FRANCESCA VIRDIS WIELDS HER PRUNING SHEARS LIKE ANY EXPERT NURSERYMAN, patiently snipping out dead and damaged stock and separating specimens to bump up for new growth – all 20 feet under water.
Ms. Virdis, based at Bonaire’s Buddy Dive Resort, was working in a nursery of “coral trees,” structures of PVC pipe with half-foot sections of staghorn and elkhorn coral suspended in the current. They stand in a restricted area on the sandy ocean bottom just off Klein Bonaire, big Bonaire’s smaller sister island.
Her nursery stock consisted of small colonies in the genus Acropora that create these elegant branching corals. In the age of climate change, all corals are considered potentially threatened, but staghorn (Acropora cervicornis) and elkhorn (Acopora palmata) corals have become so diminished in the Caribbean and tropical Atlantic that they’ve been listed under the US endangered Species Act as threatened, and Critically Endangered by the International Union for the Conservation of Nature (IUCN).
As coordinator for the nonprofit Coral Restoration Foundation – Bonaire (CRF-B), Ms. Virdis hopes to help restore the corals’ presence by establishing new stands of it along the island’s extensive reefs. On this day she was supervising three marine biology students from Ohio taking her specialty course in coral restoration. Under her guidance they were contributing a day’s worth of hanging new staghorn specimens and epoxying more-advanced ones in likely spots for growth.
During the dive, they found a grouping of stark-white fragments hanging on one limb, newly dead due to disease or predation. The fact that they hung all together amid other, healthy fragments suggested a fireworm had crawled up the trunk and plucked the polyp out of each corallite, all in a row. She suspected it was hiding inside the pipe on which they hung, but she couldn’t detect it.
“This happens,” Ms. Virdis said later. “It’s not a main cause of staghorn’s difficulties. It’s a localized problem. Hopefully, we’ll keep ahead of it.
She adds, “Acropora corals can grow as much as 12 inches in a year, so they’re particularly well-suited for being fostered in nurseries. We’re still in an early phase, but it seems to be working well. Our immediate problem is finding enough divers to do the work, so having visiting divers do the course is helpful.”
The project in Bonaire is one of several operated in conjunction with the Florida Keys-based Coral Restoration Foundation (CRF), which today operates five nurseries on 44 sites in the Keys. In addition to the Bonaire operation (a separate but closely aligned foundation), projects are underway in the Rosario Islands off the coast of Colombia, in Jamaica, on Mustique and at Curacao, established this past May as the Coral Restoration Foundation – Curacao.
The locations reflect the interest of its supporters as much as any scientific calculation. While similar efforts have been undertaken by marine biologists from several universities, the CRF has been driven largely by the commitment of private-citizen, non-scientist advocates.
A LUCKY SETTLEMENT, THEN AN INSPIRATION
The existence of the foundation itself began with a chance occurrence in the Florida Keys in the 1990s. There, Ken Nedimyer had a business collecting tropical fish and growing “live rocks” for aquariums near his home in Key Largo when three staghorn coral larvae settled on his reef and colonies began to grow.
“The corals settled in 1996,” he says. “We noticed them in ‘97 and set them aside. They grew, got beat up by hurricanes, grew again, got beat up by more hurricanes. Finally in 2000 we decided to find a way to grow them on stabilized structures and create a coral nursery.
“Our original intent was to grow them for the aquarium trade but as we watched them grow we began to think that they had a bigger and better use on the reef. I concluded that most researchers were so focused on studying the decline of the reefs that it took people with wild and crazy visions to try to put humpty dumpty back together again,” Mr. Nedimyer says.
“I thought this might offer a way to restore staghorn populations widely. A lot of people didn’t think it would work. We tried it. So far, it’s working well.”
After redesigning their nursery system, Mr. Nedimyer and his team started focusing on growing corals for reef restoration. They began planting corals on the reef in 2003, taking on volunteer divers – particularly high school students – beginning in 2004.
Early grant support came from NOAA and the “Sanctuary Friends Foundation of the Florida Keys along with The Nature Conservancy. Over the years, grants and sponsorship support has come from organizations as diverse as the Ocean Reef Conservation Association, the Georgia Aquarium and the Disney Worldwide Conservation Fund.
THREE POLYPS, 300,000 COLONIES
From his initial three polyps, the CRF has expanded to operate multiple nurseries in upper and lower Keys. To this date, CRF volunteers have planted more than 35,000 colonies on reefs along the Keys. In the coming years, Mr. Nedimyer hopes to have planted some 300,000 on 44 different reefs and patch reefs. Today, CRF operates with 10 staff and dozens of local volunteers. Each year, some 1,500 out-of-town volunteers arrive to help out. Today the foundation partners with universities and other organizations for research and has established its own six-member scientific advisory committee.
