The Sonoma County Water Agency and the U.S. Army Corps of Engineers will release 2,000 juvenile coho salmon into the Dry Creek fish habitat restoration areas today.
The release, which falls in areas downstream from Warm Springs Dam near Lake Sonoma, northwest of Healdsburg, marks the first release of coho into the restoration sites, beginning a period of study during which the water agency, USACE and their partners can monitor the fish and gauge the effectiveness of the habitat restoration.
“There are so few fish left in the wild, we – the group involved in the restoration – decided that we must do something,” said Mike Dillabough, San Francisco Division USACE chief of Operations and Readiness Division, citing the sharp decline of the coho in the 1990s.
The last remaining species of California Central Coast coho salmon are in the hatchery at Warm Springs, Dillabough said. “We want to make sure the habitat is working, so (the hatchery isn’t) the only reason the species is alive. We want nature to take over.”
“We are making the textbook on how to bring back a species from extinction,” Dillabough said, adding the group is developing a science as it goes with close monitoring and planning as the project evolves.
David Manning, the water agency’s environmental resources coordinator, said, “What’s important about the event is more than the release of the fish, it’s really recognizing that there is a large scale effort to initiate improving habitat conditions in Dry Creek.”
Participating agencies in the release and monitoring of the coho salmon and the Dry Creek restoration project include the National Oceanic and Atmospheric Administration, National Marine Fisheries Service, California Department of Fish and Wildlife, Dry Creek Rancheria Band of the Pomo, Construction Services Group, nearby landowners and business owners. The University of California Sea Grant will also help in monitoring the coho and its habitats.
The project, according to Manning, will span six miles out of the remaining 14-mile reach of Dry Creek, as part of the Dry Creek Enhancement Project, in response to the National Marine Fisheries Services Russian River Biological Opinion (a 15-year plan mandated to save endangered fish, like coho, and ensure water supply) that indicated the water flow in the creek had too high a velocity for resident fish to survive. Young fish need areas with lower water flow and places where they can feed and rest. Teams made a series, including protected pools and other of areas for fish to escape the high flow
The salmon, Manning explains, will come from the district’s Russian River coho salmon brood stock program, located behind the Don Clausen Fish Hatchery. This innovative program, he notes, continues to successfully raise and release the last viable endangered and threatened coho and steelhead into the Russian River watershed. Usually older, ocean-ready, salmon are released, Manning said, noting Friday marks the first time juvenile coho salmon will be released, encouraging them to rear and imprint on the water for future return.
“To truly understand the biological response will take many years,” Manning said, “we have to tease out factors that affect the fish population not related to these habitats and test and monitor biological and physical responses.”