How Does Sunscreen Affect Coral Reefs?
Everything You Should Know About It

With up to 14,000 tons of sunscreen being washed off people into oceans each year, it’s time for all of us to understand how sunscreen damages coral reefs. Our simple and allegedly healthy habit of putting on lotion before exposing ourselves to UV radiations is indeed taking its toll on marine life and biodiversity.

Record heat registered in the past years, pollution, and a series of other environmental factors caused the bleaching of over 50% of the coral in Australia’s Great Barrier Reef. Based on the latest trends, scientists predict that about 90% of the world’s coral will be threatened by 2030 (NOAA Coral Reef Risk Outlook).

Since the ocean gives us most of the oxygen we breath, a loss of marine bio-diversity poses a risk to human life everywhere.

According to research (International Coral Reef Initiative, 2018), one of the main causes of coral bleaching is sunscreen; more precisely oxybenzone and octinoxate (NCBI, 2018), two compounds found in most sunscreens.

Specialists concerned about the decline of coral reefs have conducted numerous studies that showed the impact cosmetic products, and above all sunscreen, have on the ecosystem.

NOAA 2016 coral stress levels map

The results speak clearly. Chemical sunscreens are the third-biggest cause of coral bleaching. Things, however, are slightly different in the case of reef safe sunscreen.

Several studies carried out in various parts of the world showed that these chemicals could stress corals and awaken their viruses. When corals become sick, they expel their life-giving algae. The result is coral bleaching, followed by coral death.

With research telling us that tons of sunscreen is washed into the reef areas annually, the negative effects could be devastating. This is why world's most popular snorkeling destinations have started to ban sunscreens containing the harmful chemicals.

Up to date, four of the most popular beach destinations (including Palau, see beautiful coral reefs view below) have introduced official bans, numerous vacation spots in one country ban non-biodegradable sunscreens despite the lack of official regulations, and many other countries are believed to follow the example.

palau islands and coral reefs

In this article, we will take a deep dive into why and how toxic sunscreen chemicals are damaging the marine life, destinations that already banned toxic sunscreens, and what you can do to help protect both yourself and the corals of our oceans.

A study published in the journal Archives of Environmental Contamination and Toxicology in 2016 highlights that the chemical oxybenzone may be contributing to the destruction of coral reefs (Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral...).

It has been shown that oxybenzone causes DNA damage and endocrine disruption which could lead to coral bleaching and potentially death.

Coral bleaching is by far the specialists’ main concern. Through this process, corals reject their symbiotic organisms and lose their color. The rejection of these organisms also weakens corals, making them more prone to contracting viral infections.

oxybenzone and coral bleaching

Considering that toxicity occurs at a minimal concentration, people swimming in the proximity of coral reefs should avoid the use of chemical sunscreen completely.

According to a study conducted by the University of Tel Aviv, the equivalent of a drop of sunscreen into an Olympic swimming pool can pose a significant ecological threat.

Besides damaging the coral reefs, specific chemicals in sunscreens may also be harmful to humans. Oxybenzone, alongside other chemicals found in regular sunscreens, can trigger skin allergies, irritation, rashes, and may even cause skin cancer.

How Can We Protect Both Ourselves and The Coral Reefs?

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While the researches mentioned above highlight the huge negative impact sunscreens can have on the coral reefs and marine life, the researchers’ intention was not to advocate against the use of sunscreen. Parallel studies have shown that sunscreen protects against skin cancer and it is essential to wear it when planning to stay out in the sun for longer than 20 minutes.

Perhaps the most misunderstood thing about sunscreen bans regards the products that are indeed banned. Many people believe they can’t use any type of sunscreen in these areas, which is simply untrue.

In fact, governments know that skin cancer is one of the main causes of deaths in the world; therefore, certain types of sunscreens can still be used throughout the world to protect yourself against sunburns and skin cancer.

Furthermore, there are additional ways to keep harmful UV rays away from your skin while safeguarding the corals too.

