[env-trinity] Times Standard: Mixed outcomes for local Chinook salmon

[Tom Stokely]

http://www.times-standard.com/general-news/20150516/mixed-outcomes-for-local-chinook-salmon
Mixed outcomes for local Chinook salmon
Eel River fall Chinook salmon milling in a pool in Dos Rios waiting for rain last November. Cathy WarrenBy Tabitha Soden, tsoden at times-standard.comPOSTED: 05/16/15, 10:13 PM PDT |0 COMMENTSChinook salmon spawning below Outlet Creek during low flows last November. PATRICK HigginsWhile Chinook salmon in the Eel River are maintaining healthy population levels, juvenile Chinook in the Klamath River are struggling against a deadly parasite, according to annual monitoring of migration and spawning in the two rivers.A parasite, Ceratomyxa shasta, is infecting and killing juvenile salmon before they complete their migration to the sea. The parasite is present in many rivers in the Pacific Northwest, but this year is causing the highest mortality rate among juvenile salmon in the Klamath since 2008, according to Jerri Bartholomew, a professor of microbiology at Oregon State University.“The parasite is not just one parasite, it has different genetic strains, and the different strains infect different species. What’s unusual about this year is we are only seeing one strain, and it’s the strain that affects Chinook salmon,” Bartholomew said.She said that while that is good news for other species of salmon, which have contracted the parasite in past years, it presents a problem for the Chinook. “Every species goes through cycles, but it is never good to be losing a large number of your juvenile year class,” she said.Bartholomew said this year has been one of the worst in terms on infection. As of April 30, all of the salmon tested in the Shasta to Scott reach of the Klamath river were infected with the parasite and all the salmon tested from the Scott to Salmon reach of the river had the parasite as of May 4, according to Ca-Nv Fish Health Center Data.Karuk Tribe Klamath Coordinator Craig Tucker said another disease called Ichthyophthirius multifiliis, referred to as ich, is also infecting returning adult salmon. He said these diseases result from the steady the water flows released from dams on the Klamath.“In a normal river, or a river that’s not dammed, when it rains there is a dynamic flow pattern. But when you dam a river you don’t get those dynamic flows ... and it creates a stable environment for these parasites,” Tucker said.He said one solution would be to remove the dams and restore normal flow patterns, something the tribe has been advocating for years. Tucker said people also need to understand how the death of juveniles fits into the bigger picture.“In terms of the salmon population, these juveniles dying at the rates they’re dying, is probably one of the biggest factors affecting the health of the Klamath River salmon,” he said.Joe Janisch, the president of the Salmon Restoration Association in Fort Bragg, said that while drought and water diversion are affecting Klamath River salmon, the news is a little brighter for Eel River salmon. Despite the four-year drought, a high number of adults returned in December and January to spawn, and he said they appeared to do OK, considering the circumstances.“The salmon are never doing well or great. They’re always struggling because the system hasn’t changed much in the last 60 years,” he said.The Salmon Restoration Association helps fund the monitoring projects that look at salmon on the Eel River.Patrick Higgins, the managing director of the Eel River Recovery Project, said the monitoring project conducted in October and November last year showed that Chinook salmon are maintaining population levels estimated in the tens of thousands, a number equal to those measured by the U.S. Fish and Wildlife Service in the 1950s.In the past silt and sand, washed into the river during the 1964 flood, prevented Chinook from thriving. As the largest of Pacific salmon species they have adapted to spawning in large gravel and cobble, according to an Eel River Recovery Project press release.“The fines from the record 1964 flood have been flushed, and it left us with a record amount of spawning gravel,” Higgins said.The group estimates the number of two-year old Chinook salmon that will return to Eel River to spawn is about 26 percent of the 2013-14 population, a high number despite the four year drought.But while Chinook salmon in the Eel River are thriving, summer steelhead and coho salmon may face challenges with the drought and low tributary flows, according to the release. Bartholomew said several management actions could help mitigate population decline, but there are no guarantees.“The problem is these actions get taken at the sacrifice of something else,” she said.Tabitha Soden can be reached at 707-441-0510.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www2.dcn.org/pipermail/env-trinity/attachments/20150517/464a6dcb/attachment.html>