Plastic is Killing Our Coral Reefs

Fagjun | Published 2018-02-01 14:16

Scientists have found that coral reefs clogged with plastic are 20 times more likely to catch diseases.

Plastics are choking our reefs. [Photo via Shutterstock]

Plastics are choking our reefs. [Photo via Shutterstock]


Our coral reefs have a lot to contend with. Not only are they in danger of coral bleaching due to climate change, but they also have overfishing and toxic chemical runoffs from human industries threatening their survival. All these problems can mean death for coral reefs, which harbor diverse marine life. Now, a new study has found a new threat to the reefs: the billions of pieces of plastic waste choking our oceans.


Plastic is cheap, disposable, convenient—and very hard to get rid of. The study’s authors estimate that there are about 11 billion pieces of plastic caught in coral reefs, and that number is projected to grow by 40 percent in just seven years. Unfortunately, this is bad news for the world’s coral reefs. Research shows that the likelihood of corals contracting disease jumps from four percent to 89 percent when they come into contact with plastics.

Choked With Plastic

A diseased coral with a piece of plastic lodged in it [Photo by Joleah Lamb]

A diseased coral with a piece of plastic lodged in it [Photo by Joleah Lamb]


The researchers studied over 124,000 corals found in 159 reefs in Australia, Indonesia, Myanmar, and Thailand. This area, known as the Asia-Pacific region, is home to half of all the coral reefs in the world. According to the researchers, almost anywhere they turned, they saw bits and pieces of plastic.


“We came across chairs, chip wrappers, Q-tips, garbage bags, water bottles, old nappies,” said Joleah Lamb, lead author of the study. “Everything you see on the beach is probably lying on the reef.”


Findings showed that pieces of plastic cut corals and deprived them of light and oxygen. In these conditions, pathogens had more of a change to infect the corals. The researchers also found that the spikier the coral is, the more likely that it will snag a piece of plastic. 89 percent of the reefs that had plastic in them were diseased, while the same was true for only four percent of the plastic-free reefs.


According to Lamb, because plastics are porous, they’re ideal vessels for microorganisms. Like in humans and other animals, the wounds of corals tend to get infected. Thus, not only do plastics cause lesions in corals, they carry the microorganisms that infect those wounds as well.

Our Coral Reefs

A spawning coral with plastic wrapped around it [Photo by Lalita Putchim]

A spawning coral with plastic wrapped around it [Photo by Lalita Putchim]


Every year, about eight million metric tons of plastic find their way into our oceans. The researchers were able to include plastic pieces more than five centimeters in length in their study, but were unable to include smaller pieces. Thus, it’s likely that there are more plastics choking the reefs, since microplastics weren’t included in the study.


The study presents convincing evidence that plastics do indeed serve as a vector of disease for coral reefs. However, if you add climate change and other threats into the mix, it all adds up to very bad news for corals. These reefs not only house marine life, but they’re also a buffer against storms and typhoons. The degradation or maybe even the outright and eventual loss of our coral reefs may impact us in worse ways than we may expect.

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