11/5/12
Chinook salmon are moving up the Eel River in unusually large numbers this fall, according to a series of counts undertaken in September and October by volunteer divers from the Eel River Recovery Project (ERRP) and Humboldt Redwoods Company (HRC).
ERRP volunteers counted a total of approximately 5,000 Chinook salmon, hundreds of steelhead, and over a dozen Coho salmon in the lower reaches of the main stem Eel River on three dives taken on Sept. 28, Oct. 13, and Oct. 27.
On Monday, Oct. 29, a volunteer team organized by HRC counted a total of 2,500 adult Chinook and 500 jacks (immature males) in a deep pool at Holmes, near Redcrest, and at least 400 adult Chinook at the confluence with the South Fork Eel at Scotia.
But it’s still early in the fall run, with November usually the month of "the Charge of the Light Brigade" -- the highest numbers of migrating Chinook -- according to Pat Higgins, consulting fisheries biologist and volunteer coordinator of ERRP.
Chinook and steelhead migration should still be strong in December, and some Chinook are usually seen in January as well, Higgins said.
With this in mind, Higgins estimates a total run of Chinook as high as 50,000.
This large run is occurring in a year in which water levels in the Eel River system are unusually -- and somewhat puzzlingly -- low.
In spite of nearly normal rainfall in the 2011/2012 season the U.S. Geological Survey gauge at Scotia showed the Eel flowing at only 63 cubic feet per second on Sept. 28, the day of ERRP’s first dive. This is only half the long-term average flow for this time of year.
"This likely means that there is increased diversion and changes in basin-wide hydrology causing this depletion," ERRP’s Sept. 28 report states.
Higgins noted that the report is referring to diversions other than the notorious Potter Valley Project, where water from the upper main stem Eel is diverted into the Russian River basin through a tunnel at Van Arsdale Reservoir in Mendocino County. The Potter Valley Project has been diverting water for over a hundred years and its effects on the river are well known and accounted for.
A small amount of rain fell in the area on Oct. 12 and the flow at Scotia increased slightly to 70 cfs by the time of the Oct. 13 dive, ERRP’s second report states. With low barometric pressure and the likelihood of more rain on the way, numbers of salmon also increased in the dive area as the fish sensed a good time to move upriver.
A third count on Oct. 27 has not yet been officially compiled and reported, but Higgins said he personally saw 3,000 fish on an independent dive on the following day, Oct. 28.
When heavy winter rains set in, river conditions will prevent further counts by divers. When water levels drop following storms, redds (clusters of salmon eggs) and carcasses of spawned-out salmon can be seen along the banks, and these are good indicators of how many fish came upriver.
The Wiyot Tribe and the Bear River Tribe of the Rohnerville Rancheria co-sponsored the dives. Volunteer divers included members of the Wiyot Tribe environmental department, students from the Humboldt State University scientific dive class, and staff from the U.S. Fish and Wildlife Service and the National Marine Fisheries Service.
When Humboldt Redwoods Company became aware of ERRP’s work in the river, the company decided to establish a similar program.
Because their operations include gravel extraction, HRC must monitor the physical habitat in the river, including types and depths of pools, but they are not required to do any biological monitoring, HRC hydrologist Nick Simpson explained.
In order to better understand the condition of fisheries and the river in their area of operations, HRC instituted river monitoring last summer, sending out teams of snorkelers to look for pools and riffles that would be the best places to count salmon in the fall.
After collaborating with ERRP, HRC’s team of volunteer divers got into the water on Monday, Oct. 29, at three spots, one near Scotia, one at Holmes, and one at the confluence of the South Fork and main stem Eel.
The water at the Scotia site was stagnant, with poor visibility. Only four Chinook were seen there, although Simpson reported 28 steelhead "half-pounders," immature fish from 12 to 18 inches long.
Conditions at the confluence were "not great," Simpson said, but divers counted 400 Chinook.
But at Holmes, where even at this year’s low flow the divers entered a pool 37 feet deep, they swam into "a solid wall of fish," estimated at 15 feet in height, 20 feet wide, and 60 feet long. The team counted 2,500 adult Chinook and 500 jacks at this location.
If river conditions permit, HRC will host more dives, but Simpson felt that late October was the optimal time, as rain will cause the fish to spread out too much for accurate counts.
ERRP also held a retreat at Emendal on the main stem Eel east of Willits on Oct. 13. Speakers from many groups throughout the watershed made presentations, as well as Erick Burres from the Regional Water Quality Control Board, who spoke about effective citizen monitoring.
Among others, members of the Wiyot Tribe spoke about the importance of the river and fisheries to their way of life, Scott Greacen of Friends of the Eel River talked about the impacts of water diversions, and Gordon Russell from Phillipsville described the success of Water Day at the Mateel Community Center in creating a community forum for water issues.
ERRP is "a grassroots group dedicated to monitoring the health of the Eel River and fostering its recovery." The Trees Foundation, a 501c3 non-profit corporation, "umbrellas" ERRP and provides fiscal support, so donations can be made by writing a check to "Eel River Recovery Project" and sending or bringing it to The Trees Foundation, P.O. Box 2202, Redway, CA 95560.
The Rose Foundation and the Patagonia Foundation provided funding for the volunteer monitoring program, which was co-sponsored with ERRP by the Wiyot Tribe and the Bear River Tribe of the Rohnerville Rancheria.
Anyone interested in volunteering for the monitoring project should contact Higgins at 223-7200 or
