Level of contamination in sediments affected by the Prestige oil spill and impact on the embryo development of the sea urchin

The level of contamination in sediments from several sites on the coast of Galicia (Spain) diversely affected by the Prestige oil spill was evaluated 18 months after the accident. Data of metal and total hydrocarbon concentrations in sediments were integrated with data on the toxicity of these sediments on sea urchin embryos, obtained through bioassays using an aqueous sediment extract (elutriate) containing the soluble phase of fuel. The results of the chemical analyses show that significantly high levels of hydrocarbons and metals accumulate at some localities. Moreover, in some of these cases, they can enter the water column and become available to planktonic organisms, as shown by the results of the bioassays using the larval phases of a local species of sea urchin (Paracentrotus lividus).