Green Pages

The Electric Reef

A new technology offers hope for coral reef preservation.

By Brian Riggs, Fernando Perez and Dr. Thomas Goreau

While the Turks & Caicos Islands still have some of the best remaining coral reef in the Caribbean region, it is clear from recent fieldwork that even our corals are slowly declining due to episodic damage and progressive increases in environmental stresses, both natural and man-made.

The current state of Caribbean reefs in general, and TCI reefs in particular, was outlined in the Summer 2006 edition of this magazine. We reported that even though our local reef systems were in much better shape than those of most of our neighbors, Turks & Caicos reefs were still feeling the effects of higher than average sea surface temperatures over the past decade. Another problem that may face our reef habitats in the future is the pollution and sedimentation from marine works that accompany accelerated development, especially in Providenciales, Grand Turk and North Caicos.

biorock-gdt2Collecting the data . . .

The first statistics of reef health were provided in the 1970s in a report by Ray and Sprunt. In the late 1980s, when TCI played host to one of the first Operation Raleigh expeditions, teen volunteers collected coral coverage and growth data as a one-time environmental project and passed it along to the Department of Environment. But regular and systematic coral monitoring started over 15 years ago when permanent monitoring stations were set up by Dr. Gudrun Gaudian under the auspices of the Ministry of Natural Resources. These original stations on Grand Turk and newer ones on Providenciales and South Caicos have been monitored over the years by department employees, School for Field Studies students and diver-volunteers from many of the professional dive operations around the Islands. This data, along with regular diver statistic reports over the past decade, have given us a pretty clear idea of the state of Turks & Caicos reefs.

A widespread reef survey project in early June 2006 covered the original monitoring sites but also went further afield to have a look at almost all of Grand Turk’s and Providenciales’ seaward coasts and areas from East to South Caicos that were not covered by the monitoring stations. Information from this wide-ranging survey, showing perceptible coral declines even in areas well away from diver pressure or development, led to the inauguration of a project to develop a National Sustainable Strategy for Coral Reef Restoration. The Project was paid for by the TCI Conservation Fund, a special project fund earmarked for environmental studies and work. (The Conservation Fund was established in 1999 to sustain and expand ongoing management of our Protected Areas, and to safeguard our country’s national and historic treasures. It is financed by 10% of the Accommodation Tax collected at Turks & Caicos hotels and dining establishments.) The Sustainable Strategy is now in the implementation phase which is being funded by the Conservation Fund and the private sector.

What it means . . .

The recent survey puts us on notice that even with the best and most complete recycling efforts and treatment of wastewater on land, the level of stress from factors beyond local control is likely to increase. Global sea temperature rise, associated coral bleaching and disease outbreaks and more severe storm activity are likely to escalate rather than decline in the future. Therefore, there is an urgent need to begin coral reef restoration studies and efforts now, in the early stages. The aim is to preserve coral reef species diversity, fish habitat, the shore protection functions of a healthy reef and, of course, our eco-tourism potential.

biorock-indonesiaThe northeastern part of Providenciales and the southeastern part of Grand Turk were specifically identified as good spots for the introduction of artificial reefs to provide additional areas for snorkeling. These easily accessible, near-shore snorkeling sites should ease the pressure on existing natural snorkeling and diving reef resources.

A pilot demonstration project using the relatively new BioRock technology was recently started on Grand Turk. The long, official names of the process, “electrodeposition of minerals in sea water” or “mineral accretion technology” give us a vague idea of how the process works. Developed by architect Professor Wolf H. Hilbertz and coral ecologist Dr. Thomas J. Goreau of the Global Coral Reef Alliance, BioRock technology may have profound implications for coral propagation, the preservation of existing corals, coral reef restoration, shoreline protection, and even mariculture.

The essence of Biorock technology is to apply a low voltage electrical current to a metal structure in shallow water. The current causes dissolved minerals to precipitate quickly on the structure. The mineral coating of calcium carbonate then becomes a substrate that easily attracts the floating embryonic polyps of a wide range of sea creatures. New Biorock structures are soon populated by a full range of coral reef organisms, including fish, crabs, clams, octopus, lobster, sea urchins and barnacles. Another astounding effect of the weak electrical current running through the structure is that corals, in particular, grow as much as five times faster than in surrounding habitats due to the electrical stimulation. They are also much more likely to survive and thrive in polluted or degrading conditions.

In a BioRock structure in the Maldive Islands, an area that has suffered greatly from high sea temperatures in the past several years, only 1 to 5% of corals on some reefs have survived. On Biorock structures in the same areas, between 50 and 80% of transplanted corals have survived. While our reefs have not suffered anything like the devastation of Indian Ocean reefs, it will be good to know that there may be a relatively simple technological solution to a problem of which we are beginning to see the earliest stages.

Building a reef from scratch . . .

The Grand Turk Reef Project is a joint effort between the Department of Environment & Coastal Resources and Oasis Divers, Grand Turk’s largest and most active dive operation. With materials supplied by Captain Everette Freites, and under the direction of Dr. Tom Goreau, the Oasis crew built a group of substantial structures from construction re-bar. They were then installed on a sandy open space in 20 feet of water just offshore from the Oasis Dive Center, near the new cruiseship terminal on the south end of the island. Four quonset hut shaped structures, 20 feet long, were built on the beach and moved into position. They are temporarily hooked up to shore power by a long cable buried in the sand, but it’s possible that they could eventually be powered by buoyed solar cells directly over the site as they are in similar projects in Japan, Jamaica and the Maldives.

Oasis divemasters, DECR staff and a number of volunteers, including Joel Johnston from Grand Turk’s new Cockburn Farm and Village Visitor Centre, visited reef sites near the newly built cruise dock and salvaged a number of small hard and soft coral fragments that had been affected during the construction. These were affixed to the BioRock structure after it was put into place.

After less than a month in the water, Everette reports that the structure already has a thin skin of limestone and the manually attached coral fragments are quickly accreting to the structure. The “electric reef” is attracting hundreds of fish and other creatures. It’s already an interesting site for snorkelers.

It is expected that within a few years the structures will be densely colonized due to the increased growth rate of the transplanted corals, providing a new habitat for an array of reef creatures. These in turn will attract the myriads of gorgonians, worms, crustaceans and larger animals that live in and around them. Calcareous algaes will be producing sand particles for beach renourishment and the solid, self-repairing structure will be fulfilling one of the natural reef’s most important functions, the defense of the nearby shoreline from the battering of stormy seas.

The production of seemingly “instant” reefs being formed by the BioRock method is only one of a number of strategies that are being investigated for the preservation of our most important natural asset, but there is room for many approaches in a national strategy to protect and maintain our important reefs.

For more information about Electric Reefs, go to http://globalcoral.org/.



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Hobbyist photographer and Assistant Director for Research & Development at the TCI Department of Environment & Coastal Resources Dr. Eric F. Salamanca took this rare photo of a Bahama Woodstar hummingbird enjoying the nectar of Moringa flowers.

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