Here are three simple steps you should take to protect both yourself and the coral reefs:

1. Understand Which Sunscreen Ingredients to Avoid:

With the bans in place, it is clear that you can only use reef-friendly sunscreens free of oxybenzone and octinoxate. Most of these products are defined as mineral-based sun blocks due to their active ingredients, which are either zinc oxide, titanium dioxide, or both.

However, not all mineral-based sunscreens were created equal. In an attempt to make their product more cosmetically appealing, some manufacturers use nanoparticles of these minerals that can be ingested by corals.

For this reason, the sunscreen you use in reef areas should contain non-nano size particles which are slightly larger. They may leave a whitish residue on your skin, but that’s a small price to pay if you care about our environment.

Furthermore, the Haeraticus Environmental Lab and the Environmental Working Group are two other important resources. The former publishes annual lists of chemicals that can damage the reefs and the environment, while the latter explains the environmental impact of standard sunscreens, including the potentially harmful effects oxybenzone may have on adults and children.

Mama Kuleana Reef Safe Sunscreen SPF 30, Waterproof, 2 oz.

Also please keep in mind, when choosing the sunblock, you should also avoid aerosols, as the mist of sunscreen is very probable to fall on the sand, from where it can easily wash into the ocean. Creams and lotions are the way to go.

2. Which is Better? Nano or Non-Nano Particles Sunscreen?

With most cosmetic brands using fancy names to describe the qualities of their products, understanding what’s the difference between a sunscreen with nanoparticles and one that contains non-nanoparticles could be confusing.

In essence, it’s all reduced to size. A nanometer is one thousand-millionth of a meter. A particle this size can only be observed with a special microscope, and a nanoparticle is any particle with a size between 1 and 100 nanometers.

Research has evidenced that zinc oxide nanoparticles larger than 35nm are safe to the environment. However, according to cosmetic industry experts, they provide poorer UV protection.

So, why do some brands use nanoparticles in their sunscreen?

The reason is simple. Zinc oxide, as well as titanium dioxide, in its non-Nano form, is a white powder that keeps its color when mixed with the other components of sunscreen lotion. The result is a whitish shade on your skin after applying the product.

Zinc oxide nanoparticles are clear and provide an aesthetically more appealing finish. That’s why some people tend to choose biodegradable sunscreens containing nanoparticles of the active compounds.

nan nano zinc oxide comparison

Some research has shown that sunscreens that employ nanoparticles of titanium dioxide and zinc oxide can produce reactive oxygen species under UV radiations.

These reactive oxygen species are free radicals which, in high concentrations, cause oxidative stress to marine organisms including corals, with subsequent cell damage and ultimately death.

Zinc oxide nanoparticles with a size lower than 35nm are more harmful than their titanium dioxide counterpart, mainly because titanium dioxide nanoparticles are often coated with magnesium, aluminum, or silica, compounds that eliminate the UV reactivity.

Considering that photoactive nanoparticles used in sunscreens also provide lower sun protection, it only makes sense to pick a biodegradable sunscreen containing non-nanoparticles of active ingredients.

3. Wear Protective SPF Clothes, Pick Shady Spots

Many apparel manufacturers, especially brands making beach apparel or beach umbrellas, incorporate UV protection factors directly into the fabrics they use. These garments are a great alternative to sunscreen, helping you limit its use with up to 90% when you’re not sunbathing.

two kids wearing rashguards at beach

These garments include shirts, shorts, hats, and even scarves. Furthermore, SPF beach gear, including beach tents and umbrellas, can further reduce the risk of sunburns and skin cancer even if you’re not using sunscreen at all.

Using these alternative options to reduce the use of sunscreen is not only good for the environment. It will also save you money in the long run.

While going to the beach is synonymous with soaking in the sun, you should do it responsibly. Avoid exposing yourself – or the youngsters – during peak hours. The best time to sunbathe is early in the morning and in the afternoon.

For the rest of the day, pick a shady spot for beach games and relaxing. Mini pools smartly positioned under an umbrella or beach tent provide sufficient entertainment to the little ones, keeping them protected from the harmful rays.

