Poster: Temporal Trends of Trace Element Levels in Macroinvertebrates from Stormwater Retention Ponds
 
Stephanie N. Atueyi, Judith A. Simon, Joel W. Snodgrass, Ryan E. Casey

 
Stormwater retention ponds are placed in urban areas to collect runoff, especially from impervious surfaces. These ponds have been shown to collect many pollutants including trace elements which may be ingested by aquatic invertebrates as they feed. A study conducted in 1993 by Karouna-Renier and Sparling (2001) measured the quantity of zinc, copper and lead in invertebrates, water and sediments of stormwater retention ponds. Our goal was to determine if any temporal changes occurred in invertebrate trace element concentrations between 1993 and 2003, possibly from changes in fluxes from adjacent land use. Invertebrate samples were collected from the same ponds studied by Karouna-Renier and Sparling (2001) and were grouped by their land use such as commercial, highway, residential, and open space. Samples were analyzed for trace element content (zinc, copper, aluminum, lead, chromium, nickel, arsenic, and cadmium) by inductive coupled plasma mass spectrometry (ICPMS). Trace element concentrations in invertebrates were generally similar to levels measured in 1993, indicating that continual influx of urban runoff is not necessarily resulting in increased contamination of biota in ponds. Levels of Cr, As, Cd, and Pb were generally similar between invertebrate types, whereas Ni levels were generally higher in molluscs than odonates and composite invertebrates. Zn levels were higher relative to other elements and had higher variability. Molluscs and composites had low trace element concentrations in open space ponds and were higher in other land uses; in contrast, trace element concentrations in odonates were similar in all land uses. These data may be useful in assessing risk to predators ingesting prey from stormwater retention ponds.