In last month's issue, we ran a story about the actual
results of many high-SPF sunscreens, and how many of
them just use high numbers as a gimmick. We listed the
results of Consumer Reports' survey of sunscreens, and
then listed the ones they ranked as best buys.
But how well do those sunscreens protect the reefs,
asks subscriber Lisa Evans (Fort Collins, CO). "I was
dismayed to see there was no information about the
damage done to coral from many commercial sunscreen
products. I've researched this, and while I still use conventional
sunscreen for land-based activities, I make it a
point to buy reef-safe sunscreen for my dive trips. Right
now I have Goddess Garden 30 SPF ( http://goddessgarden.com ). I encourage you to help readers become
aware of the potential damage their sunscreen is causing
to coral reefs."
You're right, Lisa. While it's counter-intuitive to
think that 15 divers from a liveaboard, each putting
on two tablespoons of sunscreen before diving over
an area several acres across and 75 feet deep, will be
wearing enough of any chemicals to affect the reefs
below, washed-off sunscreen can damage corals. The
U.S. National Park Service reiterates what Evans says:
Chemicals in sunscreen can lead to bleaching, dying
coral. A 2008 study in the journal Environmental Health
Perspectives found that up to 6,000 tons of sunscreen
enters reef areas annually and it does not spread out rapidly or evenly over the entire ocean, but concentrates
on popular tourist sites. It's estimated that 90 percent of
snorkeling and diving tourists are concentrated on 10
percent of the world's reefs, meaning our favorite dive
spots are exposed to the majority of sunscreens.
So with the corals in mind, "reef safe" biodegradable
sunscreen is better than the conventional choices.
Look for a brand that uses physical sunblocks such as
titanium dioxide and zinc oxide instead of chemical
ones. And read the label. A product advertising itself
as "reef safe" doesn't necessarily mean what it says.
Look at ingredient lists to make sure reef-damaging
substances (such as oxybenzone, butylparaben, octinoxate
and 4-methylbenzylidine camphor, all of which have
been shown to cause coral bleaching even at low levels)
aren't included. Apply sunscreen at least 10 to 15 minutes
before going in the water so that the lotion absorbs
into your skin. PADI lists its recommended reef-safe
sunscreens at www.padi.com/blog/2013/06/27/coral-reef-safe-sunscreen-for-scuba-diving
Ironically, the environmentally-friendly sunscreens
on Consumer Reports' survey got the lowest marks for
sun protection. The only one that got decent marks was
California Baby SPF 30, scoring 50 out of 100. So divers
have a dilemma: Protect against melanoma and harm
the reefs, or save them at the expense of your own hide.
Better yet, just stay out of the sun.