CSA Ocean Sciences Inc. was contracted by EcoAnalysts, Inc. to identify fish eggs and larvae from the Sacramento San Joaquin Delta in support of a California Department of Water Resources (DWR) study to identify meroplankton, holoplankton, and drift invertebrates. The DWR Aquatic Ecology Section collects zooplankton, drift invertebrate, and fish eggs and larval samples to verify planktonic assemblages in two aquatic habitats to better determine habitat quality and productivity.

Two sites were sampled every other week: the Sacramento River at Sherwood Harbor and the Yolo Bypass screw trap site. The Yolo Bypass is a major seasonal flood plain in the Central Valley and the Delta provides rearing habitat and serves as a migratory pathway for juvenile Chinook salmon and Splittail. This program was designed to investigate habitat evaluation criteria in the Yolo Bypass under a range of flow conditions and in years when spatial and temporal trends in juvenile Chinook salmon use were monitored.