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Salmon bounty

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The leader of the catch, an Alaska pink salmon/Wikimedia Commons

For the fourth time in the last six years, Alaska is on the verge of recording a season-long salmon harvest at or above 200 million fish.

Harvests of this size have happened only seven times in state history and never in territorial history. Three of those seven harvests have come this decade. If 2019 clears the 200-million-salmon bar, four of the eight seasons of 200 million or more will have come this decade.

But even if 2019 doesn’t hit the magic number, it already ranks number eight in a state harvest history going back to 1975 when the harvest was was but 26 million fish. 

These big catches have come at a time when the popular perception is that Alaska salmon are threatened by a warmer North Pacific Ocean.  A Dwindling Catch Has Alaskans Uneasy” the New York Times headlined only a year ago.

The 2018 catch 114 million salmon was indeed down from the big harvest of the year before and but 77 percent of the average harvest since the state developed a more sophisticated management system 44 years ago and began carefully tracking annual harvests.

The drop, however, was also part of a pattern of oscillating harvests driven by huge numbers of pink salmon returning to Alaska waters in odd-numbered years. The state record salmon harvest of more than 280 million in 2013 was followed by a 2014 catch of but 156 million salmon.

Color Alaska pink

Eighty percent of that 2013 harvest – about 219 million salmon – was pinks, according to Fish and Game, and more than 40 percent of them were hatchery fish.  The state has taken great pride in Alaska hatcheries driving up the harvest.

“Since the volume of hatchery releases largely stabilized in 1997, approximately 34 percent (range: 21 percent to 51 percent) of the total common property harvest is from enhancement operations, primarily pink and chum salmon,” a 2018 review of the state hatchery system bragged.

“To put the magnitude of…production in historical perspective,” the Alaska Salmon Fisheries Enhancement Annual Report 2017 notes, “the hatchery harvests alone in both 2013 and 2015 were greater than the entire statewide commercial salmon harvests in every year prior to statehood except for 7 years (1918, 1926, 1934, 1936, 1937, 1938 and 1941).

The year 2015 saw the second-largest harvest of salmon in territorial and state history with an all-species catch of more than 263 million with more than 190 million pinks leading the way. The harvest dropped to 111 million the next year only to shoot up to 223 million in 2017.

That year marked the third-highest catch in state and territorial history.

“Record wild salmon harvests like these are a testament to Alaska’s sound, science-based management, the professionalism of ADF&G’s staff, and thoughtful stakeholder engagement,” Deputy Director of Fish and Game Forrest Bowers raved in a public statement at the time.

 It overlooked the fact 47 million of those “wild” fish were “hatchery-produced salmon worth an estimated $331 million in first wholesale value,” as a later state report duly noted. “Hatchery fish contributed 21 percent of the statewide commercial salmon harvest, which is the lowest percentage of hatchery fish in the harvest since 1995, and due largely to an extraordinary wild stock harvest that was the third highest in Alaska history.”

Some Alaska wild salmon stocks – most notably pinks – have indeed flourished as Alaska has become a major producer of farmed salmon it prefers to call “ranched” and “wild caught.”

How much of the increase in wild stocks is linked to streams being seeded by hatchery strays is unknown, but the hatchery fish have been shown to stray widely.  Also unknown is the influence of all these pinks on the ocean ecosystem.

Trophic cascade

Some scientists have suggested their abundance can trigger a “trophic cascade” that affects not only other salmon – primarily Chinook and coho – but also seabirds, plankton stocks possibly even sockeye salmon. Trophic cascades are changes, usually predation related, that ripple through an ecosystem from top to bottom. The suggestion here is that pink salmon are so numerous they can drive the change from the bottom up by overgrazing the North Pacific pasture. 

Bill Templin, the state’s chief fishery scientist, however, has attacked the theory as a conclusion gone way too far beyond the evidence. Scientists know little about what happens once salmon disappear into the big black box of the Pacific, he told the state Board of Fisheries last October, and thus no one can say whether adding ever more pink salmon to the ocean is hurting other fish.

Scientists all agree there is a limit to the salmon carrying capacity of the ocean, but no one knows what it might be. And when it comes to overall maximum salmon production, there are no indication it has as yet been reached.

Scientists Greg Ruggerone from Seattle and James Irvine from British Columbia, Canada have concluded there are now more salmon in the Pacific than at any time in recorded history, and Alaska harvests have only served to underline that conclusion.

