Agricultural pesticides and runoff-associated contaminants can enter aquatic ecosystems, potentially exposing fish during sensitive stages of their life cycle. Our research investigates how these contaminants affect aquatic organisms, from development and physiology to behavior and survival, with particular emphasis on species of conservation concern. Using controlled laboratory exposures, we examine biological responses to contaminants and how environmental conditions, such as salinity, can influence their toxicity. By linking contaminant exposure to biological effects, we aim to provide scientific evidence to support aquatic ecosystem protection and management.
Selected Research Findings
Delta Smelt — Pyrethroid Toxicity and Salinity: We demonstrated that low concentrations of bifenthrin and permethrin can alter larval behavior, with salinity influencing the magnitude and nature of these responses (Segarra et al., 2021).
Longfin Smelt — Developmental and Behavioral Effects: We found that bifenthrin exposure during early development can alter larval behavior and produce smaller hatchlings with reduced yolk sac volumes, highlighting potential consequences for this threatened species (Mauduit et al., 2023).
When it Rains, it Pours – Stormwater Contaminants
During California’s wet season, rainfall can transport pesticides and other contaminants from agricultural and urban landscapes into aquatic ecosystems. These runoff events can overlap with sensitive early life stages of fish species of conservation concern, raising questions about their potential biological effects. We investigate how stormwater exposure affects Delta Smelt by exposing fish to water collected before, during, and after rainfall events. Using DanioVision and EthoVision tracking software, we assess behavioral responses in Delta Smelt larvae under controlled laboratory conditions.
