European Killer Whales May Become Extinct, Study
Research by the Zoological Society of London says that U.K.'s final school of killer whales will become extinct with levels of PCB pollution in the western region of European waters. The oceans are polluted by chemicals banned in the 1980s, which have the tendency to bring down "immune efficiency and breeding success". They are probably responsible 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."
With long-term studies of more than 1,000 stranded or biopsied whales, dolphins and porpoises from the cetacean family, scientists discovered high levels of blubber in European killer whales and striped dolphins.
"The levels are really high, probably the highest in the world right now," Jepson said. "These are global PCB hotspots."
Hence, unless we take some drastic steps to conserve these whales, it is not likely that they will survive.
"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 Jan.16,2016 issue of Scientific Reports.