MP13 Aquatic Ecotoxicology
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(CAS-1117-816121) Toxicity of stormwater pond sediments for embryo and larval amphibians.

Snodgrass, J¹, Joseph, D¹, Casey, R¹, ¹ Towson University, Towson, MD, USA

ABSTRACT- Stormwater management ponds are common features of newer development projects. Because stormwater ponds may attract pond-breeding amphibians and the sediments of ponds often contain a complex mixture of pollutants, these ponds may represent ecological traps for amphibians. To assess the toxicity of stormwater pond sediments to early developmental stages of amphibians potentially utilizing stormwater ponds as breeding sites we exposed eggs and larvae to pond sediments and clean sand controls in laboratory microcosms. Developing wood frog eggs (Rana sylvatica) exposed to pond sediments experienced reduced hatching success in comparison to controls and no larvae exposed to pond sediments survived to metamorphosis. In contrast, hatching success of American toad eggs (Bufo americanus) exposed to pond sediments was high and similar to eggs exposed to clean sand. Furthermore, while metamorphs showed sublethal effects of exposure to pond sediments, metamorphic success was similar between larvae exposed to pond sediments and those exposed to clean sand. Analyses of trace metal levels and water chemistry in the microcosms suggested contamination of sediments from road salting was responsible for the lethal effects observed among developing wood frogs embryos and larvae. Overall, our results suggest contamination of stormwater ponds with road salt is a factor in reducing the wildlife habitat quality of ponds and the role of ponds as ecological traps for pond-breeding amphibians warrants further investigation.

Key words: stormwater management, amphibians, sediments, road salt