Sunblock and Coral Reefs

How can we protect our skin and the coral reefs?



Coral reefs are one of the most fragile, diverse, and important ecosystems on the planet! They are also sometimes called the rainforests of the sea. They are typically found in warm, shallow, clear, sunny, tropical waters, however deep cold-water reefs exist but on a smaller scale. Though coral reefs only occupy 0.1% of the ocean they are home to an average of 25% of sea life. Most don't realize that corals are actually living creatures and not just colorful rocks, and most importantly they don't understand how fragile they are. From 2009 to 2018, coral reefs worldwide declined 14% and the rate is increasing every year due to various factors. We will mostly be discussing and focusing on sunblock as it is the most prevalent problem in our little corner of paradise.


The Riviera Maya, including Cozumel, lies along the second largest barrier reef in the world, making this a splendid area for snorkeling and scuba diving. People flock from all over the world for some of the best scuba diving there is. Unfortunately the more people that visit the reefs, the more stress that it causes them. The perfect example of this is in Akumal, Mexico. The bay of Akumal used to have one of the most pristine, colorful reefs of the Riviera Maya coastline. It is home to many creatures such as rays, tropical fish, and the most sought after, the sea turtle. Once people knew that it was the place to go to snorkel with the turtles, the area became inundated with tourists. More and more people were going to the reef and not following the proper protocols when entering the water. What do I mean by this? First, they were not required to wear life jackets, even though they may be a good swimmer, when you need to get the water out of your mask or adjust equipment, it is natural to want to stand up in the shallow water. The problem here is that people would stand on the reef causing severe damage. Secondly, and most importantly, visitors would lather up on sunblock or sun accelerator before entering the water. It's estimated that 14,000 tons of sunscreen are deposited worldwide into the ocean every year! Now the reef in Akumal is severely damaged and may never recover.


Now let's talk about sunblock and how it affects the reef. Research has found that one of the main chemicals that is found in over 3,500 sun care products that causes the most damage to the corals is Oxybenzone (Benzophenone-3).


Coral Bleaching
Photo: THE OCEAN AGENCY / XL CATLIN SEAVIEW SURVEY

These chemicals can lead to coral bleaching, damage the DNA of corals, and increase abnormal growth and deformities. Sunscreen is likely just one more stressor that is making corals more susceptible to disease, such as the Stony Coral Tissue Loss Disease that is affecting reefs across the Caribbean sea.

How does sunscreen cause coral bleaching? Corals are usually covered in zooxanthallae. These tiny creatures absorb light and use photosynthesis to create food for the coral. When corals become stressed due to increased water temperatures or pollution from chemicals found in sunscreen, they expel the zooxanthallae. These tiny creatures are a lifeline for the coral, and without them they lose the main food and oxygen source and also the wide array of colors that make coral so attractive. Bleached corals are more vulnerable to disease. Their growth is stunted and the damage will negatively impact the surrounding marine life. Although it is possible for some to recover, most bleached corals will starve to death. But it’s not only chemical sunscreens that are harmful. Mineral sunscreens sometimes contain nano-particles which are so small that they can be absorbed by marine life. These minerals are toxic to many ocean species and can cause stress and ultimately death, even at low concentrations.


So what can you do to help protect the reef?


Here are some tips to stay sun-safe and reef-safe!


  1. The first step to buying reef-safe sunscreen is to check which active ingredients are in the bottle. Unfortunately, you can’t rely on brands that make “reef-safe” or “reef-friendly” claims, as there is no government regulation for this and manufacturers are not required to test if the product is impacting reefs. Key ingredients to avoid are Oxybenzone and Octinoxate. Additionally, look out for Benzophenone-1, Benzophenone-8, OD-PABA, 4-Methylbenzylidene camphor, 3-Benzylidene camphor, and Octocrylene. These can affect corals’ reproductive cycle, damage DNA, and worsen the effects of coral bleaching.

  2. Instead of using a type of sunblock, consider covering up. You can use a t-shirt, hat, swimwear, etc. that contains UV protection in the material. Remember! If you are wearing a wetsuit there is NO reason to put on any kind of sun protection.

  3. Stay out of the sun and/or under some shade when the sun is at its most intense, especially between the hours of 10 am - 2 pm.

  4. Luckily, you don’t have to give up sunscreen altogether! ‘Reef-safe’ is not regulated and has no agreed specifications, so when purchasing your next bottle of sunscreen check the labels and consider the following:

  • Avoid aerosols – spray-on sunscreens create a chemical cloud that settles onto the sand. When the tide comes in these chemicals wash into the ocean.

  • Opt for mineral sunscreens that use ingredients such as zinc oxide or titanium dioxide. But remember that not all mineral sunscreens are reef-safe. In order to be reef-safe, the ingredients must be “non-nano,” or larger than 100 nanometer in size, as this makes it less likely that it will be absorbed by marine life. Choose mineral products that indicate that the ingredients are non-nano, for example “non-nano zinc oxide”.

  • Look for products with the Protect Land + Sea Certification.



Spread the word. You can help by driving consumer demand by advocating for more-reef safe sunscreen options and raising awareness. Educate others about the consequences of certain sunscreens and let them know how they too can keep themselves and the reef safe!


Click this link for Sunburn Treatments and Tips!

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