Flow Augmentations Modify an Estuarine Prey Field

Zooplankton density and community composition in estuaries can be affected by variation freshwater inputs, with important implications for higher trophic levels. In the San Francisco Estuary, management agencies have initiated autumn flow augmentations form of changes to reservoir releases or exported water from South Delta increase improve available habitat endangered Smelt, Hypomesus transpacificus, during season when their body condition most influences fecundity. Autumn augmentation only occurs years precipitation, effectively moving Low-Salinity Zone (LSZ) downstream key foraging habitats Smelt Suisun Bay Marsh. To assess whether augmented enhanced prey resources we compared zooplankton abundance, biomass, spatial distribution, was (2017, 2019) reference not (2018, 2020). years, detected total abundance altered Increased these regions associated Pseudodiaptomus forbesi, a preferred while species salinities—Acartiella sinensis Tortanus dextrilobatus—were less abundant. Thus, influence availability underscoring complex responses estuarine communities response salinity regimes. This study is management- relevant because it shows that items X2 lower. Whether results remains seen.