Salmon ceasefire

Alaska’s salmon farmers and their critics have come to an agreement that the almost 2 billion hatchery fish the 49th state dumps in the Pacific Ocean each year at warrant an annual state review.

The meeting of minds came Friday after a day-long meeting of a committee of the state Board of Fisheries to discuss how little is known about the potential consequences of what the state prefers to call its “ocean ranching” industry.

Alaska in 1990 banned net-pen rearing of salmon to marketable size – the now established means for farming salmon. But Alaska allowed private, nonprofit (PNP) aquaculture associations – a couple run by private companies but most under the control of regional aquaculture associations controlled by commercial fishermen – to raise salmon to be sent to sea to fatten and return to be harvested.

Twenty-four of those PNPs released about 1.8 billion young fish into the Pacific last year, a new state record, Sam Rabung, the director of the state’s Division of Commercial Fisheries told the Board.

The Kenai  River Sportfishing Association, the state’s biggest and most active recreational organization, and the Fairbanks advisory committee to the Board have charged the state knows way too little about the consequences to wild fish of this massive hatchery release.

But it is learning daily.

Most of Friday was devoted to the minutiae of identifying hatchery salmon by their genes and by the markings on the otoliths, small bones in the inner ear. Using Information Age science, Fish and Game has been able to document salmon straying up to hundreds of miles from hatcheries to look for new homes in wild streams and rivers and sometimes mate with wild fish.

Preliminary data from genetic studies indicates the survival of the offspring of the hatchery fish mated with wild fish is lower than for the pairing of wild fish. But some commercial fishermen attending the hearing said that’s OK; the more fish in Alaska streams the better, no matter their origins.

The big unknown

Far less time was devoted to the ocean interactions between wild fish and hatchery fish which now comprise a quarter to a third of the annual, statewide salmon harvest.

Scientists Greg Ruggerone from Seattle and Jennifer Nielsen from Anchorage 15 years ago authored an oft-cited paper offering evidence that pink salmon – a main stay of Alaska hatcheries – have gained a competitive advantage in the North Pacific and could threaten to depress populations of sockeye, coho and Chinook salmon.

Twenty years ago, former Board member Virgil Umpenhour testified to the Board, the Alaska Department of Fish and Game was asked to deliver a report on the interactions of hatchery and wild fish, but that never happened. Umpenhour is now a spokesman for the Fairbanks advisory committee to the Board.

He thought it was about time for some answers on what biologists often call “density dependent interaction.” He didn’t get them this time either.  The day-long meeting dominated by testimony by state Fish and Game biologists was heavy on straying, which might or might not mean anything in the views of many who testified during the brief public comment period, and short on any discussion of interactions.

Bill Templin, the state’s chief fishery scientist, quickly skimmed over the topic.

“That’s been proposed in the literature,” he said. “The verdict is still out.”

Scientists from the northwest Fisheries Science Center of the National Ocean and Atmospheric Administration (NOAA), the University of Alaska Fairbanks (UAF) College of Fisheries and Oceans, the University of California Santa Barbara, the U.S. Forest Service Fisheries Program, the University of Washington, and Fish and Game in 2017 reported discovering Prince William Sound hatcheries linked to wild Copper River sockeye by “a negative relationship between adult hatchery pink salmon returns on sockeye salmon productivity.”

The scientists were looking for lingering damage from Exxon Valdez oil spill in the Sound when they stumbled on the connection. It was reported in peer-reviewed study at PLOS One titled “Evaluating signals of oil spill impacts, climate, and species interactions in Pacific herring and Pacific salmon populations in Prince William Sound and Copper River, Alaska.”

The scientists found no significant, long-term damage from the oil spill, but concluded their were clear, annual implications to the continuing spills of hatchery fish.

“All sockeye salmon stocks examined exhibited a downward trend in productivity with increasing PWS hatchery pink salmon returns,” they wrote. “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.

“Pink salmon have been found to negatively affect sockeye salmon productivity and growth from British Columbia and Southeast Alaska, Bristol Bay, Kodiak, and Russia. Pink and sockeye salmon compete in the marine environment due to a high degree of similarity in diets, including similarities in diets of adult pink salmon and juvenile sockeye salmon.

