Thursday, 23 July 2015
Porpoises in Europe are having difficulty reproducing due to PCB, according to a study published on Wednesday. These chemical pollutants have been banned on the continent for over thirty years, but it hangs around in the cetacean’s adipose tissue. Exposure to PCB (polychlorinated biphenyls) can weaken this marine animal’s immune system and affect their reproduction, British researchers say. They looked at Porpoises (Phocoena phocoena) living near British ports, and their study was published in the American review PLOS ONE.
“PCBs have been banned in Britain since 1981, but concentration remains high among many Porpoise groups. This shows the negative effects these pollutants have on the cetacean’s health and reproduction can last a long time”, says Paul Jepson, chief vet for the British program looking into why the cetacean is having trouble reproducing.
And the problem gets worse from one generation to another, as the babies are contaminated by PCB when they suckle from their mother, researchers from the London Zoological Society (ZSL) have warned.
The study showed that a high number of sexually mature female Porpoises (20%) are failing to reproduce, for example because the foetus dies. These problems could be linked to the presence of infections or tumours in the reproductive organs, which were found in 16.5% of the animals examined.
The scientists also found that the birth rate among female Porpoises living near British ports is much lower than the birth rate among those living in areas less contaminated by PCBs.