Scientists have revealed that the
deal dead killer whale found off the Scottish island of Tiree had extreme levels of polychlorinated biphenyl (PCB) pollution ever recorded making it the most contaminated on the planet.
deal dead killer whale, Lulu, was well known to researchers for it was one of the last surviving whales in the waters around Britain. According to scientists the whale died after becoming entangled in fishing rope in January 2016.
After being found dead, scientists at the Scottish Marine Animal Stranding Scheme and the University of Aberdeen carried out an extensive investigation which led them to conclude that the killer whale the “most contaminated on the planet.”
According to scientists invovled with the investigation of Lulu’s carcass, studies have shown that killer whale populations can have very high levels of PCB, but such levels of PCB as found in Lulu haven’t been recorded ever before. The levels seen in Lulu are some of the highest scientists have ever recorded. Lulu’s skeleton is preserved at National Museums Scotland. The stranding scheme was set up in 1992 to analyze and report data for all marine mammals, marine turtle and basking shark stranding.
Scientists found PCB concentrations 100 times higher than the accepted toxicity threshold for marine mammals in Lulu. High PCB levels are linked to poor health, impaired immune function, increased susceptibility to cancers and infertility. Once PCBs get into the marine environment, they accumulate through food chains and are difficult if not impossible to remove.
While Lulu was at least 20 years old, scientists believe the whale apparently never reproduced, despite being much older than the average age for maturity in killer whales. Brownlow called Lulu’s apparent infertility an ominous warning and said it is “increasingly likely that this small group will eventually go extinct.” Lulu lived in a pod of about eight whales.
PCBs were banned in the U.S. in 1979. From the 1920s until their ban, an estimated 1.5 billion pounds of PCBs were made for things such as microscope oils, electrical insulators, capacitors, and electric appliances such as television sets or refrigerators, the U.S. National Ocean Service says. PCBs were also sprayed on dirt roads to keep the dust down. Traces of PCBs have been detected in people and animals around the world.