More grim news on Lake Washington sockeye.
This year’s second lowest count at the Ballard Locks was followed by an “all-time low” spawning run of the red salmon up the Cedar River.
“Now just about everything that can go wrong is going wrong,” laments longtime metro lake angler and sportfishing advocate Frank Urabeck.
Preliminary figures show just 7,476 sockeye back to the King County river and only 3,687 of those spawning on the gravel in the wild, both record lows, according to state fisheries biologist Aaron Bosworth.
“Another data point in a declining trend,” he terms the figures.
The other 3,789 fish were taken to the Seattle Public Utilities hatchery for broodstock.
Back through at least 1998, the previous low marks for river return and natural spawners were 10,431 and 7,191 in 2015.
Highest were 203,618 and 192,395 in 2002, the parents of the run that eventually yielded what may go down as the final fishery, in 2006.
There have been few bright spots since then, as a host of problems combine to make for what might one day be all but “an aquarium run,” in Urabeck’s words.
More and more it appears that PSM, or prespawn mortality, is really what’s hurting the fish, killing the hens before they can even lay most if not all of their eggs.
Seventy-seven percent of this year’s run (32,103) went missing between the Ballard Locks and the river, second highest to only 2016’s 80 percent.
In the Cedar, PSM hit early entrants hardest this year.
According to SPU survey data Bosworth shared, 95 percent of hens checked in the lower reach of the river in September’s last week suffered PSM, 85 percent in October’s first week.
Even as late as last month’s last full week, half of the females in the bottom end of the Cedar died with eggs largely still in their belly.
The percentages were lower for fish that managed to make it into two stretches higher in the system and declined over time, but “were still pretty high overall,” says Bosworth.
It’s a confounding factor for biologists and managers.
“We used to think that predation in Lake Washington on juvenile sockeye was the biggest limiting factor for this stock, and that ocean conditions played an important role in some years,” says Bosworth. “Those challenges have not gotten any easier, but now the PSM problem seems like it might be just as bad or worse than the predation problem.”
PSM issues appear to have grown in recent years too.
At a presentation earlier this year before the Cedar River Council and anglers, Bosworth said that between 1995 and 2013 — a period that included five fisheries — from 45 to 85 percent of the sockeye that went through the locks turned up in the Cedar.
But since 2014, only 20 to 33 percent have. At 23 percent, this year’s figure is on the low end of that range.
Bosworth allows that some of those “missing” sockeye went up the Sammamish River instead but only “a very small number.”
While PSM is also striking urban coho, that’s due to toxic stormwater runoff. For sockeye, it’s other things entirely.
“It seems to be a combination of previously existing diseases — columnaris, parvicapsula, etc. — that are becoming more prevalent/effective with the higher water temperatures,” says Bosworth.
After salmon leave the cool waters of Puget Sound via the locks, they transit the relatively shallow and warm Lake Washington Ship Canal in June and July.
Sockeye are particularly sensitive to hot water issues, as illustrated by 2015’s quarter of a million missing Columbia River fish, and Army Corps of Engineers data from this past mid-July showed the lake’s Montlake Cut ranging from 70 to 74 degrees at 21 feet, and nearing 70 degrees at 35 feet late in the month.
As for predation, sockeye fry rear in the lake for a year or so and are gnawed on by native cutthroat trout and northern pikeminnows, along with an increasing suite of nonnative fish that now includes some walleye.
As the human population around the lake and in the metropolis has grown, the glow from all the home, street and business lighting we’ve strung up in the area makes it easier for cutts, etc., to see their prey at night and that essentially means there is no time they are going hungry for a salmon snack anymore, according to a county biologist.
Anymore just 2 to 4 percent of fry that enter the lake escape it for a multi-year North Pacific sojourn.
Survival in more northerly sockeye systems is much better, 16 to 20 percent.
The Pacific has been far rougher on salmon in recent years too. 2004’s return might have otherwise been the last fishery if not for “insanely high” 50 percent at-sea survival for the 2006 year-class.
Essentially, all parts of the equation for Lake Washington sockeye are failing.
Urabeck, the angler advocate, says it’s “sad” what’s happened.
“It’s hard for me — we were out there in about anything that floated,” he recalls.
He modeled flood control as a grad student in the late 1960s/early 1970s to show how it could help shelter the stock’s redds, as well as fished for the salmon on the lake then and in the following decades.
A storied breakthrough came in 1988 when anglers ditched trolling the orange banana plugs that worked only so-so for single red hooks that did stunningly well, revolutionizing the fishery.
With 1993’s temporary hatchery having yielded four fisheries in the late 1990s and early 2000s, Urabeck dreamed that production at SPU’s new, state-of-the-art mitigation facility at Landsburg Dam on the upper Cedar would mean seasons every other year instead of once every four.
But it has not come to pass — not even close.
“There were forces at work that none of us understood,” Urabeck reflects.
Last year he called for a “token, for old times’ sake” fishery if that year’s run were to reach 100,000 at the locks.
It did, but nothing was opened.
He’s still not entirely ready to throw in the towel, but he does point out that the decline of this run makes Baker Lake sockeye — Western Washington’s other major run — “more important” to sportfishing than ever.
WDFW recently held a public workshop on that run and ways to improve angling up there.
As for how to fix Lake Washington sockeye, at that Cedar River Council meeting a state researcher said doubling the current smolt survival rates would help over time.
“We were talking about trying an extended rearing program to counter the inlake predation issue,” says Bosworth, the state fisheries biologist.
“That probably won’t fix the adult PSM, though,” he adds. “Maybe we should try bringing in eggs from Alaska and rearing them in floating net pens in Lake Washington. Not sure who will pay for that, though.”
In the meanwhile, the nearly 3,789 sockeye taken to the SPU hatchery — at 50 percent, an “all-time high” percentage of the run — should yield 5 million eggs.
“Full capacity at the hatchery is about 34 million, so it’s far from full but better than none,” Bosworth says