Researchers found corals in the Great Barrier Reef are actually munching on plastic, and the unhealthy snacks could have deadly side effects.
Microplastics are tiny fragments of plastic that have been contaminating the world's oceans and taking a toll on marine ecosystems, the ARC Centre of Excellence in Coral Reef Studies reported.
"Corals are non-selective feeders and our results show that they can consume microplastics when the plastics are present in seawater," said Mia Hoogenboom, a Chief Investigator with the ARC Centre of Excellence for Coral Reef Studies at James Cook University. "If microplastic pollution increases on the Great Barrier Reef, corals could be negatively affected as their tiny stomach-cavities become full of indigestible plastic."
To determine the impact of these pollutants, a team of researchers placed corals from the Great Barrier Reef into water contaminated with microscopic plastic fragments. After only two nights they observed the corals had consumed the plastic particles.
"Corals get energy from photosynthesis by symbiotic algae living within their tissues, but they also feed on a variety of other food including zooplankton, sediment and other microscopic organisms that live in seawater," said study lead author Nora Hall, a James Cook University Masters graduate. "We found that the corals ate plastic at rates only slightly lower than their normal rate of feeding on marine plankton."
A closer look revealed the plastic was deep inside the coral polyps and wrapped in digestive tissue. The researchers are concerned the plastic could reduce the coral's ability to digest its actual food source.The research team also analyzed the impact of these microplastics by sampling waters near inshore reefs and around the Great Barrier Reef itself.
"During this testing we found microplastics, including polystyrene and polyethylene, although only in small amounts," said study co-author, Kathryn Berry, a PhD student at James Cook University and the Australian Institute of Marine Science.
In the future the researchers hope to further determine the impact of the plastic on coral health.
"We are also investigating whether fish on coral reefs eat plastics, and whether plastic consumption influences fish growth and survival." Hoogenboom concluded.
The findings were published in a recent edition of the journal Marine Biology.