Wildlife

Polluted Killer Whale

An orca that was found dead last year is now considered one of the most polluted whales ever found: The marine animal contained some of the highest levels of polychlorinated biphenyls (PCBs) — human-made organic chemicals known to cause a variety of adverse health effects — ever recorded.

Lulu, an adult female killer whale, was a member of the last orca pod living near the United Kingdom. When the dead whale was discovered in January 2016 on the Isle of Tiree, Scotland, after becoming entangled in fishing rope, researchers analyzed the orca's body in hopes of determining the health of the rest of the small pod. They found that Lulu might have been the most contaminated whale ever discovered.

The PCB concentrations in Lulu's blubber were 100 times higher than the toxicity level scientists have determined is safe for marine mammals, according to researchers from the Scottish Marine Animal Stranding Scheme at Scotland's Rural College (SRUC).

High concentrations of PCBs can cause a range of health issues for marine mammals, including impaired immune function, increased susceptibility to cancers, and infertility, according to the SRUC researchers.

Though Lulu was at least 20 years old when she died, an analysis of the orca's ovaries showed that she had never reproduced. In fact, researchers have not verified a single calf in the 23 years that the U.K. orca pod has been monitored.