Reef-safe sunscreen?

[rb1685]

I'm going to be spending a week in St. Thomas at the beginning of September. Can anyone make any recommendations for a good reef-safe sunscreen? Any brands in particular?

Thanks!

[jwing]

Thank you for caring! I love snorkeling and diving; the less clothing, the better.

Unfortunately, I find that water proof sunscreens aren't waterproof and therefore are not sunscreens! For diving, I don't worry; I never got burned diving. For snorkeling, I have resigned myself to strategic timing. Go early or late, avoid the middle of the day. If I go in the middle of the day, I wear a rash guard on my upper body, lycra tights on my lower body, and a Buff on my noggin. Ways to Wear

The whole kit takes about 15 seconds to put on, which is a lot quicker than applying sunscreen.

[rb1685]

Originally Posted by jwing

Thank you for caring! I love snorkeling and diving; the less clothing, the better.

Unfortunately, I find that water proof sunscreens aren't waterproof and therefore are not sunscreens! For diving, I don't worry; I never got burned diving. For snorkeling, I have resigned myself to strategic timing. Go early or late, avoid the middle of the day. If I go in the middle of the day, I wear a rash guard on my upper body, lycra tights on my lower body, and a Buff on my noggin. Ways to Wear

The whole kit takes about 15 seconds to put on, which is a lot quicker than applying sunscreen.

Yes I intend to do a bunch of snorkeling and diving whilst I'm down there. I do a lot of fishing here in Texas, and I've considered getting a Buff. It seems that sunscreen is more of a hassle than anything. If I need it during the day, why not just cover up with some clothes? I'm already at risk for skin cancer, so I don't need a tan anymore.

[bstreep]

I'm a molecular biologist (PhD dropout from Rice University). I'm also a life-long reefer (the coral kind, not the dope kind) - I've had large reef tanks packed with corals that I've grown from tiny little pieces (called frags).

There's no way the amount of sunscreen you use will have ANY effect on the reefs. MAYBE with a large group from a cruise ship. But not a few individuals on a reef.

It's called dilution. Let's do the math. Say you use an ENTIRE ounce of sunscreen on your body (really?). It's 1/3 "active ingredients" and we'll include them all, but only 1 or 2 are actually problematic. Reefs are constantly washed with fresh seawater. But let's ignore that. A 100 x 100 x 10 foot section of reef contains 12,000,000 gallons of water. Your dump of 1 ounce of sunscreen into that yields 1/4 of one part per BILLION. Generally, reef-toxic chemicals are measured in parts per MILLION. For instance, ammonia - EXTREMELY toxic - appears in up to .7ppm in natural seawater! That's 2800 times as much as your sunscreen.

And the current in a reef is almost always huge - water turnover is insane.

ALWAYS remember, it only takes one idiot scientist to post one supposed "scientific" article to get the entire world going crazy. Everyone repeats it, believing it to be true. Science runs on money, and on recognition. The internet is a GREAT tool for that. Use some common sense...

I can tell you that "reefers" do worry about what's on their hands when working on a tank - we try and keep our hands clean. But my 215 gallon tank, it would be equal to about 1/50,000th of a grain of salt sized toxin in my tank. Not gonna be toxic in any way.

[belizesailor]

Yeah, I've always assumed these "reef safe" sunscreens were marketing rubbish.

[rb1685]

Originally Posted by bstreep

I'm a molecular biologist (PhD dropout from Rice University). I'm also a life-long reefer (the coral kind, not the dope kind) - I've had large reef tanks packed with corals that I've grown from tiny little pieces (called frags).

There's no way the amount of sunscreen you use will have ANY effect on the reefs. MAYBE with a large group from a cruise ship. But not a few individuals on a reef.

