Influence of Bird Activity and Urban Runoff on Nutrient Dynamics in Coastal Wetlands

Restored wetlands, often intended to reestablish habitats and ecosystem functions, receive nutrients from both bird feces (guano) and urban runoff. We examined spatial variation in nutrient concentrations in the UCSB Lagoon and Devereux Slough (Santa Barbara, CA). Water samples were collected from sites differing in bird activity and proximity to a storm drain and analyzed for nitrogen, phosphorus, and chlorophyll-a concentrations. Bird communities were grouped by feeding guild (piscivorous, herbivorous, invertebrate-feeding) to assess links between diet and nutrient inputs. Because piscivores tend to contribute more phosphorus and herbivores more nitrogen, we expect nutrient patterns to vary with bird composition and habitat. Preliminary results show spatial variability in nutrients, with higher concentrations and productivity near areas of high bird density and storm drain input, suggesting both biological and urban sources influence wetland nutrient dynamics.