DOI: 10.6073/pasta/eb7be8561889821e02cd5afbde0d17ee
title: Monitoring juvenile Chinook salmon outmigration using rotary screw traps on the Sacramento River at Knights Landing

description: Since 1995, the rotary screw traps (RSTs) at Knights Landing have
 provided water management agencies an early warning of emigrating
 juvenile Chinook salmon (Oncorhynchus tshawytscha) and steelhead
 trout (O. mykiss) making their way to the Sacramento-San Joaquin
 Delta (Delta). Due to the proximity of the site to other major
 tributaries of the Sacramento River, such as the Feather and
 American Rivers, it is assumed that salmonids captured at the
 Knights Landing RSTs originate from the upper Sacramento River and
 its tributaries, a stretch of river that provides spawning and
 rearing habitat for all four runs of natural origin Chinook salmon:
 winter-run (State and federally listed as endangered), spring-run
 (State and federally listed as threatened), late fall-run and
 fall-run, as well as steelhead trout (federally listed as
 threatened).  
 
 
 The near real-time information RST monitoring data provides on
 emigration timing and relative abundance for protected runs of
 juvenile Chinook salmon and steelhead improves the ability for
 resource agencies and water managers to implement protective
 measures that help them navigate through the maze of waterways in
 the Delta. By utilizing emigration data in adaptive management,
 reservoir releases, export rates, water transfers, and Delta Cross
 Channel Gate operations can be modified to minimize the risk of
 predation, entrainment, and take, thereby maximizing juvenile
 salmonid survival through the Delta.   
 
 
 The primary goals of the Knights Landing Monitoring Program are to
 (1) Provide early warning of listed salmonids emigrating toward the
 Delta, (2) Document passage of emigrating salmonids including
 timing, relative abundance, and environmental conditions, (3)
 Develop passage estimates of salmonids emigrating through the lower
 Sacramento River above the Delta, and (4) Develop a long-term
 dataset on juvenile salmonid emigration to compare changes over
 time.
 
 
 The California Department of Fish and Wildlife (CDFW) issued ITP
 2081-2019-066-00 to DWR on March 31, 2020, for the long-term
 operation of the State Water Project (SWP) in the Delta. Condition
 7.5.2 of the ITP requires the development and establishment of a
 spring-run Chinook salmon juvenile production estimate (JPE) to
 increase understanding of the impacts water operations have on the
 spring-run Chinook salmon population in the Sacramento River
 watershed and inform the development of minimization measures to
 reduce take of spring-run Chinook salmon at Delta fish salvage
 facilities. Data from the Knights Landing RST will be used along
 with other datasets from juvenile salmonid monitoring programs in
 the Sacramento River Watershed to inform the development of JPE
 modeling approaches.
 
 
 Salmonid data collected from the Knights Landing RST, among other
 datasets, is also used by the Salmon Monitoring Team (SaMT) to
 understand the movement of juvenile salmon in the Sacramento River
 Watershed to estimate the number of winter-run and spring-run
 Chinook salmon that have entered the Delta. SaMT is a real-time
 operations monitoring team required by Condition of Approval 8.1.2
 of the ITP which meets weekly from October through June, to provide
 advice for real-time management of SWP operations to DWR, CDFW, and
 the Water Operation Management Team (WOMT) to minimize take of
 winter-run and spring-run Chinook salmon in the Delta.
 
 
 Note: data within the current year’s monitoring season are
 considered provisional.