Yuba Salmon Numbers Drop Again

Written by Gary Reedy, Consultant, Yuba Partners

Less than 4,000 salmon spawned in the Yuba River in 2016 according to a Monitoring Update from the Yuba Accord River Management Team. Such low numbers have not been seen since the California Salmon Stock Collapse of 2007 and 2008 when the estimated total for the Yuba River was 2,604 and 3,508 salmon, respectively. Over the last 30 years, the average annual estimate exceeds 15,000 salmon, with occasional runs above 30,000. No surveys precede the construction of Englebright Dam in 1941, which blocks access to historic spawning habitat in the watershed. However, fisheries historians have estimated that the salmon run in the Yuba River watershed originally comprised up to 15% of the historical abundance of Central Valley Chinook, or roughly 100,000 salmon.

The low salmon run size for the Yuba River appears to be part of another regional salmon collapse. The California Department of Fish and Wildlife point to preliminary data from the Sacramento River that indicates salmon runs have also dropped to record low levels. According to Dan Bacher’s reporting, last year’s salmon run on the Klamath River was a 38-year low, and estimates for the Sacramento River basin in 2016 suggest the need for fishing restrictions that would have a devastating impact on an already beleaguered salmon fishing industry. Salmon live a 3-4-year life cycle, and we are likely seeing just the beginning of a period of low returns resulting from five years of drought.

A new crash for the Central Valley Chinook salmon is not unexpected. Efforts to restore salmon habitat have been small compared to the ongoing impacts of water diversions, dams, invasive species and hatcheries. We need to really step up restoration efforts or else we are going to lose one of the most valuable components our watershed ecosystems and our natural heritage.

There is also news in the Yuba River Monitoring Update from the Yuba Accord River Management Team regarding Spring-run Chinook salmon, the rarer form of Yuba Salmon that is officially threatened with extinction under the Endangered Species Act, and historically dependent on habitats in the upper watershed. Prior to August when the run shifts to predominantly fall-run salmon, only 148 salmon were found migrating up the Yuba River.  And yet some help for spring-run salmon is coming.  In the one-mile below Englebright Dam, 89 salmon redds or salmon nests were found in spawning gravel put in the river by the Army Corps of Engineers to mitigate for the impacts from their dams, a program which only recently began, thanks in large part from SYRCL’s advocacy. And another spawning habitat project, near Timbuctoo Bend, is expected to begin in fall 2017. The spawning habitat created below Englebright supports Spring-run Chinook because those are the salmon which have the stronger urge to spawn further upstream.  Of course, the ultimate help for these imperiled fish would be passage and restored flows to habitats upstream of the dam.

The estimate for total salmon in 2016 (3,565 total salmon with a 95% confidence interval of 3,136 – 3,897) was made by counting, marking and recapturing carcasses. Hatchery fish, likely originating from the Feather River hatchery, marked with clipped adipose fins comprised 24% of all carcasses inspected. However, the total proportion of hatchery fish that stray into the Yuba River is actually higher because most hatchery salmon are not marked. Hatchery practices that allow such rampant straying are a “Road to Salmon Collapse” as described by FishBio who conclude: “It is time to decide whether we want to base our salmon production goals on sheer numbers of genetically similar hatchery fish, or on diverse, wild fish naturally supported by our local rivers.”

Amidst ongoing impacts — dams, hatcheries, drought, striped bass and poor habitat downstream – what can be done to help wild Yuba River salmon? SYRCL is working with local stakeholders to aggressively restore conditions in the Lower Yuba River so that juvenile salmon can leave the Yuba in the very best condition to survive their migration to the ocean and return. SYRCL is developing Lower Yuba River Restoration Action Plan that builds on work already underway – for example, the Hammon Bar Riparian Enhancement Project and the Hallwood Side-Channel Project — to chart a restoration course and gather support for the large-scale restoration vision necessary to recover wild and self-sustaining Yuba River salmon.

SYRCL is also promoting a longer-term vision that would involve volitional fish passage to habitats in the upper Yuba River watershed currently above dams. SYRCL participates in the River Management Team (RMT) along with three other non-governmental organizations, the Yuba County Water Agency, PG&E and state and federal agencies. The purpose of the RMT is to both monitor and evaluate conditions in the Lower Yuba River and to identify and support enhancement actions. SYRCL is holding the Army Corps of Engineers accountable to an effective Ecosystem Restoration Program for the Yuba River. SYRCL also works in the regulatory process to ensure dam operators in the watershed are contributing to better conditions for salmon.