SEA URCHIN TOXICITY BIOASSAYS FOR SEDIMENT QUALITY ASSESSMENT IN THE LAGOON OF VENICE (ITALY)

This paper focuses on the evaluation of two sea urchin bioassays (sperm cell and embryo toxicity) using the Paracentrotus lividus, as possible methods for quality assessment and monitoring of estuarine and lagoonal environments. Some queries allow us to describe the reasons which led us to carry out this research. A step-wise method adopted to own reliable and robust techniques based on a QA/QC (Quality Assurance/Quality Control) procedure is briefly illustrated. The suitability of bioassays to assess lagoonal sediments quality was then tested by their application at sites in the Lagoon of Venice characterized by differing kinds and levels of pollution. Elutriates were chosen to assess the potential effects of pollutants which are made available in the water column as a consequence of sediment resuspension (dredging, fishing gear, etc). Both tests were effective in discriminating several different pollution/bioavailability situations, although their combined use showed higher efficacy in discriminating among stations and periods. Embryotoxicity was higher than spermiotoxicity in almost all stations, as expected. Toxicological responses generally fitted contamination levels to a satisfactory extent.