"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.
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. "Plastic debris can cause physical injury and abrasion to coral tissues by facilitating invasion of pathogens or by exhausting resources for immune system function during wound-healing processes", the authors of the study write.
Dr. Lamb is now a NatureNet Fellow at Cornell University with The Nature Conservancy and holds a PhD in Tropical Marine Ecology and Fisheries Biology from James Cook University in Australia. We estimate that there are 11.1 billion plastics remains on coral reefs throughout the Asia Pacific and they are projected to increase by 40 percent in seven years, Lamb said. Indonesia was found to be the worst offender, with the coral in Australia suffering the least - possibly due to Australia's intense clean-up and disposal efforts. A 2017 study found that 83% of tap water samples taken around the world contained plastic pollutants.
Kelly, now a PhD student at Carleton University in Ottawa, participated in the Australian surveys while doing her master's degree at James Cooke University in Townsville, Queensland: "I didn't mind one bit". They determined that plastic fragments cut corals, choke them of light and oxygen, and provide a means for pathogens to invade.
Garbage like disposable diapers, plastic bags and snack wrappers is getting into the ocean and snagging on coral reefs, leading to deadly infections that literally eat the corals alive, a new study suggests. Secondly, plastic also blocks sunlight from reaching the corals, which can also pose a long-term threat. Of the plastic-free reefs, which were few and far between, only 4 percent were infected with other diseases.
Once corals are already infected, it is logistically hard to treat the resulting diseases.
Lamb said the good news in light of the findings published in Science is plastic pollution is something that can be more easily dealt with in the short term than numerous other problems, by helping countries in Southeast Asia reduce the amount of plastic garbage going into the ocean. For example, the United Kingdom recently implemented its first "Seabin" to extract oil, plastic, and other debris from Portsmouth harbor, while the city of Rotterdam has been using an aquatic drone known as the "waste shark". This has potentially dire implications for the numerous marine species that shelter under or within these corals, and in turn the fisheries that depend on them.
Joleah Lamb is a research fellow at Cornell University.