Salmon migration routes/Global Change Biology

Scientists looking for evidence that climate-caused ocean acidification is harming North Pacific salmon have instead discovered something else – a threat to wild fish from Alaska’s massive, commercial-fishermen-funded, ocean-farming business.

“Using 60 years of data on wild pink salmon abundances, hatchery releases, and ecological conditions in the ocean, we find evidence that hatchery pink salmon releases negatively affect wild pink salmon productivity, likely through competition between wild and hatchery juveniles in nearshore marine habitats. We find no evidence for effects of ocean acidification on pink salmon productivity,” they reported.

Their peer-reviewed study was published last week in Global Change Biology.

While it concludes the Alaska hatchery program is in some cases merely trading away wild pinks in favor of hatchery-bred pinks, it concedes that the jury is still out on the extent to which hatcheries might also be trading away far more valuable wild stocks of Alaska Chinook, coho and sockeye salmon in order to up the production of pinks, as other studies have suggested.

“…Because Pacific salmon migrate long distances at sea, large-scale hatchery production may have unintended adverse effects on other species of salmon originating from distant regions,” wrote the team of researchers led by Jan Ohlberger from the University of Washington….”(But) quantifying the tradeoffs between industry performance in the fishery supported by the large hatchery program and productivity and abundance of wild salmon populations within and outside (Prince William Sound) are left for future extensions of this work.”

The Alaska Department of Fish and Game – once considered a global leader in salmon research and management – has too date refused to address this issue despite dramatic declines in the numbers of king (Chinook) salmon, the state fish, in the past decade.

Bill Templin, the agency’s director of fisheries research, in 2018 told the Alaska Board of Fisheries that the at-sea interactions between salmon and the myriad other fishes that inhabit the North Pacific are simply too complicated to study.

He said then that there is no definitive proof that the use of hatcheries to boost the commercial production of salmon is harming wild fish.

Templin and his superiors at Fish and Game, however, dodged the key question posed by Board member Israel Payton, who wanted to know when the “rehabilitation” of faltering wild salmon runs that fueled the creation of the Alaska hatchery program in the 1970s would be considered complete.

Hatchery origins

The program was begun by the Fisheries Rehabilitation and Enhancement Division (FRED) of Fish and Game in the early 1970s as Alaska commercial salmon harvests fell from 68 million in 1970 to 47.5 million in 1971 to 32 million in 1972 to 22 million in 1973 and 1974.

With harvests crashing, then Alaska Gov. Jay Hammond “instructed ADF&G to develop an Alaska salmon plan,” according to a Fish and Game history. “The plan was completed in 1976 and was used to assist the state of Alaska in developing and implementing the
Alaska hatchery program.

“The Alaska salmon plan suggested the salmon resources of Alaska could support a commercial fishery with average annual harvests in excess of 100 million salmon – given reasonable survival conditions, improved management technology, and improved
budget support.

“At the time the plan was written, the highest decadal commercial harvest level
was in the 1930s when the average harvest was about 90 million salmon,” according to the agency’s official history. “At the time, many salmon stocks had been overfished, the runs depleted, and in need of rehabilitation. Plan developers in the early 1970s were optimistic that with improved management tools and better inseason management, these historic harvest levels could be surpassed.

“While most people familiar today with the Alaska salmon fishery would consider
annual commercial salmon harvests of less than 100 million as a disaster, from the inception of the salmon fishery in the late 1800s through the 1970s, such harvest levels were considered a godsend. Prior to the plan being written, annual commercial harvest levels in excess of 100 million salmon had only happened in six years.”

Much has changed since then. Fish and Game reported a harvest of 233.8 million salmon this year. It marked the seventh time the catch has gone over 200 million in the last 20 yeares, but as has become the norm, nearly seven out of every 10 of the fish were low-value pinks.

“Pink salmon accounted for approximately 28 percent of the value at $178.8 million, and 69 percent of the harvest with under 161 million fish,” the season summary said. 

