Banned pollutants threaten to wipe out UK’S orca population
BRITAIN’S only killer whale pod will be wiped out by the end of the century because of chemical pollution in the surrounding seas, says a report.
Analysis by international researchers including the University of St Andrews and the Zoological Society of London has found that half of the world’s orca population will vanish in the most heavily contaminated areas. The pollutants – Polychlorinated biphenyls, or PCBS – were once widespread in paints, adhesives and electronics but were banned in the Seventies. However, the paint from old bridges, boats and buildings can still flake into the sea, or leach into waterways from disused mines, where it was used as hydraulic oil, or from landfill sites.
Around the British Isles, killer whale numbers have halved to around 10 because of the chemicals, and the mammals are likely to vanish altogether in the coming decades, the new research found. Last May, a dead orca called Lulu was found washed up on the Hebridean Isle of Tiree with the highest levels of PCBS ever recorded and it is feared the rest of its pod will have the same level of contamination. “This suggests that the efforts have not been effective enough to avoid the accumulation of PCBS in high trophic level species that live as long as the killer whale does,” said Dr Paul Jepson, of the Zoological Society of London. Killer whales, because they sit at the top of the food chain, accumulate huge amounts of PCBS that have been ingested by animals further down.
The chemicals can also be passed down from mother orca to its offspring through the mother’s fat-rich milk.
Following the 2004 Stockholm Convention, more than 90 countries agreed to end all use of PCBS by 2028. Yet little is done to ensure companies are complying. Willie Mackenzie, oceans campaigner at Greenpeace UK, said: ‘‘Thirty years after they were banned, it’s staggering that polluting PCBS are not only still getting into our ocean, but that they are pushing our killer whales towards extinction.
“The Government has to take a global lead: that means legally binding measures on the disposal of PCBS in the forthcoming UK Environment Act and urging other countries to take similar measures.”