It's called dilution. Let's do the math. Say you use an ENTIRE ounce of sunscreen on your body (really?). It's 1/3 "active ingredients" and we'll include them all, but only 1 or 2 are actually problematic. Reefs are constantly washed with fresh seawater. But let's ignore that. A 100 x 100 x 10 foot section of reef contains 12,000,000 gallons of water. Your dump of 1 ounce of sunscreen into that yields 1/4 of one part per BILLION. Generally, reef-toxic chemicals are measured in parts per MILLION. For instance, ammonia - EXTREMELY toxic - appears in up to .7ppm in natural seawater! That's 2800 times as much as your sunscreen.

And the current in a reef is almost always huge - water turnover is insane.

ALWAYS remember, it only takes one idiot scientist to post one supposed "scientific" article to get the entire world going crazy. Everyone repeats it, believing it to be true. Science runs on money, and on recognition. The internet is a GREAT tool for that. Use some common sense...

I can tell you that "reefers" do worry about what's on their hands when working on a tank - we try and keep our hands clean. But my 215 gallon tank, it would be equal to about 1/50,000th of a grain of salt sized toxin in my tank. Not gonna be toxic in any way.

Very good points. I too am a reefer. I have a little 14 gallon tank that is approaching four years old. Though I'm extremely cautious when putting my hands in the tank, there is no way to avoid every possible toxin that could enter on the hands.

I suppose my logic was based on a "everyone does their part" approach. Besides, after reading all the mixed reviews for sunscreens on Amazon, there doesn't appear to be a good solution anyway.


Sent from my iPhone using Cruisers Sailing Forum

[gamayun]

This came across my news feed today: Sunblock poses potential hazard to sea life -- ScienceDaily

Personally, when snorkeling I use a light dive skin (rash guard) that covers me from neck to ankles. Can stay in the water for hours and not get burned, while sunscreen would wash off in that time. It's good for warm water, too. For diving, no problem. I always wear a wetsuit, but if you get too hot even in a 3mm, a skin is great for that, as well. For laying on the beach, I can't help you there. I don't have the patience to do that anymore, and sunscreen is probably necessary though you can never go wrong in a good floppy hat and lightweight clothes. I grew up in Florida before sunscreen and have had basal cell carcinomas removed about every year since I turned 37. Vitamin D is good for you on bare skin just make sure it stays in small doses...

[bstreep]

Originally Posted by gamayun

This came across my news feed today: Sunblock poses potential hazard to sea life -- ScienceDaily

Ok, that is HILARIOUS. Seriously, go visit some reef sites. Reef Central Online Community. Then search for "hydrogen peroxide dosing". Really, I am drop-dead-serious. Reefers dose with H2O2 ON PURPOSE. I did for quite a bit of time. My poor wife was buying GALLONS of peroxide at the drug store for me. I can't believe these so-called "scientists" didn't do some research first.

I'm STILL laughing.

[gamayun]

Originally Posted by bstreep

Ok, that is HILARIOUS. Seriously, go visit some reef sites. Reef Central Online Community. Then search for "hydrogen peroxide dosing". Really, I am drop-dead-serious. Reefers dose with H2O2 ON PURPOSE. I did for quite a bit of time. My poor wife was buying GALLONS of peroxide at the drug store for me. I can't believe these so-called "scientists" didn't do some research first.

I'm STILL laughing.

Are you saying there's no difference between the control of algae in a fish tank and algae on a natural reef?

I wasn't actually much convinced by that study, especially given all the other pollutants causing significant damage to corals such as your tropicals often being collected by cyanide, but you're talking about H2O2 dosing in an artificial system.

Also, most everyone has long gotten past "the solution to pollution is dilution" mantra that had been spewed for so long.

[bstreep]

Originally Posted by gamayun

Are you saying there's no difference between the control of algae in a fish tank and algae on a natural reef?

I wasn't actually much convinced by that study, especially given all the other pollutants causing significant damage to corals such as your tropicals often being collected by cyanide, but you're talking about H2O2 dosing in an artificial system.

Also, most everyone has long gotten past "the solution to pollution is dilution" mantra that had been spewed for so long.

