From Undercurrent online:

"Skip The Sunscreen While Diving : It can damage and even kill coral reefs, says a study in the journal Environmental Health Perspectives. Italian marine biologists have linked four UV-blocking chemicals in sunscreens to coral bleaching because they cause viral infections in the symbiotic algae that live inside reef-building coral. The viruses replicate until their algae hosts explode, infecting neighboring coral. The researchers estimate that 5,000 tons of sunscreen wash off people in oceans annually, and that up to 10 percent of coral reefs are threatened by sunscreen-induced bleaching."

I remember years ago being told sunscreen was prohibited while snorkeling on Isla Mujeres, have never seen any reference to it on Bonaire or anywhere else I've been diving/snorkeling. I personally just cover up, my sun-worshipping days are over, but wonder why no mention/concern from STINAPA?

While I don't doubt the importance of what the researchers have found, I believe they (or perhaps Undercurrent, of which I am a subscriber) may be misrepresenting some of the facts. Are they saying that the 5,000 tons of sunscreen that wash off people in oceans annually all comes from divers (as I believe is implied in the statement) or does it come from all people who use our oceans. And if from all people, then what percentage of that 5,000 tons comes only from divers. Perhaps some other BTer's have additional facts to add.

Dr. Director...with all due respect, I think that you are missing the point. The point here is that sunscreen does damage the reefs. I don't see anywhere that implies that this is solely from divers, it just appears in a diving publication.

In my opinion, it does not matter what percentage is caused by divers. The bottom line is that anyone who chooses to use sunscreen in the ocean may be causing harm to the reefs of the world. I think that this is plenty reason to not use it.

You know the old addage...Think globally, act locally.

This is very interesting so I did some quick searches on google and found a lot of information. Many resort destination ask you to wear reef-safe sunscreen, some even give you small tubes of it for free for the snorkelers. I will definately be picking up some for our April trip to Bonaire. So far I have only found this site that advertises reef-safe sunscreen.
CaribbSol Doesn't seem to be available in Canada though
I will also check all the sunscreen in our drugstore to see if the regular sunblock manufacturers are offering an eco-friendly line.

Here's a link to the actual study, for those who'd like to know more:

http://www.ehponline.org/members/2008/10966/10966.pdf

Got to go with the good Doctor on this, this warning is based on one very shakey experiment. He enclosed the coral in a closed tubes and exposed them to differing amounts of the active ingredients in sunscreen. It died, OK where's the water exchange that happens in real coral.

It's just silly, it could be proved that not one molecule of my sunscreen will ever come in contact with the coral as I swim by. How many gallons of seawater are between me and the coral, and the stuff is designed to not dissolve in seawater (be pretty worthless otherwise).

It reminds me of brain cancer from cell phones, or cancer from power lines. On the other hand I could be wrong.

Cecil, this is not the only experiment done on this. I think you should investigate a little more before coming to your conclusion. To compare it to an urban myth is misguided.

Channkanaab Lagoon in Cozumel died after about ten years exposure to snorkelers using sunscreen , fact not myth . To think that the small amount of sunscreen one person may use in the sea is like saying a few drops of bulk oil wont hurt either . If its artificial dont use it , there are natural sunscreens avaliable everywhere that leave no more pollution than a bit of lemon peel .

Does the report state what ingredients specifically are harmful to the reef? I know when we were in Mexico at Xel-Ha they were very strict about not putting on sunscreen before snorkeling.

Hello Lloyd -- Is there a link describing this study? All I could find was this link, but it's more about the damage caused by dolphin enclosures, etc.

http://www.globalcoral.org/Dolphin%20enclosures%20and%20algae%20distributions%20at%20Chankanaab,%20Co.htm

Jennifer -- It does. Just look at the tables towards the end.

