A New Study from Stanford Just Revealed How Sunscreen Damages Coral Reefs

Sunscreen is a summer necessity to protect our skin from the sun's intense rays. If you're planning a vacation—especially one that requires long days on the beach—you'll need to lather up and reapply over and over again. However, there's a downside to this protection.

Most sunscreens contain harsh chemicals—ones that negatively impact the ocean's beloved coral reefs. But how does sunscreen harm coral reefs, exactly? It's been a mystery for quite some time, but a recent Stanford study got to the bottom of it.

How Sunscreen Harms Coral Reefs, According to Experts

In a May 2022 study published in the journal Science, Stanford researchers discovered oxybenzone, a toxic chemical in most sunscreens, "caused high mortality of a sea anemone under simulated sunlight including ultraviolet (UV) radiation." In other words, the chemical that protects humans from the sun's UV rays has the opposite effect on corals.

Previous research has already determined that oxybenzone and other chemicals like benzophenone-1 and octinoxate are harmful. And this chemical doesn't only harm coral reefs—it also harms green algae, dolphins, sea urchins, and other marine wildlife. The only question left unanswered was how.

With the recent Stanford research findings, we now know that the oxybenzone designed to disband the sun's light energy as heat actually gets metabolized by corals and anemones. And the end result is damaged, dying corals that are overexposed to the sun's radiation.

Additionally, our previous research shows that our oceans have already lost about 50% of coral reefs. And coral reefs support 25% of ocean life, boosting biodiversity. But the increases in light exposure and warming ocean temperatures can cause coral bleaching (aka when coral reefs lose their vibrant colors and become susceptible to diseases).

On the bright side, the findings may give rise to more reef-friendly sunscreens on the market. Or at least, we may see new eco-friendly innovations in the world of sunscreen and skincare.

In a statement for Stanford, the study's lead author Djordje Vuckovic, a PhD student in civil and environmental engineering, says he hopes the discovery can have a positive impact on marine life.

“It would be a sad irony if ecotourism aimed at protecting coral reefs were actually exacerbating their decline,” Vuckovic told Stanford. “I hope that our research will help the development of sunscreens that are less likely to harm reefs.”

If you plan on soaking up the sun and spending time at the beach this summer, it's time to get your hands on reef-friendly sunscreen.

What Is Reef-Friendly Sunscreen?

You may have heard of reef-friendly sunscreen, but let's refresh our memories. Unlike traditional options you'll find on store shelves, it doesn't contain UV filters or harsh chemicals that can negatively impact coral reefs and marine life. That means no oxybenzone and octinoxate.

Instead, you can opt for mineral-based sunscreens that deflect the sun's rays from your skin. (Instead of absorbing them how chemical sunscreens do!)

Some states have even banned the use of chemicals like oxybenzone. Hawaii, for example, banned toxic sunscreens in 2018—and other cities and states are following suit. Stanford's new findings could lead to more protection for ocean life, especially in places with heavy tourism.

For now, be sure to pack your reef-friendly sunscreen for your beach trip. And don't forget to reapply!