State-funded hatcheries drove this pink salmon boom.

From the late 1970s into the early 1980s, FRED was involved in the construction and often the operation of about 20 hatchery from Southeast Alaska north to the Noatak River near the Arctic Circle. The program became so large that questions arose as to whether the state could afford it.

“North Slope oil revenues to Alaska declined in the 1980s and natural salmon production increased,” the official Fish and Game history reflects. “As a result, Alaska explored the option of private sector operation of state salmon enhancement programs.”

Privatization

The eventual result of the budget crunch was the creation of private, non-profit hatchery (PNP) operations overseen by collectives of commercial fishermen and the elimination of the FRED Division. By the mid-1990s, most of the hatcheries were in private hands, and “by the later 1990s, the Division of Commercial Fisheries neither funded nor operated salmon hatcheries,” according to the state history.

Since then, Alaska salmon harvests fueled in significant part by hatchery production of pinks have just gone up, up, up. State harvest data reflects annual average catches of 122.4 million per year in the 1980s, 157.5 million in the 1990s, 167.4 million in the 2000s, and about 181 million in the 2010s.

But catches have also begun to oscillate wildly from year to year as pinks – a short-lived species far more productive in odd-numbered years than in even-numbered years – have come to dominate the catch.

The 59.4 million pinks Fish and Game reported harvest in 2020 – an even numbered year -was only 37 percent of the number caught this year. Still, 2020 was a decent year for the hatcheries and the fishermen now dependent upon them.

The 2020 hatchery-related harvests accounted for about 42 percent of that year’s pink catch, according to the state’s Alaska Salmon Fisheries Enhancement Annual Report 2020 as the PNP hatcheries continued to help Alaska lead the way to the nation’s status as the number-one salmon farmer in the North Pacific.

The country still holds that distinction, and of the more than 2 billion hatchery salmon the U.S. pumped into the ocean this year, according to the North Pacific Anadromous Fish Commission, more than 86 percent came from Alaska hatcheries. 

Big business

Prince William Sound pinks are the focal point for this Alaska fish farming business referred to instate as “ranching,” so is to differentiate it from the net-pen farming practices favored in Norway, Chile, the Faroe Islands and elsewhere.

Net-pen farming was banned by the state in 1989 in the belief that it could corner the market on salmon production.

Instead of raising hatchery fish in pens to keep them separate from wild fish as much as possible and accepting the high costs of feeding them, Alaska decided it would be more efficient to produce salmon in hatcheries, dump them in the ocean by the hundreds of millions as fingerlings or smolt, and wait for the adults to later return from the sea.

This business model had proven a failure in the 1970s in Oregon where the likes of British Petroleum, Union Carbide and the Weyerhaeuser Co. tried to kickstart ranching with long-lived, expensive-to-produce coho (silver) salmon, but it became a success in Alaska where the hatcheries opted for short-lived, cheap-to-produce pinks.

Coho – which average 6- to 8-pounds in weight at maturity – must spend a year in freshwater being fed before going to sea, and once there they spend another two to three years before returning. Pink salmon – which average 3- to 3.5-pounds in weight at maturity – are ready to go sea shortly after they hatch and spend only about 18 months there before returning.

Unfortunately, the smallish pinks don’t produce the sort of filets now in demand in a market dominated by farmed fish of 6- to 8-pounds, and thus the low value of pinks. State catch and value data would indicate pinks were worth about 32 per pound on average this year.

Norwegian farmed salmon of 6 to 8.5 pounds are now trading at about $2.30 per pound at the farm, according to NASDAQ numbers, with fish of 8.5 to 11 pounds netting a premium of about 15 cents more per pound.

Still, fishing interests in the Sound communities of Valdez and Cordova have hailed Alaska’s pink-salmon ranching success as an economic miracle for a still wild and little inhabited region southeast of Alaska’s largest city. Before the hatcheries were built, the region’s salmon fishery was a fraction of what it is today.