Decadal average, commercial salmon catches have continued to climb, a clear indication the carrying capacity has not been exceeded. This year is on track to end the 2010s with an average annual harvest of approximately 180 million salmon per year.

The average has been going up every decade, according to Fish and Game reports:

  • 122.4 million on average in the ’80s.
  • 157.5 million on average in the ’90s.
  • 167.4 million on average in the 2000s.

Biggest loser

But not all species of salmon have benefited equally. Chinook salmon – the biggest of the fish, the ones Alaskans call “kings,” and the state fish for the 49th state – are at record low numbers.

A statewide harvest of under 250,000 this year will see the last three years mark the lowest harvests in history, well below even the five-year average of 359,000.

“Chinook harvests by the commercial fishery in Alaska have not varied much
over the past 90 years with the last 10 decadal averages ranging from about 600,000
to 800,000 fish,” state biologists wrote in a 2006 report. “On the other hand, significant use of Chinook salmon in Alaska occurs in sport and subsistence fisheries and those harvests have increased substantially. In several areas of Alaska, Chinook harvests
in the commercial fishery are restricted to provide for other users. Alaskan Chinook salmon populations are currently at high levels of abundance.”

Shortly after that report was written, king salmon harvests started plummeting in all of those fisheries. Other fisheries for other species of salmon have also seen smaller but significant declines since the 2000s.

Sockeye salmon in Cook Inlet, the waterway at the front door of Alaska’s largest city, have been trending generally downward since the 1980s. Declines in returns of sockeye to the Copper River east of Anchorage have been linked to big year returns of pink salmon to Prince William Sound, although no has as yet identified a direct cause for that correlation. 

Overall, though, Alaska salmon have been flourishing.

Only twice in the 1990s did the harvest go over 200 million. Hitting that mark for the first time in Alaska history in 1995 and topping it in 1999 (odd years both) when it peaked at more than 216 million.

The story was the same in the next decade. The 2007 harvest reached near 213 million and the 2005 harvest (odd years both, again) set a then-record of 221 million that stood until 2013.

Even bigger bounties were to come this decade even many worrying about a generally warmer North Pacific and “The Blob” reducing salmon survival. The ocean has now cooled off a little since the 2013 to 2017 run of massive catches.

And as of today, according to the state’s weekly harvest report, the 2019 salmon catch stands at about 196 million. There are officially four weeks left in the season, and the five-year-average harvest for those weeks is 1.8 million.

That would bring the total for the year to about 198 million, and given that the preliminary end of season number is usually lower than the actual catch because of reporting lags this season could join the group of 200 million.

Fish and Game at the end of the 2015 season reported a preliminary harvest of 263.5 million salmon, but by the time the tally was final that had grown to more than 265 million.

But even if the season falls a hair short – and it’s clearly not going to meet the preseason forecast of 213.2 million – it will go down as the eighth-best in the state harvest history going back to 1975.

Meanwhile, to the west, a warmer Bering Sea is pushing Russian pink salmon harvests sky high. Tradex, a global seafood company, reports odd-year Russian stocks, which are the weaker of pink salmon runs in that country, are on track for a record harvest of pinks five to 10 times that the historical average.

Large returns of pink salmon to waters in Northwest Alaska have also been reported, but the magnitude of the run is hard to quantify given the minimal commercial catch of those salmon because of the lack of salmon buyers.

If there are bright sides to global warming, this would appear to be one at least in the short term. In the long term, no one can say even though Swiss scientists have concluded the metabolic theory – which dictates that marine productivity increases as water warms up – is so far holding. 

 

2 replies »

  1. Trophic cascade is a top-down disruption of an ecosystem by removing predators that are essential aspects of the ecosystem function and well-being. Trophic cascade ecosystem disruption results when humans remove predators like wolves, cougars and king or silver salmon thus allowing, deer, beaver and pink and sockeye salmon to become destructive. Sockeye and pink salmon have become destructive.
    It is trophic of cascade destructive to convert millions of wild king and silver salmon into millions of artificial hatchery sockeye and pink salmon. It is also illogical for anyone to suggest that (high farmed trophic cascade sockeye and pink production) is acceptable knowing the destructive forces it unleashes on predators that are essential aspects of the ecosystem. Your article focuses on a maximum commercial harvest instead of maintaining the wild numeric balance between salmon species. Your omission is a fatal flaw

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