How Sunscreen Is Killing Our Coral Reefs

Sunscreen – it’s everywhere. Widespread availability combined with endless consumer choices have enabled it to become one of the most used skin-care products on the planet. 

For decades, health organizations have pushed and pleaded for the daily use of sunscreen. Most dermatologists will tell you that, come rain or shine, you should be applying sunscreen daily, and reapplying every two hours. And this isn’t a bad thing – sunscreen is an incredible invention that has saved countless lives. It protects the skin against harmful ultraviolet rays, and when used correctly, can prevent sunburns, signs of aging, and reduce your risk of developing skin cancer. As such, it’s not surprising that there are so many people who swear by its use and consider it a miracle product. But not all is as it seems.

Modern sunscreen is a new phenomenon. When it was created, we didn’t understand the long-term impact it would have on us or our surroundings. And as the years have passed, we’ve begun to understand just how much of an impact certain types of sunscreen are having on our environment. Ingredients that were only ever found it small quantities in select environments have now flooded the entire planet, and are wreaking havoc on our oceans and damaging our vital, vulnerable coral reefs.

But it doesn’t have to be this way. With just a simple switch to a different sunscreen, this issue could be eliminated. My goal in writing this article is to help you understand the serious issue we’re all facing and enable you with the information to change your habits and the habits of those around you.

So let’s begin.


Before we get into HOW sunscreen is damaging our coral reefs, let’s cover two things: the real reasons our coral reefs are dying, and why you should care.


Our coral reefs are dying at an alarming rate, and the trend doesn’t seem to be stopping soon. Over the past 30 years over 50% of our ocean’s coral reefs have died, and it’s predicted that if changes aren’t made, over the next century we could lose 90% of all coral reefs. That would be one of the worst, if not the worst environmental catastrophe ever recorded. 1

Why is this happening? Why has there been such a steep decline in healthy coral reefs, and why is it only happening now? There are six main factors that come into play. 

1. Overfishing

Overfishing near coral reefs can cause ecological balance and biodiversity issues. For instance, overfishing of carnivorous fish can lead to excess herbivorous fish. This then leads to low algae levels, which can cause a significant strain on a healthy coral reef. The opposite is also true. If herbivorous fish were over-fished, this would lead to excess growth of algae which would block sunlight and consume the oxygen corals need for respiration.

2. Destructive Fishing Methods

Dynamite fishing, or the illegal practice of using explosives to stun or kill schools of fish, can easily damage a coral reef. If dynamite is set off near a reef, the blast will shatter and kill surrounding coral tissues, and the rubble left behind will prevent adjacent coral colonies from recovering.

3. Ocean Acidification

Ocean acidification is the ongoing decrease in the pH of our oceans, caused by the absorption of carbon dioxide from the atmosphere. Yet another harmful side effect of excess CO2, this process strains coral reefs and impedes their growth.

New research published by Woods Hole Oceanographic Institution shows that ocean acidification prevents the thickening process of coral reefs, which decreases their density, leaving them vulnerable and prone to breakage. 2

4. Inland Activities

Activities happening inland can also affect the health of coral reefs. Erosion caused by industrial and agricultural industries result in sediment being deposited into our oceans. This makes it impossible for corals to function normally, and in some cases, breathe.

Pesticides and herbicides found in agricultural runoff affect the growth and reproduction of coral reefs, and can harm the symbiotic algae that acts as corals primary food source. 3

5. Plastic

You can find plastic anywhere. Just take a walk around your neighborhood, and odds are you’ll see a plastic bag or bottle littering the street. It’s in your synthetic clothing, soda cans, chewing gum, cosmetic products, and even in your food.

Plastic pollution is easily one of the biggest, most urgent issues our world is facing. As the global population continues to grow at an unsustainable rate, and as businesses continue to use plastic as their primary source of packaging – with consumers continuing to support said businesses – the problem will only get worse.

According to a study published by Science Magazine, over 11 billion pieces of plastic larger than five centimetres wide are littering coral reefs across the Asia-Pacific region, and this number will likely grow by 40 percent in the next seven years. To put this into perspective, if we were to line these bits of plastic up next to each other, they would reach around the Earth nearly 14 times. 4

This is bad news for coral reefs, who are 20 times more likely to become infected with a disease when exposed to plastics. Unless we see significant reductions in plastic usage within the next decade or two (especially single-use), and a plastic industry reform, things look bleak for not just our oceans, but for every environment and organism on our planet. 5

6. Climate Change

While all the previously mentioned issues play a role in the destruction of our coral reefs, the biggest threat is ongoing climate change, which is continuously raising sea water temperatures and causing coral bleaching worldwide. Bleaching occurs when corals are stressed by environmental changes, such as changes in water chemistry, salinity, and temperature.

