Sampling was not conducted from July 2000 through March 2002, while
funds were being secured through the California
Bay-Delta Authority (formerly CALFED). Sampling at RBDD resumed in
April of 2002 and has been continuous to the present day. The Dam, located
at river kilometer 391 on the Sacramento River about four kilometers
southeast of the city of Red Bluff, CA, has proven to be an ideal site
for juvenile Chinook monitoring. Moreover, the site is superlative for
the monitoring of state and federally listed Endangered winter Chinook
salmon for two reasons. First, the winter Chinook spawning grounds lie
almost exclusively above RBDD (Vogel and Marine 1991) and up to four,
eight-foot diameter traps can be attached to the dam and sampled simultaneously
within a transect across the river. The physical structure and operations
of RBDD control the channel morphology and the hydrological characteristics
of the area providing for consistent sampling conditions for evaluating
trends in juvenile abundance within and between years, and for developing
a time invariant trap efficiency model. The model and quantitative methodologies
were developed to estimate numbers of outmigrants passing RBDD while
decreasing the program’s reliance on and need for experimental
fish, thereby minimizing impacts on Threatened and Endangered species.
These methodologies have been independently reviewed by biological statisticians.
The primary objectives of this project at present are to (1) obtain
juvenile winter Chinook production indices, (2) to correlate these indices
with estimated escapement from adult counts at RBDD and the winter Chinook
carcass survey, and (3) define seasonal and temporal patterns of abundance
of winter Chinook passing RBDD. Additionally, the juvenile monitoring
program currently provides “real-time” sample data to the Interagency
Ecological Program and summarized daily passage estimates (of all
four “runs” of Chinook and steelhead trout) to the Bay-Delta
and Tributaries website. Passage data is provided to agency personnel,
stakeholders and water managers at the Central Valley Project's Tracy
Pumping Plant and the State Water Project's Harvey Banks Delta Pumping
Plant diversions on a real-time basis such that winter Chinook juvenile
entrainment at these facilities may be limited. Further funding is being
sought to establish RBDD as a permanent winter Chinook monitoring location.
Final reports of information derived from Juvenile Salmonid Monitoring at RBDD
Abundance and Seasonal,
Spatial and Diel Distribution Patterns of Juvenile Salmonids Passing the Red Bluff Diversion Dam, Sacramento River (6 MB)
Estimating the Abundance of Sacramento River Juvenile Winter Chinook Salmon with Comparisons to Adult Escapement (3.5 MB)
Brood-Year 2002 Winter Chinook Juvenile Production Indices with Comparisons to Adult Escapement (350 KB)
Brood-Year 2003 Winter Chinook Juvenile Production Indices with Comparisons to Adult Escapement (500 KB)
Brood-Year 2004 Winter Chinook Juvenile Production Indices with Comparisons to Juvenile Production Estimates Derived from Adult Escapement (740 KB)
