Plastic trash linked to disease in corals, says study

Scientists have found that plastic trash ubiquitous throughout the world's oceans massively increases the chance of disease in corals."We examined more than 120,000 corals, both plastic-free and with plastic present, on 159 reefs from Indonesia, Australia, Myanmar and Thailand," said Joleah Lamb, from the Cornell University in the US.

"We found that the chance of disease increased from four per cent to 89 per cent when corals are in contact with plastic," said Lamb.Coral are tiny animals with living tissue that cling to and build upon one another to form "apartments," or reefs, according to a study published in the journal Science.Bacterial pathogens ride aboard the plastics, disturbing delicate coral tissues and their microbiome.

"What's troubling about coral disease is that once the coral tissue loss occurs, it's not coming back," said Lamb."It's like getting gangrene on your foot and there is nothing you can do to stop it from affecting your whole body," the researcher said.She said the problem of plastic waste looks to be getting worse."We estimate there are 11.1 billion plastic items on coral reefs across the Asia-Pacific and forecast this to increase by 40 per cent within seven years," she said.The researchers said the finding adds to the burden of climate-related disease outbreaks that have already had an impact on coral reefs globally."Bleaching events are projected to increase in frequency and severity as ocean temperatures rise.

Theres more than 275 million people relying upon coral reefs for food, coastal protection, tourism income, and cultural significance," said Professor Bette Willis, from the James Cook University in Australia."So moderating disease outbreak risks in the ocean will be vital for improving both human and ecosystem health," Willis said.The scientists forecast that by 2025, plastic going into the marine environment will increase to roughly 15.7 billion plastic items on coral reefs, which could lead to skeletal eroding band disease, white syndromes and black band disease."This study demonstrates that reductions in the amount of plastic waste entering the ocean will have direct benefits to coral reefs by reducing disease-associated mortality," Lamb said.