Protecting the ocean, protecting our skin, two sides of a growing debate.

"It's not just coral. It is also toxic to fish, it's toxic to algae. Oxybenzone is almost like an herbicide," Craig Downs, Exec. Director, Haereticus Environmental Laboratory.

UVA rays from the sun penetrate deeper layers of skin and are linked to melanoma. UVB rays damage outer layers and cause sunburns.

While some sunscreens only block one type of ray, the American Academy of Dermatology says oxybenzone is among the few FDA approved ingredients able to blocks both.

"The AADs recommendations are based on the existing body of scientific evidence. It may evolve if science evolves but right now the research is not very persuasive," said Dermatologist Dr. Terrence Cronin.

For those concerned about the environment, there is some middle ground.

"Using sunscreen is just part of a comprehensive sun protection plan. Sun smart behavior is seeking out the shade, wearing sun protective clothing," said Cronin.