Killing Coral Reefs: 5 Villains of Underwater Biodiversity

1 of 6

Bye-Bye, Coral

A year ago I dove in the Maldives with marine biologist Kate Wilson, who has lived and worked there for the past four years. We boated to the middle of a lagoon in one of the chain’s thousand atolls for an up-close look at the health of what was once a Mecca for coral lovers.

A pair of significant warmings in the past decade have heated the ocean by four to six degrees and killed off much of the previously vibrant coral reef. As we dove we signaled to each other ‘thumbs down’ as we floated over reefs blanched the color of cement, the tips of the coral broken off exposing bare rock on the ocean floor.

Unfortunately what we witnessed that day in the Maldives is being repeated around the globe—coral reefs are dying, and fast.

After 250 millions years as a highly successful life form, disruptions in the biological and communication systems of coral reefs—many of them manmade—are causing similar coral bleaching and collapse of reef ecosystems around the world.

Warming sea temperatures are one reason, but not the only cause.

On top of the bleaching caused by warming sea temps, here’s what’s killing off the planet’s coral reefs:

Photo: David Loh/Reuters

Ocean Acidification

One third of the carbon dioxide pumped into the atmosphere by man’s dependence on fossil fuels falls into the ocean, the equivalent output of 24 million Volkswagen Bugs each day. As the ocean acidifies, it eats away at coral, and shellfish too.

Photo: Lou Dematteis/Reuters

Disease

A fungus-growing bacteria encouraged by photosynthesis is killing all of the coral it strikes in bays off Hawaii, at the rate of one to three inches a week. That’s just one example of various ailments around the world that wildlife disease specialists say for now are not endangering fish or humans. Just coral.

Photo: Handout/Reuters

Ships and Boats

Careless boating is a huge problem for coral reefs, including dive boats, cargo ships, tourist/passenger boats and fishermen.

Photo: Adrees Latif/Reuters

Overfishing

In large part due to poverty, fishermen around the globe ignore the right thing to do and employ horrific techniques in the course of pursuing their daily catch. Ranging from spear fishing to the use of dynamite and poison, illegal fishing impacts reefs in two ways: It destroys the reefs while simultaneously eliminating fish, which are integral to the ecosystem on which they both thrive.

Photo: Pichi Chuang/Reuters

Seaweed Growth

The use of fertilizers and pesticides around the world is booming and eventually they all end up in the ocean. The poisons of nutrient runoff from agriculture and sewage are hugely harmful to near-shore reefs.

Photo: Mal Langsdon/Reuters

Related Stories on TakePart:

• Moviegoers Protect 35,000 Acres of Coral Reef in the Bahamas Through OCEANS Program

• Killing Nemo: Coral Reefs Are Dying to Fill Aquariums with Colorful Fish

• Haitian Eco-Village Inspired by Coral Reefs

Related Gallery

Ocean Kill-Free Zones: 6 of the Biggest Marine Reserves See Full Gallery

A six-time grantee of the National Geographic Expeditions Council, Jon Bowermaster has spent the past two decades circling the world’s ocean, studying both its health and the lives of the people who depend on it. He is the author of 11 books (his most recent, OCEANS, Threats to Our Seas and What You Can Do to Turn the Tide, was published by Participant Media) and producer of a dozen documentary films. His blog—Notes From Sea Level—reports daily on issues impacting the ocean and us. Follow Jon on Facebook. @jonbowermaster | Email Jon | TakePart.com