An autopsy of a killer whale, named Lulu, that was found on the Isle of Tiree in Scotland showed her body contained some of the highest levels of polychlorinated biphenyls (PCBs) ever recorded. Lulu’s body was said to contain twenty times more of the toxic chemical than the safe level that cetaceans are able to handle. These chemicals which were banned in the 1970s are still present in the oceans and build up in animals. Now scientists fear that the other members of Lulu’s pod could also be highly contaminated.
Along with being highly toxic, PCB is also incredibly hard to break down naturally and is resilient to extreme temperatures and pressures. This means that even though the production of PCB has been halted for decades, the chemical continues to persist in our oceans and contaminate all animal life. Top predators such as killer whales and other cetaceans are more susceptible to PCB contamination because it accumulates with all of the prey they consume.
Scientists believe that the threshold when PCB begins to have a physiological effect on a whale is around 20 – 40 mg/kg in the tissue. Lulu’s body was found to have 957 mg/kg of PCB stored in her tissue. Researchers believe that these high levels could be caused by the large amount of PCB produced in the UK and also Lulu’s age. Estimates were made that Lulu was twenty years old when she died meaning that she had been accumulating PCB for a considerable amount of time.
PCB can have a wide range of health effects including immune system impairment and reproductive failure. Unfortunately, scientists found that Lulu’s ovaries showed no evidence of any reproductive activity. PCB also can impact the brain, which could have had implications in Lulu’s died while trapped in a fishing line, which is an unlikely death for killer whales in the UK. One can speculate that the PCBs played a role in impairing her ability to remove herself from the entanglement.
Sadly, there are only eight individuals left in the pod that Lulu was a member of. Like Lulu, there have been no calves observed in the last 25 years which could mean that they too are suffering from high PCB contamination.
While there is a high chance that killer whales will eventually disappear from UK waters, there is still a push for Europe to take action with PCB pollution. Unlike the US, Europe has no plans for decontaminating its waste of PCB. These decontamination processes, which are regulated in the US thanks to the EPA, have shown to decrease the levels of PCB contamination in humans and other animals such as fish.
Lulu should stand as a cautionary tale that our actions can have long lasting effects on our environment. We need to do better.