Eel River Forum Hears Science Research Related to Steelhead in Benbow

Silhouette of Dr. Stephanie Carlson at the Eel River Forum. [Photo by Kelley Lincoln]

On June 14, the Eel River Forum met in Benbow. The 22 public agencies and non-profit organizations charged with stewardship roles in the giant Eel River watershed came together to share their research and project information with each other so that they each have a broader understanding of the work of their peers and of the life and health of the Eel River in its entirety.

Membership includes the National Marine Fisheries Service, US Fish and Wildlife Service, PG&E, Potter Valley Irrigation District, Sonoma County Water Agency, Friends of the Eel, North Coast Regional Water Quality Control Board….

Last year in June, the Eel River Forum released its Action Plan. The forum’s website states,

The [The Eel River Forum’s Action] Plan identifies priority actions needed to recover the Eel River watershed and its native fish. It aims to achieve these goals while maintaining multiple land uses and recreation in the watershed. Priority actions in the plan address water diversions, water quality issues, habitat restoration, community engagement and protecting the Eel River Delta.

Eel River

Eel River from the Hurlbutt Ranch. [Photo by Kym Kemp]

Below are the highlights of what was covered in the forum:

PG&E begins re-licensing Potter Valley Project for 2022

PG&E submitted its Pre-Application Document in pursuit of its application to re-license the Potter Valley Project to FERC, the Federal Energy Regulatory Commission. Public Comments on the Pre-Application are due by August 4th. There will be two public scoping meetings on one day, the 28th of June in Ukiah at the Convention Center. They will be held at 9 a.m. and at 6 p.m.  There is also a site visit to the Potter Valley Project itself the day before on June 27th.

These will be the only two meetings on the pre-application document.

You can find links to the documents at FERC’s eLibrary here:

ERRP will hold Pike Minnow Counting Dives

And on June 29th and 30th, the Eel River Recovery Project (ERRP) is having two days of Pike Minnow Counts in the South Fork Eel from Rattlesnake downriver to Standish Hickey. The public is invited to participate.

The Forum on Oncorhynchus mykiss

This month instead of reporting to the group from within, Forum participants got to have a college day as three sets of professors and their students presented recent research findings involving Steelhead and often Chinook as well.

Wikipedia describes Steelhead like this:

The rainbow trout (Oncorhynchus mykiss) is both a trout and species of salmonid native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called “steelhead trout”) is an anadromous (sea-run) form of the coastal rainbow trout (O. mykiss irideus) or Columbia River redband trout (O. mykiss gairdneri) that usually returns to fresh water to spawn after living two to three years in the ocean.

Premature Migrators

Dr. Mike Miller, a geneticist from UC Davis, presented research he helped author that up-ends long held genetic assumptions that underpinned the decision to reject the 2011 application to list Spring Run Chinook in the Klamath River System for Endangered Species Act protection. Spring and Summer runs are termed “premature” because they enter fresh water but do not spawn until almost as late as the winter runs. Historically, in every watershed, there were both mature (late run) and premature (early run) populations. When geneticists tested individuals from different places they find more genetic common ground among the two phenotypes from the same watershed than among the same phenotypes from different places. In other words, fish from any watershed show marked genetic differences from the same species in any other watershed. The fish from any watershed are more like each other despite whether they are early or late run varieties.  And as any fisherman knows, the spring run fish seem very different from their late run counterparts.  The presumption had been that there were separate evolutionary triggers in each watershed that caused each geographically distinct population to develop early run phenotypes.  The adaptation was deemed a highly plastic phenotype. In other words, the adaptation came along so frequently, that it could be expected to return if it stops in a given river system.

Dr. Miller says because the price of DNA mapping has come down to pennies per individual, this study was able to sample thousands of individual fish for the first time ever. The study looks across five watersheds and finds that all early-run phenotypes have the same genetic difference from late run phenotype in the same chromosome set. The study team hypothesizes the premature migration phenotype arose prior to watershed dispersal of the population. Further testing supports that and indicates the evolutionary change appears to have come after the Chinook and Steelhead evolved away from a common ancestor species.

