Marine and Estuarine Microalgal Sediment Toxicity Tests

Abstract

Current guidelines for toxicity bioassays concerned with marine or estuarine sediments do not include any probe involving elements from the microphytobenthos [microalgae living on the surface of the (temporary or not) submerged sediments], in spite of the importance of the benthic microflora on coastal trophic and geodynamical processes. Here, a revision of the importance of microphytobenthos in the benthic trophic nets as well as in the structure of the upper part of the marine coastal and estuarine sediments is performed, and the most recent efforts to develop sediment toxicity bioassays on marine microphytobenthos are reviewed and discussed. The benthic mobil pennate diatom Cylindrotheca closterium (formerly known as Nitzschia closterium ) seems to be a good target organism in toxicity testing for marine and estuarine sediments because of its easy handling, fast growth, sensitivity, low nutritional requirements, and wide distribution in temperate coastal waters. Additionally, there exists a good literature background about this species.