Ecotoxicological tests used as warning system for Danube Delta quality assessment

Abstract

The Danube Delta water and sediment toxicity effects have been assessed using a biotests battery based on representative species of primary producers (Selenastrum capricornutum, Sorghum saccharatum, Lepidium sativum, Sinapis alba) and consumers (rotifers – Brachionus calyciflrus, crustaceeans – Daphnia magna, Heterocypris incongruens). The ecotoxicological tests results revealed no acute to minimum toxic effect classified as Class I and II of hazard for water samples and Class II and III, in case of sediment samples. In order to control water and sediment-quality, these results indicated the need to integrate within a water and sediment-quality triad different tests such as toxicity tests, chemical analyses as well as field data from water phytoplankton, soft-sediment meio- and macro-invertebrates. Overall, the ecotoxicological results were modulated by organisms sensitivity, sampling locations, season and climate change issues.