Water toxicity assessment of Santos Bay under different climate conditions

Climate conditions and the movement of water masses are among the main factors that influence the destination of pollutants, acting upon transport and dispersion affecting, thus, the quality of water. Samples from Santos Bay were collected under normal conditions (08/21/2008) and during the entrance of a frontal system (08/22/2008) and tested for chronic ecotoxicity using fertilized eggs of sea urchin Lytechinus variegatus. Samples were toxic for stations near Xixova-Japui State Park, Port of Santos, Submarine Outfall and Moela’s Island, sites related to pollution sources. Differences in climate conditions were observed and its contribution on toxicity seemed to be significant at the entrance of Sao Vicente estuary and Moela’s Island. At the stations in Santos Bay under influence of contamination from multiple sources such as the presence of outfall and sediments disposal from dredging, the continuous release of compounds still plays an important role in environmental quality.