For a toxicity assessment of substances entering the marine environment, it is preferable to carry out ecotoxicological tests on a base-set of taxa utilizing target species belonging to different trophic levels. In this study a battery composed of Vibrio fischeri (bacteria), Dunaliella tertiolecta (algae), Tigriopus fulvus (crustacea), Paracentrotus lividus (echinodermata), and Dicentrarchus labrax (pisces) was used for acute toxicity testing of sodium dodecyl sulfate (SDS). SDS is an anionic surfactant widely employed in industry, agriculture, and domestic usage and therefore is found in abundance in the environment, particularly in the sea. The mean values of EC50 obtained were 2.6, 4.8, 7.4, 3.2, 7.3 mg L(-1), respectively, for V. fischeri, D. tertiolecta, T. fulvus, P. lividus, and D. labrax. The results indicate the high acute toxicity of SDS with respect to all the trophic levels represented by the target species. In addition, they highlight the usefulness of employing a base-set of taxa rather than a single species in toxicological tests, in order to obtain more reliable information for the evaluation of toxicity and potential hazards to the marine environment of selected substances.

The availability of standardized protocols for both organism culture and bioassay with ecologically relevant species is of great concern in ecotoxicology. Acartia tonsa represents an important, often dominant, member of zooplankton communities and meets all the practical criteria suggested for model species. New standardized procedures for laboratory culturing of the copepod A. tonsa and standardized methods for acute (24- and 48-h) and semichronic (7-d, static-renewal) toxicity tests with the nauplius stage are described. In both cases, eggs are the starting stage, and nauplius immobilization is the endpoint. The methods were the object of an intercomparison test involving nine laboratories, and nickel was the reference toxicant. Relative reproducibility was 24, 25, and 34% for 24-h, 48-h, and 7-d tests, respectively.

During the last years many authors have char-acterized the produced formation waters (PFWs) with respect to chemical compounds and toxic-ity. Most of data are related to PFWs collected on offshore platform after treatment process. The available results showed that the particulate phase had an influence on PFW toxicity. As-suming the toxicity of PFWs treated on platform, the aim of this paper is to study the toxicity of these PFWs after a further filtration treatment carried out in laboratory. For this purpose PFWs were sampled from three natural gas platforms located in the Adriatic Sea (Italy) below treat-ment system. The eco-toxicological bioassays have been conducted on test-organisms be-longing to different trophic levels such as bac-teria, algae, crustaceans and fishes. The PFWs resulted toxic according to an overall assess-ment obtained through the bioassays. Further-more, it has been possible to identify the spe-cies that were more sensitive to the tested PFWs, namely Tigriopus fulvus, Dicentrarchus labrax and Vibrio fischeri. Besides, a chemical char-acterization was reported related to the con-taminants present in the PFWs to go with eco-toxicological assessment. Barium, zinc and manganese showed the most concentrations among the metals and the lower molecular weight components were common among the organic compounds. Some differences among PFWs were observed both for toxicity and chemical composition. The highest toxicity was recorded in PFWs (PFW1 and PFW2) containing the highest concentrations of some metals (Ba, Mn and Zn) and/or BTEX

No abstract

No abstract