Undersea Forests

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Coral restoration is key to preserving biodiversity

BY SID DOBRIN

I first marveled at the beauty of Florida Keys coral reefs nearly 40 years ago as a boy on a family trip. Even then, I was awed by the fantastic variety of life forms that inhabited that ecosystem.

Since then, I have snorkeled and made dives on the Keys countless times, and sadly, I’ve watched those magnificent reefs decline in vibrancy and vitality. In a much more formal fashion, the National Oceanic and Atmospheric Administration (NOAA) and other organizations and agencies have documented the devastation of Florida Keys reefs. According to NOAA, over the last four decades, “Nearly 90% of the live corals that once dominated the reefs have been lost.”

Several causes are at play, many of them resulting from human activity — ship groundings, improperly deployed anchors, overfishing, pollution and ocean acidification, to name a few. Even naturally occurring factors such as storms or disease may be exacerbated by humankind’s impact on climate change and ocean warming.

Once healthy reefs are turning a ghostly white due to coral bleaching, which results when corals dislodge the living algae in their tissues in response to changes in water temperatures, light absorption or access to nutrients.

A recent and more insidious threat to the reefs is posed by stony coral tissue loss disease (SCTLD). Combatting this disease is essential to protecting and restoring slow-growing species including brain, maze, boulder, star and pillar corals, all of which are foundational to the iconic 350-mile reef tract that includes the Keys.

The reefs of the Florida Keys comprise the third largest reef system in the world behind Australia’s Great Barrier Reef and

JUAN MARCOS BORSATTO / ISTOCK / GETTY IMAGES PLUS The blanching of this brain coral indicates that is has been affected by stony coral tissue loss disease, which overtakes slowgrowing corals.

Divers combine to plant corals at a damaged reef. Recovery requires that at least 25% of the reef be covered with healthy coral.

COURTESY OF MOTE MARINE LABORATORIES the Yucatan’s Barrier Reef. Th e island chain depends heavily on the reefs in terms of both ecological and economic health. Tourism and recreation account for billions of dollars in revenue to the State of Florida, and a signifi cant amount of that comes from money travelers spend during visits to the Keys.

People are unlikely to want to snorkel on bleached-white or diseased corals. Th ey have in mind robust reefs that are rich with life and provide dynamic opportunities to see thousands of species of animals and, of course, the stunningly beautiful corals themselves.

Tourism dollars are not the only reason to protect and restore these ecosystems that support more species than any other marine habitat. Florida Keys reefs are made up of more than 45 species of stony corals and 35 species of soft corals — seven of which are currently listed as threatened under the Endangered Species Act. Th e reefs host more than 6,000 species of tropical and subtropical fi sh, as well as sponges, lobster, crab, shrimp and sea urchins. Healthy reefs are also important to marine mammals, including seven species of dolphin, 13 species of whales, and West Indian manatees, all of which spend time in the waters of the Florida Keys. More than 285 species of shorebirds and seabirds also depend on these habitats. Th e Gulf side of the Keys provides a habitat for the largest populations of sea turtles in the Gulf of Mexico. Likewise, the Keys are home to the endangered American saltwater crocodile, and though they are not found on the reefs, they and countless other marine animals are dependent upon contributions made by reefs to the overall health of the larger ecosystem.

Seven reefs fall within the Florida Keys National Marine Sanctuary: Carysfort Reef, east of Key Largo; Horseshoe Reef, also east of Key Largo; Cheeca Rocks, southeast of Upper Matecumbe Key; Sombrero Reef, south of Boot Key; Newfound Harbor Key, south of Big Pine Key; Looe Key, also south of Big Pine Key; and Eastern Dry Rocks, southeast of Key West.

With both the economy and the environment in mind, myriad organizations have stepped up eff orts to protect and restore

NOAA scientists working to restore coral reefs usually begin by planting elkhorn coral, which grows quickly and is disease resistant.

the Florida Keys reefs. NOAA is employing a phased-restoration approach that begins with the removal of invasive species and nuisance species that use the resources that coral larvae need to establish themselves and grow.

After removing those species, NOAA scientists plant fast-growing corals. According to NOAA, for a damaged reef to recover and support a healthy ecosystem, 25% of it needs to be covered with new, healthy coral.

NOAA scientists generally start by planting elkhorn corals, which grow quickly and are resistant to some of the diseases that kill corals. After the elkhorn coral grows to cover about 15% of a damaged reef, NOAA scientists then add other faster-growing corals such as star, brain, pillar and staghorn corals before finally adding slower-growing stony corals like finger and blade to increase the reefs’ biodiversity and reach the 25% threshold. Throughout the phases, NOAA monitors the reefs, removing debris, predators that eat corals and other species that inhibit coral growth.

NOAA is not alone in working to restore this reef tract. Offices within NOAA have established partnerships with organizations including the Florida Aquarium, the Florida Department of Environmental Protection, the National Marine Sanctuary Foundation, the Nature Conservancy, Reef Renewal, the University of Florida, the Florida Fish and Wildlife Conservation Commission, the Fish & Wildlife Foundation of Florida, the Coral Restoration Foundation and Mote Marine Laboratory & Aquarium.

Mote Marine Laboratory’s Coral Reef Restoration Program, IC2R3, is based at Mote’s Elizabeth Moore International Center for Coral Reef Research and Restoration on Summerland Key, Florida. Scientists working at this research center breed and grow many types of corals that are used in restoration projects. The IC2R3 uses land-based coral nurseries and underwater nurseries where Mote scientists grow corals on “trees” made of PVC pipe.

