A coral reef nursery project in Little Cayman is showing signs of success, with endangered coral species growing at rates seen in the wild, according to marine conservationists.
The island’s coral reef nursery is home to some 250 endangered coral colonies, and the aim of the underwater project is to grow thousands before transplanting them to reefs.
The study, funded by the U.K. Darwin Initiative and conducted by the Central Caribbean Marine Institute and the Department of Environment, investigates re-population methods for the endangered staghorn coral species.
“CCMI and our project partners at Department of Environment are thrilled with the progress of the nursery project so far,” said conservation scientist Katie Lohr, who regularly monitors the corals.
“The corals in the nursery are healthy and growing, and we have already discovered potential new techniques to maximize growth in the nursery,” she said.
Staghorn coral is a branching, stony coral with branches ranging from a few inches to more than 6.5 feet in length and height.
The corals grown in the nursery are consistent with the average size in the wild. “Growth rates of corals in the nursery are consistent with published growth rates for staghorn coral, with branches growing approximately 10-20 centimeters (4-8 inches) per year,” said Ms. Lohr.
Staghorn coral populations have been devastated in the region over recent decades as a result of disease, bleaching and hurricane damage, according to officials.
The study, which began two years ago, aims to “demonstrate that in Little Cayman, we can multiply the population of this very threatened species,” said Carrie Manfrino, president of the Central Caribbean Marine Institute.
“It is a private study to determine how well we can grow and propagate this particular species because it is the most threatened species in the ocean right now.”
After growing the coral, researchers must determine the “best strategies for taking them back out to the wild,” said Ms. Manfrino.
CCMI’s research team has been using the coral nursery to gain insight into the species and its vulnerabilities to different environmental factors.
“We will continue to use the nursery as a tool for increasing knowledge about this threatened species and finding new ways to increase its abundance locally and throughout the Caribbean,” said Ms. Lohr.
Over the past two years, scientists have removed 120 coral colonies from the nursery and planted them at two sites in Little Cayman to determine the best areas for re-population.
Ms. Lohr said coral fragments were planted in sets of 30 at two reef sites on both the north and south of the island, with coral regrowing better on the south side the island, said Ms. Lohr.
Now scientists are investigating what “environmental factors increase the success of out-planting.”
Ms. Manfrino said, “The problem is that it is a lot of work; it’s a huge project to be able to do this. We need to demonstrate the best way to do this, ecologically, so that when other folks want to work on a project like this, they know how to do it in the best way.”
This particular species of coral has some rare defining features over other coral species found in the Caribbean.
“Staghorn coral represents one of only two species of branching corals in the Caribbean, so conserving this species is important for ensuring that our coral reef ecosystems function properly,” said Ms. Lohr.
“With careful maintenance and strict scientific oversight, coral nurseries can be an excellent tool for increasing populations of the threatened staghorn coral and other coral species and for conducting studies to understand why these corals are in decline and how we can help.”
The habitat that the staghorn coral create also supports “certain fish and other underwater organisms that prefer that type of habitat,” said Ms. Manfrino.
If the re-population of the coral in the wild proves to be successful, the plan is to help implement similar staghorn restoration projects in other Caribbean countries.