2006 BES Annual Meeting Presentation and Poster Abstracts
Toxicity of zinc and tire amended aged soils to Rana sylvatica
Co-Authors: Camponelli K.M., Snodgrass J.W., Landa, E.R. and Casey R.E.
Abstract: Tire wear is a major contributor of particulates and zinc to stormwater runoff in urban ecosystems. Runoff from highways and parking lots is diverted into stormwater retention ponds where particulates and zinc can accumulate in pond sediments over time. These retention ponds are potential habitats for a variety of organisms and there is concern that tire-derived zinc could adversely impact pond inhabitants. We conducted a bioassay using Rana sylvatica (wood frog) and four sediment treatments. Treatments consisted of clean sand and three sediment treatments: unamended sediment; sediment amended with ZnCl2; sediment amended with ground tire material. Tire material was amended such that the tire Zn contribution was similar to levels observed in retention ponds. ZnCl2 was amended to match the total Zn level of the tire amendment. Wood frog eggs were placed into each treatment and allowed to hatch and metamorphose. Time to rear leg completion, front leg completion, and complete metamorphosis was recorded for each organism. There was no significant mortality in any treatment. Both the ZnCl2 and tire treatments took longer to complete each developmental stage than organisms in the clean sediment, indicating a decrease in development rate. The sand treatment also took longer to complete all three stages compared to the unamended sediment, possibly due to lack of micronutrients in the sand matrix. These results suggest that realistic levels of Zn and tire material in retention ponds may adversely impact larval amphibian development.