No, what I'm saying is that peroxide, in any concentration that would evolve from sunscreen, is harmless to corals. When dosing it out of the bottle, we DO have to be careful that fish don't swim right in it before it's diluted.

As for the "solution" thing - who the hell said that? I didn't - you just took my use of "dilution" out of context. I just said that BECAUSE of dilution, the concentration is so low it won't have any effect.

[thinwater]

Oh no, someone waved the bloody shirt and only war will do now.

But as for real sun protection while snorkeling and diving, rash guards work, lotion does not after a few minutes. It's that simple, wear a shirt. Even on the boat, I lotion like crazy, high SPF every few hours, and I still tan... but not under the shirt. Obvious.

[GordMay]

A common sunscreen ingredient turns toxic in the sea — anemones suggest why

Sea anemones and coral turn a common sunscreen ingredient into a toxin activated by light.
Sea anemones, which are closely related to corals, and mushroom coral can turn oxybenzone — a chemical that protects people against ultraviolet light — into a deadly toxin, that’s activated by light.

The good news is that algae, living alongside the creatures, can soak up the toxin, and blunt its damage, researchers report [1] in the May 6 Science.

But that also means that bleached coral reefs lacking algae may be more vulnerable to death. Heat-stressed corals and anemones can eject helpful algae that provide oxygen and remove waste products, which turns reefs white [bleaching].

The findings hint that sunscreen pollution and climate change combined could be a greater threat to coral reefs and other marine habitats than either would be separately.

Previous work suggested that oxybenzone can kill young corals or prevent adult corals from recovering after tissue damage. As a result, some places, including Hawaii and Thailand, have banned oxybenzone-containing sunscreens.

In the new study [1], environmental chemist Djordje Vuckovic of Stanford University and colleagues found that glass anemones (Exaiptasia pallida) exposed to oxybenzone and UV light add sugars to the chemical. While such sugary add-ons would typically help organisms detoxify chemicals and clear them from the body, the oxybenzone-sugar compound instead becomes a toxin that’s activated by light.

Anemones exposed to either simulated sunlight or oxybenzone alone survived the length of the experiment, or 21 days, the team showed. But all anemones exposed to fake sunlight while submersed in water containing the chemical died within 17 days.

The anemones’ algal friends absorbed much of the oxybenzone and the toxin that the animals were exposed to in the lab. Anemones lacking algae died days sooner than anemones with algae.

In similar experiments, algae living inside mushroom coral (Discosoma sp.) also soaked up the toxin, a sign that algal relationships are a safeguard against its harmful effects. The coral’s algae seem to be particularly protective: Over eight days, no mushroom corals died after being exposed to oxybenzone and simulated sunlight.

It’s still unclear what amount of oxybenzone might be toxic to coral reefs in the wild. Another lingering question, is whether other sunscreen components that are similar in structure to oxybenzone might have the same effects. Pinning that down could help researchers make better, reef-safe sunscreens.

Much more about ➥ https://www.nature.com/articles/d41586-022-01271-4

[1] “Conversion of oxybenzone sunscreen to phototoxic glucoside conjugates by sea anemones and corals” ~ by D. Vuckovic et al
➥ https://www.science.org/doi/10.1126/science.abn2600

“Sunscreens threaten coral survival” ~ Colleen M. Hansel
Abstract ➥ https://www.science.org/doi/10.1126/...128.1593714421

[tamicatana]

Cover up. Not only against UV, but against the critters that sting.

[PNWSalmon]

Please see this article from Sailing Totem, which covers the topic comprehensively along with what ingredients to look for. It’s all about ingredients not brands. https://www.sailingtotem.com/blog/re...screen-big-lie

They do an excellent job with examples and information.

[leecea]

When we went to the BVIs a couple of years ago they wanted reef safe but we could not find any in the shops there. Some Googling told us that baby or kid lotions didn't use the bad chemicals, so we bought them. Much easier to find.

Now they have added something about avoiding nano particles so no idea if the ones we used would still qualify.