A study of bottlenose dolphins living in the English Channel found they are exposed to a ‘cocktail of pollutants’.
A team of researchers, led by Dr Krishna Das of the University of Liege, Belgium, took tissue samples from more than 80 dolphins living off Normandy and Brittany. The Channel is home to one of the last remaining large European populations of bottlenose dolphins.
The study, published in the journal Scientific Reports, explains scientists discovered some of the highest recorded levels of toxic chemicals and mercury in the animals.
Researchers found high concentrations of mercury in their skin and polychlorinated biphenyls, or PCBs, and other industrial chemicals, such as dioxins and pesticides, in blubber samples.
According to BBC News, PCBs, used in plastics, paints and electrical equipment, were banned several decades ago but they still linger in the environment, where they can build up in the blubber of dolphins and whales as the compounds are able to dissolve in oils.
Those conducting the study have said more needs to be done to tackle the ‘invisible’ problem of pollutants in the oceans as it’s believed the chemicals are passed from parents to their young.
The report explained female dolphins ‘offload a significant portion of this cocktail to their offspring during gestation and lactation, placing foetuses and newborns at a higher risk’ and added male dolphins are also at risk as they ‘continue to bioaccumulate PCBs throughout life’, EuroNews report.
The highest levels of mercury ever recorded have been found in the blubber of dolphins living in the English Channel ☹️. Scientists also found worryingly high levels of toxic organic pollutants (PCBs) that were banned as long as 40 years ago. https://t.co/CnDsHclzfh pic.twitter.com/PSu8mD4eXL
— ActionforDolphins (@Act_4Dolphins) September 13, 2019
The team commented:
Our results indicated the important transfer of PCBs by females to their young, which may raise concern for the population.
Dr. Das added PCBs can disrupt hormone receptors and affect the immune system.
Rob Deaville, from the Zoological Society of London and the UK Cetacean Strandings Investigation Programme, said the findings corresponded with data from investigations of strandings, where whales and dolphins become stranded on land.
The chemicals have also been found in the blubber of bottlenose dolphins washed up on beaches around Europe.
As per BBC News, Rob said:
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.
The scientists believe the Normanno-Breton Gulf, where the bottlenose dolphins’ habitat is located, should become a special area of conservation in order to protect the population.
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Emily Brown first began delivering important news stories aged just 13, when she launched her career with a paper round. She graduated with a BA Hons in English Language in the Media from Lancaster University, and went on to become a freelance writer and blogger. Emily contributed to The Sunday Times Travel Magazine and Student Problems before becoming a journalist at UNILAD, where she works on breaking news as well as longer form features.