Coral and Sunscreen: Chemical in 3,500 Products Washes into Ocean, Kills Coral

We've talked about the harms of certain chemicals in commercial sunscreens, which wash off in oceans and can harm marine life. But a recent study conducted on seawater taken from near Hawaii and U.S. Virgin Islands coral reefs shows that oxybenzone, which is found in possibly 3,500 sunscreens worldwide, specifically threatens coral and is having a real impact, according to a release. 

The study was conducted by marine scientists from Virginia, Florida, Israel, the National Aquarium (U.S.) and the U.S. National Oceanic & Atmospheric Administration (NOAA).

Oxybenzone affects coral reefs by washing off swimmers but also arrives in the water through municipal sewage, coastal septic systems, and other wastewater discharges along the coasts.

This news, of course, arrives about two weeks after NOAA noted the third-ever global coral bleaching event and warned that coral is very vulnerable.

The team says their study shows that baby coral, or coral planulae, that is exposed to oxybenzone experiences serious deformities in morphology, damaged DNA, and endocrine blocking. In the last case, coral builds up its own skeleton and leads to death.

The study says that such effects resulted when the exposure was only 62 parts per trillion--this is like one drop of water in 6.5 swimming pools of Olympic size, according to the release.

The researchers found oxybenzone in the seawater tested at concentrations from 800 parts per trillion to 1.4 parts per million. They said that these amounts are more than 12 times higher than concentrations that concentrations necessary to affect coral, as the release noted.

"The use of oxybenzone-containing products needs to be seriously deliberated in islands and areas where coral reef conservation is a critical issue. We have lost at least 80% of the coral reefs in the Caribbean. Any small effort to reduce oxybenzone pollution could mean that a coral reef survives a long, hot summer, or that a degraded area recovers. Everyone wants to build coral nurseries for reef restoration, but this will achieve little if the factors that originally killed off the reef remain or intensify in the environment," noted the study's lead author Dr. Craig Downs, of Haereticus Environmental Laboratory, in Virginia, in the release.

Just to give an idea of the amounts involved, consider that around 6,000 to 14,000 tons of sunscreen lotion ends up in coral reef areas each year. Of that, much contains between one and 10 percent oxybenzone.

Their study was recently published in the journal Chemosphere. 

The nonprofit The Environmental Working Group (EWG) released this list of sunscreens that don't contain oxybenzone. 

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