Strikingly, we find that premature migration is associated with the same single locus across multiple populations in each of two different species. Patterns of variation at this locus suggest that the premature migration alleles arose from a single evolutionary event within each species and were subsequently spread to distant populations through straying and positive selection. Our results reveal that complex adaptive variation can depend on rare mutational events at a single locus, … suggest that a supplemental framework for protecting specific adaptive variation will sometimes be necessary to prevent the loss of significant biodiversity and ecosystem services.

The evolutionary basis of premature migration in Pacific salmon highlights the utility of genomics for informing conservation

Daniel J. Prince, Sean M. O’Rourke, Tasha Q. Thompson, Omar A. Ali, Hannah S. Lyman, Ismail K. Saglam, Thomas J. Hotaling, Adrian P. Spidle, Michael R. Miller

Currently, in the entire Klamath River system, early runs only continue in the Salmon River.  Because the whole species is under such serious threat, the usual re-introduction of the early run phenotype through wandering individuals is unlikely to occur, said Miller.

Summer run Steelhead also still have an advantage in the Van Duzen fork of the Eel River.  UC Davis graduate student Samantha Kannry is beginning research to see if she can learn what factors make that so.

Climate Change Adapters

Dr. Stephanie Carlson, Assistant Professor of Environmental Science, Policy & Management in the Department of Environmental Science, Policy & Management, seeks to use the salmonid’s response to the winter event of 2013-14 to better understand how organisms adapt to climate change.  That winter saw very low precipitation and the precipitation that came did not arrive until late February.  Looking at the arrival times of the various runs of Chinook she found they arrived in a foreshortened timeline, negating the biological advantage of the early run’s advantage of getting into watersheds earlier and going higher up than the mature phenotype.  Carlson observed that they predominately spawned in the mainstream rather than in their traditional tributaries and that the year was a biological bust because almost no juveniles were observed the following year.  However, due to dynamics still under investigation, fish from other cohort years appear to be taking up the void and returning this year.

Flow-rates Impact Feeding and Fighting

Gabe Rossi is a student under Dr. Mary E. Power, U.C. Berkeley Department of Integrative Biology, and faculty director of the lab at the Angelo Coast Range Reserve outside of Laytonville. Rossi is examining Steelhead feeding behaviors and strategies. Rossi uses go-pro cameras mounted to film in stereo to triangulate and pinpoint individuals in several stream pools. Using GIS, Rossi precisely maps each individual’s territory in the pool and how far and fast they each travel.  He has observed that behavior and travel patterns change as stream flows diminish over the season. Fish are calm and utilize drift feeding until late July when many more fish enter the pools. Defensive and aggressive behavior increases and the number of ways fish find food increases at this time also. Then in late August, for reasons still under investigation, the fish become more stationary, feed less and in fewer ways, and become less interested in defending territory.

Native Fish Society seeks River Stewards in the Eel River

The Eel River Forum voted to add the Native Fish Society to its membership. Native Fish Society advocates for the recovery of wild, native fish and promotes the stewardship of the habitats that sustain them.  And the Society is hoping to add River Stewards in the Eel River Watershed. You can learn more about that at

These are just highlights of what was presented.  You can see more of the information presented after it’s posted in a few days at the Eel River Forum’s website



  • The Salmon River is one of the most beautiful rivers on earth!

  • Great article!

  • Always informative, Kelly. Thanks Kym, Kelly.

  • I believe the Salmon River is in North Humboldt by Orleans and Happy Camp, and it connects to the Trinity River. If you drive North on Highway 96 out of Hupa Indian land you will cross the Salmon River Bridge. So why are they having meetings in Benbow and talking about the Eel River water shed ? What am I missing ?

  • Good question….. The Eel River Forum focuses their attention exclusively on the five branches of the Eel River, but the forum had this study session on Steelhead and not all the studies were conducted exclusively in the Eel. I included that fact about the Salmon River, (and yes the very Salmon River you are thinking of except that it connects to the Klamath River at the Siskiyou/Humboldt County line) to give the context of how the premature migration phenotype is shrinking back to the point extinction seems a real and present danger. I hope this answers your question.

    • I am an author on the premature migration paper and I thought I would also mention that our study included samples of steelhead and Chinook from the Eel River. Thanks for helping spread the news!


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