Poor water quality could be killing killer whales

Poor water quality could be behind the decline in killer whale numbers, it has been claimed.

According to sea mammal expert Dr Ingrid Visser, who grew up watching the creatures off the coast of New Zealand, the fact that they are apex predators - ie they are at the top of the food chain - means they are extremely susceptible to waterborne pollutants.

The process of bioaccumulation is well documented, with heavy metals and other potentially-dangerous substances travelling up the food chain and becoming more concentrated.

Speaking to the BBC, Dr Visser said: "Their prey is definitely polluted - we are seeing spikes in the same chemicals as are seen in [killer whales]."

"Studies have identified high levels of flame retardant chemicals in [the creatures] particularly from the Northern Hemisphere," she added.

Recently, Greenpeace urged trainer manufacturers Nike and Adidas to take action against a textile factory in China they use that is damaging water quality in the country's Yangtze and Peal rivers.

Posted by Lauren Steadman