[env-trinity] TimesStd: Eel River flows still too low in peak salmon spawning period

Sari Sommarstrom sari at sisqtel.net
Tue Dec 1 11:34:48 PST 2015


Eel River flows still too low in peak salmon spawning period

http://mn4-njweb.newscyclecloud.com/apps/pbcsi.dll/storyimage/NJ/20151129/NE
WS/151129865/AR/0/AR-151129865.jpg&maxh=400&maxw=667

A Chinook salmon swims up a river bar on a low flowing Eel River this month.


Photo courtesy of the Eel River Recovery Project 

 

By Will Houston
<http://www.times-standard.com/environment-and-nature/20151129/eel-river-flo
ws-still-too-low-in-peak-salmon-spawning-period#author1> , Eureka
Times-Standard 

Posted: 11/29/15, 4:02 PM PST | Updated: 10 hrs ago 

0 Comments
<http://www.times-standard.com/environment-and-nature/20151129/eel-river-flo
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http://mn4-njweb.newscyclecloud.com/apps/pbcsi.dll/storyimage/NJ/20151129/NE
WS/151129865/EP/1/1/EP-151129865.jpg&maxh=400&maxw=667Tire tracks running
through riffles on the South Fork Eel River near High Rock show that the low
flowing waters have allowed for crossings that are atypical for this time of
year. Eel River Recovery Project board member Eric Stockwell said cars on
the river could accidentally run over salmon eggs, which are lain at the
head of these riffles. Photo courtesy of the Eel River Recovery Project 

This month's rainfall and cooler temperatures have helped lessen the strain
on salmon migrating on the Eel River, but not near enough to ease the
concerns of local researchers.

And they have their reasons.

Since Chinook salmon began entering the drought-stricken river this year,
they were met with near-historic low flows preventing their upriver
migration to spawning areas, a currently unexplained blindness and
"zombie-like" behavior, poachers, and cars running over what spawning
grounds they can find.

"It's a hard thing to watch," Eel River Recovery Project board member and
research diver Eric Stockwell said.

So far, Stockwell said, there have been a reports of a few hundred fish
having made it to the main stem Eel River and the South Fork Eel River about
20 to 30 miles south of Fortuna.

National Marine Fisheries Service fish biologist Zane Ruddy said this time
of year is a "peak" time for salmon spawning, but added that salmon would
normally be much farther upriver and would have spread out among different
tributaries. Instead, many of them have been forced to lay their eggs right
on the river due to the low flows, which presents several uncertainties.

"This is the time," Ruddy said. "It's not to say that they can't be
successful in spawning in place. It all depends on the flows that occur
after they spawn."

If a large number of fish can't reach their preferred spawning ground,
they'll lay the eggs on the river and essentially "put all their eggs in one
basket," Ruddy said. 

These fish run the risk of having their eggs scoured should a strong winter
storm touch down on the area and wash them away. Ruddy said the Chinook
salmon are able to "diversify the risk" and increase the chance of their
offsprings' survival by spreading out among different tributaries.

Spawning success relies on a fragile balance with river flows.

Ruddy said that salmon will not move upriver until triggered to do so by
high river flows caused by storm events.

While a few spurts of rain have allowed some fish to move, U.S. Geological
Survey flow data shows the Eel River flows near Scotia are currently at only
one-sixth of their normal levels of about 1,400 cubic feet per second.

"If you look at storms last year, we had flows over 10,000 cubic feet per
second and sustained storms from November and all the way through December,"
Ruddy said. "This year we haven't had any substantial storms."

Ruddy said fish would normally be showing up at the California Department of
Fish and Wildlife's Van Arsdale fish counting station near Willits around
now, but none have made it as of Tuesday.

Stockwell said the salmon that are currently spawning are those that entered
the river in the late summer and early fall. During this long wait, some of
the fish crowded in small pools that were filled with oxygen-consuming
algae.

As a result of these stressful conditions, many fish showed strange signs of
blindness and lethargy to the point that researchers could hover their hand
over the fish's face with no reaction. Fish samples are currently being
assessed at the University of California Davis to determine the cause of
these troubling symptoms.

Some of these "zombie fish" have made it to the main stem about 20 miles
south of Fortuna, though Stockwell did not know if they were spawning.

For the fish that have just been entering the river from Fernbridge,
Stockwell said the rains and cool temperatures will cushion them from these
poor conditions.

"I think that it's almost impossible that these fresher fish coming in are
going to be affected by what got the fish with the lower flows and warmer
temperatures," he said.

That doesn't mean there aren't challenges. Evidence of poachers has been
seen along the banks of the river, including one instance where a rearing
female's eggs were found on the gravel, Stockwell said.

Near High Rock on the South Fork Eel River, Stockwell said he and others
have been noticing tire tracks going across the river.

"When the river is low the places to cross are at the head of a riffle. But
it's also the place that salmon spawn," Stockwell said. "Usually this time
of year the river would have gone up so much that people wouldn't be driving
on the river. This is one of the bad things about the drought."

Will Houston can be reached at 707-441-0504.

 

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