea thanks in part of changing environmental conditions.
A wide variety of studies point to a warming ocean benefiting northern salmon over southern salmon with some species of Alaska-origin salmon, especially pink salmon, the biggest winners. The smallest of the salmon and the one most heavily farmed in the 49th state, pinks now power record Alaska salmon harvests.
The Norway-like net pens in Crayfish Inlet/NSRAA
Growing chums
Over the last 10 years, the statewide chum catch itself has more than doubled that of the 1970s to reach an average of 17.5 million per year with the bulk of the fish coming from hatcheries in Southeast and to the north in Prince William Sound. Of the 12.8 million chum caught in Alaska in 2021, a bit of an off year, the Alaska Department of Fish and Game’s “annual enhancement report records that 9.3 million, or about 73 percent, were hatchery fish.
“Although most of the harvest of a species in a region may be made up of hatchery production – pink salmon in Prince William Sound or chum salmon in Southeast Alaska, for example – this does not mean that hatchery production is intended to replace wild stock production,” that report added.
With the catch of 3.5 million wild chums in 2021 less than half the average of the decadal harvest for the pre-hatchery years of the 1970s – when scientists agree Alaska salmon production was depressed by cold waters in the North Pacific Ocean – and but 30 percent of the harvest of the 1980s – when Alaska harvests were beginning to increase everywhere as the ocean warmed – some might question that conclusion as to replacement.
In 1985, with Fish and Game’s Fisheries Rehabilitation and Enhancement Division (FRED) still running the state’s hatchery program, the agency reported to the Alaska Legislature a harvest of approximately 660,000 hatchery chums or about 6 percent of a statewide harvest of approximately 10.6 million of the fish that year.
With private operators in charge, the production of hatchery chums kept climbing and the production of wild chums started slipping downward. There has, in the past, been debate about whether Alaska hatchery programs are augmenting or replacing the production of wild fish, but the discussion has in recent years largely been shouted down by a state commercial fishing industry that now has a huge vested interest in farming the sea with hatcheries while denying Alaska is in the fish-farming business; they prefer to call their farming “ranching.”
They concluded the big rise in statewide production of salmon came as the North Pacific began to warm in the 1980s and wrote that “hatchery production did not become the dominant factor in Prince William Sound until the mid-1980s, long after the wild population had expanded.”
Since that paper was written, hatchery production in the Sound has only gone up, returning hatchery pinks have strayed into almost every stream and river in the 2,500-square-mile area, and the interactions of hatchery and wild stocks have become almost impossible to untangle.
Hatchery interests now rave about the swarms of “humpies,” the common Alaska name for pink salmon, they generate every year. They hit the jackpot a decade ago when 219 million pinks drove a record state harvest of a never before imagined 272 million fish.
State fisheries officials credited the hatcheries with producing almost 39 percent of that catch in a report that said “an estimated 97 million fish, or 36 percent of the commercial common property harvest, were produced by the Alaska salmon hatcheries. (And) approximately 9 million salmon were harvested for hatchery cost recovery” for a total hatchery catch of 106 million.
This was a 13-found increase from 1985 when FRED reported a hatchery harvest of 8 million salmon of all species, but told the Legislature that it was finding increasing success in farming the sea.
“In 1975 the enhancement goal of 25 million salmon for harvest seemed ambitious, especially when the salmon harvests for the entire state had fallen below that number in 1973 and 1974. (But) a large investment in hatchery technology and a commitment to rehabilitate and enhance our fishery has led us to realize that we can attain these goals.”
Seemingly huge success
Three decades later, hatchery businesses boast that they are responsible for producing an annual average of 538 million pounds of salmon worth $322.8 million dollars. That is nearly half of what Fish and Game reports as the state’s “long-term average” harvest of 762 million pounds, but most of the hatchery production is in low-value pinks.
Last year saw an unprecedented, record run of wild sockeye salmon to hatchery-free Bristol Bay in what was an off-year everywhere for pink salmon, but Fish and reported the pink catch still accounted for 43 percent of the statewide salmon harvest but only 14 percent of the value. Pink harvests yo-yo wildly in the North Pacific with Alaska harvests of pinks in even-numbered years such as 2022 about half those in odd-numbered years.
Some scientists have theorized the annual up-down nature of pinks is tied to production so high in odd-numbered years that the fish essentially graze the ocean pastures down near to dirt making it harder for the fish of the even-numbered years to find enough food to survive.
High pink abundance in odd-numbered years has also been linked to a decline in the production of Gulf of Alaska sockeye and suggested as a possibility for the huge fall in the production of Chinook salmon from the Columbia River north to Kodiak Island.
“From 2005 to 2015, the approximately 82 million adult pink salmon produced annually from hatcheries were estimated to have reduced the productivity of southern sockeye salmon by approximately 15 percent on average,” Brendan Connors of the Institute of Ocean Sciences with Fisheries and Oceans Canada in British Columbia and colleagues reported in a peer-reviewed paper published in the peer-reviewed Canadian Journal of Fisheries and Aquatic Science in 2020.
The Canadian plan ironically comes at a time when hatcheries in the Lower 48 are being accused of doing little to rebuild depressed wild salmon populations and the Japanese, who pioneered industrial-level farming of the sea after World War II are seeing decades of hatchery success starting to fade away.
Lords of the seas
After the end of World War II, Japan largely abandoned the idea of managing wild salmon fisheries in favor of replacing them with hatchery operations. From then into the 1970s, Japanese salmon harvests grew slowly before exploding into the ’80s and ’90s as the ocean warmed and hatchery techniques were perfected.
