[env-trinity] Klamath River fish diseases spreading

Thomas Weseloh caltrout at sbcglobal.net
Thu Mar 25 12:09:51 PDT 2010

Klamath River fish diseases spreading

Eureka Times-Standard-3/24/10

By John Driscoll


Biologists expect to see the host of a lethal fish disease continue to
spread in the middle Klamath River unless high flows scour out the silty
areas where it lives. 


Researchers on Monday reported their work on the Klamath over the past year
at the River Lodge in Fortuna. They said more of the tiny polychaete worms
that host the fish parasites were found packed more densely into a larger
area than in other recent years. 


Sascha Hallett, a researcher with Oregon State University, said that there
is more silty material that the worm inhabits, and with it more young fish
have been killed by the parasite over the past three years. Hallett said
that situation will probably become more problematic until heavy river flows
strip some of that habitat away. 


"I think this will get worse this year, if that's possible," Hallett said. 


The hot zones are in a roughly 50-mile stretch of river between the Shasta
and Scott rivers, but have been stretching downriver toward Orleans
recently. Essentially there are more parasites, called Ceratomyxa shasta, in
a larger area than before. 


Yurok Tribe biologist Joshua Strange said that it appears that increased
flows from the Trinity River in summer for ceremonial purposes does not tend
to speed up the migration of salmon. But higher flows can stop the outbreak
of diseases during peak chinook salmon migration in late August and late


Strange hypothesized that with more than 80,000 fish running upriver, and
less than 2,000 cubic feet per second of water running downriver, there is
the possibility of a fish kill. He referenced the 2002 event that killed
68,000 chinook in a hot, shallow river.


He said that removal of four dams on the Klamath -- called for as part of
two agreements signed among 28 parties in February -- temperatures in the
river should also begin falling as salmon begin to migrate in the fall. 


The plankton released from the reservoirs would no longer concentrate just
below Iron Gate Dam and continue to provide nutrients for the polychaete
worms. Iron Gate Dam is also where a huge number of adult salmon are stopped
in their upstream migration, and when they spawn and die, the release C.
shasta spores, which are taken up by the polychaete worm, concentrating the
host in that area. 


Until the dams come out -- scheduled for 2020 -- Strange suggested that a
short, high, additional flow of 3,000 cfs from Iron Gate in February could
disturb the silty, flat stretches of river where the worm is abundant.#








Thomas J. Weseloh, Northcoast Manager

California Trout

email sig fish Keeper of the Streams

1976 Archer Rd. McKinleyville, CA 95519


caltrout at sbcglobal.net



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