PARENT SESSION
PS6 - Contaminant Effects on Amphibians & Reptiles
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P092) Standardization of an Amphibian Toxicity Testing Methodology: Our Progress and Priorities for Test Method Development.
Edginton, Andrea*,1, Scroggins, Rick2, 1 University of Guelph, Guelph, Ontario, Canada2 Method Development & Applications Section, Environment Canada, Ottawa, Ontario, Canada
ABSTRACT- Amphibian toxicity testing is not currently required by governmental regulating agencies for new chemical registration or effluent testing in Canada. One reason is due to a lack of standardized testing methods. Environment Canada is embarking on a multi-year project to develop a standardized method for culturing and testing using a native Canadian amphibian species. The first phase of the method standardization process was to review current culturing and toxicity testing procedures, examine existing standardized methodologies and to recommend further focused research that must be undertaken before a method is ready for the peer review process and inter-laboratory validation testing. This review document, completed in October 2001, helped direct the discussion at an amphibian toxicity testing workshop. This January 2002 workshop was attended by 40 individuals including experts from government, industry and academia. Three working groups were formed at the workshop to provide a focused forum in which to discuss the key elements of a standard method, more specifically, amphibian culturing, toxicity testing procedure and relevant endpoint measurement. Consensus was reached on the scope of the standard method and recommendations for future research were identified. First, a decision was made that the northern leopard frog, Rana pipiens, be the species around which the methodology should be standardized. Second, it was recognized that current published testing procedures on amphibian early life stage toxicity testing do not fulfill the needs of a Canadian method, either due to the non-specificity of procedures or because test species used are not relevant to the Canadian environment (i.e., Xenopus). Third, it was recommended that the standard method include two test options: 1) an embryo exposure; and 2) a short-term chronic exposure encompassing embryonic to late larval stages. Further discussions revolved around procedure type (flow-through vs. renewal), water quality requirements, statistical issues, validity criteria and the importance of the development of a laboratory induced breeding protocol for R. pipiens. Environment Canada is planning a research program to generate the data needed to support methodology decisions for this standard.
Key words: standardization, amphibians