[env-trinity] Trinity Journal: Studies show poor fish returns, spawning in 2015

[Tom Stokely]

http://www.trinityjournal.com/news/environment/article_be765f44-ca16-11e5-8074-63301f00a21e.html

Studies show poor fish returns, spawning in 2015
By AMY GITTELSOHN The Trinity Journal | Posted: Wednesday, February 3, 2016 6:15 am
Fisheries Technician Chris Laskodi
Fisheries Technician Chris Laskodi from the U.S. Fish and Wildlife Service marks a redd on foot near Junction City.Fisheries experts report that the 2015 fall chinook salmon run in the Klamath and Trinity river basins fell short of the forecast.A return of 119,000 adults — both hatchery and wild fish — had been forecast to enter the mouth of the Klamath at the ocean, headed farther up the Klamath or into the Trinity. That would have been about average. Instead, the preliminary estimate for the run is 83,862 adults and early-returning jacks, which ranks the run as the 11th lowest since 1978.DFW Senior Environmental Scientist Wade Sinnen said abnormally warm ocean conditions are thought to be the main factor.“We attribute the low returns to poor ocean conditions (poor survival) primarily, however, four years of drought may also have impacted freshwater production,” he said in an e-mail.Some of those returning fish were caught in the river, with the tribal harvest put at 28,513 and the in-river sport harvest at 9,405, both below the allocations.The ocean catch was also low, said Sinnen, an ocean sport fisherman himself. “The fish just weren’t really out there.”Natural spawning will not meet the target set, and the Trinity River Hatchery had its sixth lowest return of fall chinook since 1977 at 3,460 fish.“It’s one of our down years,” Sinnen said. “Down on the Trinity, down on the Klamath, probably down along the West Coast. Two or three more like this is a down cycle but we hope that isn’t the case.”“But not record lows by any means,” he added, calling the numbers around the bottom third of the range.Regarding the natural spawning, fisheries workers floating down the Trinity River in boats in 2015 scanning for salmon carcasses and spawning nests had low counts.“It was a poor spawning year,” said Derek Rupert, fish biologist for the U.S. Fish and Wildlife Service who coordinates the surveys.To look at a stretch of the Trinity River, for example, from September through December crews mapped 2,162 nests, called redds, in reaches from Lewiston Dam to the confluence with the Klamath River at Weitchpec. That’s the lowest it’s been in the past 12 years using the current methodology, and about 40 percent of average for those years, Rupert said.That doesn’t necessarily mean that the resultant fish returns in a few years will be low, he said, noting that each female can lay 3,000 eggs.By examining the fish carcass nearby each redd, the researchers determined that 2,103 of the redds were from chinook salmon, with 331 of those built by hatchery chinook that had strayed. There were 59 redds from coho salmon.The teams from the U.S. Fish and Wildlife Service, U.S. Forest Service, California Department of Fish and Wildlife and the Yurok and Hoopa tribal fisheries programs floated the upper 40 miles of the Trinity River from the dam every week and the section from Big Flat to the confluence with the Klamath River every other week during the survey, minus the Pigeon Point run and Burnt Ranch Gorge.Estimates are also developed for spawning in the Klamath River and in tributaries.From the Trinity River Restoration Program, acting Chief Executive Director Brandt Gutermuth said this has been “a terrible year” for fish returns.“We’re not happy about that,” he said.As to why the numbers dropped as they did, Gutermuth said, “that is the million dollar question” and the answer could relate to any of the four H’s: habitat, hydrology, hatcheries and harvest.Gutermuth and Rupert said one positive trend shown by the surveys is the rising proportion of wild fish redds to redds from straying hatchery fish in the river. More of those wild fish redds are being built downstream indicating better habitat, they said. The Trinity River Restoration Program has worked to improve habitat on the river.“For a long time the Trinity was dominated by hatchery fish,” Rupert said, adding that the fish are probably taking advantage of habitat from restoration projects.He also noted that the proportion of fish that died before spawning was low, indicating that the fish that did return were healthy prior to spawning.
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