Concrete and corals?

Meredith Price Levitt, The Jerusalem Post 7 May 08;

For most people, the idea of concrete blocks replacing coral reefs might seem far-fetched. But for a group of marine scientists at Ben-Gurion University of the Negev, it is just what the doctor ordered.

Sturdy enough to last, yet porous enough to be implanted with corals, concrete is the basis for an innovative technique that may help save coral reefs in the Red Sea from further destruction from overzealous divers.

According to leading experts, more than 25 percent of the world's coral reefs have already been destroyed. The causes are varied, and they include pollution, global warming and irresponsible fishing, but another large factor is uncontrolled and careless tourism.

And perhaps more alarming is the fact that although coral bleaching (the most obvious sign of sick and dying coral) has been happening since at least the turn of the last century, most of the dramatic damage has occurred over the last 20 years.

The Red Sea has a reputation for being one of the most spectacular places to dive, and Eilat attracts thousands of vacationers a year, most of whom come to dive and snorkel in the coral reefs. But the very attraction they come to enjoy is suffering from the intensive tourism, and more and more of it is disappearing every year.

According to Dr. Nadav Shashar, a marine biologist at Ben-Gurion University of the Negev who worked side by side with Dr. Faud al-Horni in Jordan on the project funded by the US State Department's USAID-MERC program, the challenge was to find a solution that would go beyond mere conservation without limiting tourism.

What the team came up with was to create specially designed concrete blocks that are implanted with real coral and are intended to attract both fish and, in turn, divers. "In the marine environment, people have tried to create artificial reefs by throwing in junk like old ships and tires, but it's like putting old train tracks in a nice, new location. People don't move in by the herds," Shashar says.

To lure both fish and divers, the unique design also had to consider a diverse array of factors - from water currents and sand patterns to size and shape. Each concrete block in the Tamar Reef, as it is called, weighs four tons. Shashar says that since their introduction near the natural reef last April, the same number of species of fish can be found in the blocks as in the natural coral. "The numbers of fish in the concrete are lower, but the divers are attracted to them, and this is an important accomplishment in preserving the natural reef."

Shashar says that there are three main innovations in this particular project. The first is the ability to build whatever size artificial reef is necessary rather than having to maintain the traditional, small structures. Second, the concrete reef is supported by a coral "nursery" so that if parts of it are lost or broken, they can be easily replaced by others that are already being grown. In the nursery, the young coral is placed in optimal conditions to encourage rapid growth, which then enables the scientists to place it wherever it is needed in the reef.

Finally, Shashar points out that until now, most of the experimental artificial reef projects have focused on conservation and not sustainability. "If you only conserve what you have and don't increase your area, it's a losing concept, because if any parts of the area are damaged, you lose it. Our challenge was to find a way to increase the area and the species to make it truly sustainable," he says.

This was made even more challenging by the fact that it traditionally takes between 80 and 100 years for coral to completely cover an artificial structure. "I don't have that kind of patience," says Shashar, whose nursery concept has reduced the amount of time it will take to just five years. Nevertheless, since its inception, 10%-15% of the coral has been lost by careless divers inadvertently knocking it down. "This is experimental, and we are still learning. The next project in Jordan, which is supposed to be planted in a few months, has a better design and is 10 times the size of the one in Israel."

Of course, this project has also attracted the attention of foreign press and scientists from around the world who are interested in emulating its success.

Shashar, who wanted to be a marine biologist since he went diving in Sharm e-Sheikh at 10, says that the idea came from two places: an emotional one as a human being and another as a scientist who believes if scientists don't lead the way in saving the coral, no one else will. "This type of project allows me to play God. With water and sand I get to create an environment that I hope will be successful ecologically. Whether or not we know exactly what we're doing is another question."