Sunscreen – we all are constantly reminded to use sunscreen to reduce the chance of sunburn or skin cancer, especially when visiting southern Florida from some northern location and your skin is almost as white as the snow where you live.
Makes sense, especially for those of us whose friendly dermatologist reminds us to protect our skin as he or she freezes off those pre-cancerous spots on our faces, hands and other locations on our bodies.
As a dive instructor I always tell divers not to harm the reef by standing on it, kicking it or even touching it.
Now, it turns out, that some types of sunscreen products are part of the growing list of human activities and pollutants that are harmful to coral reefs.
A team of scientists (from Haereticus Environmental Laboratory; the U.S. National Oceanic and Atmospheric Administration (NOAA); the National Aquarium in Baltimore; the University of Hawaii, and Tel Aviv University and Ben-Gurion University of the Negev, Israel) has discovered that certain chemicals in sunscreen are highly toxic to coral. One culprit, Oxybenzone is found in over 3,500 sunscreen products worldwide.
Other bad actors in sunscreen include Butylparaben, Octinoxate and 4-methylbenzylidene camphor (allowed in Europe and Canada, but not in USA or Japan) -- all shown to cause coral bleaching. .
The team’s study published in the December 2013 issue of Ecotoxicology (See http://link.springer.com/article/10.1007/s10646-013-1161-y) showed even very low concentrations of Oxybenzone can kill juvenile corals, causes colorful corals to bleach.
Executive director and researcher Craig Downs of the non-profit scientific organization Haereticus Environmental Laboratory in Virginia led the team, which collected samples from reefs in Hawaii, the U.S. Virgin Islands and Eilat, Israel.
In laboratory experiments, the team exposed coral larvae and cells of adult corals to increasing concentrations of oxybenzone and discovered that the chemical deforms coral larvae by trapping them in their own skeleton -- making then unable to float with currents and disperse.
The team also found that the chemical can potentially induce or increase the frequency of mutation in corals.
Downs says oxybenzone can deform coral cells at a concentration as low as 62 parts per trillion—that's one drop in around 6.5 Olympic-sized swimming pools. This is something to consider when, according to the report, as many as 14,000 tons of sunscreen enters water around coral reefs every year.
According to the study, the harmful products in sunscreen are not removed from most municipal wastewater treatment facilities. The discharge is often directly released in coastal waters of the Caribbean and the Indo-Pacific, threatening near-shore coral reefs.
In his Oct. 20, 2015 story in the Washington Post entitled “ How we are all contributing to the destruction of coral reefs: Sunscreen,” Darryl Fears points out that, “ beach crowds aren’t the only people who add to the demise of the coral reefs found just off shore. “
“Athletes who slather sunscreen on before a run, mothers who coat their children before outdoor play and people trying to catch some rays in the park all come home and wash it off,” Fears says.
“Cities such as Ocean City, Md., and Fort Lauderdale, Fla., have built sewer outfalls that jettison tainted wastewater away from public beaches, sending personal care products with a cocktail of chemicals into the ocean. On top of that, sewer overflows during heavy rains spew millions of tons of waste mixed with storm-water into rivers and streams. Like sunscreen lotions, products like birth-control pills contain chemicals that are endocrine disruptors and alter the way organisms grow. Those are among the main suspects in an investigation into why male fish such as bass are developing female organs,” Fears adds.
"In the case of (the) pollution, there are a range of options that can be considered for reducing its impact to reefs — from working with manufacturers and innovating more environmentally sustainable products to educating consumers regarding product selection and product disposal," Downs said.
The highest concentrations of the harmful chemicals were found in reefs most popular with tourists.
“Coral reefs are the world’s most productive marine ecosystems and support commercial and recreational fisheries and tourism,” said research team member and University of Central Florida (UCF) associate professor of biological sciences and diving enthusiast John Fauth, Ph.D.
“In addition, reefs protect coastlines from storm surge. Worldwide, the total value of coral reefs is tremendous. And they are in danger,” Faith cautions.
“Local economies also receive billions of dollars from visitors to reefs through diving tours, recreational fishing trips, hotels, restaurants, and other businesses based near reef ecosystems,” NOAA says on its Web site. “Globally, coral reefs provide a net benefit of $9.6 billion each year from tourism and recreation revenues, and $5.7 billion per year from fisheries.”
“Although pollution is a major cause of coral reef degradation and is the easiest factor to mitigate (the harmful chemical in sunscreen) as a pollutant has largely been ignored,” according to Downs.
“The use of oxybenzone-containing products needs to be seriously deliberated in islands and areas where coral reef conservation is a critical issue,” Downs said.
“We have lost at least 80 percent of the coral reefs in the Caribbean. Any small effort to reduce oxybenzone pollution could mean that a coral reef survives a long, hot summer, or that a degraded area recovers. Everyone wants to build coral nurseries for reef restoration, but this will achieve little if the factors that originally killed off the reef remain or intensify in the environment,” he emphasized.
So, what can divers do to protect the reefs?
The good news: “More companies are now offering sunscreens that use mineral blockers such as zinc-oxide instead of chemicals like oxybenzone,” says Luke Whelan in his October Oct. 21, 2015 article in a Mother Jones website. (See: Here Is the Kind of Sunscreen That Won’t Destroy Coral Reefs at http://www.motherjones.com/blue-marble/2015/10/your-sunscreen-massacring-world%E2%80%99s-coral-reefs)
Another link to coral-safe sunscreen can be found at http://www.badgerbalm.com/s-35-coral-reef-safe-sunscreen.aspx
Dr. Fauth takes it a step further and suggests: “Wear rash guards or scuba wetsuits and skip all the hygienic products when you go diving. “
When you are out of the water, cover yourself with a hat and shirt. If possible, seek shade during peak sun hours.
So, next time you decide to trowel on the sunscreen on yourself or the kids, take time to read the label and use products that won’t hurt our fragile coral reefs. Even better, use protective clothing to cover those parts of your body that will be exposed to the intense sunshine in south Florida.
Don Rhodes, in addition to a career in government affairs, has taught scuba for 29 years. He and his wife retired to Tavernier four years ago, where he works as an instructor for Conch Republic Divers