Effects of Urban Stormwater Runoff on Fathead Minnows: Mitigating Potential of Best Management Practices

Aquatic ecosystems located near urban landscapes are often contaminated by a complex mixture of contaminants of emerging concern (CECs). These landscapes are defined by an abundance of impervious surfaces that act as conduits during precipitation events moving contaminants into aquatic ecosystems. Prior research on the introduction of CECs into surface waters frequently focused on municipal wastewater treatment plants and agricultural runoff. This study investigates the effects of urban stormwater runoff on fathead minnows. In addition, I examined the mitigating potential of retention ponds and iron-enhanced sand filtration (IESF) as best management practices. I collected inflow and outflow water samples following precipitation events during snow melt, spring flush, and summer rains from seven stormwater ponds across the greater metropolitan area of St. Paul, MN, USA. CECs were commonly detected in stormwater runoff with greater concentrations in inflows when compared to pond outflows. In some instances, CEC concentrations rivaled those reported for treated wastewater effluent. Endpoints measured include survival, growth, foraging efficiency, and predator avoidance performance. Results indicated that seasonality had a significant effect on all biological outcomes (