Are hatchery-born pinks causing a decline in the size of wild salmon returning to Alaska’s rivers and streams? Alaskans might well ask that question after reading a recent study published in the science journal Nature Communities, which found widespread declines in the length and weight of returning sockeye, silvers, chums, and kings that it attributed to the effects of climate change and increased competition between wild and hatchery-born salmon at sea.
Yet while the study’s findings about the size of returning salmon are definitive and concerning, the explanations it offers for the causes of the decline are speculative and open to debate. As the study’s authors warn, “Understanding the causes of body size declines is daunting given the influence of numerous, potentially interacting factors.”
Popular news articles largely buried that qualification in the rush to publish the study’s findings. Headline after headline cited only climate change and competition with hatchery fish. A Seattle Times report, carried in the pages of this newspaper, was titled “Alaska salmon returning smaller amid climate change and competition with hatchery fish, study finds,” but referenced hatcheries only in the last two paragraphs.
Concerningly, both the study and subsequent media reports failed to provide adequate context about the population of hatchery-born pink salmon in the North Pacific. It is true pink salmon are the most numerous salmon species in the North Pacific, but they are not the largest salmon population in the ecosystem. Chums, which are larger and take longer to mature, comprise 60% of the total salmon biomass in the North Pacific—three times the biomass of pinks. More to the point, only 15% of pink salmon in the North Pacific were born in hatcheries, representing only 3% of total salmon biomass. Alaska’s hatchery-born pinks represent a fraction of that 3%. It is misleading and irresponsible for news outlets to sensationalize hatchery pink salmon impacts while ignoring its relative volume compared to total salmon biomass.
As the leaders of Alaska’s nonprofit salmon hatcheries, we are concerned that these context-free headlines feed into the misperception that hatchery operations harm wild stocks. Let us be clear: As Alaskans and scientists, we wouldn’t do what we do if evidence demonstrated harm to Alaska’s wild salmon. Since the founding of the hatchery nonprofits in the 1970s, we have designed and refined operations to ensure salmon born in hatcheries don’t harm their wild counterparts. After all, we exist to enhance — not replace — wild salmon stocks.
Our hatcheries work closely with state regulators and biologists to ensure hatchery-born salmon have a minimal impact on the environment and wild stocks. In compliance with state regulations, our facilities and release sites are located away from large populations of wild salmon, with each having gone through a rigorous review process to receive approval. In doing so, we help to prevent hatchery-born fish from returning to lakes, streams, or estuaries native to wild runs.
To protect the genetic diversity of wild stocks, we use only eggs and milt taken from a large number of local adult fish selected without regard for size or any other trait. Per state law and Fish and Game regulations, breeding or manipulating stock genetics is prohibited. That way, if a hatchery- born fish happens to stray, as a few occasionally do, it will have genes similar to local wild populations. Not to mention, hatchery fish are marked so that state biologists and others can tell the difference when research calls for that.
Furthermore, the number of hatchery-born salmon we release every year is tightly controlled by state regulators, who hold sole authority over production increases. In fact, production levels have remained relatively stable in recent years. Per open discussions with Alaska Department of Fish and Game last year, we do not anticipate any production increases anytime soon.
None of what we write here is to discredit the scientists working to enhance our understanding of wild Pacific salmon populations. Indeed, at this very moment, we are working with the Department of Fish and Game to support the state-backed Alaska Hatchery-Wild Salmon Interaction Study, which aims to investigate potential genetic concerns, document stock interactions, and measure potential changes in the fitness of wild populations. Overseen by an independent science panel selected by the Department, the comprehensive research study, which began in 2011, expects to publish its findings in 2023, following a rigorous peer review process.
By and large, we believe Alaska’s nonprofit salmon hatcheries have succeeded. Despite the ups and downs of year-on-year returns, relatively stable hatchery production has buttressed fishermen from all user groups and simultaneously reduced pressure on wild stocks. Alaska’s hatchery salmon produce more than a billion meals of healthy protein per year. That is an achievement we stand behind even as we, as Alaskans and fishermen, face unknown climate and environmental challenges in the years ahead. Statewide, Alaska’s salmon fisheries — its strong runs, sustainable harvests, and robust, science-based management — are a model for those in the Lower 48 and around the world. As Alaska’s hatchery operators, we stand by to foster strong salmon harvests and healthy ocean ecosystems in every way possible for generations to come.
Mike Wells is executive director of Valdez Fisheries Development Association; Tina Fairbanks is executive director of Kodiak Regional Aquaculture Association; Tommy Sheridan is CEO of the Prince William Sound Aquaculture Corporation; Katie Harms is executive director of Douglas Island Pink and Chum; Dean Day is executive director of Cook Inlet Aquaculture Association; David Landis is general manager of Southern Southeast Regional Aquaculture Association; Scott Wagner is general manager of Northern Southeast Regional Aquaculture Association. To learn more about Alaska’s private non-profit salmon hatcheries, visit salmonhatcheriesforak.org.
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