Sediment–water interface and water toxicity tests with mysids (Crustacea, Mysidacea) to assess the quality of tropical estuaries.

Abstract

The current research aimed to evaluate the environmental quality of Poxim river estuary (Sergipe, Brazil) using the acute toxicity test with superficial water, and sediment-water interface (SWI) as an innovative approach with the microcrustacean Mysidopsis juniae. Superficial water and sediments were sampled in three sites along the extension the Poxim estuary, from the inner regions to the mouth of the estuary. The mysids were exposed to water and to the SWI system to test for acute toxicity (96 h). Water samples were less toxic to mysids than SWI samples, showing water acute toxicity only in inner part of estuary SWI showed toxicity to all samples only during the rainy month. The SWI and water toxicity tests with mysids were a valuable assay for the identification of toxicity from substances that can be remobilized from sediment to water column and therefore an important tool for assessing contamination in tropical estuaries.