Home
Field Notes
 
U.S. Fish & Wildlife Service
Field Notes Entry   
LODI FWO: Fall-run Chinook Salmon Redd and Carcass Survey in the San Joaquin River, Fall 2016
California-Nevada Offices , November 1, 2016
Print Friendly Version
Fall-run Chinook Salmon redd discovered in the San Joaquin River downstream of Friant Dam in Fall 2016.
Fall-run Chinook Salmon redd discovered in the San Joaquin River downstream of Friant Dam in Fall 2016. - Photo Credit: USFWS
Fall-run Chinook Salmon carcass retrieved from the San Joaquin River downstream of Friant Dam in Fall 2016.
Fall-run Chinook Salmon carcass retrieved from the San Joaquin River downstream of Friant Dam in Fall 2016. - Photo Credit: USFWS

Historically, the San Joaquin River was home to large runs of southernmost populations of Chinook Salmon Oncorhynchus tshawytscha. However, due to habitat degradation following the construction of dams and water diversions the wild salmon populations have been extirpated from the confluence with the Merced River to Friant Dam (Restoration Area). The Restoration Area is separated into 5 reaches approximately 240 river kilometers (rkm) long beginning at Friant dam and ending at the confluence of the Merced River. To date, the river is dry in certain areas and salmon are unable to migrate to suitable spawning grounds.

 

Presently, the San Joaquin River Restoration Program (SJRRP) is working towards restoring the river, and maintaining naturally-reproducing and self-sustaining populations of Chinook salmon. The current quantity and quality of suitable salmon spawning habitat in the upper reaches of the San Joaquin River remains unclear. To address this concern the Fish and Wildlife (USFWS) and the California Department of Fish and Wildlife (CDFW) conducted fall-run Chinook salmon redd and carcass surveys from November 1st 2016 to January 4th 2017. Fall-run Chinook salmon were transported from Hills Ferry (below the confluence of the Merced River) to Reach 1 of the Restoration Area below Friant Dam. The USFWS and CDFW surveyed approximately 37 rkm of Reach 1 beginning at Friant Dam extending downstream to Donny Bridge. The spawning success of 176 female and 422 male adult fall-run Chinook salmon was assessed. A total of 85 (39 females and 46 males) salmon carcasses were found and 128 redds were observed in Reach 1 of the Restoration Area during redd and carcass surveys. The estimated spawning success of females to the Restoration Area was 73%, which is below the SJRRP target of 85%. However, the SJRRP target was established for spawning success under restored conditions. Therefore, further research is needed to assess ideal habitat conditions and requirements for successful spawning of Chinook salmon in the Restoration Area of the San Joaquin River. These surveys will continue to be conducted annually to evaluate trends and gather information during various water year types to inform management decision concerning Chinook salmon reintroduction activities, habitat suitability, and habitat restoration (i.e. gravel augmentation) activities in the Restoration Area of the San Joaquin River.

The SJRRP is a collaborative effort between the Department of the Interior [U.S. Fish and Wildlife Service (USFWS) and Bureau of Reclamation (USBR)], National Marine Fisheries Service (NMFS), California Department of Fish and Wildlife (CDFW), and California Department of Water Resources (CDWR).


Contact Info: Christina Perez, 209-334-2968 ex. 404, christina_perez@fws.gov
Find a Field Notes Entry

Search by keyword

Search by State




Search by Region


US Fish and Wildlife Service footer