Effect of increasing salinity on the acute toxicity of a commercial endosulfan formulation to the bdelloid rotifer Philodina acuticornis odiosa

Abstract

Pesticides, such as endosulfan, can enter surface waters such as lakes and rivers, potentially posing an ecological risk. Rotifers are a dominant zooplankton species in many inland freshwater lakes in Australia; such lakes can also experience increased salinities. Acute toxicity tests (24 h) were conducted to determine the toxicity of a commercial formaulation of endosulfan to the freshwater rotifer Philodina sp. and to investigate the influence of increasing salinity on endosulfan toxicity. Rotifers were found to be relatively tolerant to endosulfan with an EC50 of 1.75 mg L⁻¹ (a.i.), with results also suggesting that there are no interactive effects of salinity on endosulfan toxicity.

Keywords:

• endosulfan
• toxicity
• rotifer
• salinity

Acknowledgments

The research was, in part, supported by Department of Primary Industries Agriculture Development Division (DPI Project # 06889). We thank Iain Ellis (Murray-Darling Freshwater Research Centre) for providing data on zooplankton communities in Lake Hawthorn and Cardross Lakes.