Atlantic Orcas could be wiped out due to PCBs in ocean plastic.

Polychlorinated biphenyls (PCBs) are synthetic chemicals once used in electronics, heating and cooling fluids, and lubricants. They are extremely stable and can remain in the environment for decades.

Plastics absorb PCBs from the environment, and release it into the tissue of any animal that ingests it. It builds up in the tissue of that animal, and any predators, reaching extremely high concentrations in the bodies of apex predators, such as orcas.

PBCs cause birth defects, organ damage, hormone imbalance, and interfere with reproduction in animals. There is no feasible intervention. There is so much plastic in the oceans, it is impossible to keep planton, birds, fish, seals, and other animals from ingesting PCB contaminated plastic.

Find out more at:

https://www.theatlantic.com/science/archive/2018/09/pcbs-are-killing-killer-whales/571474/