At an Alaska Board of Fisheries meeting in Cordova at the start of the month, the hatchery boosters convinced the state to reject proposals to reduce hatchery production.

“Several proposals were brought up…that, if passed, would’ve threatened the health and vitality of our salmon fisheries, particularly through the aggressive targeting of salmon hatcheries,”  Geoff Clark and Mike Wells wrote in an op-ed for The Cordova Times after the meeting. “Alaska’s hatcheries, as regional institutions since the 1970s, work to supplement – not replace – wild stocks. Because of this, we’ve seen some of the highest wild returns in recorded history in recent years. The 2021 season, for example, marked the third-largest ex-vessel value in state history on the whole. Fish born in hatcheries are vital to supporting those harvests and the coastal communities that depend on them, making up nearly half of the fish harvested in Prince William Sound in the past few years.”

Clark is the chief executive officer for the Prince William Sound Aquaculture Corporation (PWSAC), which operates five salmon hatcheries in the region.  Wells is executive director of Valdez Fisheries Development Association, which operates the Solomon Gulch Hatchery in Valdez.

As to their claim of the “highest wild returns in recorded history in recent years,” the state says only that “the pink salmon run was above average in 2021, encouraging given that wild fish were from the parent year in 2019 when spawners returned to dewatered streams amid a record-setting drought.”

All of the Sounds streams appear to have met spawning goals this year, the agency added, but no one knows how many of those fish were truly wild and how many hatchery strays. A 2021 study of pink salmon in the Sound from 2013 to 2015 found that up to 90 percent of the spawners in some streams were strays though the Sound-wide average ranged from 4 percent in 2013 to 15 percent in 2014.

The authors of that study concluded that the overall straying rate was low, but the size of the hatchery production resulted in “absolute numbers (of strays) ranging from 0.8 to 4.5 million hatchery fish in natural spawning streams.”

There is no estimate for how many million might have strayed this year.

The authors of the Global Change study, which included several state biologists, took a more objective view of hatchery production than the hatchery managers.

“The question remains whether negative impacts of pink salmon releases on the productivity of wild populations are acceptable considering that hatchery production increases total abundances of pink salmon,” they wrote.

“Higher hatchery return abundances increase harvest opportunities, but do not appear to stabilize revenue of pink salmon fisheries in PWS.  Furthermore, because Pacific salmon migrate long distances at sea, large-scale hatchery production may have unintended adverse effects on other species of salmon originating from distant regions. Hatchery salmon interbreeding with wild salmon can also affect the genetic composition and reproductive success of wild salmon.

“Hatchery pink salmon that stray into wild streams have lower reproductive success
than wild fish and could exacerbate density dependence on the spawning grounds, which may bias estimates of wild recruits/spawner when escapement surveys do not discern between hatchery and wild fish. Quantifying the tradeoffs between industry performance in the fishery supported by the large hatchery program and productivity and abundance of wild salmon populations within and outside Prince William Sound are left for future extensions of this work.”

Money, money, money

Who might fund such research is unclear.

Alaska fishery managers have shown little interest in investigating offshore intereactions between wild and hatchery fish, and the commercial fishermen who’ve long held sway over the politics of fishery management in Alaska generally view such research as a threat to hatchery production.

Even Alaska commercial fishermen gillnetting off the mouth of the Copper River or in Cook Inlet, where it appears hatchery pinks could be reducing returns of more valuable sockeyes, have been big packers of the PNP hatcheries.

Commercial fishermen largely dismissed or ignored a 2017 study of the Exxon Valdez Oil Spill that found the beach-fouling crude did no significant damage to salmon, but warned that all the region’s “sockeye salmon stocks examined exhibited a downward trend in productivity with increasing Prince William Sound hatchery pink salmon returns.

“While there was considerable variation in sockeye salmon productivity across the low- and mid-range of hatchery returns (0–30 million), productivity was particularly impacted at higher levels of hatchery returns.”

