Reef safe sunscreen may seem silly and unimportant, but it's really not. The amount of sunscreen that gets into the water from a single day of diving may appear inconsequential when contrasted with the vast oceans, but an estimated 4,000 to 6,000 metric tons of sunscreen rinses off of swimmers every year.
Recent reports of the Great Barrier Reef dying off were premature, but not by much. The bleaching in 2016 was the most severe yet, and the coral is extremely fragile now.
Sun protection is essential for our skin, whether we're recreating on or in the water. The problem is that many sunscreens use benzophenone-2 (BP-2), oxybenzone, octocrylene, 4MBC, butylparaben, and octinoxate, which, in excessive concentrations, kill young coral and can cause mutation in older coral.
Studies on other personal care ingredients continue, as the search for a proven reef safe sunscreen continues. Researchers in Australia are investigating a UV-resistant ingredient that is found in coral. In January 2017, a bill was introduced to Hawaii's Congress to ban oxybenzone and octinoxate in sunscreen in the state as a measure to protect their coral reefs.
Of course, sunscreen isn't the worst problem that coral is facing. Industrial pollution, oceanic warming, and shore runoff are all doing serious harm to coral reefs. Yet adding any additional threat to coral that is fragile from other threats may tip the scales and be part of what kills it.
What You Can Do
The research on the effect of different sunscreen ingredients on coral is not accepted by everyone, of course. Few studies have been replicated, and there are valid criticisms of the studies that have been done. Still, a responsible diver should minimize their impact on the oceans in any way possible.
Sunscreens using titanium oxide or zinc oxide may wash off into the water, but they are not yet known to cause harm to ocean life. Rash guards and neoprene suits also provide protection from the sun, minimizing the skin that needs a reef safe sunscreen. There are multiple manufacturers producing reef safe sunscreens and after care products. With these options and appropriate clothing that blocks harmful rays, the need for products that ultimately harm the very reefs we dive to see will be lessened.