Reefs along the Keys once commonly had coral cover of 30 to 40 percent of its surfaces. Those healthy reefs protected the Keys from storms, nurtured fish and lobsters and helped create a thriving tourism industry that relies heavily on diving, snorkeling and fishing.
Now the coral cover is more like 2 percent on a lot of the reefs that still draw tourists.
"Frankly, we cannot afford to let these declines continue. We cannot afford not to act," Sarah Fangman, the sanctuary superintendent. "These systems are in a state that without our active help, they cannot recover fast enough."
The National Oceanic and Atmospheric Administration, the agency that oversees the sanctuary, wants to restore seven reefs along the Keys reef tract from Key Largo to Key West.
Those reefs range from Carysfort off Key Largo to Eastern Dry Rocks off Key West. They are among the most popular with divers and snorkelers. The new plan calls them "iconic."
"These are America's reefs," Fangman said. "We must protect them and we must rebuild them."
The decline of coral reefs is blamed on several causes, many of them regional or global. That includes climate change and water quality. And the already ailing reefs are more susceptible to damage from storms and boat groundings.
"This is not something that we can do without addressing those global challenges," said Tom Moore, who leads NOAA's coral restoration efforts. "But if we just wait for those global challenges, we're not going to have reefs left."
The first phase of the project is expected to last 5 to 7 years and cost about $97 million.
"It is a big investment," Moore said. "But in the big scheme, of the economic drivers that this system has, it's not that big of an investment. It's something that's tangible and achievable."
Fast-growing corals like elkhorn and staghorn will be transplanted first. Those are also corals that are not affected by stony coral tissue loss disease.
"We've lost a system over 50 years. We're not going to get that system back overnight," Moore said.
The second phase of the project would last another 10 to 12 years. The goal is to eventually get to 25 percent coral cover at the restoration sites.
"I think success, for me, is going to be when we have people that come to dive on these reefs, come to snorkel on these reefs and get in and go to one of these sites and hop out of the water and say, 'Wow that looks a lot better than it looked five years ago,'" Moore said.
The project is coordinating and expanding reef restoration efforts that the sanctuary and nonprofit groups have been working on for years in the Keys.
The Coral Reef Restoration Foundation, based in Key Largo, is already working on restoration projects at six of the seven iconic reefs selected by NOAA.
"Coral reefs are very resilient," said Jessica Levy, restoration program manager for the Foundation. "They're particularly resilient to really local impacts so if you can manage for the local impacts, that actually helps them to have a better chance against those global, bigger ones that take a lot more effort to try to mitigate against."
Levy said it's also important for the local tourism industry to acknowledge the decline in corals over the years, and face it head-on with projects like this.
"I feel for the industry. There's a lot of economic value on our coral reefs and I understand it's scary to admit how bad it is," she said. "But glossing over it doesn't do anyone any favors. It's only going to get worse if we don't admit that there's a reason restoration is needed."
The restoration will include growing corals in nurseries and planting them offshore. They also want to bring back sea urchins, which graze algae from coral. Sea urchins suffered from a mass die-off in the early '80s and the population has not recovered.