About 70 percent of the summer steelhead trout that were supposed to be released into the Cowlitz River last May and June didn’t make it, most likely lost to disease and predatory birds who lurked around the Tacoma Power hatchery’s ponds.
Of the 626,000 that were expected to be released from the Cowlitz Trout Hatchery, only 186,000 were counted leaving the hatchery’s ponds and entering the river. And only 18,600 cutthroat trout were released, out of a target of 90,600.
That major loss of fish entering the water could mean the number of fishing licenses drops this year, staff from the Washington Department of Fish and Wildlife, which operates the hatchery, told a state senate committee this week. They did not offer an estimate.
Tacoma Power, which owns the hatchery, said anglers who fish only for steelhead in the Cowlitz may decide not to purchase licenses.
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“In our discussions with anglers, we’ve found that most fish for multiple species in many different waters, so they may purchase licenses to fish for other species and/or for other locations if the Cowlitz fishery is significantly reduced,” spokeswoman Chris Gleason said in an email.
Steelhead trout are one of the top sport fish in North America. They can reach 55 pounds and more than three feet in length. Steelhead and rainbow trout are the same species, but steelhead go to sea and return, while rainbows stay in fresh water. Unlike salmon, they can survive spawning, and can spawn for several seasons.
Tacoma Power built the hatchery in the late 1960s as a condition for the utility’s hydroelectric project on the Cowlitz River. It also owns a salmon hatchery about 10 miles further up the Cowlitz, said Keith Underwood, manager of the natural resources program for Tacoma Power.
It’s not known exactly what caused the major loss of fish, Underwood said, but it’s historically noteworthy: 20,000 fewer fish were released in 2016 than in other low-release years, Tacoma Power said.
There are probably a few factors at play, Underwood said: A huge increase in predatory birds that hang around the hatchery’s five-acre ponds, where the trout spend nine months before being released into the river, is at least partly to blame, he said. The ponds are only partially netted, meaning birds have some access to the fish, with the philosophy being that fish will learn survival skills that way before being released into the wild.
Disease earlier on in the rearing process of the 2016 cohort also could have contributed to their low numbers, said staff from the Washington Department of Fish and Wildlife, which runs the hatcheries for Tacoma Power, in their presentation to the senate committee.
And with a much-reduced overall count flowing out of the ponds and into the river, the accuracy of the hatchery’s counting system — which sometimes counts two fish as one, or counts debris as fish — is also in question.
“We recognize now that the birds probably had a significant impact on the numbers of fish going out, but we don’t know how well that counting system performs when there’s fewer numbers of fish,” Underwood said.
The aging hatchery infrastructure needs upgrading, and the utility budgeted $8 million in the 2017-18 budget for improvements there. Planning is happening now, Underwood said, and construction is expected to start in 2018. Projects include improving raceways and water delivery systems ($1.8 million), renovating the five-acre ponds ($1.9 million), and replacing the water treatment system ($4.3 million).
In the meantime, hatchery workers have done more to try to scare birds away, from randomizing the times of day that they shoot pop guns and spray water over the ponds, to discussing the possibility of lethal hazing — killing birds — to protect the trout. More netting has been added around the ponds, and barriers are being built so predators like heron can’t walk in and hunt fish.
Still, last year’s cohort could end up not amounting to a total loss, depending on how well they fare in the wild, Underwood said.
“Even though we released fewer fish than we anticipated, if ocean conditions are very favorable … we will likely see a drop in adult return, but it may not be as bad as a 70 percent reduction in adult returns,” he said.