The stunning colours in corals come from a marine algae called zooxanthellae, which live inside their tissues. This algae provides the corals with an easy food supply thanks to photosynthesis, which gives the corals energy, allowing them to grow and reproduce.
When corals get stressed, from things such as heat or pollution, they react by expelling this algae, leaving a ghostly, transparent skeleton behind. This is known as ‘coral bleaching’. Some corals can feed themselves, but without the zooxanthellae most corals starve.
Several Environmental Health scientists found that baby coral exposed to oxybenzone and octinoxate exhibited signs of distress, including coral bleaching. Logically, when we swim with sunscreen on, chemicals can seep into the water, where they’re absorbed by corals.
On a bright side, in 2018, Hawaii became the first state to ban the sale of sunscreens containing two most common chemicals, oxybenzone and octinoxate, which many researchers worldwide have identified potentially harmful to marine life. Hopefully others. will follow.
If you do plan to go to the beach, the best way to protect both, yourself and the environment is to start using physical or mineral sunscreens with “non-nanotized” zinc oxide or titanium dioxide which appear to be safer for coral reefs than chemical ones, according to the National Park Service.
However, figuring out which sunscreens are kinder to the planet isn’t always crystal clear so we made the research for you.