How will released salmon survive in a habitat where they have not run in nearly 100 years? The Klamath River is 257 miles long, winding its way from Southern Oregon, through northern California to the Pacific Ocean. Numerous dams within the mainstem of the Klamath River have blocked fish passage to the upper watershed, creating unfavorable water quality and habitat conditions, contributing to fish kills in the lower basin. Four large dams are slated for removal beginning in 2023, marking the largest dam removal project in US history.
Over the last century, the Klamath River watershed has experienced dramatic declines in the number of returning adult salmon. The four dams slated for removal have blocked access to robust salmon spawning and rearing habitat in the upper basin and have contributed to the near extirpation of Klamath River spring-run Chinook salmon (Oncorhynchus tshawytscha). Since spring-run haven’t inhabited the upper basin in almost a century, the research team is interested in their use of upper basin habitat, outmigration timing, and survival. To inform management post dam removal, a collaborative effort between Oregon Department of Fish & Wildlife (ODFW), NOAA, The Klamath Tribes, and UC Davis will release the first spring-run Chinook salmon in the upper basin in over 100 years.
There is uncertainty as to how this species will survive within the highly altered habitat of the upper basin. This project will use acoustic telemetry to estimate survival of fish released in spring-fed tributaries as they migrate through Upper Klamath Lake towards the ocean. These results will help target future conservation efforts in the basin by identifying areas of high mortality and offering valuable insight into how these fish will use the upper basin once the dams are removed.