Eel River Fall Chinook Run Well Underway, Says ERRP

Early Fall Chinook Salmon [Photo from the Eel River Recovery Project]

Chinook salmon holding in a lower South Fork Eel River pool. [Photo by Pat Higgins. 11/20/22.]

This is a press release from the Eel River Recovery Project:

Despite sparse rainfall so far this fall, several thousand Eel River fall Chinook salmon have disbursed throughout the watershed. While some are holding and waiting for rain, others have commenced spawning in main Eel River channels. The early portion of the run is not robust, but late run Chinook salmon may enter the river, if flows increase. This article is based in data available from agencies and non-profit groups, but also observations of Eel River Recovery Project volunteers throughout the watershed.

Historically, Chinook salmon entered the Eel River in late August and could hold in the deep estuary and pools in the lower river. Today the fish need rainfall to move up out of the ocean and migration was triggered in late September by a mild rain event and a rise in flow to 250 cubic feet per second (cfs) at the U.S. Geologic Survey Scotia gage at Scotia. Light rains in early November stimulated more movement and ERRP volunteers began to see fish moving in the evening over riffles near Shively. The Eel River flow at Scotia peaked at 880 cfs on November 10, and a wave of fish moved upstream with opportunity and disbursed into the South Fork, upper Eel and Van Duzen River.

Peak flow on the Van Duzen River at Bridgeville was just over 200 cfs, but elevated flows were of short duration. If flows are ample, the Van Duzen can sometimes have several thousand Chinook salmon. There is a spawning hot-spot in lower tributary Yager Creek, but flows were likely not sufficient for the fish to gain access. The Van Duzen River is extremely over-supplied with sediment below Yager Creek and subject to channel shifts that would be lethal to salmon eggs. Early entering Chinook are likely using the reach upstream of Yager Creek extending to above Carlotta, where their eggs have a better chance of survival.

Fish began arriving on November 13 at the Van Arsdale Fish Station at Cape Horn Dam on the main Eel River, having traveled 140 miles upstream. A total of 82 Chinook salmon were counted, and by November 20, that number had risen to 122 with at least 20% of the fish being jack salmon. The latter are smaller fish that have spent less than one year in the ocean and their levels are indicative of ocean survival of the previous year class. They also can be harbinger of future returns, due to the variable age of Chinook salmon maturation.

There is insufficient flow in the Middle Fork Eel River for Chinook migration; therefore, spawning is now taking place in the main channel of the Eel River everywhere from below Dyerville to Cape Horn Dam. The flow being maintained at the Ft Seward USGS gauge of 200 cfs in late November is enough for passage and spawning. This elevated flow is in part owing to the fact that the Potter Valley Project turbines are not functioning and less water is being diverted to the Russian River than in the past. It is important that driving in the Eel River below Dyerville be avoided at this point, because fords ten to coincide with gravel chosen for spawning.

Cal Trout is operating a dual frequency sonar (DIDSON) on the lower South Fork Eel River that counts migrating salmon and steelhead. Matt Metheny, who oversees operation, reported that an estimated 1770 Chinook salmon passed upstream triggered by a flow increase to 275 cfs at Miranda around November 10. ERRP volunteers reported fish holding in a pool below Garberville and a group of more than 200 were photo and video documented (https://vimeo.com/eelriverrecoveryproject). Other volunteers have reported a small number of fish as far upstream as Leggett. However, without additional rain and flow increases, Chinook are now being forced to spawn in the lower SF Eel River channel that is impaired by excess sediment. Spawning conditions improve upstream of the Humboldt County line, but the bulk of spawning will likely take place downstream where survival could be compromised by subsequent high flow and bed load movement.

 

A stationary high off the northern California coast is causing storms to arc to the north. As a result, in the Eel River watershed is sparse and tends to be more robust in the north and tapering in the southern and eastern part of the watershed. To compound problems, it appears that the next storm system will be cold, resulting in precipitation falling as snow that may dampen flow increases.

The paucity of rainfall prior to Thanksgiving was once rare and is now common, an indication that climate change is impacting Eel River salmon. Also, ocean conditions in 2022 failed to produce abundant cold-water krill and recruitment of juvenile Chinook salmon from last year’s strong brood appears modest. Chinook salmon may spawn into January or later in response to the drought. However, unless that late run is robust, it appears that this year’s return will be around 10,000 fish maximum, at the lower end of the spectrum since ERRP began assessments in 2012. For more information or to report Chinook salmon observations, call 707 223-7200.Water levels in Humboldt rivers Water levels in Humboldt rivers Water levels in Humboldt rivers Water levels in Humboldt rivers

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12 Comments
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Jeffersonian
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Jeffersonian
1 year ago

When the fish are forced to spawn in lower reaches the probability of success is low since if the flows raise to traditional levels the nests are buried in sediment. 10000 fish is a pure guess as only 5000 were observed in the lower river before the early november rains. Futher, Chinooks no longer enter the river until late September. The earlier runs are extinct. The run is mostly over in the lower river by early December. A shame to see a once world class fishery of half a million Chinooks destroyed by man.

Steve Koch
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Steve Koch
1 year ago
Reply to  Jeffersonian

How did man destroy a world class fishery of half a million Chinooks?

ABA
Guest
ABA
1 year ago
Reply to  Steve Koch

Dams. Water diversions for agriculture. Dumping harmful chemicals in and near waterways. Overfishing. Decades of poor management.

Entering a world of pain
Guest
Entering a world of pain
1 year ago
Reply to  ABA

I think you forgot the decades of clear cutting the forests

ABA
Guest
ABA
1 year ago

Yep, probably a few other things too…

Entering a world of pain
Guest
Entering a world of pain
1 year ago
Reply to  ABA

Basically all human activity…sadly we live to destroy

Last edited 1 year ago
willow creeker
Member
1 year ago

Mostly Europeans actually. Pre European, salmon ran on the east coast as far south as Chesapeake Bay, and on the west coast south of Santa Barbara.

c u 2morrowD
Member
1 year ago

and rebuild

Martin
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Martin
1 year ago
Reply to  ABA

Add freeway building and poor logging practices for years to your list. We can either make an effort to repair the damage or just let the fishery slowing slip into zero fish. I pray that day never comes! Clean the rivers and streams to give the fish a fighting chance.

mindyourhead
Member
mindyourhead
1 year ago
Reply to  Steve Koch

Watch the documentary “Rivers of the Lost Coast”

Last edited 1 year ago
Steve Koch
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Steve Koch
1 year ago

What an informative and well written press release, well done!

Steve Koch
Guest
Steve Koch
1 year ago
Reply to  Steve Koch

With the exception of the following quote:
“an indication that climate change is impacting Eel River salmon”.

The writer should prove that statement, which they can’t, because proving specific changes in a microclimate due to global climate change is rarely (never?) possible.