A Kenai River sockeye salmon/Craig Medred photo

News analysis

As the sockeye salmon return to the rivers of Cook Inlet and the famed late-run king salmon nose into the Kenai River, there are reasons for fishermen of all persuasions to be optimistic.

Unfortunately, history weighs against getting too excited about expectations of abundance in the state’s most contentious fishery this year. But more on that later.

First the good news:

Sockeye returns to the Copper River have come back after a weird 2018 when the run collapsed early only to rebound late with an unusual August return of fish which ensured the spawning goal was met.

This year looks more normal.

As of Thursday, more than 736,000 sockeye had escaped the driftnets of commercial fishermen off the mouth of the river and were above a fish-counting sonar far upstream. 

That puts the Copper near the upper limit of the sockeye escapement goal of 750,000, and if the run continues as strong as it has been the final escapement could well reach 1 million.

Meanwhile, the commercial harvest is already over 1 million. The preseason harvest forecast of 756,000 sockeye is in the rearview mirror and fading fast. It’s likely the 1.2 million estimate at the upper end of the harvest range will be exceeded.

Upstream the story is generally more of the same. Personal-use dipnetters working the river near Chitina and subsistence fishermen upstream from there were reporting good catches until slowed by high water caused by warm weather and melting glaciers at the start of the month.

Meanwhile, anglers on Copper tributary streams have all been enjoying healthy catches given rivers flush with Chinook (king) and sockeye (red) salmon. The Gulkana River, a Copper tributary upstream from Glennallen, welcomed a historical record count of 6,800 kings by the Fourth of July and a sockeye count 10 times what it was on the same date last year.

The combined catch of anglers, dipnetters and subsistence fishermen now appears certain to climb above the projected 199,000 for the year.

By the time all these catch numbers and the escapement are added together after the season, the total return is sure to climb above the 1,801,000 sockeye upper limit of the preseason projection range, and probably top the 10-year average, total return of just over 2 million fish.

The known commercial catch and escapement combined already account for about 1.8 million sockeye. After a disastrous 2018 when escapement was met at 702,000 but the commercial fishery harvested fewer than 44,000 sockeye, a slightly above average year will strike most fishermen as a bonanza.

And the Copper isn’t the Southcentral region’s only bright spot.

Sockeye in June swarmed the Russian River, a clearwater tributary to the Kenai famous for both its unique, early-run of sockeye and its gin-clear water in a land dominated by glacially turbid streams.

The river is home to two, genetically distinct runs of sockeye: one in June and another spanning late July and early August.

So many early-run fish hit the river in June this year that the Alaska Department of Fish and Game early on raised bag limits for anglers from the traditional three-fish per day to six, an unusual boost, and then to nine, an unheard of increase.

The intent was to try to keep the return flowing through a weir upstream within the escapement goal of 22,000 to 42,000 fish. The plan didn’t work.

More than 105,000 sockeye escaped anglers to enter the upriver lakes that nurture the Russian drainage and future returns. It will be a good year for the grizzly bears that frequent the area, just as it was a good year for early-season anglers.

But in the broader context of the Kenai – the river which powers the region’s big, summer, salmon show – it would appear meaningless.

There is no clear linkage between returns of early Russian sockeye and late-run sockeye, though the latter is normally orders of magnitude bigger than the former.

The late run has a maximum escapement goal of 110,000, which reflects on the ultimate size of the return. But the minimum goal of 30,000 was barely met in 2016 with a return of 38,000.

The early-run escapement that same year topped  38,000. Historically, this was rare. Through the 1960s and into the 1970s and ’80s, the late-run was thought of as about three times the size of the early run, but that isn’t always the case anymore.

So forget any ideas that the big early Russian return holds any meaning for the late Russian return let alone the historically much larger return to the Kenai mainstem and consider the broader history.

Up equals down

And the history is this:

When the state overall witnesses huge returns of salmon, Upper Cook Inlet harvests usually turn out to be mediocre or worse.

When the state set a record harvest of more than 280 million salmon in 2013, the Kenai sockeye harvest “of 2.6 million sockeye salmon was approximately 33 percent less than the 2013 preseason forecast harvest estimate of 3.9 million fish,” the Fish and Game reported. “This harvest was also approximately 23 percent less than the 2003–2012 average annual harvest of 3.4 million fish.”

The story was much the same in 2015 with the state’s second highest statewide harvest of more than 265 million salmon.

Fish and Game that year reported a “commercial sockeye salmon harvest of 2.6 million fish,” but couched the situation differently than in 2013, describing the 2015 catch as “approximately 10 percent less than the 1966–2014 average annual harvest of 2.9 million fish.”

The context distorted the history. Statewide salmon harvests were chronically low in the 1960s and 1970s due to a so-called “regime shift” that turned the waters of the North Pacific frigid.

