In October, 2015, the National Oceanic and Atmospheric Administration (NOAA) raised the alarm about the terrible plight facing the Earth’s coral reefs. For the third time in history, the world is in the midst of a global coral bleaching event. Coral bleaching is triggered by stresses on coral reefs. During bleaching, the coral expel the algae that live within them, exposing the coral’s white skeleton. The symbiotic algae not only provide coral with its color, they also provide crucial nutrients. Without them, the coral eventually will starve.
“The coral bleaching and disease, brought on by climate change and coupled with events like the current El Niño, are the largest and most pervasive threats to coral reefs around the world,” said Mark Eakin, NOAA’s Coral Reef Watch coordinator. “As a result, we are losing huge areas of coral across the U.S., as well as internationally. What really has us concerned is this event has been going on for more than a year and our preliminary model projections indicate it’s likely to last well into 2016.”
The difference between the third coral bleaching event and the previous two is that the current study points to pollution as one of the sources that is undermining the health of the coral, making it unable to resist bleaching or recover from the effects.
Why the concern about coral reefs? Aren’t they just pretty playfields?
“Coral reefs are the litmus test of our oceans, a visual representation of the health of our seas,” said CNN anchor and meteorologist Derek Van Dam. “When coral becomes bleached or white in color, this sensitive ecosystem is negatively impacted, which creates a profound ripple effect on the world’s food chain.” Think of coral reefs as being the underwater equivalent of rainforests – they are some of the most diverse and valuable ecosystems on Earth. Coral reefs support more species per unit area than any other marine environment, including about 4,000 species of fish, 800 species of hard corals and hundreds of other species. Scientists estimate that there may be another 1 to 8 million undiscovered species of organisms living in and around reefs. This biodiversity is “considered key to finding new medicines for the 21st century,” NOAA said. “Many drugs are now being developed from coral reef animals and plants as possible cures for cancer, arthritis, human bacterial infections, viruses and other diseases.”
Storehouses of immense biological wealth, reefs also provide economic and environmental services to millions of people. Coral reefs may provide goods and services worth $375 billion each year. This is an amazing figure for an environment that covers less than 1 percent of the Earth’s surface
Coral reefs also act as a buffer to adjacent shorelines from wave action and prevent erosion, property damage and loss of life. Reefs also protect the highly productive wetlands along the coast, as well as ports and harbors and the economies they support. Globally, half a billion people are estimated to live within 100 kilometers of a coral reef and benefit from its production and protection.
A new study published October 20, 2015  brought the bad news about pollution and the world’s dying corals. According to researchers the oft-overlooked threat to reefs worldwide is sunscreen – specifically sunscreen which contains oxybenzone.
Scientists who conducted their research in Hawaii and the U.S. Virgin Islands found that the chemical oxybenzone — used in more than 3,500 sunscreen products worldwide, including those by popular brands such as Coppertone, L’Oreal Paris, Hawaiian Tropic and Banana Boat — was extremely harmful to fragile coral reefs. There are alternative sunscreens with no oxybenzone provided by the non-profit Enironmental Working Group (click here for the EWG list) http://www.ewg.org/search/site/sunscreen
The researchers said even a tiny amount of oxybenzone-containing sunscreen can damage corals. As The Washington Post noted, “the equivalent of a drop of water in a half-dozen Olympic sized swimming pools” was sufficient to cause harm. Measurements of oxybenzone in seawater within coral reefs in Hawaii and the U.S. Virgin Islands found concentrations ranging fro 800 parts per trillion up to 1.4 parts per million,” according to the autors of the NOAA study. That’s 12 times the concentrations needed to harm coral. Adverse effects on coral started with concentrations as low as 62 parts per trillion.
John Fauth, an associate professor of biology at the University of Central Florida in Orlando, said that “another way (oxybenzone sunscreen) gets into the environment is through wastewater streams. People come inside and step into the shower. People forget it goes somewhere.” Cities such as Ocean City, Maryland and Fort Lauderdale, Florida, 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 stormwater into rivers and streams. Like sunscreen lotions, products like birth-control pills contain chemicals that are endocrine disruptors and alter the way organisims grow. Endocrine disruptors are amont the main suspects in an investigation into why mail fish such as bass are developing female organs.
So I’m quite excited that this blog post has something – something – proactive that you can do, and that is to use “reef-friendly” sunscreen which uses titanium oxide or zinc oxide instead of oxybenzone. Some tourist destinations have even instituted sunscreen rules to protect their reefs. In Akumal, Mexico, for instance, visitors are urged to apply eco-friendly sunscreen.
“We have lost at least 80 percent of the coral reefs in the Caribbean,” Craig Downs, lead author of the study said. “Any small effort to reduce oxybenzone pollution could mean that a coral reef survives a long, hot summer, or that a degraded area recovers.”
 Dunnakey, Adam, “Coral reefs endangered by bleaching in global event, researchers say”, CNN, October 8, 2015
 Downs, Craig, et al; “Toxicopathological effects of the sunscreen UV filter, Oxybenzone (Benzophenone-3) on coral planulae and cultured primary cells”, Archives of Environmental Contamination and Toxicology, 20 October 2015
 Fears, Darryl, “How we are all contributing to the destruction of coral reefs: Sunscreen”, The Washington Post, October 20, 2015
 Fears, op. cit.