PARENT SESSION
PS6 - Contaminant Effects on Amphibians & Reptiles
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P077) Toxicity of Copper to the Northern Leopard Frog and American Toad in Water- and Sediment-Exposures.
DuFresne, Doree*,1, Pillard, David1, Naddy, Rami1, Bleiler, John2, Barclift, David3, Speicher, Jason3, Fowler, Amy4, 1 ENSR International, Ft. Collins, CO, USA2 ENSR International, Westford, MA, USA3 U.S. Navy EFANE, Lester, PA, USA4 U.S. Navy NFESC, Port Hueneme, CA, USA
ABSTRACT- Amphibians are often exposed to a variety of contaminants when wetland habitats receive runoff from point (e.g., industrial activities) and non-point (e.g., roads or agricultural activities) sources. As part of a project to develop a sediment toxicity test procedure for amphibians, tadpoles of Rana pipiens (Northern Leopard Frog) and Bufo americanus (American Toad) were exposed to copper, as CuCl2, in both water-only exposures and spiked sediments. Tests were conducted for various lengths of time using organisms of different ages. Younger tadpoles were found to be more sensitive to copper than older organisms. The survival NOEC of 1-day old R. pipiens, for example, was 38.81 mg/L while the survival NOEC for 26-day old R. pipiens was 167.8 mg/L. It was also found that Bufo was more sensitive to copper than Rana. Copper toxicity to amphibians was strongly correlated with the dissolved organic carbon concentration in the water column. In sediments with little or no TOC, acute toxicity occurred at much lower copper concentrations. These data indicate that toxicity of sediment-bound constituents to amphibians is highly correlated with sediment characteristics.
Key words: amphibians, copper, sediment toxicity, total organic carbon