Monitoring juvenile Chinook salmon outmigration using rotary screw traps on Feather River

California Department of Water Resources (DWR) currently operates multiple eight-foot rotary screw traps (RSTs) in both the Low Flow Channel (LFC) and High Flow Channel (HFC) of the upper 21.5 river miles of the Lower Feather River. The LFC extends from the Fish Barrier Dam at river mile (RM) 67.2 to the Thermalito Outlet (RM 59). The HFC extends from the Thermalito Outlet to the confluence with the Sacramento River. This survey has been ongoing since 1997 with the objective of documenting general salmonid emigration attributes, such as timing, abundance and composition of salmon and investigating the influence of environmental factors thought to initiate emigration, such as flow, turbidity and water temperature. Data from this monitoring will also be used to inform the development of a juvenile production estimate (JPE) for spring-run Chinook salmon in the Sacramento River Watershed as required by Incidental Take Permit No. 2081-2019-006-00 issued by CA Department of Fish and Wildlife (CDFW) to DWR for the long-term operation of the State Water Project.

加州水资源部（California Department of Water Resources, DWR）目前在下费瑟河上游21.5英里河段的低流量河道（Low Flow Channel, LFC）与高流量河道（High Flow Channel, HFC）内，部署并运营多台8英尺旋转螺旋式诱捕器（rotary screw traps, RSTs）。低流量河道的范围为河英里（river mile, RM）67.2处的鱼障坝至特马里托出水口（RM 59）；高流量河道则从特马里托出水口延伸至与萨克拉门托河的汇流处。本监测调查自1997年起持续开展，旨在记录鲑科鱼类降海洄游的一般性特征，包括洄游时间、种群丰度与组成，并探究被认为会触发洄游的环境因子（如流量、浊度与水温）的影响。本次监测获取的数据还将用于支撑萨克拉门托河流域春季洄游奇努克鲑幼鱼产量估算（juvenile production estimate, JPE）模型的开发，该工作需符合加州鱼类与野生动物部（California Department of Fish and Wildlife, CDFW）向DWR颁发的第2081-2019-006-00号附带捕捞许可的要求，以支撑州水利工程的长期运营。