Among the fishery suffering when pink returns are high is the fishery which produces fabled Copper River king and sockeye salmon, pound-for-pound the most valuable salmon in Alaska.

When the Exxon Valdez study was released, its authors noted, they did “not know if possible deleterious interactions between hatchery pink salmon and wild sockeye salmon in this study are from predation or competition, or whether they occur in nearshore or offshore areas.

“Pink salmon feeding may cause a general depletion of prey availability that could impact sockeye salmon without tight spatial overlap of these two species. In this regard, the apparent impact to sockeye productivity may reflect a general increase in pink salmon abundance across the northeast Pacific rather than increased abundance of hatchery pink salmon to PWS (Prince William Sound) in particular.”

Little more has been learned since then as to the causes of the association between pink salmon increases and sockeye decreases. But at-sea competition for food between pinks and the various other salmon species has been suggested as a likeley explanation for major declines in coho and Chinook salmon as well as sockeyes.

Plummetting Chinook numbers in British Columbia, Canada and the Pacific Northwest long blamed solely on hydroelectric dams, agriculture, urbanization and logging were last year linked to ocean-survival problems in a peer-reviewed study published in Fish and Fisheries.

Canadian David Welch and colleagues reported a coastwide, 65 percent decline in the productivity of Chinook salmon streams from the Alaska Panhandle south to Oregon. The consistent drop in productivity whether in wild and undisturbed watersheds in northern British Columbia or developed watersheds in the Pacific Northwest pointed directly at some sort of problem with ocean survival.

Welch’s study has, however, come under fire from Lower 48 environmental organizations who fear it could be used as leverage by those opposed to removing dams from the Snake River, a major salmon-spawning tributary to the Columbia.

And his and other other studies pointing to what are called “density-dependent” issues driving declines in the longer-lived species of Pacific salmon have been largely ignored by environmental groups, apparenlty because of concerns about upsetting commercial fishing interests considered brothers-in-arms against mining, logging, hydroelectric and other business interests.

The Canadian response to its drastic salmon declines, meanwhile, has been to suggest a $647 million, Alaska-style hatchery program to boost production despite the belief of many scientists that the North Pacific’s salmon pastures are already at or above carrying capacity.

“In 2019, a record number of salmon from hatcheries – 5.5 billion – were introduced into the Pacific Ocean, according to the NPAFC. But British Columbia, Canada “introduced a mere 384,404 salmon through hatcheries, compared with roughly 2 billion each from Japan and the U.S., and 1.2 billion from Russia,” reported the Vancouver, B.C.-based North Shore News.

More than half the commercial salmon fisheries along Canada’s West Coast were closed this year to protect struggling salmon runs. To the south, returns of most species of salmon to the Columbia River of Washington and Oregon remained generally weak.

So weak that a federal court judge in Seattle is threatening new restrictions on Alaska coastal fisheries that intercept chinook bound for the Columbia. That action came in repsonse to a lawsuit by the Seattle-area-based Northwest Wild Fish Conservancy.

The Conservancy went court to try to eliminate the tiny, Southeast-Alaska based troll fishery for Chinook salmon to help feed Southern Resident killer whales instead of demanding answers as to why Chinook salmon production has slumped so badly.

A fishery that dates back to the start of the 20th century,  the troll fishery historically harvested more than 200,000 Chinook per year, but is now down to a catch of about half of that, according to state data. 

But its catch remains largely omprised of big Chinook headed south along the Alaska coast to spawning streams in Canada and the Pacific Northwest, and there were once a lot more of those fish than at present for reasons still fully unsorted.

Along with suggesting problems with “potential adverse effects of large-scale hatchery production,” the Global Change study also notes a shifting climate, which has generally warmed the North Pacific. The warm water appears to favor pink salmon over other species.

And that raises even more questions about how much Alaska should be doing to boost pink salmon production if a changing environment is already providing them a competitive advantage.