Let’s talk photo-toxic sunscreens and coral!
How much sunscreen is in the ocean? An estimated 6,000 to 14,000 tons of sunscreen go into coral reef areas every year
As a marine scientist, often times you find yourself on various listservs focused on all kinds of topics. It gives you the opportunity to ask important questions to others in the field and to be privy to conversations about recent publications. Sometimes, the back and forth debates keep you glued to your inbox to see what the next rebuttal or apology will be from squabbling scientists. This happened recently between a bunch of coral scientists who were hotly debating whether or not sunscreens are damaging to coral. The truth of the matter is that we don’t truly know how sunscreens affect coral in natural environments. The science is still in progress.
However, what we do know is that laboratory studies have shown that coral larvae exposed to oxybenzone, a chemical found in sunscreen, has serious damaging effects such as deformation and bleaching on coral larvae- read this article. Additionally, a 2016 study suggests that sunscreen chemicals such as oxybenzone and octinoxate promote coral bleaching and slow their growth (in vitro)-click here to read the study. However, before you reach for a mineral based sunscreen free of these photo-toxicants, such as one containing zinc oxide, be advised that zinc oxide was recently found to impede photosynthesis in zooxanthellae (symbiotic algae that live within coral tissue)-read study here. Interestingly, titanium dioxide derivatives did not to cause bleaching of coral and was determined to have low environmental impact.
So, what were the coral biologists arguing about? Well, the science of course! Ever since data appeared almost ten years ago pointing to the dangers of certain sunscreen chemicals to corals, the push to stop the widespread use of these sunscreens has grown to the point where people are not protecting their skin and are perhaps increasing their risk for melanoma. The scientists in the listserv were arguing over whether or not the public has been properly informed of the damage these toxic chemicals have to corals based on the science that is known. I would argue that they have a point as in one article I read, a claim was made that toxic sunscreens cause more harm to coral reefs than climate change.
Again, while it is tempting to believe a statement like this, the truth is that there is not much data to support this claim. The issue is that scientists need to begin to control how the media spins data so that people have a realistic view of where the data are coming from and what the studies actually entailed. Rigorous science must go hand in hand with serious action and change must be based on as much knowledge as possible. As scientists we know that photo-toxic sunscreen chemicals harm coral in the laboratory. While ideally, we would like to wait for an in situ study, by the time the results come out, it could be too late.
The good news is that people are taking action and bravo to the state of Hawaii for banning the sale of sunscreens with oxybenzone and octinoxate starting in 2021. As scientists continue to research the harmful effects of sunscreens on coral, we have a responsibility to change our behavior and change our sunscreen use and the way in which it is marketed, consumed and developed. To be clear, you need to protect yourself if you are a human being with skin! It doesn’t matter what color you are or how much melanin you do or do not have. The sun’s rays are extremely damaging, and protection of UV rays is paramount. What can you do?
COVER UP! Use clothing to protect your skin like UPF clothing and rashguards while at the beach.
READ LABELS and stop buying sunscreens with chemicals that are harmful to corals such as oxybenzone and octinoxate.
Use reef-safe alternative sunscreens.
Educate yourself on the importance of coral reefs and understand their role in supporting economically important species.
Reef safe alternatives are out there and we can all make small changes now to avert a more serious crisis in the future. Protect your skin…protect the reefs!
In the end, what did the squabbling scientists agree on? Some argued that the media tends to jump on issues that are not as important as larger issues such as climate change. Many feel that the sunscreen ban movement is detracting from the real problem: climate change.
The scientists in the listserv at least agreed in the end and one poignantly suggested that the only way we can truly make change is to drive that change ourselves. So yes, toxic sunscreen chemicals are problematic, but, climate change, bleaching events, sewage run-off, nutrient loading and other toxic chemicals entering the ocean, are all just as pressing concerns if not more. While it may feel good for us to stop using toxic sunscreens, the reality seems to be that we have even bigger problems to address and solve.
