Coral Trove Found Off Madagascar

By Bijal P. Trivedi
National Geographic Channel
May 15, 2002
Madagascar, the world's fourth largest island, is a nature-lover's
paradise on land, but its underwater treasures are only now being
explored, yielding up previously unknown species of coral and fish.

A recent one-month marine survey more than doubled the number of corals previously thought to exist in island waters and identified several new species of fish and as many as nine new corals.

"Madagascar gets a lot of attention for its biodiversity on land, but its marine habitats are equally precious and threatened," said Dr. Sheila McKenna of Conservation International, the Washington, D.C.-based non-profit organization that sponsored the research.

Located 250 miles off the eastern coast of Africa, the island is slightly less than twice the size of Arizona yet has six different microclimates ranging from rain forest to desert. It hosts nine-tenths of the world's lemur population, 1,000 different orchid species and more than 10,000 varieties of plants with new ones being discovered daily. Its Eden-like diversity has made it a number one priority in international conservation efforts, but now the reefs surrounding the island like lacework are moving up on the list of marine biodiversity hot spots.

"The diversity of corals was much larger than I had expected," said Dr. John Veron, chief scientist at the Australian Institute of Marine Science and a member of the international research team.

Coral are tiny spineless animals essential in building reefs, one of the planet's oldest and most complex ecosystems. Supporting 25 percent of all marine life, many reefs around the world are threatened today by both man and nature.

Donning scuba gear, the researchers surveyed 30 sites off the northwestern coast, documenting 304 coral species, some found on reefs no bigger than a few hundred yards. The number of coral described during the 20-day expedition in January comes close to the 340 species recorded for the entire western Indian Ocean and suggests that the island and the nearby Comoro Islands have the highest number of corals in the region. Dr. Veron discovered all the coral not previously identified.

"Finding nine to ten new species of corals is about the yearly quota, but for one person to fulfill this quota is quite unusual," said Stephen Cairns, a curator of coral at the National Museum of Natural History in Washington, D.C.

Dr. Veron, who has discovered and described over one-quarter of all reef coral, was surprised himself.

"I rarely come to a place where there are undescribed species. Usually if it's new to me, it means that it is a new species, but that doesn't mean some Frenchman didn't see them in 1880," he said. He was particularly amazed to discover one spectacular coral "like a bowl of flowers, with mostly red flowers but also some blue and green."

More research will be needed before the samples are accepted as new species, because classifying coral is as much an art as a science.

"Corals are like trees, they can change their appearance depending on where they grow. They can look different in shallow and deep water and on the coasts of other countries," Dr. Veron explained.

The survey also found a richer diversity in fish than anticipated and what may be three new species of damselfish.

"Two of these three fish got me very excited because I have studied this family for more than 30 years," said Gerald Allen, Ichthyology and Science team leader for Conservation International's Marine Rapid Assessment Program. "There are 350 species worldwide and I know them all like the back of my hand. I immediately recognized two of these three as new." The third may have been masquerading as another species, he suggested.

Cataloguing new species was only one goal. The expedition also collected socio-economic and biological data to help develop reef-protection policies. The researchers interviewed local fishermen and considered reef health. They found great ecological awareness and little evidence of coral bleaching, related to increased water temperatures.

"The state of these reefs was surprisingly good," Dr. Veron said. "Within 50 years, coral reefs around the world will be decimated, but I think the Madagascar reefs will be largely protected from the effects of global warming because of cold currents from the Southern Indian Ocean. If these reefs are looked after, in 50 years they will be there."

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