According to the NOAA, over the last 10,000 years, staghorn and elkhorn have been among the most important Caribbean corals contributing to reef growth and development and providing essential fish habitat. Elkhorn was formerly the dominant species in shallow water throughout the Caribbean and on the Florida Reef Tract, forming extensive, densely aggregated thickets (or stands) in areas of heavy surf.
But Acropora species have suffered particularly in the past 30 years or more. All corals are threatened by factors like the warming ocean temperatures and acidification of ocean water associated with climate change, increasing pollution of coastal ocean waters and expanded prevalence of algae in the Caribbean due to the decades-old die-off of algae-eating sea urchins. Elkhorn and staghorn species have been hit hard by Acropora white band and patch diseases, and elkhorn by white pox, recently determined to be caused by a bacterium found in human waste (abetted by poor waste water treatment systems).
FIRST SPAWNING, THEN CLONING
Corals reproduce in two ways. The first polyp in a colony is the result of the night-time male and female polyp spawning that is a staple of cable nature programs. Once a single polyp anchors itself to a substrate, or solid surface, it begins a process of growth by cloning, creating a structure of hundreds, even thousands, of identical animals.
Acropora species have another advantage: Branching corals are somewhat fragile, and often break off due to storm surge, the weight of overextension, or just things that go bump in the night. But when that happens, if an appropriate substrate is present, the broken section can become attached and begin growth as a new colony. NOAA cites this as the dominant method of elkhorn reproduction.
“This is our ace in the hole,” Mr. Nedimyer says. “It’s key to our program of growing coral branches in nurseries. We can grow a tiny fragment hanging in a nursery into a 10-inch specimen ready to be planted in about nine months.” Acropora corals especially need this help, he adds. “Some corals can rebound on their own, but Acropora species have become so diminished that regeneration is difficult for them.”
Just as finding the right epoxy for gluing branches was an extended process, it took time to come to the approach of hanging coral specimens out on lines. Originally Mr. Nedimyer sought to grow corals on stationary discs planted on the sea bottom; they accumulated too much algae. He moved on to hanging fragments on long lines strung across the bottom. Marine scientists cited a risk that turtles would get hung up on them. Eventually, he arrived at the coral tree approach.
Through this work, Mr. Nedimyer became known as an authority on coral restoration (he has been recognized as, among other things, a “CNN Hero” in 2012 and a “Disney Conservation Hero” in 2014). In 2010, friends suggested he talk to contacts in Colombia’s Rosario Islands. He since has worked there with local organizations, including the Living Coral Foundation, The Center for Research Education and Recreation (CEINER) Oceanarium and the Colombian National Park Service to create nurseries to plant some 4,000 fragments in this region.
And in 2010, Mr. Nedimyer was asked to go to Bonaire to consult on reef preservation. There, he talked with Augusto Montbrun, head of dive operations at Buddy Dive Resort, who immediately signed on to develop a Bonaire program based at Buddy Dive. Not only Mr. Montbrun and Ms. Virdis, but Buddy Dive Resort quickly got on board, donating staff time and encouragement to make the initial nurseries possible beginning to 2012.
Recently, the Harbour Village and Eden Beach resorts have joined the program as active supporters with nurseries on their house reefs. Overall the Bonaire operation has on Klein Bonaire and along the big island’s southern coast.
“Getting started required perseverance,” Mr. Montbrun says. “Before we could do anything significant, the political process in Bonaire took two years – we needed coral fragments to get started and the Bonaire Marine Park was reluctant to let us collect coral. They finally got on board and today are very supportive of the project.”
The first Bonaire nursery was established with a demonstration project of about 10 trees right off the resort and a larger collection of 20 trees in a restricted area at Klein Bonaire. Ms. Virdis notes that they began by taking five-centimeter fragments from marine park reefs. Soon, they were growing enough fragments to make the project self-generating. Thus far, they’ve planted some 4,000 fragments at the half-dozen locations.
“We have capacity for 10,000 fragments,” Ms. Virdis says. “We’re not close to filling that. The issue is manpower. So far they’ve trained 10 volunteers from the Bonaire community, including retirees to the island and long-time residents.
And, they started a one-and-a-half-day Coral Restoration Course to train visiting divers. Training two to six divers per week, the first morning is spent in a classroom session followed by practice working with fragments at the demonstration nursery. In the afternoon, the class moves to the nursery at Klein and the following morning they plant fragments. Some participants return to volunteer on the project in subsequent years.
“Through the course,” Ms. Virdis says, “we get people helping us with a day’s work. But more importantly, we hope they’ll go home and raise awareness about this need.”
Mr. Montbrun sees this work as important to the oceans and to Bonaire. “Healthy corals are essential to the survival of the reef,” he says. “They’re also essential to island tourism and to the island’s economic well-being.
“The long-term prospects are uncertain,” he says. “It’s too early to say if this is going to solve the problem, but we feel very positive about it. And we can’t just sit back and do nothing.”