Oscillations

As Alaska’s 2018 commercial salmon season slides toward its end, 2018 is looking a lot like 2016 – the year of the big bust after the bonanza of 2015.

Twenty-fifteen was the second largest salmon harvest on record in the 49th state. And 72 percent of the catch – 190.5 million fish – was pink salmon, according to the Alaska Department of Fish and Game. 

A year later, the state went from the second best catch in Alaska history to the 10th worst  in more than four decades.  The harvest was less than half the previous year – down from 263.5 million to 111 million.

And pinks were a big no-show, the statewide catch falling from 190.5 million to 38 million. But most salmon returns were down with the exception of sockeye propped by up strong returns in Bristol Bay.

Scientists have long theorized that a pink salmon cycle of strong years and weak years is driven by the consumptive power of the fastest growing of the Pacific salmon. The thinking is that the large numbers of pinks of odd-numbered years eat so much that the even-year pinks must make do with the leftovers of a heavily grazed ocean.

In keeping with that theory, the Alaska catch rebounded last year. The 2017, odd-year, statewide salmon harvest was 224.6 million. The ocean that had been able support only 38 million pinks in 2016 produced more than 141 million pinks that accounted for 63 percent of the 2017 salmon catch.

“Tremendous harvests occurred across Alaska from Kotzebue to Southeast, highlighted by an all-time record statewide chum salmon harvest,” Forrest Bowers, the deputy director of the Division of Commercial Fisheries crowed in the 2017 commercial salmon harvest summary. “In addition, 2017 is the third year in a row statewide sockeye salmon harvest exceeded 50 million fish. 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.”

There was no mention of 2016. It’s hard to tell where the state’s 2016 commercial salmon harvest summary went, but you can spend a lot of time Googling and not find it. The year-by-year harvests are easier to find, and there is a pattern there.

It is a big oscillation:

• 2013 – 280 million.
• 2014 – 156 million.
• 2015 – 265 million.
• 2016 – 111 million.
• 2017 – 223 million.

The 2017 harvest ranked third biggest in state history behind 2015 and 2013. In all of those years, pinks were the bulk of the harvest. The smallest but fastest growing of the salmon comprised 80 percent of the catch in 2013, 72 percent in 2015, and 63 percent in 2017.

2018

All of which brings this to the present.

As of the end of the week, the statewide harvest stood at just over 98 million salmon – about half of the 182 million at this time last year. Once again, the biggest missing component is pink salmon.

Pink catches that stood at 104 million at this time in 2017 are now at 34 million.  Intrafish, a commercial fishing website, describes this as  “pink salmon season a little slow.”

It may be more than that. Bristol Bay, which appears to be isolated from whatever is going on in the Gulf of Alaska from the Panhandle north and west around the coast to Chignik on the Alaska Peninsula, did well on sockeye, but it was a different story most everywhere else.

The returns of sockeye to the Copper River, Cook Inlet and Chignik were generally failures. Chignik never even had a season. The Copper River and Cook Inlet will meet spawning goals, but only because commercial fishing was sharply curtailed.

The Copper River harvest was fewer than 44,000 sockeye, according to Fish and Game data. The state’s preseason forecast called for a harvest of more than 1.2 million fish.

The Cook Inlet harvest was 693,000 sockeye, according to Fish and Game. The state’s Upper Cook Inlet forecast called for a harvest of 1.9 million. 

Some have blamed the year’s faltering returns on The Blob, a huge pool of unusually warm water in the Gulf of Alaska that began forming in 2013 and spread through 2014 and 2015 before beginning to fade in 2016. 

The Blob doesn’t explain the oscillations.

Nancy Hillstrand, a Homer, AK-area critic of Alaska’s ocean-ranching pink salmon hatcheries, has a different theory. She has begun talking about a “pink blob,” a wave of hatchery spawned pink and chum salmon about a billion strong dumped into Alaska coastal waters every  year.

Lower 48 scientists have been worrying about voracious pinks over grazing the Pacific range for years.  Some Alaska fisheries biologists have privately raised similar concerns, and they are now starting to take those views public.

State fisheries biologist Kevin Schaberg, who does research on Kodiak Island where some sockeye runs also faltered this year, on Friday suggested to KMXT radio in Kodiak that food competition could be a problem.

The concern is significant. If pink salmon production has reached the point where pinks go beyond their even-year/odd-year influence on each other and begin influencing all Alaska salmon, Alaska has a problem.

If the hatchery boosting of pink salmon is helping to depress wild salmon populations, Alaska has a bigger problem.

Commercial fishermen who worry about what a possible accident at a possible Pebble mine in the Iliamna Lake region might do to Bristol Bay salmon might want to give some thought to what existing hatcheries could already be doing to Copper River and Cook Inlet salmon.

Seabird researchers Alan Springer from the University of Alaska Fairbanks and independent research Gus van Vliet of Auke Bay have suggested the abundance of pink salmon in the North Pacific now at times controls food supplies that affect both fish and birds.

The influence of pink salmon “during years of high abundance apparently derives from voracious consumption to fuel exceptionally rapid growth in spring–summer of their second year—the mass of maturing fish increases by some 500 percent, from about 300 to 1,500 g, in just 4 mo between March and July when they spawn,” the wrote in a peer-reviewed study published in the Proceedings of the National Academy of Sciences in 2014.

“In years of high abundance, (pinks) now constitute a pelagic consumer front as they return to their spawning rivers, exert top-down control over the open ocean ecosystem by out-competing other species for shared prey resources, and drive major ecological shifts between years of high and low abundance,” they concluded. “Their effect on competing species must be considered in international conservation policies and when developing informed ecosystem-based management strategies.”

“Top-down control over the open ocean ecosystem” has the power to influence everything in the ecosystem. Birds were dying, apparently of starvation, in far Western Alaska again this spring. The 2019 cohort of pink salmon were then moving onto the feeding grounds.

Some were blaming “The Blob” for the bird deaths as others blamed it for missing fish. But the real question here might be “which Blob?”

There appear legitimate reasons to ponder whether the problem is the blob of warm water, the blob of pink salmon or some combination of the two.