Is Sunscreen Killing Earth's Coral Reefs?

If you’re one of the millions of beachgoers who slathers yourself in sunscreen before hitting the surf, here’s an additional reason to feel personally responsible for the sixth mass extinction. Your sunscreen, my sunscreen, all of our sunscreen is contributing to the death of Earth’s coral reefs.

Climate change may be Public Enemy #1 when it comes to reef-building corals, but for years, scientists have warned that oxybenzone, an ultraviolet-absorbing compound found in practically every major brand of sunscreen, might also be doing damage.

Now, a study published in Archives of Environmental Contamination and Toxicology has confirmed our suspicions. Oxybenzone kills coral. It disrupts their growth, increases the rate of coral bleaching, damages DNA, and can even cause the larval form of coral (called planula) to become trapped in their own skeleton.

According to the new study, a minuscule amount of sunscreen — the equivalent of a single drop in six Olympic sized swimming pools — contains enough oxybenzone to begin disrupting coral growth.

Across the world, 14,000 tons of sunscreen lotions are discharged into coral reefs each year. And it isn’t just beachgoers who are at fault. No matter where you live, your skincare products wash off in the shower and wind up in a local waterway. Eventually, some of that water reaches the ocean.

Coral reefs harbor a quarter of the ocean’s biodiversity, spawn many of the fish we eat, and protect thousands of miles of coastline from storm surge. Two weeks ago, a report from the National Oceanic and Atmospheric Administration concluded that we’re in the midst of a massive coral bleaching event, a phenomenon which occurs when high temperatures disrupt the symbiotic relationship between coral and its photosynthetic food source, a green alga called zooxanthellae.

This year’s coral bleaching could impact a full 38% of coral reefs worldwide. If current trends continue of ocean warming and acidification continue, some marine scientists think reefs could disappear entirely within the next several decades.

“The use of oxybenzone-containing products needs to be seriously deliberated in islands and areas where coral reef conservation is a critical issue,” study co-author Craig Downs told The Washington Post. “We have lost at least 80 percent 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.”