All of this success ended near the start of the new millennium. Harvests started to fall then and have continued to fall since. The Japanese harvest is now down to near when it was in 1980 when the country’s hatchery production was starting to mushroom.
Marine heat waves (MHW) in the 2010s (remember The Blob) appear to have been detrimental to Japanese salmon, he writes, but “in the Northwestern Pacific Ocean, including the entire Sea of Japan and part of the Sea of Okhotsk intense MHW occurred in July and August 2021. However, there was no clear impact on salmon.
“Conversely, some researchers reported that cold coastal sea surface temperatures in May 2013 and May 2014 resulted in lower juvenile growth rates during coastal residency and poor adult returns for Japanese chum salmon.”
Still, as Kaeriyama notes, there is an over-arching, long-term trend underway that cannot be overlooked.
North Pacific-wide harvests of pink, chum and sockeye salmon – which together comprise 96 percent of the annual, “wild caught” salmon catch – “have shown a decreasing trend in Japan since the mid-2000s and in British Columbia, Canada, since the 1990s,” he writes. “In contrast, their catches have increased in Russia since the mid-2000s and have been highly stable in Alaska since the 1990s; that is Pacific salmon productivity has reduced in southern areas but increased in northern areas during this century.”
With or without hatcheries, it would appear, Alaska would have been the biggest beneficiary of warming, but Alaska hatcheries clearly added to the bounty. Whether this has come at the expense of wild salmon runs in Alaska, Canada or the Pacific Northwest is hard to say although Kaeriyama blamed Russian salmon increases, partially fueled by hatcheries, for some of Japan’s production declines.
“Based on the Lotka-Volterra competition model,” he writes, “against Russian chum salmon, Japanese chum salmon was the winner until the 2011 brood year and became coexistent or a loser after that. Japanese chum salmon were almost a loser against Russian pink salmon after the 1995 brood and always a winner against Russian sockeye salmon.”
A still warming North Pacific Ocean he added, appears as if it will continue to favor Russian and Alaska salmon, and he suggests that much of what scientists learned about salmon productivity in the last century might now be worthless due to changing ocean conditions.
“In the 20th century, carrying capacity and productivity of salmon were linked with climate change indices such as the Pacific Decadal Oscillation (PDO) and the Aleutian Low Pressure Index,” he writes. “However, since the start of the 21st century, the salmon carrying capacity has been linked with the sea surface temperature (SST) in the Sea of Okhotsk and the Bering Sea despite there being no correlations with climate change indices. This suggests that SST variability has a critical effect on biomass and the carrying capacity of salmon in the North Pacific Ocean.”
Given this and citing archaeological history, he goes on to theorize that Japan’s success at farming the sea might well be coming to an end.
A grim future?
Ice cores from Antarctica going back 350,000 years, Kaeriyama observed, “show that the global temperature from the mid-Initial to early Jomon periods was approximately two degrees celsius higher than at present. Accordingly, this period was called the ‘Jomon transgression’….(and) salmon remains from the Pacific side in Honshu (Island) disappeared during the Jomon transgression period.
“The global mean temperature has increased by one-degree celsius, and the current chum salmon situation is approaching that of the Jomon transgression period. While the temperature rose by two degrees celsius over 2,000 years in the Jomon transgression period, it has recently risen by one-degree celsius in just 100 years owing to global warming; that is, the current rate of warming is 10 times faster than that during the Jomon transgression period.
“Southern populations of Pacific salmon in Asia and North America may not be able to adapt to the future environmental conditions owing to global warming.”
He makes no mention of one significant compounding factor at play – the well-documented loss of genetic diversity in hatchery-spawned salmon – but does suggest that given what is happening in the northern oceans warrants a Pacific-wide discussion and global cooperation to set some goals “for the sustainable conservation management of Pacific salmon…as follows:
- “Conservation…and zoning between wild and hatchery-produced salmon.
- “Long-term research and monitoring of aquatic ecosystem and salmon….
- “Restoration and resilience of wild salmon and river ecosystems.”
Thanks largely to the efforts of Canadian fisheries researchers, most notably Dick Beamish, the second of those initiatives is already underway. It is the easy one. The others are hard.
As Kaeriyama notes, Russia and Alaska have been big winners as the ocean has warmed, and they would likely have to give up some of those gains to aid salmon from Japan, British Columbia and the Pacific Northwest. The Russians, and likely Alaskans as well, would seem unlikely to go along with such a scheme.
Alaskans are already in court fighting efforts to further restrict the Southeast troll fleet to allow more migrating Columbia Chinook salmon to escape commercial fisheries to help feed endangered killer whales and populate spawning grounds in the Lower 48. And Alaska hatchery interests in 2018 beat back efforts to limit hatchery production to protect wild, home-state salmon
Meanwhile, the Russians are facing down huge international pressure and ignoring economic sanctions intended to force them to end their invasion of Ukraine, which they believe is in their national interest. They would seem especially unlikely candidates to roll back hatchery production or alter salmon management to help the Japanese or anyone else.
It is possible the U.S. government – which has taken the position that it has more authority over resource management in the 49th state than it does in other states – might have the ability to throttle back Alaska’s salmon production and harvests, but any such attempt to do so would be sure to ignite a political firestorm involving not only Alaskans but the Outside interests that make more off Alaska’s fisheries than Alaskans do.
Canada and Japan might well be destined to remain the Pacific’s biggest losers as Alaska and Russia roll on as the biggest winners.