PT06 Organic, Metallic, Organometallic Pollutants
Exhibit Hall
8:00 AM - Tuesday
(PT081) Land-use effects on amphibian use of stormwater retention ponds and anuran larvae metal concentrations.
Simon, J.1, Snodgrass, J.1, Casey, R.1, 1 Towson University, Towson, MD, USA
ABSTRACT- Stormwater retention ponds, designed to mitigate the effects of runoff from impervious surfaces, may provide amphibian habitat, especially given marked global declines in natural wetlands. However, because retention ponds sequester a wide range of pollutants such as heavy metals and are located in human-dominated areas, scientists have expressed concern over the use of these ponds by wildlife. We investigated the effects of adjacent land-use on amphibian species richness and metal (Cr, Ni, Cu, Zn, As, Cd and Pb) concentrations in anuran larvae (guts and bodies separated), sediments and water from seventeen retention ponds in Anne Arundel, Howard and Prince Georges Counties, Maryland. Each site was categorized based on surrounding land-use (residential, commercial, or highway). Three constructed wetlands, with less than one percent impervious surface cover in their watersheds, were classified as open space ponds and were used as reference sites. We determined species richness using calling and larval surveys. Metal concentrations were determined using inductively coupled plasma mass spectrometry (ICPMS). Mean species richness was lowest at highway ponds (3.8 ± 2.3; ± 1 SD), and greatest at open space ponds (9.7 ± 1.5; ± 1 SD). Residential and commercial ponds showed intermediate levels of species richness. Metal analyses suggest differences in metal concentrations in tadpoles and sediments based on land use categorization. Gut and body concentrations for Ni, Cd and Cr were greatest in tadpoles from commercial sites, while tadpoles from residential sites exhibited the highest gut and body As concentrations. These results indicate that breeding habitat suitability and use of retention ponds is related to surrounding land use, and that planners may enhance the wetland function of retention ponds by considering their placement in the landscape.
Key words: heavy metals, amphibians, land-use, retention ponds