Destinations That Have Banned Toxic Sunscreens

With all the studies quoted in this article specifying regular sunscreen chemicals are bad for corals, popular destinations have started to ban non-reef-safe sunscreens. Currently, you will have to rethink your UV protection when visiting the following states and countries:

1. Hawaii

hanauma bay hawaii beach

Hawaii set the trend of sunscreen bans when its state lawmakers passed the bill in May 2018. The bill will go into effect January 1, 2021, when the sale or distribution of sunscreens containing reef-damaging oxybenzone and octinoxate will be prohibited.

The ban doesn’t include SPF makeup products nor sunscreens prescribed by a doctor for medical reasons; nevertheless, Hawaii is a pioneer in the fight against coral bleaching.

See the crowds below right next to the coral reefs at Hanauma Bay, Hawaii: 

2. Bonaire

bonaire coral reefs

Following Hawaii’s example, the Caribbean island of Bonaire banned the same types of sunscreen later in the same month. Voted unanimously by all council members, the bill in Bonaire will also go into effect January 1, 2021.

This ban comes as a logical consequence to the results of research showing that about 90% of the coral reefs in the Caribbean have disappeared since 1980.  

3. Palau

palau islands and reefs view

In October 2018, Palau signed a bill that makes it the first country to outlaw a series of potentially harmful sunscreens.

The law will become effective January 1, 2020; unlike Hawaii and Bonaire, Palau didn’t limit to sunscreens containing oxybenzone and octinoxate. While these compounds are banned too, they are only part of a list currently containing 10 chemicals, and that may grow as the studies reveal new potentially harmful substances.

The current list includes the following chemicals:

  • oxybenzone
  • octinoxate
  • octocrylene
  • 4-methyl-benzylidene camphor
  • triclosan
  • methylparaben
  • ethylparaben
  • butylparaben
  • benzyl paraben
  • phenoxyethanol
  • 4. Key West, Florida

    key west sunset view

    In February 2019, Key West joined Hawaii and Bonaire, implementing a law that will ban the sale of sunscreens containing oxybenzone and octinoxate. The law comes as an attempt to save the only living coral reef in North America. 

    The ban had been approved by the City Commission with a a 6 to 1 vote where it will go in effect on January 1st 2021.

    5. Mexico (Several Vacation Spots)

    mexico turtle in the ocean

    Mexico is the exception that makes a difference between the places that have started to officially ban harmful sunscreens. Technically, no spot in this country has officially banned these personal sunscreen products. 

    Nevertheless, most resorts and popular beaches implemented their own bans, preventing tourists from using sunscreens containing toxic chemicals. 

    Some of these spots include touristy Riviera Maya, most ecotourism preserves and natural water parks in the country, as well as snorkeling spots in Cozumel and Playa del Carmen.

    How Does The Sunscreen Ban Work?

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    While each state or country can set their own regulations, all sunscreen bans prevent shops and resorts in the territory to sell non-reef safe sunscreen. Some places, such as Palau, will even confiscate potentially harmful sunscreens in the airports. 

    Resorts and National Parks in Mexico follow a similar policy; they confiscate harmful sunscreens, and even if you get your product back when leaving, you’ll still have to buy a rather expensive reef-safe product on the premises unless you brought your own or unless you don’t want to sunbathe without protection. 

    If you don’t want to have your regular skin care product confiscated and spend your weight in gold on reef-safe sunscreen sold at premises, make sure to pack mineral sunscreen containing zinc oxide or titanium dioxide when visiting these places. 

    What Is the Science Behind These Bans?  

    The first results highlighting the negative effects of sunscreens on corals were released in 2008. Italian researchers conducted their experiments both in situ and in the laboratory, and their results revealed that it takes as little as 10 μL of sunscreen per liter of water to  cause the bleaching of various species of corals.

    This phenomenon involves the release of the colorful coral symbiotic algae with which the coral shares a mutually beneficial relationship, leaving the coral white and without access to food.

    ocean coral reefs damage

    While the phenomenon is reversible if the stress ebbs quickly, corals starve to death if the stressful conditions persist.

    Several other studies conducted in the past decade showed that oxybenzone – the same compound that protects us by blocking harmful rays – is one of the most dangerous for corals. Especially young corals appear to be very sensitive to this chemical.

