Coral Becomes Diseased When It Tangles With Plastic

CC BY 2.0. National Ocean Service

And the oceans are full of the stuff, which does not bode well for coral reefs.

When plastic waste drifts around the oceans, it gets snagged on coral reefs, where protrusions, fronds, and sharp edges offer an ideal place to get stuck. The damage, however, is more than aesthetic; getting entangled with plastic is a death sentence for coral.

A study from earlier this year was the first to examine the role plastic plays in promoting disease in a marine environment. Researchers found that the chance of coral becoming diseased goes from 4 percent to 89 percent when plastic is present. Why? Plastic smothers the coral, blocking oxygen and light that are crucial to its survival. Sharp edges can cut the coral, and the plastic often carries bacteria. Lead study author Joleah Lamb of Cornell University described it:

"Corals are animals just like me and you – they become wounded and then infected. Plastics are ideal vessels for microorganisms, with pits and pores, so it's like cutting yourself with a really dirty knife."

Once a single coral organism is infected, the disease spreads throughout the colony. Lamb likened it to "getting gangrene on your toe and watching it eat your body. There’s not much you can do to stop it."

plastic trash on beach

© Dr. Kathryn Berry -- Plastic pollution plagues seaside village in Myanmar

This is devastating for many reasons. Corals are already facing mass extinction from global warming and rising water temperatures. Mass bleaching events are described as "the new normal." (Watch Chasing Coral to learn more about this.) Many people depend on coral reefs for sustenance, coastal protection from storms, and tourism income, but the future looks bleak. Lamb said in a press release,

"We estimate there are 11.1 billion plastic items on coral reefs across the Asia-Pacific and forecast this to increase by 40 percent within seven years. That equates to an estimated 15.7 billion plastic items on coral reefs across the Asia-Pacific by 2025."

If there is anything to take away from this heartbreaking study, it's that individuals can make a difference by changing their consumption habits. Use less plastic. Buy less plastic. Refuse as much plastic as you can. It's the very least we can do.