Hatchery benefits to wild fish questioned
A “global synthesis” of 51 years’ worth of peer-reviewed studies examining interactions between hatchery and wild salmon has concluded that human efforts to improve on nature have often done more harm than good.
Of 206 studies on this subject between 1970 and 2021, only seven reported wild salmon were actually helped by hatchery intervention. The majority of studies – 70 percent – reported hatcheries had nothing but adverse effects on wild fish.
The study was published near the same time this summer as another which reported that the approximately $9 billion that state and federal agencies have spent trying to restore Columbia River salmon runs through the use of hatcheries produced “no empirical evidence of an increase in wild fish abundance associated with restoration spending.”
That study published in peer-reviewed PLOS One attracted considerable attention while the study published about the same time in Fisheries Management and Ecology challenging the idea that hatcheries are the ultimate solution to faltering salmon runs and the key to increasing salmon abundance slipped under the radar.
The Fisheries Management study is what might be considered a meta-analysis of all the research done to date on interactions between hatchery fish and wild fish, and it makes hatcheries look more like another threat to wild salmon than the species’ salvation.
Of the studies cataloged in the synthesis, only 3 percent found hatchery programs that benefitted wild fish. Another 8 percent judged hatchery programs benign in that they did no damage to wild runs, and a further 13 percent concluded hatchery operations had only “minimally adverse” effects on wild fish.
“Our review of over 50 years of peer-reviewed publications on how hatchery salmonids affect wild salmonids found most research reported adverse or minimally adverse hatchery effects across time, species, and countries, even for supplementation-type hatcheries, while reports of beneficial effects on wild salmonids were scarce except for a few very specific situations,” the authors concluded.
Their desire in doing the study, they said, was to try to clear away some of the smoke created “by the sheer volume of complex research that dates back several decades, covers numerous species, and spans three continents, which makes it difficult to interpret succinctly the existing weight of evidence. We sought to provide a transparent, reproducible, and updatable synthesis and database of the current global research evaluating the impacts of hatcheries on wild populations, while purposefully not delving into the complex social and political desires or tribal treaty and mitigation legal obligations surrounding hatcheries.”
America’s biggest fish ranch
For Alaska, the synthesis comes at a time when pink salmon, the smallest and least valuable of the species, are exploding in numbers in the North Pacific Ocean and many other species of salmon are in decline.
Pink numbers appear to be boosted by a combination of warmer water, hatcheries and management for so-called maximum sustained yield (MSY) in Russia and the 49th state. Nearly 148 million pinks were harvested in Alaska this year despite the record low prices being paid for the fish and some processors electing to end the season early due to weak markets for canned salmon, which is where most pinks end up.
Still, the pink harvest was by itself about 50 percent higher than the 100 million, all-species, samon harvest that state fishery managers once considered a good year. The all-species harvest topped 100 million for the first time in 1982 and for the next decade fluctuated between 96 million and 147 million, according to state data.
One more year with a harvest of more than 200 million was to come in the 1990s before the state’s commercial fishing business exploded into the new millennium.
Since the year 2000, harvests over 200 million have become an almost every other year occurrence thanks to the boom in humpies, as Alaskans often call the pink salmon easily identifiable in the state’s streams due to the large humped backs the males develop as they move onto the spawning grounds.
Humpback salmon/U.S. Department of Commerce
The state has topped the 200 million salmon mark eight times in the past 23 years. All were odd-numbered years when pink salmon, which come in odd-year and even-year varieties, hit their peak.
In 2015 state fishery managers bragged that in Prince William Sound alone, “the pink salmon harvest was the largest on record at 98.3 million fish, exceeding the 2013 harvest of 92.6 million. Wild pink salmon abundance is likely to break the previous record of 31 million fish.”
The other 67 million pinks were hatchery fish produced in the fish ranching capital of the 49th state.
Now a world leader in the production of high volumes of low-value salmon – prices for pinks were threatening to drop to near 10 cents per pound this year – the state has long been proud of a Sound hatchery industry that began with the state spending millions to build salmon hatcheries before turning them over to private, non-profit corporations controlled by commercial fishing interests.
The hatcheries were originally supposed to be funded by a tax – what the state called an “assessment” – on the commercial catches of salmon in areas where hatchery fish were available. But when those assessment fees proved unable to support hatchery operating costs, the state allowed the hatcheries to engage in so-called “cost recovery” fisheries.
Too many humpies
With pinks – both wild and hatchery spawned – flourishing in the Pacific as well as the Atlantic Ocean, where they are considered an “invasive species,” while other species of salmon – most notably Chinook, wild Atlantic, coho, Gulf of Alaska sockeye and some stocks of chum salmon – struggle, hatcheries are today coming under increasing scrutiny.
The complaint in the Pacific Northwest is that they have cost a lot and done little to do what they were supposed to do – restore strong runs of native salmon.
Meanwhile, in Alaska, the issue is with industrial-scale operations that have become so good at improving the survival rates of their fish that hatchery fish appear to be replacing wild fish in the ocean.
“Our literature review also revealed an extensive body of research focused on potential effects of annual releases of 4.5 billion hatchery Pacific salmon into the North Pacific Ocean, which represents 40 percent of the total mature and immature salmon biomass in the North Pacific Ocean,” the authors of the synthesis wrote.
“The combination of publications on the specific abundance of hatchery salmon and overall abundance of hatchery and wild salmon at sea suggest heightened abundances, particularly of hatchery chum salmon and pink salmon, have triggered density-dependent effects in wild populations resulting in reduced growth, body size, fecundity, productivity, and abundance, and delayed maturation. For example, research has found adverse effects of hatchery or total chum salmon abundance on the growth, productivity, and abundance of wild chum salmon, of total hatchery and wild pink salmon and chum salmon on body size, age, productivity, and abundance of Chinook salmon across their range, and of hatchery pink salmon on productivity of wild sockeye salmon populations in British Columbia and Alaska.”
They conceded there is no ironclad proof that hatchery salmon are the cause of any or all of these declines in wild salmon, but they argue that the preponderance of evidence leads to that conclusion.
“While it is difficult to disentangle correlation and causation,” they wrote, “the strong biennial patterns in abundant pink salmon (those differences in size between odd and every year runs) cannot be explained by the environment alone, and, consequently, concerns for wild salmon have led scientists to call for international discussions, limits on hatchery production, and hatchery taxes.
Where those discussions might lead is unknown.
But getting the Russians, now at war with Ukraine, to agree to limits on hatchery production seems unlikely, and Alaska hatchery backers made it clear to the state Board of Fisheries five years ago that they’d never support a unilateral rollback in hatchery production.
Meanwhile, backing for a tax on hatcheries seems even more unlikely in a state where the commercial fishing industry, according to the latest research from the Insitute of Social and Economic Research at the University of Alaska, remains so politically powerful that state fishing tax revenues of around $65 million per year aren’t enough to cover the more than $70 million per year the state spends managing, policing and promoting the commercial fisheries.
And that $65 million in revenue is in good years. Given that it is based on a percentage of the revenue paid fishermen when salmon are landed at processors, state revenue off fish is expected to come crashing down this year with prices tanking even for the state’s most valuable salmon.
