Wednesday March 26, 2025
SF Gate —
UC Davis researchers have documented evidence of chinook salmon returning to the Northern California creek where they were born for the first time ever, describing it as “a rare example” of a developing population in a species facing widespread declines across the state.
A new study published in the journal Ecosphere last week revealed the discovery in Putah Creek, a restored 85-mile-long stream that winds its way through Lake, Napa, Solano and Yolo counties and runs through UC Davis campus. Chinook salmon have been observed there since 2014, but were all thought to be hatchery strays; the new research shows some salmon returning to Putah Creek to spawn were also born there, meaning other altered and dam-controlled waterways around the world could have the potential to help bolster and create salmon runs, according to a news release from the university.
When Andrew Rypel, director of the UC Davis center for watershed sciences and co-author of the paper, first began studying the creek back in 2017, he said he counted only a handful to a dozen fish in the system. The creek “barely flowed at all” after the concrete Monticello Dam — which created Lake Berryessa — was built in the 1950s, drastically reducing water that ran to Putah Creek. After a lawsuit in 2000, the Putah Creek Accord mandated year-round flows to protect wildlife and habitats there, with UC Davis experts, state agencies, nonprofits and members of the community working to monitor and rehabilitate the creek year-round.