Since 2008, the scientists at Mote Marine Lab have planted more than 100,000 corals of varying types. According to Dr. Erinn Muller, a senior scientist and associate vice president for research, Mote Marine scientists have planted corals “on about 30 to 35 reefs in the lower Keys over the last decade.”

Muller points out, “We also have a partnership with Biscayne National Park and

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COURTESY OF MOTE MARINE LABORATORIES Trees made from PVC pipe are used in the offshore propagation of corals that will be planted in building back reefs.

have outplanted on two or three reefs there, as well as off of Islamorada in partnership with I.care, a community-based restoration organization.” (icareaboutcoral.org)

Right now, in their land-based nurseries, scientists at Mote are growing about 34,400 coral pieces representing 17 species and 1,120 unique genetic types of coral. In the underwater nurseries, they are growing about 21,400 massive and branching corals. In the summer of 2020, Mote Marine scientists reported that some of the massive corals they had restored, including mountainous star corals, had begun spawning, producing new generations of coral on their own.

Similarly, some of Mote’s restored branching corals, like staghorn corals, had matured enough to start reproducing as well. One of the fascinating and exciting aspects of Mote’s coral restoration program is that of all the corals they grow in their nurseries, about 80% of them are genetic strains that Mote scientists have developed to resist diseases, such as stony coral tissue loss disease, that are currently damaging the reefs.

According to Dr. Muller, all of the genetic breeding of corals with new genetic traits to resist disease makes use of local corals in a crossbreeding program. This is fantastic news for restoration programs and the future of Florida Keys reefs.

In addition to Mote Marine Laboratories, NOAA partners with the Coral Restoration Foundation (CRF), the largest reef restoration

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The Mote Marine Laboratory in Summerland Key, Florida, is home to the Elizabeth Moore Center for Coral Reef Research and Restoration.

In their land-based nurseries, scientists at Mote Marine Laboratory are growing about 34,400 coral pieces representing 17 species and 1,120 unique genetic types of coral. In the underwater nurseries, they are growing about 21,400 massive and branching corals. In the summer of 2020, Mote Marine scientists reported that some of the massive corals they had restored, including mountainous star corals, had begun spawning, producing new generations of coral on their own.

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COURTESY OF MOTE MARINE LABORATORIES organization in the world. Located in Key Largo, CRF has been working toward reef restoration in the Florida Keys since 2007. Like Mote Marine Lab, the CRF has developed methods for growing coral and then planting colonies of young staghorn and elkhorn corals at damaged reefs.

Corals reproduce both sexually and asexually; the CRF focuses its efforts on the asexual reproduction of coral called “fragmentation.” Sometimes, a coral branch, such as elkhorn, might break off and fall to the seafloor. The CRF has developed a way to use the broken pieces to grow new corals that can be replanted on damaged reefs.

The scientists break the pieces into small, finger-sized pieces and hang them on “coral trees,” frames made from PVC, much like the process the Mote Marine Laboratory scientists use. Each coral tree can hold between 60 and 100 coral fragments. The coral trees are anchored to the seafloor in the waters off the Florida Keys and sway with the movement of the water around them to keep them from breaking. The CRF has seven offshore coral tree nurseries in the Keys, the largest of which covers 1½ acres of the seafloor.

It usually takes about six to nine months for the fragments to grow on the coral trees to a size where they can be outplanted to the damaged Keys reefs. CRF scientists use a special kind of glue to attach the newly grown corals to the damaged reefs. Over the last 10 years, the CRF has used this process to plant more than 120,000 corals at Florida Keys reefs.

Unlike the Mote Marine Laboratory and CRF restoration programs, which grow new corals, the Florida Fish and Wildlife Commission’s Florida Coral Rescue program collects healthy corals from reefs ahead of the spread of SCTLD. Working with FWC, as well as Disney, SeaWorld and the Association of Zoos & Aquariums, they then protect these corals in tanks at the Florida Coral Rescue Center in Orlando, the largest facility of its kind in the U.S.

The rescued corals have started to breed in protected habitats, thus preserving the original genetic strands of corals for later return to healthy reefs. Andy Walker, CEO of the Fish and Wildlife Foundation of Florida, explained that they originally rescued 50 samples from 20 species of coral in order to preserve and protect as much coral biodiversity as possible. Once collected and protected, Walker said, the next step will be propagating new corals to eventually be returned to healthier reefs. FFWF is working with SeaWorld to develop that next phase in the program.

“It might be cliche to say so,” Walker said, “but coral reefs are the tropical rainforest of the ocean. They occupy 2% to 3% of the ocean but harbor 25% of the biodiversity. So many species use them in their life cycles, and the amount of marine life in the world will fall greatly in numbers and overall biodiversity if the reefs collapse.”

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Free of disease and housed in an environment with optimal salinity and other conditions, a healthy brain coral thrives.

Restoration projects like those overseen by NOAA, Mote Marine Laboratories, the Coral Restoration Foundation, the Florida Fish and Wildlife Conservation Commission, and the Fish and Wildlife Foundation of Florida are crucial to the future of the Florida Keys reefs. You can learn more about this important work at: mote.org/research/program/coral-reef-restoration • coralrestoration.org myfwc.com/research/habitat/coral • wildlifeflorida.org