After months of rumors and speculation coming off of the Cowlitz River, the state Department of Fish and Wildlife has confirmed what many area anglers had feared:
Of the roughly 625,900 steelhead and 90,600 cutthroat smolt reared by the Cowlitz Trout Hatchery for release in 2016, roughly 514,000, or about 70 percent of the stock, went missing prior to release.
Those losses are likely to have a negative impact on the summer steelhead runs of 2018-2019 as well as cutthroat returns as early as this summer.
To make matters worse, the WDFW says it doesn’t know where the fish went. Theories to explain the huge losses include bird predation, disease, escape from rearing pens, and inaccurate and faulty counting equipment.
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On Jan. 9, the WDFW released a fact sheet detailing the historic loss of steelhead and cutthroat trout.
“We’ve not seen anything like this before,” said Cindy Le Fleur WDFW policy coordinator for the Columbia River.
The loss of more than a half million fish that would have begun making returns to the Cowlitz River in the summer of 2017 comes on the heels of a loss of about 100,000 fall Chinook salmon smolt in May 2016, when a net pen in Lake Mayfield was vandalized, allowing the fish to escape. This time there was no outside act to help explain the loss of more than a half million hatchery fish that fuel the most popular fishery on the Cowlitz River.
Le Fleur said of the 202,000 summer-run fish released in the Cowlitz River in 2016, about 183,600 are believed to have been steelhead, with the difference made up by about 18,600 cutthroat trout. Le Fleur was unsure where the bulk of that vanishing 2016 stock went.
The cause that the WDFW seems to believe is most plausible is mass bird predation. The tiny fish are reared in lakebound net pens and are captive targets for hungry birds. Le Fleur said avian predation has been a problem for some time, so preventative measures are already undertaken. But she noted the efforts are by no means comprehensive and added that because this year’s losses are unprecedented, there was little indication that increased protection was needed.
Le Fleur said the protective bird netting at the rearing pens is not complete and allows for persistent birds to gain access to the fish. Le Fleur said Tacoma Power, which owns the hatchery as part of required mitigation efforts for wild fish losses caused by dams on the Cowlitz River, employs the U.S. Department of Agriculture to perform bird harassment operations around the pens. Those actions are not performed continuously, so the birds are free to return when harassment agents leave. Le Fleur said that there has been talk of stepping up harassment efforts to include lethal measures.
“Tacoma is looking into that,” Le Fleur said. She noted that regulations pertaining to harassment of wild birds are different for different species.
Le Fleur placed some blame on smolt counting equipment that she said is largely inaccurate.
“I don’t think it’s reliable, like if two fish go through at the same time. The counting equipment just isn’t perfect,” Le Fleur said. She said lake debris such as sticks and grass sometimes is incorrectly counted as fish.
Le Fleur said she is not sure where or when the fish counting equipment used by WDFW was purchased or if it is the most accurate option available on the market.
“We can’t count them in the lakes. What we do is we count them, and it’s an electronic fish counter, when they leave, when they are released. That’s part of the problem is you can’t know how many are in there at any given time. They’re in these great big lakes,” Le Fleur said. “I think the lakes are fairly deep and I don’t know if you can see your way through it. They are not your typical raceways that are long skinny ponds that are maybe 4 or 5 feet deep or something.”
Because of that inability to keep tabs on fish while they are in the lake-rearing pens, it is unknown precisely how long the missing smolt had been missing.
The fact sheet provided by Le Fleur noted that her department, which is contracted by Tacoma Power to undertake day-to-day operations at the hatchery, is working with the power company to figure out what went wrong and how to prevent it from happening in the future.
So far, Le Fleur said, the actions taken include improved netting and increased bird hazing during daylight hours.
“Tacoma Power is in the process of doing an evaluation on the trout hatchery for a rebuild, so all of those discussions will be a part of that, including possibly even redoing the lakes,” Le Fleur said.
Those future efforts could include nighttime patrols, shoreline pond covers to deter blue herons, and lethal action against some birds. Tacoma Power is working to obtain a contract for the lethal bird hazing and anticipates having that program in place no later than this fall.
Fully netted and covered rearing ponds are expected to be in place within the next three to six years.