Intensive Care for Coral Reefs

Currently the pres­i­dent of the Global Coral Reef Alliance (GCRA), Dr. Goreau pre­vi­ously held the post of Senior Scientific Affairs Officer at the United Nations Centre for Science and Technology for Development, in charge of global cli­mate change and bio­di­ver­sity issues. He has pub­lished some two hun­dred papers on sub­jects such as coral reef ecol­ogy, changes in global ocean cir­cu­la­tion, trop­i­cal defor­esta­tion and refor­esta­tion, and math­e­mat­i­cal mod­el­ing of cli­mate records.

Both his father and his grand­fa­ther were divers, and his obser­va­tion of coral reefs goes back even fur­ther than his cur­rent life. “My grand­fa­ther was the first per­son to take good under­wa­ter pho­tographs of coral reefs,” Dr. Goreau told Organic Connections. “My father was the world’s first sci­en­tific diver of any kind. As a result, I have the largest col­lec­tion in exis­tence of under­wa­ter pho­tographs of the 1940s, ’50s and ’60s.”

Between these pho­tographs and his own long-term obser­va­tions, Dr. Goreau has made a com­pre­hen­sive study of the world’s reefs and can speak with con­sid­er­able author­ity about the con­di­tion they are now in. “There’s just no place that you go today, that we recorded back in the past, that you wouldn’t cry to see now,” said Dr. Goreau. “In some places there’s no trace left, and in most loca­tions there’s just a tiny hand­ful of corals, a cou­ple of per­cent of what they used to be. Nearly all peo­ple who dive on reefs these days really have no idea of how they used to be.”

Biorock Reefs

Dr. Goreau has been part of a unique solu­tion that can actu­ally grow reefs—and greatly pro­mote the life around them. It is called Biorock, and it con­sists of a metal rebar frame­work through which is run a small elec­tric cur­rent. “When we started these projects, we found we were able to grow corals any­where from two to six times faster than the nor­mal rates or even record rates of those species, depend­ing on the species and the con­di­tion,” Dr. Goreau related. “So it just tremen­dously accel­er­ates their growth.”

Biorock first began as a way to grow nat­ural build­ing mate­ri­als. “The tech­nol­ogy was orig­i­nally invented by an archi­tect named Wolf Hilbertz,” Dr. Goreau explained. “Wolf was inter­ested in pro­duc­ing or mak­ing build­ings from mate­ri­als that grew them­selves. About the mid-1970s, when he was a pro­fes­sor of archi­tec­ture at the University of Texas, he redis­cov­ered what [English chemist and physi­cist] Michael Faraday had dis­cov­ered orig­i­nally a cou­ple of hun­dred years ago: If you take a bat­tery and pass a direct cur­rent through sea­wa­ter, you pre­cip­i­tate min­er­als on one ter­mi­nal. That turns out to be lime­stone, the very min­eral that coral skele­tons are made of.

“I heard about his work in the mid-eighties, and asked him to come down to Jamaica to work with me and try to apply it to corals. He came to the Discovery Bay Marine Lab, a lab that my par­ents founded and where I was based. Our reefs were being killed by sewage at that point. I found one of the last liv­ing corals we had and put it on the struc­ture. I came back three months later and it was three or four times big­ger. It really was quite staggering.

Causes of Damage

The Biorock tech­nol­ogy truly is remark­able, given the destruc­tion that has taken place. As one might expect, causes of coral death are eas­ily traced to man’s inter­fer­ence with marine life. “Back begin­ning around the six­ties or so, we started see­ing reefs really dying on a large scale due to regional causes,” Dr. Goreau recalled. “The reefs were being killed by things we did in the water: dump­ing anchors, direct dam­age, and dredg­ing. A major fac­tor has been the fail­ure to treat sewage: just dump­ing sewage in the ocean causes algae blooms that smother and kill reefs. We’ve seen those spread out from every pop­u­lated area wher­ever there are reefs, and almost any place that you go where there is a large tourist area you just have algae-covered dead reefs.”

Another con­tribut­ing fac­tor is, inter­est­ingly, our treat­ment of the land. “The other thing we’re see­ing is reefs being killed on a very large scale due to defor­esta­tion,” Dr. Goreau con­tin­ued. “We’ve wiped out the major­ity of the forests on most islands. The forests are what made the soil or kept it in place; so, with the forests gone, we basi­cally let all that sed­i­ment wash onto the reefs and smother them. These are sources of harm that don’t lie with the reef itself; they lie in adja­cent ecosys­tems that are upstream or upcur­rent and wash onto the reef.

The prob­lem has now greatly esca­lated, and there are new cul­prits at work. “In the last 20 or 30 years we’ve seen new global impacts; global warm­ing is the num­ber one killer, and new dis­eases is num­ber two,” Dr. Goreau said. “These are dis­eases that we didn’t used to see in the for­ties, fifties, six­ties or the sev­en­ties, but we are see­ing more and more of them. They’re spread­ing, and we don’t really know what the cause is, but it’s linked some­how to human activity.”

Climate Change

“Coral reefs are extremely vul­ner­a­ble and sen­si­tive ecosys­tems,” Dr. Goreau remarked. “They’re not resilient at all. Of all ecosys­tems they are the most tem­per­a­ture sen­si­tive, the most nutri­ent sen­si­tive, and the most sed­i­ment sen­si­tive; there­fore they die under lev­els of pol­lu­tion that wouldn’t affect any other ecosys­tem. In the con­di­tions of cli­mate change, they are the first ecosys­tem to go. In fact, in 1992 when the orig­i­nal nego­ti­a­tions were hap­pen­ing at the Earth Summit in Rio de Janeiro, I gave a brief­ing to the island nations say­ing, ‘Listen, if you don’t stop global warm­ing here and now, you’re going to lose most of your reefs in the next 20 years.’ Well, they didn’t do any­thing to stop global warm­ing and we’ve lost almost all the corals in the last 20 years. And high tem­per­a­tures have been the num­ber one cul­prit; there are many other fac­tors but that’s the big one.”