“Our analysis was primary designed to test drivers in the nearshore environment, which is why we stopped at a lag of two (brood) years—when the majority of juvenile sockeye salmon out-migrate from the nearshore environment as adult pink salmon are returning to spawn. We do 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 NE Pacific rather than increased abundance of hatchery pink salmon to PWS in particular. However, adult pink salmon are known to feed on a broad diversity of prey items within PWS prior to spawning, including a variety of zooplankton; and therefore have the potential to compete with juvenile sockeye salmon in PWS for the same prey.

“For example, Martinson et al. showed decreased growth of sockeye salmon out-migrating from the Karluk River (Kodiak, AK) during years when large numbers of adult pink salmon returned to the same area. Competitive interactions in nearshore and offshore environments deserve greater attention in future research in the face of general increase in the abundance of pink salmon in the North Pacific.”

Hidden mortality

Templin failed to acknowledge the study when he appeared before the Board last October to testify on a proposal to cap hatchery production, and he made no mention of the study on Friday.

Neither did he suggest how the state might obtain more and better data, if the Exxon Valdez study is flawed, or help to resolve the unsettled verdict on ocean interactions between pink and sockeye and other salmon. Ken Tarbox, the former commercial fisheries biologist for Cook Inlet, among others has suggested that increased PWS hatchery production could have played a role in decreasing Inlet sockeye returns that fell substantially from the record numbers of the late 1980s to today. .

Correlation is not causation, Templin rightly observed in October, echoing a well-known scientific truth. But the Department has made no attempt to explore the correlation despite Templin lecturing the Board on the scientific method Friday.

It begins, he noted, with observations and questions followed by investigations, data gathering and proof or dismissal of hypothesis. Fish and Game has made no attempt to sort out the observations and questions surrounding density dependent interactions between hatchery and wild fish in Alaska.

Templin did say his agency is closely watching a joint project sponsored by NOAA, Canada and the Russians to try to sort out salmon movements and food in the Gulf of Alaska. But Alaska has no participation in the program.

NOAA has billed the project as an international effort to “unravel mysteries of Pacific salmon survival.”  The project is focused on the Southeast Gulf.

“This is where most of the salmon that stream out of Northwest and Alaska rivers each year disappear, most never to be seen again,” a NOAA press release said.”Now the science team is headed into the remote Gulf of Alaska to try to find out which fish survive and why.”

The press release was wrong about Alaska salmon stocks – most of them disappear north and west of the study area – but right about how little is known.

Templin said most of the data collected to date has been “really interesting.”

Fisheries science?

But the state’s chief fisheries scientist, in his multiple appearances before the board during the day, spent as much time or more lecturing on the Alaska Constitution, the economic and political importance of Alaska commercial fisheries, the United Nations’ definition of sustainability and the media’s decidedly bad reporting on science before announcing that what he was about to say shouldn’t be viewed as an “attack on my colleagues in the scientific community.”

After that, he launched into an attack on a Ruggerone hypothesis on the problems plaguing the killer whales of the Salish Sea more than 1,000 miles south of Anchorage.

Templin did not mention Ruggerone by name, but Templin did specifically identify a paper on which Ruggerone was lead author. The paper suggested pink salmon could play a role in the high death rates and low birth rates discovered in the critically endangered southern resident killer whales inhabiting the waters of Washington State, and British Columbia, Canada.

The peer-reviewed study was published in January in the Marine Ecology Progress Series. It concluded that big schools of pink salmon could be interfering with the whales’ hunt for larger, more nutritious Columbia River king salmon and argued that could be one of the issues leading toward the population’s continuing slide toward extinction.

Templin claimed the paper and ensuing news coverage had led everyone to believe pink salmon were the cause of the decline of the killer whales although any member of the public who read the scientific paper would see problems with the analysis.

He offered the Board lessons in critical analysis, and the said the paper illustrated why Board members and the public should be skeptical of anything they read in the media.

After cautioning the Board to be skeptical, he added that “it shouldn’t be your job to try to read between the lines.”

Finally, he lit into fellow scientists.

“This also highlights for us that the peer review process is not perfect,” he said. He suggested the peer reviewers might have done a poor job on the Ruggerone paper, or maybe a good one, and “the editor might have decided to publish it anyway.”

Ruggerone was not immediately available for comment.

Just because a document was peer-reviewed, Templin said, doesn’t mean anyone paid attention to those reviews. Some scientific journals today just want the “splash factor,” he said.

There is some evidence the “splash factor” has become contagious in the U.S.