Im going on what i saw , in 1988 it was a pristine coral garden enclosed in a natural lagoon . I went back every year and saw the decline untill it was totally bleached white with just a few parrot fish left . Then they closed it and started protecting the ocean side , it too is bleached dead . It use to be one of the best places in the world to snorkle. When you see destruction happen that fast it makes you realize the effect we have on the sea.

Wearing sunscreen around the coral reef is like smoking in a car with children.

Exactly, thank you Lloyd!

I am surprised that people would be so quick to write off something like this study. I like to think that most (not all) divers are inherently environmentalists. I guess that i am quite wrong. Oh well, it is not the first time and surely will not be the last.

one more time though just in case it sticks with one person, THINK GLOBALLY AND ACT LOCALLY.

Yes we are inherently environmentalists, but I am also an engineer and on the skeptical side especially when I hear something like this where a few grams of something is going to cause a mass killing of anything in billions of gallons of dilution.

Nice straw man about the bunker oil (thousands of gallons of something noxious that floats vs. grams of something we spread on our bodies and dissolves).

My bottom line, pick your battles.

Lloyd,

I was last in Cozumel in 2004 and was planning on visiting Channkanaab. Our divemaster told us that several dolphins had died due to their excrement not being able to get through the mesh wire surrounding the area.

I dropped that idea immediately! However, I did not know it had closed. When did that happen?

As far as sunscreen goes, I don't use any myself, but I see anything wrong with erring on the side of caution, whatever your view on the matter is.

If natural is just as good, I say go for it!

The actual lagoon part of channkanaab closed in the early 1990s. Hey Cecil , I hope you are right , ive seen people pour that stuff on them and snorkle in the shallows for hours . If your dilution theory is correct the ozone should be ok as well. whew!

OK -- I have to ask -- what would be an eco-friendly sunscreen that I might be able to pick up at home here in the states? Gerald included a website that looks promising. What other choices are there?

I, for one, have not heard of this controversy until today. Color ME late! I plan to change my ways, but also need the appropriate sunscreen. What do you recommend?

Since I started the questioning of the study, let me restate my points, but do it separately:

(1) The title of the article is "Skip the Sunscreen While Diving". This is intended to get the attention of us divers, but also tends to imply that we divers are the cause of the problem.

(2) I do not doubt that some sunscreens can harm the reefs. I, like Cecil, am inherently an environmentalist. I did not question how the researchers determined that four UV-blocking ingredients (or which ones) can harm the reef. However, oftentimes the concentration of the "bad ingredients" used are extremely high just to be able to see the effects in a short time period, and sometimes this can skew the results. Suppose I do an experiment (and this example is a ridiculous extreme) to determine if nitrogen is bad for you. Rather than using air that contains only 79% nitrogen, I have my test subjects breath 100% nitrogen. Obviously my test subjects would have a problem and some might even die unless I stopped the study when I realized there was problem. How would people react if I were to publish an article that says breathing any nitrogen is dangerous to you, just because breathing an excessive amount is bad. (Remember, I said my example was a ridiculous extreme.)

(3) What I did question was whether the researchers (or Undercurrent) were implying that 5,000 tons of sunscreen wash off divers annually.

Perhaps a few additional facts could have helped explain the study and its results rather than just using an alarmist headline. How many tons of sunscreen are manufactured annually? How many tons of sunscreen are worn by people who enter our oceans (or our oceans and all other bodies of water that flow into our oceans)? What percentage of sunscreen washes off each person? Which four ingredients were the bad ones? Were there any UV-blocking ingredients that didn't cause a problem? If so, which ones? Having these additional facts would have helped me put the issue in perspective, and perhaps I would not have written my comments.

Okay, now anyone who wants can jump on me for not taking the time myself before I posted to go look up the study, read the full report, write the authors with my questions above, etc.

People with fair complexions definitely need to put something on their skin to protect themselves from the harmful effects of over-exposure. Aside from severe sunburn, there is also skin cancer and extreme misery.

