Date and location: July 28, 2025, 1:00 pm, Duffy Science Centre 204 

Title: "Agrochemical Inputs in Estuaries:  Pesticide and Oxygen Influences on Mobile Invertebrate Assemblages within Salinity Gradients with a Focus on Gammarus Species (Amphipoda: Gammaridae) Responses"

Estuaries are ecosystems with spatially variable stressors with multiple anthropogenic impacts. In agricultural landscapes, nutrient and pesticide inputs potentially influence estuarine invertebrate assemblages. This dissertation examines how estuarine gradients, particularly salinity and eutrophication, structure the abundances of mobile invertebrates. Spatial patterns of four estuarine amphipod species are shown through comparisons of multiple collection methods. Insecticide toxicity experiments examine salinity-dependent toxicity of chlorpyrifos and imidacloprid in Gammarus lawrencianus. Field collections uncover unexpected insect species in high-salinity zones. Finally, more than agricultural or natural stressors examined, local hypoxia emerges as the immediate driver of invertebrate abundances. These findings emphasize the dynamic facets of natural gradients and agrochemical inputs that shape estuarine communities.

Everyone is welcome.