What are PCBs and why do they threaten cetaceans?

16th Nov 2017

Lulu was a killer whale and part of the UK's only resident orca population (Photo credit: PA)

Polychlorinated biphenyls (also known as PCBs) are a dire threat to cetacean populations around the UK and beyond, and one of the biggest challenges facing global populations.

But exactly what are PCBs and how have they come to pose such a threat to our marine wildlife?

PCBs are a persistant organic polluntant (POP) that was widely used in a variety of industrial applications, including electrical equipment, sealants and paints. They were banned in the 1980s under the Stockholm Convention but action has been slow and many countries are still on track to miss their targets for the reduction of their use, meaning they represent an immediate threat.

The chemicals themselves have been found to have a range of negative impacts on both human and environmental health, including increasing cancer risk and detrimentally affecting fertility.

The substances bioaccumulate in the food chain, building up in fatty tissues, with the highest concentrations being found in apex predators such as whales and dolphins.

PCBs have become particularly prevalent in recent months after a dead killer whale from the UK's only resident pod was found to have the highest recorded concentrations of PCBs in it's body after a post mortem investigation. The pod has just eight remaining members, with no calves born for almost 20 years.

ORCA partner with Wildlife & Countryside Link as a part of their PCB subgroup, working together to push government to take much needed action to address the issue of PCBs and the impact it is having on our cetaceans.