Even if the study is flawed, it draws attention to the fact that environmentally friendly sunscreen actually exists. This thread is the first time I have ever even heard of environmentally friendly sunscreen. Maybe raising awareness of the existence of environmentally friendly options would be an alternative approach to address the issue of polluting our marine environments.

I read the same material in an article in CDNN online, about research from Italy.

I did not see any implication there that divers are 'the cause of the problem', just that divers can contribute to the problem.

Perhaps Dr. Director has read more into the article than it really said.

your skin could very well become tolerant of the bonaire sun...with enough visits...i do not use sun screen anymore...

bug spray is a different matter...

I am extremely grateful for any research that will make me aware of environmentally-safe alternatives, and have not worn any sunscreen in the ocean since becoming aware of this issue.

That said, I think that complex systems, whether large bodies of water, climate, or civilizations, are usually not altered overnight by one variable, but a confluence of several variables. Simply saying, "A" causes "B" makes for a good article (and perhaps encourages needed funding) but it may or may not reflect reality as a whole.

In other words, I am convinced that sunscreen most likely has contributed to the terrible harm done to Cozumel. But I cannot currently see how it is the single factor behind coral bleaching.

When I made my original post, I had not read the full article. Was only commenting on the implications. I have since read the full article, which includes information/estimates on how much total sunscreen is manufactured, how much is used in tropical areas, how much washes off, the percentage of coral reefs in the tropical areas, etc. Also details on their test methodology, and the specific problem-causing ingredients. Did not directly/solely implicate divers, so it seems the alarmist title and implication that the 5,000 tons were from divers may have been more from Undercurrent. And while I may not agree with the test methodology, at least I now have some additional information on which to decide what to do.

Dr. Director,

I've re-read the Undercurrent blurb, and still don't see how it implies that divers are the source of the majority of the contamination. I just read it as a heads-up that this has been identified as a problem (and moreover that the mechanism for this toxicity which has been observed empirically in the past has been identified). I'm not arguing with your take on it, we just obviously came away with very different takes on the same statement.

I've also read the full article. While it's been a long time since I have been involved in bench research, this looks like a carefully done and carefully controlled study.

As for the issue of sun screen while diving, I wear SPF 10,000 - AKA a wetsuit. I swap my hat for a scuba-do-rag when I get in the water. I can't really stand sunscreen, tend to stay out of the sun or cover up during the day.

I did a Google Scholar search on sunscreen and coral and found many articles on UV protective chemicals produced by coral but nothing else about toxicity from sunscreens, although I know this is not a new issue. A standard Google search of the topic leads to a gazillion popular press citations of the paper we are discussing here (and to this thread!).

I agree that this is a complex issue. Water temperature, water pH, iron content from African dust which blows across the Atlantic, runoff, direct diver impact, loss of algavores eg diadema and parrotfish, cruiseship waste are all either known or putative causes of reef deterioration. There aren't many that we can directly affect by individual actions and choices. This is one.

Ah, yes, headline writers! All the same the world over: suck in the reader regardless of how benign the real content may be. TKS for the update, Dr. :–))

Dave wrote:

"As for the issue of sun screen while diving, I wear SPF 10,000 - AKA a wetsuit. "


Good one! ;)

Hummm...cover up? Stay away from the man-made SPF chemicals? I think I like that approach. Must be why I don't use the stuff in the first place. If I could only say the same thing about Deet.

Does the article mention PABA free???

OK - I'm a "Janie come lately" to this discussion BUT - what exactly makes a sunscreen environmentally safe? Sorry but I HAVE to wear it. Yes - I wear a hat, a wetsuit, a do-rag, a rash guard and everything else but I also wear sunscreen on my face, hands and feet. I put it on exposed skin as soon as possible when I'm out of the water and try not to apply it too close the to time I am going in the water.