In the early 1800s, the era known as the Industrial Revolution began, and it radically changed the way humans live their lives and treat their environment. We began burning massive amounts of fossil fuels, and stripping our environments of resources such as wood, oil, coal, and anything else of value. This then caused an increase in carbon dioxide in Earth’s atmosphere and kick-started global warming.

Only about one percent of the heat trapped by CO2 has stayed in the atmosphere, which is a very, very good thing, considering that measly one percent has caused a 1°F temperature rise across the entire Earth’s surface over the past two centuries.

But where is the rest of the heat going?

Almost all of it has been absorbed by our oceans – over ninety percent, in fact. This has resulted in a little over a 1°F temperature rise throughout our oceans, and the speed at which they’re warming is increasing. The top portion of our oceans are warming about twenty-four percent faster than it did a few decades ago, and this rate is likely to continue increasing. 6

Our coral reefs cannot cope with these warm temperatures, and have began experiencing mass bleaching on a scale we’ve never seen before, increasingly often. Normal, healthy corals have symbiotic algae living in their tissue that synthesize sunlight and carbon dioxide to create nutrients, and serve as their main food source. But this symbiotic relationship only thrives within a fairly narrow temperature band. When the water surrounding coral reefs gets too warm, said algae’s metabolism goes into overdrive and begins producing harmful toxins. In response, corals expel the algae from their tissue. This causes a once healthy, vibrant, life-harboring organism to becomes ill, white, and starved for food. Often, the corals don’t survive.

If you want to know what coral bleaching really looks like, watch the clip below.


1. Our Air

The most crucial thing we will lose if our coral reefs die is the very air we breathe. While corals only cover 0.0025 percent of the ocean floor, they generate half of the world’s oxygen and absorb 30 percent of man-made carbon dioxide.

Professor Ove Hoegh-Guldberg, the lead-author of an Australia-U.S. report published in Science magazine, explained that our oceans act as Earth’s “heart and lungs”, and that “We are entering a period in which the very ocean services upon which humanity depends are undergoing massive change and in some cases beginning to fail.” 

He then stated that, “Quite plainly, the Earth cannot do without its ocean. This is further evidence that we are well on the way to the next great extinction event.” 7

2. Biodiversity


Coral reefs cover just a tiny fraction of the ocean floor, but support more than a quarter of all marine life. They’re the world’s largest living structure and are the most diverse ecosystem on the planet – even more diverse than tropical rainforests.

Reefs provide spawning, nursery, refuge and feeding areas for countless organisms, and without them, many species would become endangered, and go extinct.

3. Coastal Protection

A world without coral reefs is a world with vulnerable coasts. Reefs offer significant natural protection to coastlines, by preventing coastal erosion and flooding. A study published by the Nature Communications Journal found that coral reefs provide substantial protection against natural hazards by reducing wave energy by an average of 97%. There are over 100 million people who depend on the protection provided by reefs worldwide. 8

4. Medicine

Healthcare is one of the most rapidly changing industries in the world, and our knowledge of medicines, treatments, and procedures are constantly improving.

Due to the sheer biodiversity and adaptability of coral reefs, scientists around the world look to them for medicinal remedies. Coral ecosystems are the sources of new medicines being developed to treat cancer, arthritis, bacterial infections, asthma, Alzheimer’s disease, heart disease, viruses, and other diseases. If coral reefs die out, the medical industry and all its patients will suffer. 9

5. Economy

Losing coral reefs wouldn’t only be bad for the environment – it would be an economic disaster.

The World Wildlife Fund (WWF) estimates that coral reefs provide an annual $30bn worth of goods and services. And that’s no surprise, considering a well-managed square kilometre of coral reef can yield 15 tonnes of seafood per year – or 750 times the world’s per capita fish consumption. Reefs also attract millions of tourists every year and play an important role in coastal and marine tourism. It’s estimated that about one billion people have some dependence on coral reefs for food and income. 10


There’s no denying that climate change currently plays the biggest role in the destruction of our coral reefs. That being said, other factors also come into play, including the use of certain types of sunscreen. 

There are two different types of sunscreen used today – physical and chemical.

Physical sunscreen, also known as mineral sunscreen, contains tiny particles of titanium dioxide and zinc oxide, and work by absorbing into the very surface layers of skin and deflecting the sun’s harmful rays. Although traditional physical sunscreens were pasty and difficult to blend into the skin, modern formulas rarely have these problems, and are much more tolerable. Mineral sunscreen is generally less irritating and more moisturizing than chemical sunscreen and is a better fit for sensitive skin.

Chemical sunscreens contain oxybenzone, avobenzone, octinoxate, and a variety of other chemicals. They work by absorbing into the skin and converting UV rays into heat, then releasing it from the body. Most people who use chemical sunscreens do so because of their convenience. They are often more water-resistant than physical sunscreen and absorb faster. (which means less frequent application when swimming/sweating)

But these benefits come at a cost.

