You are here:
Evaluation and Standardization of a Short Term Chronic Method using Daphnia magna
Citation:
Lazorchak, Jim, A. Kascak, W. Thoeny, A. Johnson, L. Glimsdal, Dave Mount, R. Hockett, C. Flinders, AND M. Griffith. Evaluation and Standardization of a Short Term Chronic Method using Daphnia magna. SETAC Europe 32nd Annual Meeting, Copenhagen, DENMARK, May 15 - 19, 2022.
Impact/Purpose:
This presentation will provide a status of the development of a new Whole Effluent Toxicity using Daphnia magna short term growth as an endpoint.
Description:
In 2009, US EPA’s Office of Research and Development (ORD) published a paper wherein a 4-d static-renewal survival and growth test was developed for use with Daphnia magna. The test results were compared to performance criteria and results from 7-d survival and reproduction tests with Ceriodaphnia dubia, to compare the level of sensitivity between the two methods. Results from tests using the 4-d D. magna survival and growth method indicated that this method produced consistent results with CVs < 20% with various reference toxicant materials and provided data that were both reproducible and useful for detecting potential toxicity in aquatic environments. Since that publication, there has been an increased interest in using the D. magna method in Whole Effluent Toxicity (WET) tests associated with NPDES permits where source water chemistry, i.e. conductivity, may be more appropriate for D. magna. In 2020, ORD began re-evaluating the method in a bi-laboratory approach at US EPA laboratories in Cincinnati, OH and Duluth, MN as well as a collaboration with National Council for Air and Stream Improvement (NCASI). During the early testing phase, it was decided to look at influence of different foods and amounts on growth, in addition to revising the test performance criteria from the final control weight being 10 times higher than the initial weight, to one that is based on a minimum final weight criterion. Various food combinations: alfalfa and algae; yeast, cerophyl, trout chow (YCT) plus algae; and flaked food, alfalfa, yeast (FFAY) plus algae were tested in different concentrations to see which gave a consistent final weight. Once the final food and amount was chosen, tests were conducted with three reference toxicants, NH4Cl, ZnSO4 and diazinon, using newly released young < 8 hr old with six replicates per treatment. This presentation will highlight the latest progress of the different food and rationing as well as reference toxicant testing.
