Though many people think of coral reefs as plants, they are actually animals. Even if you don't live near the Florida Keys, water from your area could still have an effect on the coral reefs if it drains into the Gulf of Mexico. (Courtesy: The Southern Company)


Billy:  Coral reefs are an exciting environment. It’s probably one of the most diverse, one of the most complex marine ecosystems on Earth. They’ve often been called the “rainforest of the sea,” for many reasons. Coral reefs have a certain amount of relief off the bottom. They have a multitude of colors. Coral reef fishes are some of the most diverse groups of fish in the world. And you’ll have hundreds of species of colorful tropical fish swimming around in this array of sharp pinnacles and ledges and overhangs. 

Mary:  You have your predators out there and they kind of lurk around the edge, and so you're kind of keeping an eye on them all the time. But then you go down to the little neon gobies that are resting up on the corals and are so tiny, you know, inch-long little fish, brightly colored, you know, and all. And it’s so pretty. I think everybody’s always amazed at the variety of the fish in the corals that they see. Many people think that corals, when they first look at them, they’ll say, “Oh, it’s just some rocks down there.” It’s actually an animal.

Tony:  They have a lot of similarities to plants, a lot of similarities to plants. A lot of people actually think they are plants. But in actuality, they are animals. However, they do have plants that live within their tissue. So it’s kind of almost like a cross in between.

Billy:  You have the coral itself is made up of millions of tiny polyps that look like little tiny sea anemones that make up the coral, the living tissue. But then you also have within that tissue zooxanthellae, that are plants, and those plants are very important metabolic processes for the coral and the living tissue.

Art:  Live coral is only at the very surface, whereas all the rest of it beneath that very thin layer of polyps, all the rest of it is dead limestone skeleton from tens of thousands of prior generations. 

Tony:  Fish and invertebrates use the coral structure and the coral reefs in two different ways. One is like a condominium or a city, if you will, with all the nooks and crannies and they all establish their own little territories in certain areas and, “This is my street,” and, “This is my little neighborhood.” And there are other fish that specialize in feeding on some of these corals, strictly. And if the corals wasn’t -- weren’t there, they wouldn't have anything to eat, ‘cause that’s about all they eat.

Harold:  One of their main features and purposes is to protect land masses from major storms. It reduces the land erosion. I don't believe the Florida Keys would probably be here if it weren’t for our reef tract out front.

Mary:  While corals need the sunlight for the zooxanthellae and for the water temperature, to keep it nice and warm, is that, you know, a little bit is good, but too much can be damaging to it. The coral is only growing in two feet of water and you have day after day of the intense sunlight and the warm temperatures; it would almost be like a person getting a sunburn and the corals just can't survive that intensity.

Billy:  Well, just think of it this way, we’ve turned up the temperature in our oceans. We’re speeding up the metabolism of some of the problems that affect fish. For instance, we’re seeing more fish diseases. We’re seeing more algae blooms occurring as a result of elevated temperatures. People living in middle America can affect their coral reef, either positively or negatively. Over 40% of North America drains into the Gulf of Mexico. Whatever is draining into the Gulf of Mexico eventually passes the Florida Keys and America’s only living barrier coral reef. So what’s happening up the Mississippi, what’s happening in St. Louis, can affect our coral reefs. Here in the Florida Keys, we get three million tourists every year. They come down here primarily to go snorkeling and scuba diving and recreational fishing. 

Mary:  One of the things that we try not -- we try to have people do is obviously not touch the coral. The direct impacts are the easiest to -- you know, touching the coral, standing on the coral. But one that people probably don't think about is what happens when they’re snorkeling or diving and they start to stir up the sediment and the sediment then lay -- covers the coral. The coral does have a mucus layer that they can move this sediment off. And they can do that. But if somebody does this at 9:00 and then they do it again at noon, and again at 3:00, these poor corals have this sediment on them and they spend all their time trying to remove the sediment that’s been kicked up on them. So we ask that people be aware of their body position in the water, not to directly touch it, not to drop their anchor on it.

Art:  A four foot diameter coral head growing at the rate of a quarter of an inch a year took over 90 years, 90 to 100 years to develop. How long does it take to destroy that 100-year old coral? It can be done in an instant with contact with a boat anchor or a boat bottom or a diver’s fins. That means the whole colony is gone.

Billy:  In the last two decades, since 1983, we’ve had ten of the warmest years on record. Seven of those occurred in the 1990s. In 1997 and 1998, we had back to back coral bleaching years. That year here in the Florida Keys, we lost 30 percent of our living corals. There were some islands in the Indo West Pacific that are totally away from populated areas that lost 90 to 95 percent of their shallow corals. So we know this phenomenon is occurring on a global scale. Coral reefs are an excellent indicator ecosystem. We are seeing holes in the ozone. We have greenhouse gasses that are trapped in our atmosphere. These are leading to warmer surface temperatures on Earth, leading to the stress that are occurring on coral reefs. It’s not too late. Coastal environments are very resilient. If you protect the habitat, if you clean up the water quality, and if you give it good management, green organisms will rebound. We can make even coral reefs rebound.


NATURAL SOUTH: Coral reefs
Learn more about coral reefs in this episode of the Natural South.