Cadmium, copper and lead contamination of the seawater column on the Prestige shipwreck (NE Atlantic Ocean)

As a result of the Prestige tanker sinkage on 19 November 2002, vast amounts of heavy fuel were dump from the shipwreck lying on the bottom to the surface of the NE Atlantic Ocean. The heavy metal contamination of the water column was studied from 4–8 December 2002 taking advantage of an opportunistic cruise onboard the R/V Atalante. Clean laboratory procedures were used in order to analyse 32 water samples and two heavy fuel samples (cargo tanker and surface seawater of the shipwreck area) by means of differential pulse anodic stripping voltametry and electrothermal atomic absorption spectrometry. Around 25 kg of Cd, 170 kg of Cu and 10 kg of Pb were released into the ocean water over seventy days of which 2% (Cd), 23% (Cu) and 71% (Pb) remain in the floating fuel patches on the sea surface. In the Prestige shipwreck area, where the seawater was free of oil patches, copper (2.8–8.5 nM) and lead (0.10–0.78 nM) contamination was only observed in the uppermost ocean layer, from 100 m depth for copper and the top ocean for lead. On the contrary, the cadmium levels (0.02–0.41 nM) observed were within typical or uncontaminated values.