Colossus of the deep no match for curse of plastic
The largest fish on the planet, the whale shark, is under threat from plastic pollution off one of Britain’s most remote island possessions, conservationists have warned.
The tiny volcanic island of St Helena, which lies 6500km from England in the South Atlantic, is Britain’s second-oldest overseas territory, and was where an exiled Napoleon died in 1821.
Yet despite its isolated location, the island is now plagued by plastic rubbish that washes in from South America and beyond, even though its nearest neighbour is thousands of kilometres away.
In 2003, there was estimated to be one plastic item per every 3m on the black volcanic beaches. Now, ecologists say that they are finding hundreds of items in the same area, with each tide bringing in a new batch of refuse.
Environmentalists and wildlife groups are concerned that the amount of plastic could prove deadly for whale sharks, which inhabit St Helena’s waters from November to June as they migrate across the South Atlantic.
The sharks are already listed as endangered by the International Union for the Conservation of Nature because they often become tangled in fishing nets, or collide with boats.
Whale sharks are particularly at risk from refuse in the ocean because their main diet is plankton which they need to suck up in huge gulps, and they often accidentally ingest micro-plastics at the same time. David Barnes, of the British Antarctic Survey, said: ‘‘There has been an absolutely dramatic change in St Helena.
‘‘In 2003, there was one plastic item per every three metres. By 2007, that had grown by three times the amount and now we’re finding hundreds of plastic items per metre in some places so that’s a thousandfold increase – there are unbelievable levels of change and it’s happened in our lifetime.
‘‘The animals that eat plankton and smaller algae are not discriminating between microplastics and their food. They can process the natural food but the micro-plastics stay in their stomach and build up until they have a stomach full of plastic which, in some circumstances, can weigh more than the actual organism. Then they die.’’
It is estimated that eight million tonnes of plastic are dumped in the world’s oceans each year and the Ellen MacArthur Foundation has estimated there will be more plastic than fish in the oceans by 2050. It also states that 83 per cent of the world’s tap water is now contaminated by micro-plastic.
As well as problems with micro-plastic, large pieces can pierce stomach linings, and plastic bags are mistaken for jellyfish and can block intestinal tracts when consumed.
There is growing evidence that plastic is entering the marine food chain with fish, turtles, sea birds and cetaceans from around the world all testing positive for plastic contamination.
Although the locals on St Helena organise regular beach cleans, experts say the plastic onslaught is relentless and have urged people to cut down on single-use items.
Beth Taylor, the St Helena National Trust marine project manager, said: ‘‘Given the remoteness of St Helena, if there are still plastics washing up from other places, it shows how huge a global issue it is and it does need to be highlighted.
– Telegraph Group