GSSA was excited to see and participate in the March 23 release of 428,184 Coleman Hatchery brood year 2023 fall-run Chinook salmon into the Sacramento River at Butte City. This builds upon the excellent data recently obtained from a joint GSSA-USFWS pilot project started in 2019, which was also supported by the Nor-Cal Guides & Sportsmens Association who provided boats and captains.
Results:
- 15x more fish returned to Battle Creek when trucked and released at Butte City Bridge
- 6x more of the trucked fish were caught in the ocean when trucked and released at Butte City Bridge
- 2x as many fish released at Butte City Bridge during the critically dry spring of 2022 returned to Battle Creek as jacks this year
Our three-year pilot study with USFWS saw about 200,000 Coleman Hatchery fish, 100 percent clipped and tagged, released at several downstream sites starting in the spring of 2019. The study’s trucked fish release locations were strategically selected to ensure 1) enough upstream distance to prevent trucked fish from imprinting on Sacramento mainstem water tainted by large tributaries such as the Feather or American Rivers; and 2) sites were far enough downstream to significantly reduce predation.
To date, 195 Coded Wire Tags (CWT) have been recovered in Battle Creek from Brood Year (BY) 2020 two- and three-year-old fish that were released at Butte City Bridge during the critically dry spring in 2021. That is an incredible 15 times more than the 13 fish that returned from the control group released at the hatchery.
Of those total 195 BY 2020 trucked fish that returned, 11 returned as jacks in 2022, compared to zero jack returns from fish released at the hatchery. BY 2020 data also shows that six times more of the trucked fish were caught in the ocean than those from the control group.
Battle Creek saw a return of twice as many BY 2021 trucked jacks released during the critically dry spring of 2022 this year compared to the control group released at the same time from the hatchery.
This study provides strong evidence that trucking Coleman fish to Butte City Bridge is not only important to survival during drought years, but with 15 times more fish returning, they are also helping provide critical broodstock to avoid the problematic shortages at the hatchery like that in 2023. They could also be key to recolonizing the upper river.
Thanks to everyone involved: U.S. Fish and Wildlife Service, Golden State Salmon Association, the Nor-Cal Guides & Sportsmens Association, UC Davis, and the Bureau of Reclamation who came together on this experiment.