Is ocean garbage killing whales?

Millions of tonnes of plastic debris dumped each year in the world’s oceans could pose a lethal threat to whales, according to a scientific assessment presented at a key international whaling forum last week.

A review of research literature from the last two decades reveals hundreds of cases in which cetaceans – an order including 80-odd species of whales, dolphins and porpoises – have been sickened or killed by marine litter.

Entanglement in plastic bags and fishing gear have long been identified as a threat to sea birds, turtles and smaller cetaceans.

For large ocean-dwelling mammals, however, ingestion of such refuse is also emerging as a serious cause of disability and death, experts say.

In 2008, two sperm whales stranded on the California coast were found to have a huge amount – 205 kilos in one alone – of fish nets and other synthetic debris in their guts.

One of the 15-metre animals had a ruptured stomach, and the other, half-starved, had a large plug of wadded plastic blocking its digestive tract.

Seven male sperm whales stranded on the Adriatic coast of southern Italy in 2009 were stuffed with half-digested squid beaks,fishing hooks, ropes and plastic objects.