New research conducted by the Zoological Society of London claims that the U.K.'s last pod of killer whales will go extinct due to the high levels of PCB pollution that affect the western European waters. These chemicals, which were banned in the 1980s and are known to decrease immune efficiency and breeding success, are still making their way into oceans and could also be to blame for the decline in the European dolphin population, according to The Guardian.
"The long life expectancy and position as apex or top marine predators make species like killer whales and bottlenose dolphins particularly vulnerable to the accumulation of PCBs through marine food webs," Paul Jepsen, who headed the research, said in a press release. "Our findings show that, despite the ban and initial decline in environmental contamination, PCBs still persist at dangerously high levels in European cetaceans."
The research utilized long-term studies of over 1,000 stranded or biopsied whales, dolphins and porpoises, all of whom belong to the cetacean family, and found that the blubber in European killer whales and striped dolphins contain some of the highest PCB levels in the entire world.
"The levels are really high, probably the highest in the world right now," Jepson said. "These are global PCB hotspots."
With a low amount of killer whale populations in western Europe and the remaining ones suffering from low to nonexistent rates of reproduction, the survival of the species does not seem likely without taking drastic actions.
"Our research underlines the critical need for global policymakers to act quickly and decisively to tackle the lingering toxic legacy of PCBs, before it's too late for some of our most iconic and important marine predators," added Robin Law, co-author of the study. "We also need to better understand the various pathways through which these iconic species are able to accumulate such high PCB concentrations through their diets."
The findings were published in the Jan. 16 issue of Scientific Reports.
