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(W/EH047) Use of the USEPA method for estimating the chronic toxicity of receiving waters to evaluate the environmental quality of sensible waters in the Southwest of Spain. Carmen, Garrido1, Enrique, Nebot1, Diego, Sales1, 1 ABSTRACT- Seawater quality is currently assessed using a range of chemicals to determine the extent of contamination or the degree of environmental quality. Analysing a complex mixture of chemicals is both time consuming and expensive, whereas the use of an ecotoxicity test provides information both on the potential effect of the contamination on any surface water body. With the purpose of deriving an adequate ecotoxicity test, methodology from USEPA with marine microalgaes was applied and adapted in this study. Two of the most important variables in the test were the nutrient solution and the exposure time, so the bioassays were conducted with and without a supplementary stock of nutrients and growth evaluation at classic 72-h response (short-term toxicity) and unusual 10-d response (long-term toxicity). The test organisms were resident species in the study areas: Thalassiossiria pseudonana, Nannochloropsis gaditana, Tetraselmis suecica and Isochrysis galbana. Key words: bioassay, water quality, ecotoxicity, microalgae |
