Integrative assessment of coastal marine pollution in the Bay of Santander and the Upper Galician Rias

Sediments from the Rias of A Coruña, Ferrol, Betanzos and Ares (n=26) and the Bay of Santander (n=11) were sampled in July 2012. The concentration of organic contaminants in sediment elutriates (CBs, PAHs, pesticides and personal care products) and sea urchin (Paracentrotus lividus) embryotoxicity were assessed. Relevant concentrations of organic pollutants were detected in the elutriates (ΣContaminants<400ng/L) but their interpretation in terms of the observed toxicity was not straightforward. A clear gradient of toxicity from the inner to the outer areas of the Bay of Santander was observed. Sediment elutriates from three stations situated close to the city of A Coruña showed moderate toxicity values, whereas sediment elutriates from the Rias of Ares and Betanzos showed no marked toxicity. Stations located close to the city of Ferrol showed moderate to high toxicity, which is indicative of a nearby source of contamination. On the contrary, the outer area of the Ria of Ferrol was classified as “Good” according to the calculated toxic units. These results allowed for an integrative assessment of the environmental quality of the studied areas.