Coho Recovery A Major Boon Along the North Bay Coast

Coho Salmon in Dutch Bill Creek from on Vimeo.

A few years ago I hiked through Muir Woods with my sisters. Many of the trails we traversed were along Redwood Creek, which empties into the nearby Pacific Ocean. I later spoke with a Golden Gate National Recreation Area aquatic ecologist about salmon and steelhead in those waters. Here’s what I found out back in our November 2015 story:

In 2014, the San Francisco Chronicle reported that less than 10 coho salmon – Redwood Creek is thought to be the southernmost range for silvers in the West – had returned to spawn in five of the previous seven years. Another year of drought only worsened the population.
“We have two salmon species present in Redwood Creek: coho and steelhead. Redwood Creek is not a very large coastal stream and the persistent drought has made it difficult to maintain good summer habitat for both these species,” Golden Gate National Recreation Area aquatic ecologist Darren Fong said in an email.
“This September we had to rescue some coho and steelhead in these drying pools and move them upstream where streamflow conditions were a bit better. The coho population has not been faring well and we have had a dramatic decline in two-year classes following winter 2007-2008.”
Fong added that there is a joint project involving multiple agencies – California Department of Fish and Wildlife, National Marine Fisheries Service, U.S. Army Corps of Engineers, and nongovernment organizations at the Golden Gate National Parks Conservancy and Friends of Lake Sonoma – “to establish a captive rearing program to try to save the Redwood Creek coho population from blinking out,” he said.

Three years later, Redwood Creek and other Russian River tributaries continue to hold out hope for returning coho. The CDFW program made progress as they planted hatchery coho into the waters, including releasing 188 adult coho – 89 3-year-old females,  87 3-year-old males and 12 jack 2-year-olds in January 2018 with more surveying expected.

Further north in Russian River tributaries, the California Sea Grant Russian River Coho and Steelhead Monitoring Program  is working hard to help re-establish coho along these North Coast streams (Redwood Creek along Muir Woods is believed to the coho’s southernmost habitat on the West Coast.) Here’s more from a Sonoma County Gazette report from this week from a different Redwood Creek in Sonoma County:

In search of juvenile coho, CSG biologists opportunistically snorkeled a few pools in Jonive Creek in 2015 and Redwood Creek in 2015, 2016, and 2017. They saw steelhead but not coho; however, those few pools represent only a small proportion of the fish habitat in each stream, so the lack of coho presence was not conclusive.

What makes Redwood Creek exceptional is the cold, clear water it contains—and contributes to Jonive Creek—even through the driest summer months. Ample perennial streamflow is a relatively rare and valuable asset in Russian River streams, many of which become intermittent or dry each summer. Indeed, insufficient summer flow is a significant bottleneck to recovery of local salmon and steelhead, who rely on freshwater habitat for juvenile rearing. …

…In December 2017, the US Army Corps personnel who raise the fish for the Broodstock Program released 3,041 coho young-of-the-year throughout 1,200 meters of the stream. Just over 600 of them (20%) were tagged with Passive Integrated Transponders (PIT tags) to allow for tracking at CSG fish monitoring stations, or antennas, in Green Valley Creek and throughout the larger Russian River basin.

The story also states just two of the tagged fish were spotted again the following spring, but when another 3,000-plus juvenile coho were released in December, a new PIT-tag attenna was installed to help improve detection.

Bottom line: When I wrote about the lack of fish in Marin County’s Muir Woods waters, things looked pretty bleak. These days there does seem to be some hope, and that’s all we can ask for.