    But it’s not only non-biodegradable sunscreen to worry about. While biodegradable sunscreens containing zinc oxide nanoparticles have been deemed as safe for years, recent tests showed that the exposure to these nanoparticles interferes with the photosynthesis of the coral’s symbiotic algae, leading to coral bleaching.

    Which Coral Reefs Are Most At-Risk?

    coral reefs and fish

    While reefs around the world are threatened by global warming and pollution, some of the most popular destinations are more at-risk than others.

    Australia’s Great Barrier Reef is especially vulnerable, above all after the heat waves in 2016 and 2017 that have caused the bleaching of over 50% of the coral in the region. The bays of Hawaii, the US Virgin Islands, and Israel are also at risk.

    From all these places, only Hawaii has regulated the use of sunscreens so far.

    But the implications of using non-reef safe sunscreen in these at-risk spots could be more severe than you might think.

    The Great Barrier Reef, for instance, is home to a spectacular marine ecosystem comprising thousands of species of fish, most of which depend on the corals to survive. Oahu’s Hanauma Bay impresses with the largest reef in Hawaii and is home to over 400 species of marine life.

    Another popular vacation spot, the Coral Reef National Monument in the Virgin Islands, comprises 22 miles of protected marine habitat and 30 species of coral.

    In Israel, the famous Eilat Coral Beach Nature Reserve is also home to dozens of species of coral and fish threatened by multiple factors.

    Losing these reefs means much more than losing beautiful snorkeling or diving opportunities.

    If coral reefs die, a vital ecosystem will die with them. This would not only hurt our global economy, but it could threaten all life on earth, including ours.

    Sustainable tourism and the limited use of sunscreens containing harmful compounds in at-risk areas, regardless of the local laws and regulations, is the least we can do to safeguard our planet and ultimately our life.

    How Does The Ban Affect You? 

    Beyond studies and research showing why sunscreen is bad for corals, you might wonder how the current and future bans will affect you.

    Dermatologists and oncologists recommend using sunscreen liberally when exposing ourselves to the sun, to block the harmful effects of the UV radiations. Furthermore, many of those who militate against the bans claim that many of the research behind these regulations have been carried out in laboratories. Thus it might be inconsistent and insufficient.

    Nevertheless, the precautionary principles suggest that in the absence of robust evidence, suggestive data is sufficient to justify a change in laws and personal behavior.

    Therefore, the main change these bans produce is the way you’ll choose your skin care products to achieve essential UV protection.

    You can either leave the sunscreen at home or replace it with a reef-friendly alternative lacking harmful compounds.

    hard corals bottom of the ocean

    In Conclusion

    Overfishing, pollution, climate change, and sunscreen are threatening coral reefs and the overall biodiversity.

    Despite many claims that there haven’t been carried out sufficient studies regarding the effects of sunscreen on corals, all research available up to date suggests the same thing – oxybenzone and octinoxate, two compounds commonly found in sunscreen, can cause coral bleaching.

    Besides being amazing, coral reefs play an important role in the world at large. They not only contribute to local economies by drawing tourism, but they also protect the environment by retaining carbon dioxide and releasing oxygen into the atmosphere.

    Awareness is the first step to protecting our planet, and a simple change in your habits can dramatically improve the health of these delicate species.

    All you have to do is change your regular lotion with a reef safe sunscreen so that we can all enjoy the beauty of the ocean for longer.

    Sunscreen bans in reefs areas are, therefore, a logical and expected consequence. Safeguarding the marine ecosystem is a matter of global importance that shouldn’t be dismissed based on cosmetic or monetary considerations.

    If coral reefs die, and along with them the marine biodiversity, we will hardly survive. That’s why using environmentally friendly skincare products when vacationing in these areas is the least you can do to safeguard our planet and ultimately our wellbeing.

    Click Here to Leave a Comment Below

    Stacy - June 18, 2019

    This is great information about how the sunscreens are damaging coral reefs.
    I wrote an article about how using sunscreens are bad for us and I linked to this post because I feel like it is something everyone should learn about. Amazing how a simple lotion we think is protecting us is actually doing so much damage.
    This is important!

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