Before sunscreen was invented, sunburns were a nasty fact of life most people were forced to deal with if they wanted to enjoy being outside in the sun. The cycle went something like this: Get a sunburn on the first few warm days, let it peel, enjoy your tan all summer, and then watch it fade over winter. Repeat annually. Today, there are a number of sunscreens available, many of which are water resistant or waterproof, and which are suitable for protecting divers and snorkelers from the ravages of the sun's intense rays. While all sunscreens help to prevent sunburns and mitigate the risk of skin cancer, many have unintended consequences for our coral reefs.
Sunscreen and Coral Reefs
Some ingredients in sunscreens are not biodegradable. Both zinc oxide and titanium dioxide are popular ingredients in effective sunscreens, but neither is biodegradable and both have the potential to harm coral reefs and other sensitive marine life. Petroleum products degrade slowly in water and have the potential to harm birds and aquatic life; if you've ever been at a busy reef and you've noticed a light sheen on the water's surface, you're very likely looking at a very light oil slick - not from a spill of any kind, but from the lotions and sunscreens divers have applied to protect their bodies. While some of these oils are harmless and are quick to dissolve in water, those containing mineral oil have a very low solubility rate.
Lest you think that the small amount of sunscreen or other lotion you apply to yourself has no impact, take a look at this figure: 4,000 to 6,000 metric tons. That's how much sunscreen washes off swimmer's bodies annually. Now you might understand how these products could cause damage to the sea's frail ecosystem. Some ingredients in standard sunscreens have been proven to contribute to coral bleaching, opening corals up to harmful viruses that can increase the rate of degradation.
The Solution
Luckily, some top manufacturers are well aware of the potential problems these products could cause, and they have decided that it's time to make a change. At the top of the list is Reef Safe, which is based in Ormond Beach, Florida under the Beach Buff brand. Approved by the Ocean Futures Society, this sunscreen is nontoxic to marine life.
Another popular reef safe sunscreen is EcoLogical, manufactured in Australia, but easily obtained online; and another brand offering biodegradable sunscreen is Caribbean Solutions. Caribbean Solutions offers several different types of sunscreen, some of which are not reef safe - be sure you read the ingredients list on this or any other sunscreen you plan to use while diving. You'll still see a slick when you use these brands or one of the others that is available; this is because even the harmless ingredients used take about 90 days to biodegrade. While they often need to be applied more frequently, natural nontoxic sunscreens are also potentially better for you than some of the chemicals used in standard sunscreens.
Choosing the right kind of sunscreen is just one of many things you can do to protect marine life. Deciding how to fertilize your lawn and garden, determining which fish and other foods are suitable for consumption, and understanding how the products we use each day affect the ocean can bring about greater awareness and help us counteract the negative cumulative impact humans are having on the planet. Remember, when you protect the ocean, you protect yourself and all life on earth; with the right sunscreen, this is true in more ways than one.