Restoring Florida’s Coral Reefs

  • Published on April 18th, 2010

(Originally appeared at

Coral reefs are among the most productive ecosystems in the ocean, harboring thousands of species from plankton all the way up to fish like the grouper and snapper.
Covering less than a quarter of a percent of the ocean’s surface, coral reefs support twenty-five percent of all marine life!

Coral reefs also among the most beautiful ecosystems in the world – painted canyons of branching coral, waving kelp, and dazzling fish in rainbow colors. They remain a huge attraction to divers and other tourists, and are a mainstay of the economies of South Florida’s Keys and countless other destinations around the globe.

Coral reefs are also among the most threatened environments in the world today. Scientists estimate that 25 percent of the world’s reefs have already been destroyed or badly degraded.
What’s killing the reefs?

  • Diseases: staghorn and elkhorn coral have been hit hard by diseases, possibly imported from the Pacific via the Panama canal; they hit corals whose immune systems are already weakened by the other factors. Both species are now listed as threatened.
  • Algae: The green growth was kept in check by voracious sea urchins, but disease has wiped out the previously large populations of urchins, and the resulting algae explosion is creating huge problems for coral reefs.
  • Cold – this winter’s unusual cold snap, which didn’t affect deep-sea coral, was devastating to corals in shallow waters along the coast.
  • Human Damage – sometimes intentional, like when dredging for a shipping channel or building a jetty; or accidental, when a ship runs aground. In either scenario, the reef gets pulverized and takes years to recover.

Florida Aquarium’s Global Reef Institute, is doing something about it.

Coral may look like a plant, but it’s actually a tiny animal – a polyp – that builds a tree-like framework of calcium carbonate to protect itself. In the wild, corals reproduce by larvae, which swim freely until they find a good place to settle down. Then they anchor themselves, and grow. When a piece of coral is smashed to bits – say, in a ship grounding – it can take months or more for the pieces to get back to equilibrium, and if they don’t land in a suitable place, they may never recover.

That’s where the researchers step in.

“We got the idea that if we could grow them in mass, we could start doing restoration,” says Craig Watson, lab director at the University of Florida’s Tropical Aquaculture Laboratory in Ruskin, who is also on the board of the Florida Aquarium. “The concept is to take coral fragments, grow them up to a size where they would be stable and growing, and take them out to a reef that’s damaged and plant them there.” They gather those coral fragments and place them in a pond or tank, where they can be carefully nurtured for six months. Once they’re healthy, they can be taken back to the wild and glued to a reef. “We can get a huge jump on nature rather than waiting for spawning to occur and a single polyp to establish itself,” says Watson. “It’s like planting a seedling rather than a seed.”

The conventional wisdom was that if you grew coral in a land-based condition, it wouldn’t be able to survive when you transplanted it, but that after three years of experimentation they’ve got it down.  “In fact,” says Allan Marshall, the aquarium’s vice president of biological operations, “the program proved that inland grown coral does even better – we’ve had a 70 percent success rate.”

Another concern, with transplanted coral, was the threat of diseases. Whenever you pen up a whole lot of organisms in an un-natural environment, there’s a risk that pathogens will run rampant through the population, and then spread to the wild (it’s a problem on big cattle feedlots and salmon farms). Wanting to make sure they could literally give their coral a clean bill of health, the aquarium has worked out a certification program. Having USDA veterinarians monitor the coral closely, then before any coral is released into the wild it is certified as disease-free.

Marshall says the reef ecosystem is a lot like the tropical rainforests: fragile, and feeling the pressure of changes big and small.  The best targets for restoration, at least for now, are reefs with physical damage, usually from a boat grounding. There is also funding there, since the shipping companies responsible are supposed to pay for that restoration work. Money is also coming into the project from the Economic Stimulus, via the Nature Conservancy.

“We’re not looking at restoring reefs where [temperature change] is the problem,” notes Watson, “the reasoning being that those spots aren’t going to be good for coral now.”
Sadly, most of their work takes place in an area that’s already supposed to be a protected zone: the Florida Keys National Reef Sanctuary.  “The reality is there are a lot of people in South Florida,” says Watson,  “so even though the reefs are already protected there are a lot of impacts associated with all those people.”  And he adds that they’re seeing good results with other species. For instance, research found that the grouper and snapper for much of the east coast spawned in one small area.  “They’ve created a no-take zone right there,” he says,  “so now spawning aggregations are taking place without harassment, so that’s going to help with recovery of those fisheries.”

What can you do?
The Nature Conservancy has an Adopt-a-Reef program that allows you to take part directly – this year, it’s a big part of their Earth Day campaign.

About the Author

Jeremy Bloom is the Editor of RedGreenAndBlue. He lives in New York, where he combines his passion for the environment with his passion for film, and is working on making the world a better place.