Dr. Goreau explained the most obvi­ous sign of coral stress—bleaching. “Bleaching is a bit of a mis­nomer, but what hap­pens when they bleach is that they appear to turn white. In fact what they’re doing is becom­ing transparent—you’re look­ing right through their tis­sue, which is only a mil­lime­ter or so thick. You’re see­ing through to the white lime­stone skele­ton that they grow, which is what builds the reef frame­work itself.

“Their abil­ity to grow that skele­ton is depen­dent on the fact that corals have micro­scopic sym­bi­otic algae inside their tis­sues. The pho­to­syn­the­sis of the algae greatly speeds up the growth of the skele­ton of the coral; with­out those algae the reef itself would not be there. The algae also give the coral tis­sue its many beau­ti­ful col­ors. When the coral becomes stressed for any rea­son, it expels the algae and sud­denly becomes trans­par­ent. It looks as if it’s dead or white; you have to look really closely to see if there’s a tiny layer of trans­par­ent tis­sue there. That means the coral is one step short of death.

“Until the 1980s all cases of bleach­ing that had ever been seen were very local­ized events, so had pretty much been con­fined to tide pools or small bays or to when they were cut off from cir­cu­la­tion at extreme low tides and had got­ten hot in the sun—things like that. But begin­ning in the eight­ies we started see­ing this hap­pen on a huge scale over thou­sands of miles, in places that had no obvi­ous local stres­sors at all. It took us a long time to fig­ure out why, but I was actu­ally the per­son who worked it out from satel­lite tem­per­a­ture data. What we found was that it took only one degree centi­grade above the nor­mal aver­age for a one-month period to bleach the corals and about two degrees above nor­mal to basi­cally kill almost all of them.”

Do Reserves Help?

Many con­ser­va­tion agen­cies are cre­at­ing oceanic reserves, in which the coral will no longer be touched by human inter­ven­tion. But Dr. Goreau points out that such moves, while laud­able, are not at all suf­fi­cient. “The solu­tion that is pro­moted by gov­ern­ments, con­ser­va­tion groups and inter­na­tional fund­ing agen­cies is to say that marine pro­tected areas will bring back our coral reefs and will bring back our fish. Well, they won’t. They won’t bring back our coral reefs if they don’t con­trol tem­per­a­ture, sewage, new dis­eases and all the things that are really killing the reefs—which they can’t. So every marine pro­tected area I dive in is full of dead and dying corals and they’re pow­er­less to pro­tect them.

“They claim coral reefs are resilient ecosys­tems, so all we need to do is sit back and they’ll recover all by them­selves. It doesn’t hap­pen at all.”

Biorock Proliferation

For the moment at least, it appears that Biorock is the only work­ing solu­tion to restor­ing coral reefs—and Dr. Goreau has put it to use wher­ever he has been allowed. “Since our orig­i­nal exper­i­ments, we’ve done hun­dreds of projects all around the Caribbean, the Indian Ocean, the Pacific and Southeast Asia,” he said. “Indonesia is really sort of our major base these days, but we have projects in more than 20 coun­tries. Wolf unfor­tu­nately died about three years ago, so I’m con­tin­u­ing his work with some of our for­mer stu­dents and so forth. We’ve been work­ing wher­ever peo­ple would let us.”

The results of Biorock in every place it has been imple­mented have been noth­ing short of spec­tac­u­lar. “We did a lot of work in the Maldives, which is one of the low­est coun­tries in the world,” Dr. Goreau said. “At that point some­thing like 95 to 99 per­cent of all their corals had died from high tem­per­a­tures. We found that the corals we were grow­ing had 16 to 50 times higher survival—that’s times, not per­cent—and we were able to keep these reefs alive where we could put a lit­tle trickle charge of cur­rent in them.”

Dr. Goreau also dis­cov­ered that it wasn’t just the corals that ben­e­fited from this slight elec­tri­cal flow. “Not only were corals grow­ing much faster than nor­mal, but so were all kinds of dif­fer­ent marine organ­isms: oys­ters, sponges, crabs and many oth­ers. So we’re cre­at­ing habi­tats that they like by speed­ing up the growth of every­thing. It’s not just those things on the struc­ture that are grow­ing faster; it’s life forms in the sur­round­ing area too, because actu­ally the elec­tri­cal field is stim­u­lat­ing their growth.”

The Long-Term Solution

Of course, using elec­tric­ity to stim­u­late and main­tain the growth of coral through­out all of the world’s oceans is not a work­able answer. “One can say this is an interim mea­sure,” Dr. Goreau con­cluded. “It’s not a long-term solu­tion. For that, we have to con­trol global warm­ing; in fact, more than that, we have to reverse global warm­ing. That is what is needed in the long run—but until then, we can keep some things alive at least where we can power them.”

The good news is that Dr. Goreau is actively engaged in the area of cli­mate sta­bi­liza­tion as well, which Organic Connections will be cov­er­ing in detail dur­ing the next few months.

To find out more about Biorock and Dr. Goreau’s work with coral, visit www.globalcoral.org.

Click here to down­load a brochure about Biorock.