Largely supported by the Interagency Ecological Program (IEP),
California Department of Water Resources (DWR) has operated a
fisheries monitoring program in the Yolo Bypass, a seasonal floodplain
and tidal slough, since 1998. The objectives of the Yolo Bypass Fish
Monitoring Program (YBFMP) are to: (1) collect baseline data on lower
trophic levels (phytoplankton, zooplankton, and aquatic insects),
juvenile fish and adult fish, hydrology, and water quality parameters;
2) investigation of the temporal and seasonal patterns in
chlorophyll-a concentrations, including whether high concentrations
are exported from the Bypass during agricultural and natural flow
events and the possibility of manipulating bypass flows to benefit
listed species like Delta Smelt (Hypomesus
transpacificus) and Chinook salmon (Oncorhynchus
tshawytscha). The YBFMP operates a rotary screw trap and
fyke trap, and conducts biweekly beach seine and lower trophic surveys
in addition to maintaining water quality instrumentation in the
bypass. The YBFMP serves to fill information gaps regarding
environmental conditions in the bypass that trigger migrations and
enhanced survival and growth of native fishes, as well as provide data
for IEP synthesis efforts. YBFMP staff also conduct analyses of our
monitoring data to address pertinent management related questions as
identified by IEP. The Yolo Bypass has been identified as a high
restoration priority by the National Marine Fisheries Service and US
Fish and Wildlife Service Biological Opinions for Delta Smelt, Winter
and Spring-run Chinook salmon and by California EcoRestore. The YBFMP
informs the restoration actions that are mandated or recommended in
these plans, and provides critical baseline data on the ecology of the
bypass and how it interacts with the broader San Francisco Estuary.
Only juvenile and adult fish catch with associated water quality are
presented in this dataset.
