Coral Conundrum

An up close image of coral underwater. The coral in the foreground is bleached white while the coral in the background is brown. Small fish swim in the background.

Could fun in the sun – mean grief in the reef?

This is Sandra Tsing Loh with the Loh Down on Science.

The sun’s ultraviolet rays cause suntans, sunburns… and an increased risk of skin cancer. Sunscreen protects our skin by using chemicals like oxybenzone to absorb harmful U-V rays. But what happens when it washes off our skin into the ocean?

Craig Downs at the Haereticus Environmental Lab fears it may be negatively impacting coral reefs.

Coral is key to beautiful, diverse reef ecosystems, and it protects shorelines from waves.

It also plays host to algae and other living organisms. But under stressful conditions, the coral expels its algae, and slowly starves. It’s known as coral bleaching; and the slightest deviation in temperature or acidity could trigger it.

Downs collected samples of young coral and exposed them to oxybenzone. He measured cell death and noted any damage to their D-N-A. His study suggested that even low levels of oxybenzone were toxic to coral.

The good news? Many newer sunscreen brands don’t have these compounds. Instead, they’re mineral based.

So let’s be sun savvy AND reef friendly! It’s the best summer style!