I want to do what is best for the environment but absolutely must do what is good for me too. I can't afford to be burned by the sun. So what a makes the Carribean Sol product environmentally friendly? I found another product that is a "natural" product - does that make it good too? http://www.aubrey-organics.com/about/articles/sun_exposure.cfm

I think it is worth it the effort even if there is only a slight chance we are affecting the reefs and the creatures that live in them. I try bring a sunblock that lists Titanium Dioxide and/or Zinc Oxide as the only sunblock ingredient. It is a physical rather than chemical sun block made from ash. Draw back of course is that it turns your skin kind of white. It's almost impossible these days to find it as the only ingredient unless you go to a heath food store. I am an Aesthetician so skin care is very important to me. For the face I like to use Fallene Total Block www.totalblock.com, the tinted one works as makeup and the clear one only gives a very slight "whitishness" to my husbands beard area. They are both around 60 SPF.

Make sure you use a low powered light so you don't blind anyone or cause the reef to fade!
LOL

Here's some info that was sent to me regarding natural marine friendly sunscreens. Sounds good to me... I don't know anything about these products so I can't tell you the best ones or anything but this is the second person to mention the titanium dioxide AND/OR Zinc Oxide so that's two more than before...

Most sunscreens — even the ones labeled “natural” -- contain petrochemical sunscreen chemicals that absorb UVA and UVB rays. The coral bleaching study that everybody is talking about identified three synthetic sunscreen chemicals as a potential hazard. The offenders include oxybenzone, the most common synthetic sunscreen in use today, plus octinoxate, a camphor derivative and benzylparaben, a preservative.

These synthetic chemicals — and many others — wash off the skin and settle onto the coral. Some apparently damage the algae that protects the coral. Others interfere with the coral’s own photosynthesis.

By contrast, Caribbean Solutions uses two mineral sunblocks — titanium dioxide and zinc oxide. Instead of absorbing the rays, they reflect and scatter the light away from the skin. They’re combined with plant oils and extracts such as sunflower oil, green coffee bean extract and cucumber extract. There’s nothing from a refinery and nothing that can cause harm when dissolved in sea water.

We’ve read a lot of labels as part of the retail marketing of this product, and checked ingredients on the Environmental Working Group’s excellent cosmetic safety database, www.ewg.org/skindeep. I’ve basically decided that if I can’t pronounce an ingredient, I’m not going to ingest it or rub it on myself any more. Why take the risk if you can find a safe product that works?

(The Aubrey product you mention is very good. There are some others, including some spa/department store skincare lines that are pricey but fabulous.)

Caribbean Solutions is launching at retail this spring in Whole Foods stores and elsewhere, at $14.99 for a six-ounce bottle. Check the website (www.caribbean-sol.com) for store locations, or order through the website or by calling 1-866-460-7363. Note: the new packaging says “marine friendly” and “biodegradable” right on the bottle, so the sunscreen police at certain dive sites should be convinced that the stuff is not harmful.

I'll just point out that the lowest concentration that they studied in that paper would be the equivalent of 450 gallons of sunscreen dumped on an area the size of Bari Reef, all at one time.

The bleaching effect was so quick at the levels that they tested, that they should at least be able to go lower by a factor of 10 and a factor of 100 to see how the effect varies with lower concentrations.

Amazing Gary. I was just thinking the same thing.

Reminded me of the Canadian study years ago that Diet Coke caused cancer in lab rats...but only when they drank the equivalent of 600 cans a day.

And Dr. I want to get absurd too. What if the same study was done with urine? Please don't answer this next question: How many of you pee while diving? Do we know the effects?

I am for saving marine life at any costs. I'm also thinking about the thousands of young children we have scared to death about the effects of the sun and skin cancer. I just don't see the majority of people who contribute to the 5000 tons of sunscreen giving that up to protect marine life when it comes to their kids.

Also, I understand about the chemicals in sunscreen, but what about the waterproof stuff? I come out of the water and I'm just as greasy as I went in. Did I leave the chemicals behind and just keep the grease?

And lastly, they have found a 'solution' with new products. What happens when we find out that those new products did something different?

Just some thoughts.