Assessment of sediment toxicity in the Lagoon of Venice (Italy) using a multi-species set of bioassays.

Within the framework of a Weight of Evidence (WoE) approach, a set of four toxicity bioassays involving the amphipod Corophium volutator (10 d lethality test on whole sediment), the sea urchin Paracentrotus lividus (fertilization and embryo toxicity tests on elutriate) and the pacific oyster Crassostrea gigas (embryo toxicity test on elutriate) was applied to sediments from 10 sampling sites of the Venice Lagoon (Italy). Sediments were collected during three campaigns carried out in May 2004 (spring campaign), October 2004 (autumn campaign) and February 2005 (winter campaign). Toxicity tests were performed on all sediment samples.

Integration of biological responses from a suite of bioassays for the Venice Lagoon (Italy) through sediment toxicity index - part A: development and comparison of two methodological approaches.

Marine and coastal quality assessment, based on test batteries involving a wide array of endpoints, organisms and test matrices, needs for setting up toxicity indices that integrate multiple toxicological measures for decision-making processes and that classify the continuous toxicity response into discrete categories according to the European Water Framework Directive. Two toxicity indices were developed for the lagoon environment such as the Venice Lagoon. Stepwise procedure included: the construction of a database that identified test-matrix pairs (indicators); the selection of a minimum number of ecotoxicological indicators, called toxicological core metrics (CMs-tox) on the basis of specific criteria; the development of toxicity scores for each CM-tox; the integration of the CMs-tox into two indices, the Toxicity Effect Index (TEI), based on the transformation of Toxic Unit (TU) data that were integrated as logarithmic sum, and the Weighted Average Toxicity Index (WATI), starting from toxicity classes integrated as weighted mean.

Ecotoxicological evaluation of Mediterranean dredged sediment ports based on elutriates with oyster embryotoxicity tests after composting process.

The ecotoxicological effect of dredged sediments was estimated by embryo-larval toxicity of the oyster Crassosstrea gigas in sediment elutriates (filtered and unfiltered). The study covers the main ports from the French Mediterranean coast. Composted sediments from a navy harbour (A), a commercial port (B) and two composite specimens (C and D) obtained after mixing various sediments were taken into consideration.

Overview of ecotoxicological studies performed in the Venice Lagoon (Italy).

This work reports on the state of the art of the bioindicators used to assess environmental quality (regarding chemical pollutant impacts) in the Venice lagoon. After a brief description of the roles, advantages and limitations of bioindicators in marine and transitional environments and a summary of the Venice lagoon characteristics, the ecotoxicological methods used during scientific studies and research projects in the Lagoon are reported. Since not all data are available and no database can be formulated, the main evidence from toxicity bioassays, biomarkers and bioaccumulation analyses since the end of the 1970s is spatially synthesized using maps and discussed according to the four Venice lagoon basins.

Influence of storage methods, refrigeration or freezing, on the toxicity of wastewater samples to oyster embryos.

One of the main concerns in wastewater whole effluent assessment is the sampling phase and the sample chain of custody before any toxicity evaluation. The major problem is related to establishing the correct method for sample storage in order to perform toxicity bioassays. The toxicity of some domestic and glass factory industrial wastewater samples stored both by refrigeration at 4 +/- 1 degrees C for no more than three days, and freezing at -18 +/- 1 degrees C for no more than one month was compared via the embryo larval development bioassay with the oyster Crassostrea gigas.