Tiny Bits of Plastic May Be Clogging Up Corals

Researchers find that microplastic pollution has become a new threat to the health of ocean reefs

Flip Nicklin/Minden Pictures/Corbis

Microplastics—those miniscule balls of synthetic material found in toothpaste, face wash, creams, and cosmetics—might just, as one expert reported, "the most numerically abundant items of plastic debris in the ocean today.” And researchers have found that corals is Australia’s Great Barrier Reef are capable of inadvertently eating these tiny balls of plastic—which could be very bad news for the organisms’ health.

Scientists placed coral in tanks of water contaminated by microplastics (which are also created when larger shards of plastic breaks off into tiny pieces). After two days, the researchers discovered the plastics wrapped inside the coral polyps' digestive tissues, reports the Arc Centre of Excellence in Coral Reef Studies.

“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. "We found that the corals ate plastic at rates only slightly lower than their normal rate of feeding on marine plankton."

The findings are worrisome, suggesting that microplastics could prevent coral from properly digesting their foods. When the researchers tested the waters around the Great Barrier Reef, they discovered evidence of the debris, though only in small amounts.

Further research is needed to better gauge the impact such pollution has on the animals’ physiology and health. The scientists involved in the study say they’re also investigating whether the growth and survival of reef-based fish are being affected.

The scientific community has been expressing concern about the rise of microplastic pollution for years, citing unanswered questions about its long-term effects. Some U.S. states, like Illinois, and New York have already taken measures to ban or restrict the use of “microbeads” in cosmetics. A ban in California was narrowly defeated in 2014; interest groups say they’ll try again this year. Some cosmetics companies have vowed to eventually phase the beads out of their products voluntarily, but in the meantime, they're still spilling into waterways as part of daily beauty routines.

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