Coral reefs, the most biodiverse ecosystems in the world, are dying. The reefs in the Florida Keys are now nearly half the size they were twenty years ago and many Caribbean reefs have declined by 80 percent over the past three decades.

Overfishing and pollution have increased the levels of carbon dioxide in the water, raising surface temperatures by about 1.5 degrees Fahrenheit over the last century, according to the National Oceanic and Atmospheric Administration.

This high temperature causes the coral to shed the colorful algae in tissue, exposing the coral's skeletons. The carbon dioxide changes the pH levels, making the water more acidic. The acid makes the coral brittle, more receptive to disease and unable to reproduce.

To bring the reefs back to life, volunteers with the Coral Restoration Foundation are building underwater coral nurseries and planting baby coral on existing reefs. They hope that these fostered reefs will buy them time until scientists find a better solution. The restoration is a small step, but more will have to be done to save the 500 species of fish living on Florida's reefs.

Saving the dying coral reefs is a critical task for residents of coastal regions, who rely on the reefs for protection and jobs. The reefs provide a buffer to incoming waves and storm surges, and are a unique tourist attraction that brings people from around the world to snorkel, scuba dive and fish.

Quotes

"Railroad cars stacked end to end to wrap around the earth seven times. That's how much carbon is going into the ocean every single year,"