Application of Ceriodaphnia dubia for whole effluent toxicity tests in the hawkesbury–nepean watershed, New South Wales, Australia: Method development and validation

Use of Ceriodaphnia dubia for whole effluent toxicity testing programs is widespread in North America. However, the methods used for this species in the United States and Canada have not been validated in Australia for use in local waters with the local variant of the species. Consequently, we compared the effects of container size and volume, diet, and dilution water on the survival and reproduction of the local variant of C. dubia (the Sydney clone). We also evaluated the results of control performance and reference toxicant tests with potassium chloride and diazinon obtained over the course of a whole effluent toxicity testing program conducted on effluents discharged from sewage treatment plants into the Hawkesbury–Nepean drainage basin. Our data indicate that the general guidelines published by the U.S. Environmental Protection Agency for conducting acute and chronic toxicity tests with C. dubia can be successfully applied to the Sydney clone with minor modifications and that both acute and chronic tests can be conducted with a high degree of success, provided that appropriate procedures are followed. Moreover, tests with a variety of chemicals indicated that the Sydney clone responded comparably to its North American counterparts, suggesting that existing databases for C. dubia can be applied to the Sydney clone. In addition, the use of test volumes between 20 and 200 ml did not affect the acute toxicity of the organophosphorous pesticide diazinon to this strain.