During the past few years, for reasons that remain largely unknown, king salmon returns throughout Alaska have been dismal. Desperate for a “fix,” some fishermen propose that hatchery-raised king salmon are the answer.
It’s more likely that hatcheries are part of the problem. Since 1970, the combined efforts of the U.S., Canada and other Pacific Rim countries have increased the number of hatchery-raised salmon released into the Pacific from 500 million to 5 billion fish. About 90 percent of these hatchery-released fish are chum and pink salmon. Since the mid-1980s, hatchery chums have outnumbered wild chums in the ocean.
Alaska’s many pink-salmon hatcheries just might be one of the problems with its king salmon runs. Pinks are hard-wired to eat lots and grow fast. They hatch in the spring, migrate to the ocean as fry the same year, overwinter in the ocean and return the following fall. It’s no coincidence that pinks aren’t on the endangered species list.
In 2010, one-third of the salmon in Alaska’s statewide commercial salmon harvest were released into the ocean by five non-profit hatcheries in Prince William Sound.
The Alaska Seafood Marketing Institute hypes these hatchery fish as being just as “Wild, Natural and Sustainable” as wild fish. A large number of these “wild” and “natural” salmon hatch and rear in very un-wild and unnatural environments, and it’s arguable whether they are sustainable. Worse, study findings indicate that they can threaten the sustainability of wild salmon.
“Ocean ranching,” the marketers call it, so as to keep these hatchery-raised fish from being mistaken for “farmed” salmon. Salmon farms grow salmon to harvestable size in pens. Hatcheries, on the other hand, raise salmon to a size that optimizes their chances of survival, then release them in the ocean. Real ranchers know how many cattle their ranches can support, but not the fish hatcheries. They just keep pumping more fish into the ocean.
The failure to recognize that the ocean is a finite “ranch,” and continuing to release vast numbers of hatchery salmon into it is bound to have unintended consequences. Wild salmon, as well as a multitude of other animals, have to compete with hatchery-raised salmon for a finite amount of food in the ocean. A recent study of chum salmon in the Bering Sea found evidence that large-scale production of chum salmon from Asian hatcheries may affect size, age-at-maturation, productivity and abundance of wild chum populations in Alaska.
Hatcheries acclimate salmon to conditions unlike those found by fish that hatch naturally, in a stream. Trouble is, when released, hatchery-raised fish take what they’ve learned into the ocean, everything from feeding habits to predator avoidance. What they learn in the hatchery is anything but natural.
Straying is another problem that comes from augmenting a natural salmon run with hatchery stock. While most salmon return to their natal streams, a few stray. Straying isn’t all bad. Strays help to repopulate streams where salmon have been extinguished. However, straying can become harmful when strays mate with salmon from a wild stock. The offspring of these fish may not have the run timing or the “homing guidance system” of the wild stock. When this happens often enough, the genetic makeup of the wild stock may be altered, eventually threatening its viability.
The use of fish hatcheries to restore and augment salmon runs has a long history of failure in the Pacific Northwest, and is now threatening wild salmon stocks in the ocean. Augment our king salmon runs with hatchery fish? That’s crazy talk.
Les Palmer can be reached at firstname.lastname@example.org.