Most organochlorinated contaminants were banned in developed countries in the 1970s and 1980s. However, their chemical properties favour long-range transport and persistence in water, air and biota, including the deepest ocean fauna.
Studies of cetaceans in Europe have reported bottlenose dolphin, Tursiops truncatus, with markedly elevated Polychlorinated biphenyls (PCBs) concentrations in their blubber. “Hotspots” include the Strait of Gibraltar, south western Iberia, the Gulf of Cadiz and the Mediterranean Sea. This latest study, published in Scientific Reports focused on one of the largest identified coastal bottlenose dolphin communities in Europe, a group of approximately 420 coastal bottlenose dolphins in the English Channel.
The researchers report that PCBs were the most abundant compounds in the blubber of the bottlenose dolphins in this area, and for male dolphins even higher than concentrations measured in animals from Galicia, North West Spain and Portugal. There was also a high concentration of mercury in the skin, very close to the concentrations previously described for bottlenose dolphins in the Mediterranean Sea and from the Florida coastal Everglades, two areas that are known for their high mercury contamination levels. These and other scientists reiterate that there is an urgent need to review the methods of PCB mitigation in the marine environment in Europe.