The average UCI sockeye harvest from 1966 to 1979 was only 1.2 million salmon per year.

Better days were to come in the 1980s and early ’90s. Commercial fishermen in UCI harvested a record 9.5 million sockeye in 1987. The statewide harvest that year was 96 million.

As statewide harvests have gone up, Cook Inlet sockeye harvests have generally gone down. Behind ’87’s record harvest, the big UCI catches rounding out the top five came  in 1992 (9.1 million), 1986 (6.8 million), 2005 (5.2 million) and 2011 (5.3 million).

In only one of those years – 2005 – did the statewide harvest top 200 million. The average statewide harvest during UCI’s top producing years is 150 million salmon.

The statewide harvest this year is forecast at more than 213 million salmon. Almost 138 million of them – about 65 percent – are expected to be fast-growing, low-value pink salmon.

There is a growing debate about how the huge numbers of pinks, some of them hatchery fish, are influencing the North Pacific ecosystem.

Scientists Greg Ruggerone from Seattle and Jennifer Nielsen from Anchorage 15 years ago theorized that pink salmon – a mainstay of Alaska hatcheries – enjoy a competitive advantage in the North Pacific and could depress populations of sockeye, coho and Chinook salmon.

Pinks are the smallest but fastest growing of the Pacific salmon. Spawned in the late summer, they go to sea the next spring as tiny fry only to spend a year at sea eating voraciously in order to return as 3.5- to 5-pound adult salmon.

Increases in pink salmon numbers have in some cases been linked to declines in sockeye, coho and Chinook salmon numbers, but as Bill Templin, the state’s chief fisheries scientist argues, “correlation is not causation.”

Still, the pinks have generated enough smoke that some scientists think it’s time to go looking to see if there is fire below.

And all seem in agreement that the number of salmon in the Pacific is at an all-time high thanks to warm water and the success of those pinks.

Sockeye, chums and pinks “are more abundant now than ever,” Ruggerone and Canadian biologist James Irvine reported in the journal Marine and Coastal Fisheries last year, but pinks have been the truly big winners of “generally favorable ocean conditions in northern regions.”

Though there are global-warming worries that climate change could lower that ocean’s fisheries productivity at some point, Swiss scientists early this year reported the “metabolic theory” is so far holding.

At the ecosystem level, the metabolic theory links ecological productivity to temperature and decrees that production will go up as temperature increases.

“Consistent with metabolic theory, phytoplankton richness in the tropics is about three times that in higher latitudes, with temperature being the most important driver,” the Swiss scientists concluded in their peer-review study published in Science Advances earlier this year.

Any ecological shift, however, produces winners and losers, and the question facing UCI is whether sockeye are on the list of losers.

“Pink Salmon dominate adult abundance (67 percent of total) and biomass (48 percent), followed by chum salmon (20 percent, 35 percent) and sockeye salmon,” Ruggerone and Irvine noted in there paper, which raised questions about what Alaska hatchery production of pinks means for other salmon.

“Salmon abundance in large areas of Alaska (Prince William Sound and Southeast Alaska), Russia (Sakhalin and Kuril islands), Japan, and South Korea are dominated by hatchery salmon,” they wrote. “During 1990–2015, hatchery salmon represented approximately 40 percent of the total biomass of adult and immature salmon in the ocean. Density‐dependent effects are apparent, and carrying capacity may have been reached in recent decades, but interaction effects between hatchery‐ and natural‐origin salmon are difficult to quantify….”

About 66.5 million pink salmon are forecast to return the Sound this year with 22.3 million of them bound for hatcheries owned by the Prince William Sound Aquaculture Association, another 20.2 million sniffing out the Valdez Fisheries Development Association hatchery, and 24 million expected to spawn naturally in the Sound’s creeks and rivers.

If all goes well, the commercial pink harvest in the Sound could reach 50 million. The commercial sockeye harvest for UCI is forecast at 3 million.

Given the broad 4.8 million to 7.3 million range estimate for the total return, however, the catch could go as low as 1.8 million or as high as 4.3 million.

Three million of the fish are to be allowed to escape into Cook Inlet’s rivers – 2 million of them for spawning, the other 1 million to provide for harvest for subsistence and personal-use fishermen along with anglers.

The latter fisheries have yet to get underway. Commercial fishing started in in the Inlet in late June, but the commercial catch to date totals only 86,000 sockeye.

Meanwhile, the early trickle of sockeye into the Kenai is ahead of last year, but it’s way too early to draw any conclusions as to what that means.

There are reasons to be optimistic, but it would be foolish to assume that the Kenai will do well because a big year is forecast for Alaska salmon fisheries or because other regional salmon runs appear to have returned to something approaching normal or better since the strange year of 2018.

Correction: An early version of this story overstated the maximum, Russian River limit.