staghorn coral just planted
Newly outplanted staghorn corals

Coral restoration projects off the Florida coast are working. And the techniques used may play a role in coral survival worldwide, including Hawaiʻi.

Eliza Garfield, University of Hawaiʻi at Mānoa Department of Biology lab coordinator, and other researchers discovered that outplanting, which involves cultivating the coral in a controlled environment before moving them to a restoration site, proved successful for at least a few years. They co-authored a new PLOS One article “Survivorship and growth in staghorn coral (Acropora cervicornis) outplanting projects in the Florida Keys National Marine Sanctuary.”

healthy staghorn coral
A healthy staghorn coral colony several years after outplanting

Using data collected from nearly 2,500 staghorn coral colonies at 20 sites in the Florida Keys, researchers discovered that survivorship was high for the first two years. However, it quickly diminished years after, and less than 10 percent survived more than seven years. Therefore, the researchers concluded that more colonies need to be outplanted so coral have a better chance of long term survival.

Garfield credited the research project to the efforts of all collaborators from other higher education institutions and the Coral Restoration Foundation.

“While our work originally felt depressing, the collaboration allowed us to publish both the harsh reality of outplant survivorship and that the future needs to ramp up the same work to meet a post-climate change goal,” Garfield said.

Coral in Hawaiian waters

headshot of Eliza Garfield
Eliza Garfield

Although staghorn coral is more abundant in the Caribbean, Garfield said most coral species worldwide have a lot in common, which would allow the use of many of the same techniques, including capturing coral sperm and eggs to fertilize and propagate in labs, and growing coral in nurseries. Many efforts are underway in Hawaiʻi to facilitate coral growth in Hawaiian waters.

However, experts said pollution and rising ocean temperatures contribute to an accelerated rate of death in corals.

“The important thing for me though is we need to make sure first and foremost that we do no harm or set back the corals we work with even further, then we can pursue varied restoration techniques with the goal of assisting them through climate change,” Garfield said.