Scientists claim that dolphins living in the English Channel are exposed to a “cocktail of pollutants”.
A recent study found some of the highest recorded levels of toxic chemicals and mercury in the bodies of bottlenose dolphins off the French coast.
Researchers state that more needs to be done to combat the “invisible” problem of lingering pollutants in the oceans. The English Channel is home to one of the last surviving large European populations of bottlenose dolphins.
For their study, researchers collected tissue samples from over 80 dolphins living in waters off Normandy and Brittany and detected high concentrations of mercury in skin and polychlorinated biphenyls, or PCBs, in their blubber.
They said that other industrial chemicals like dioxins and pesticides, were also found in blubber samples, which collectively may act as a “cocktail of pollutants”.
Unfortunately. These chemicals are passed down from mother to calf.
Dr Krishna Das of the University of Liege, Belgium who led the team of researchers, said, “Our results indicated the important transfer of PCBs by females to their young, which may raise concern for the population”.
The scientists recommend that the habitat of the bottlenose dolphin is an area known as the Normanno-Breton Gulf which should be declared as a special area of conservation to protect the remaining dolphin population.
The report recetly published in the journal Scientific Reports, echoes data from investigations of strandings, explained ZSL’s Rob Deaville, of the UK Cetacean Strandings Investigation Programme.
He elaborated, “As apex predators, bottlenose dolphins are at higher risk of exposure to some of the chemicals mentioned in this study – and as many of the European coastal populations of bottlenose dolphins are relatively small in size, they may therefore be under greater conservation threat”.
Polychlorinated biphenyls or PCBs that are commonly used in plastics, paints and electrical equipment, were banned several decades ago, but continue in the environment, where they can build up in the blubber of dolphins and whales. These chemicals have been detected in the blubber of bottlenose dolphins washed up on beaches across Europe. In a shocking 2016 incident, a killer whale was found dead off Scotland containing among the highest levels of PCBs, ever recorded.