Science activity

The overarching goal of this study is to investigate the time-varying effects of flow variation and food availability on longfin smelt population dynamics, via advanced modeling of a diverse set of environmental and ecological monitoring time series. Specifically, this project will:(1) Assess how key environmental drivers (flow, salinity, temperature) and zooplankton abundance have changed over the past 5 decades (1967 to present) across the San Francisco Estuary (SFE); (2) Examine how longfin smelt population dynamics have changed over that time period, and whether/when breakpoints in abundance and trends exist (e.g., periods of 'decline' vs' stability'); (3) Quantify the effects of environmental vs. food-related drivers--and potential interactions between them--on driving observed fluctuations in longfin smelt dynamics; (4) Determine whether/how environment-smelt relationships have changed in magnitude or sign over time; and if they changed, whether such changes have been spatially consistent across the SFE. These goals will inform ongoing conservation efforts of longfin smelt by determining the combinations of flow, habitat, and prey availability conditions that lead to stable population dynamics for the species.