Sunscreens and Coral Reefs – Making the Connection

November 15, 2018

As a diver for over seventy-three years I have had the privilege of exploring some of the most beautiful coral reefs around the world.


But today these ecosystems are some of the most threatened environments on our planet. In some of my favorite places – the Caribbean, Hawaii and the Great Barrier Reef – I have personally witnessed the decline of healthy coral reefs by over fifty percent in just the last twenty-five years. We can all be a part of creating a sustainable future for protecting coral reefs, but it starts with knowing, what are the stressors to coral reefs? And how can we, as divers and tourists, play our role in protecting these biologically rich ecosystems? Millions of people travel halfway around the world to enjoy, recreate and explore the magic of coral reefs. But we have the knowledge to better protect the world’s coral reefs through our daily actions.

Corals are one of nature’s wonders. They build on top of themselves, growing over hundreds and thousands of years. The accumulations of coral skeletons, which make up the world’s coral reefs, are a testimony to the persistence of survival; the simplest of creatures building massive structures visible from space. Although coral reefs cover less one percent of the ocean’s surface, they have created a home to over one-quarter of all known marine animal and plant species, making them a hot spot for biologically diversity. These coral reefs are also perfect models of sustainability. They are solar powered cities where the corals reach up to collect the sun’s energy. They are efficient recyclers maintaining and keeping critical nutrients within the coral ecosystems. And they are homebuilders, creating three-dimensional structures for others species to inhabit and thrive. With an appreciation for the value of coral and all reef species, we can understand how the entire ecosystem maintains itself through the acquisition of energy, recycling of raw materials, the diversity of jobs performed by the resident species and the vital interconnections that link all species together.


We know that over geologic time, coral reefs around the world have died off and come back in a continuum of vitality and catastrophe. We also know that we’re in the midst of an accelerating rate of extinction both on land and at sea. It’s very possible that coral reefs could hold some of the most valuable answers to solving medical diseases. If we take a closer look, the demise of coral reefs may be serving as one of the canaries of the sea – a warning for our future. Whether it’s the coral reef or other global systems, evidence is mounting that the patient is sick and the temperature is rising. We must now face the fact that we may know the illness, and it’s us – our human behavior – that is leading to a growing collapse of our world’s critical ecosystems, which we all depend upon.

The list of problems is long. Our global impacts to the planet include ocean warming caused by the release of heat trapping carbon dioxide through the burning of fossil fuels. The oceans are an incredible carbon sink and are absorbing over twenty-five percent of the carbon dioxide humans produce every year. This is changing the ocean chemistry dramatically. Ocean acidification is upsetting the delicate pH balance, making it harder for millions of species to survive. As daunting as some of these global issues may seem, there are easily attainable solutions to some of the local stressors impacting coral reefs. One of these easy fixes starts with what kind of sunscreen you are using. And it begins with every single one of us who value healthy, thriving coral reefs when picking our next dive adventure.

Just recently, the state of Hawaii passed the world’s first legislation to ban all sunscreens containing the chemicals oxybenzone and octinoxate by January 1, 2021.These chemicals are found in over 3,500 of the top selling sunscreen brands. Scientific studies demonstrate the toxicity of these chemicals on coral, fish, marine mammals, and even to us. In very small concentrations, we know these chemicals affect reproductive health and kill coral larvae. We also know that oxybenzone causes the coral to bleach at lower water temperature, upsetting the delicate balance between coral and its plant partner. The state of Hawaii is taking bold steps in eliminating this local stressor by banning the sale of sunscreens with these toxic chemicals in the hopes of giving corals a greater capacity to respond, adapt and survive the larger, global impacts.


“Studies have documented the negative impact of these chemicals on corals and other marine life,” Governor David Ige said in a statement. “Our natural environment is fragile, and our own interaction with the earth can have lasting impacts. This new law is just one step toward protecting the health and resiliency of Hawaii’s coral reefs.” It is inspiring to watch global leadership in taking action to protect our ocean home. There are many things we can do, and this ban on sunscreen with toxic chemicals that harm corals, is a step in the right direction.

In 2016, 8.9 million visitors came to Hawaii, spending over $15 billion dollars. Many of these visitors came specifically to enjoy the beauty of coral reefs. With bans like this, tourists will feel empowered to know that by not applying harmful chemical sunscreens, they are taking one important simple step to ensure the protection of coral reefs. Alternatives to these toxic sunscreens include wearing long sleeve rash guards and using sunblocks with non-nano zinc oxide or titanium. It is choices like these, and many more to come that will collectively help protect coral reefs and the environment so we can enjoy the natural beauty of nature now and for many more generations to come.

The time is now to hold ourselves accountable for this loss of diversity and to instead, become protectors of our one and only ocean home. There is no better time than now. Protect the Ocean and You Protect Yourself.

Warm Regards,


Jean-Michel Cousteau
President, Ocean Futures Society
with Holly Lohuis

First Photo:The coral reef is a solar powered city under the sea, full of life, activity and rich diversity. It is a city where the buildings are alive. © Richard Murphy, Ocean Futures Society

Second Photo: Most corals are brown or green because of algae living inside them.  These solar cells convert sunlight into food for corals and the waste of the corals become fertilizer for the algae. In the nutrient depleted waters of the tropics this tight recycling is essential to the productivity and survival of the reef. © Richard Murphy, Ocean Futures Society

Third Photo: The state of Hawaii passed the world’s first legislation to ban all sunscreens containing the chemicals oxybenzone and octinoxate by January 1, 2021.These chemicals are found in over 3,500 of the top selling sunscreen brands. © Holly Lohuis, Ocean Futures Society