Recent studies have found that the active chemicals in chemical sunscreens, including oxybenzone and octinoxate, are toxic to corals, algae, sea urchins, fish, and even mammals. They impair the growth and reproduction of algae, can induce defects in molluscs, damage the immune and reproductive systems of sea urchins, and decrease fertility and reproduction of fish. The two chemicals have been found at toxic levels in fish, sea turtle eggs, algae, dolphins, oysters, crayfish, mussels, and even human and dolphin breast milk, according to Craig Downs, executive director of Haereticus Environmental Laboratory. 11, 12

Sunscreen chemicals are especially harmful to corals. When these chemicals enter a coral reef’s environment, they damage corals DNA, deform their young, decrease their defense against coral bleaching, and sometimes even induce bleaching. Exposure to these chemicals make coral reefs that much more vulnerable to issues stemming from climate change, ocean acidification, plastic pollution, and more. 13

Corals don’t have to be exposed to large amounts of these compounds either. A 2015 study showed that a single drop of oxybenzone in over 4 million gallons of water is enough to endanger organisms. In Hawaii, concentrations more than 10 times that amount have been measured at popular swimming beaches. 14

To put this into perspective, that’s one drop of oxybenzone in an entire Olympic sized pool.

And I know what some of you might be thinking. If I’m nowhere near the ocean, there’s no real harm in using chemical sunscreen, right?


Due to typical wastewater treatment systems inability to filter out certain types of pollutants, chemicals like oxybenzone also enter marine ecosystems through sewage outflows. This means that whether you’re applying chemical sunscreen at the beach, or in your own backyard, you’re putting corals and other organisms at risk. 


Stopping the usage of chemical sunscreen won’t solve everything. Climate change, ocean acidification, plastic pollution, inland runoff, and many other problems will remain, whether you use chemical sunscreen or not. 

But while most issues coral reefs are facing seem almost impossible to fix, the use of chemical sunscreen is easily tackled. Just because it won’t have as big an impact as reducing carbon emissions doesn’t mean it should be ignored or seen as unimportant. We, as a species, should be doing anything we possibly can to protect our coral reefs, and using only mineral sunscreen is an easy way to make a real difference. 

Having said that, take everything I’ve written in this article with a grain of salt. While stopping the use of chemical sunscreen will make a tangible difference in the health of our coral reefs, if we don’t deal with climate change, it won’t matter what type of sunscreen you use. 


Here are eight different mineral sunscreens for various skin types. (and a much more detailed list of the best physical sunscreens for different skin types and concerns)

1. Lip Protection

Vanicream’s SPF Lip Protectant is for those of you who prefer using lip balm with sunscreen included. It’s filled with moisturizing ingredients, is water resistant for up to 80 minutes, and offers protection using both titanium oxide & zinc oxide.

2. Tinted Sunscreen

This tinted sunscreen is made by Australian Gold (one of my favorite sunscreen brands) and is part of their Botanical collection. 

It’s fragrance free, non-comedogenic, hypoallergenic, and is not tested on animals. It’s also packed with tons of antioxidant rich botanicals and offers a nice, subtle tint on days you want to even out your skin tone.

3. Spray On Sunscreen

This mineral only sunscreen, made by Babo Botanicals, is perfect for those who don’t want to give up the convenience of spray on sunscreen. It’s water resistant for up to 80 minutes and is sheer and easily absorbed.

4. Sunscreen Stick

Using a sunscreen stick is, by far, the easiest way to apply sunscreen, and I’m an avid traveler, so sunscreen sticks hold an extra special place in my heart.

MyChelle Dermaceuticals Sun Shield Stick is my favorite, and it’s the one I use. It’s got all kinds of good ingredients, including tamanu oil, shea butter, hemp seed oil, jojoba oil, avocado oil, and cocoa butter. It’s also cheap as dirt and lasts a very long time.

5. All-around Winner

This is my all-time favorite, and I love it to pieces. I have sensitive, acne-prone skin, and MyChelle’s Replenishing Solar Defense has never once broken me out or caused irritation. This is my favorite for everyday use because it provides sufficient sun protection without feeling heavy. Also, for those of you who wear make-up, this works as a decent primer in a pinch.


1: Secore International
2: National Science Foundation
3: United States Environmental Protection Agency
4: Aljazeera
5: The Guardian
6: National Geographic
7: Catholic Climate Movement
8: Nature Communications Journal
9: National Ocean Service
10: Mail & Guardian
11: Maui Ocean Center
12: KXLY
13: National Oceanic and Atmospheric Administration
14: Ocean Conservancy

Please note that this article contains affiliate links. If you make a purchase using one of them, I earn a commission at no extra cost to you. I only recommend products that I 100% stand behind.

Hi, I’m Ash!

I’m a laid back traveler who loves experiencing new things and spontaneity. My favorite hobbies are hiking, gardening, skincare, and all things tea.

My biggest goal is to spread the word about sustainable travel and show everyone how easy it is to partake in. If you wanna learn more about that or get to know me better, feel free to click here.


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