Curaçao: A Collaboration to Save Coral in the Caribbean

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Curaçao: A Collaboration to Save Coral in the Caribbean

For Senior Biologist Shawn Garner, an invitation to help oversee coral spawning conservation efforts in the Caribbean nation of Curaçao highlighted The Florida Aquarium’s growing reputation as a leader in the campaign to rescue the world’s coral reefs.

 

Before coming to the Aquarium nearly five years ago, Garner had worked with spawning corals at Waikiki Aquarium in Hawaii and other institutions. So, he was familiar with the efforts to enhance the reproduction of corals, which are dying along the Florida Reef Tract and many other locations.

 

But, at The Florida Aquarium he found coral spawning research was “in overdrive” and he quickly saw how the Aquarium was becoming a driving force in the field.

 

The Florida Aquarium, for instance, in 2014 became the first institution to reproduce staghorn coral in the lab and now is producing thousands of larvae at its state-of-the-art Center for Conservation campus near Apollo Beach. This past spring, Aquarium divers “out-planted” 3,200 lab-raised staghorn coral in the wild.

In August 2019, the Aquarium became the first in the world to induce Atlantic coral to spawn in a laboratory, bringing new hope to coral conservation in the Florida Keys and Caribbean.

 

Garner’s trip to Curaçao, a small island off Venezuela, was organized and led by Sea Life, an international organization of aquariums devoted to protecting marine creatures. It has 10 separate aquarium members in the United States, including The Florida Aquarium, and all 10 were represented on the expedition to “collect grooved brain coral spawn, get the larvae to settle on cement plates in the lab and then out-plant infant corals on reefs.”

Because of Garner’s experience, Sea Life expedition leader Skylar Snowden asked him to teach participants how to execute a process that requires speed, ingenuity and efficiency.

 

“We went over the entire coral spawn. I taught how to collect, how to do dives, how to release the corals back into the wild. We stayed there two weeks and the entire time was action packed. We had a lot of dives.”

 

While somewhat similar, the collection had key differences with the annual Florida Aquarium staghorn coral spawn collection dives in the Florida Keys. The Aquarium divers collect staghorn spawn from the Coral Restoration Foundation “Coral Nursery,” an aquatic refuge where coral fragments are attached by fishing line to PVC “trees.” The fragments can reproduce and divers put nets around the coral. The nets collect the spawn “bundles,” which contain both eggs and sperm.

 

In Curaçao, the brain coral spawn was collected from natural reefs, making it a challenge to determine which corals were actually releasing the spawn. Garner said they were aided by butterfly fish, which eat the coral spawn.

 

“We could determine which corals were releasing by watching where the butterfly fish were going.”

 

It is notable that each coral species has its own spawning “cue,” as Garner puts it. The staghorn corals in the Keys usually spawn around the full moon in July. In contrast, the brain coral in Curaçao generally spawns in late spring and Garner says the spawning trigger is the “setting sun.” The brain coral would spawn between 6 p.m.  and 7 p.m., four days in a row.

 

With the butterfly fish’s assistance, the Sea Life divers would put netting over the spawning coral “with a collection cup that catches the packets that float up; when it’s filled, it can be replaced.”

In the wild, Garner explained, the “sperm-encrusted egg packets float to the surface, where wave agitation breaks it apart and the sperm goes to look for different eggs.” The sperm and eggs in the packet have the same genotype and will not mate with each other.

 

But in many or the world’s reefs, there are not enough healthy corals close together for reproduction to succeed. Garner stressed this is why spawn collections are valuable.

 

He explained: “It helps when there is a reproduction bottleneck … where there are so few corals that genetically diverse sperm and eggs never get a chance to meet.” That, sadly is the situation throughout much of the Florida Reef Tract, where reefs are disappearing rapidly because of pollution, disease, climate change, development and other factors.

 

Once the spawn packets were collected, they were hustled to the nearby lab at Carmabi Marine Research Station and put into tanks, where the packets would disintegrate. The sperm and eggs in the same packet would be separated, so the sperm could fertilize an egg with different genotype.

 With good fortune, the resulting larvae would settle on cement plates and could soon be put back in the wild.

 

“They can go right back in the ocean once the calcium skeleton has been laid down,” Garner said. “This is about four or five days after the spawn.  Brain coral is a very fast grower.”

 

He said the team was able to produce 203,000 fertilized larvae packets and released another 500,000 back into the wild because they did not have laboratory space for them. Of the 203,000 packets, 42,000 settled on the cement plates and were placed back in the ocean in three locations.

Garner noted that the cement plates are designed to be inserted securely onto a reef without need of epoxy, cement or line. The Aquarium team surely will be interested in how this attachment strategy fares.

 

In the recent Aquarium-led staghorn “out-planting” of 3,200 lab-raised coral in the Florida Keys, the time required to put the corals in the wild, either tying them to the PVC trees or using epoxy to anchor them to reefs, limited the number of healthy corals that could be put in the ocean.

 

A less labor-intensive method could dramatically increase the number of corals that could be out-planted, but Garner warns it is not yet clear which technique is most effective.

In contrast to the dwindling Florida Reef Tract, which has lost 90 percent of its staghorn and elkhorn corals, Garner found Curaçao reefs in good shape, with little pollution or development damage. But the Sea Life collection exercise was aimed at sharpening the skills and knowledge that will advance the coral revival efforts in Florida and elsewhere.

 

Garner was honored to help lead the effort, which aptly complemented The Florida Aquarium’s commitment to coral restoration. 

 

“It is impressive that another facility would ask us to help. And it was gratifying to teach younger biologists about the spawn and interact with them. You see how enthusiastic and committed they are and feel the new generation may come up with even better ideas on how we can preserve our corals.” 

 


ABOUT THE AUTHOR

Joe Guidry, a Tampa native, worked for The Tampa Tribune Company for more than 40 years. He joined The Tampa Tribune Editorial Department in 1984, later became Deputy Editorial Page editor and took over as Opinion Page Editor in 2008, a position he held until the Tribune ceased publication in May 2016. Read more...