Undersea senior citizen


POSTED: Thursday, March 26, 2009

HOUSTON » A species of coral from off the coasts of Oahu and the Big Island is more than 42 centuries old, making it among the oldest continuously living organisms on the planet, according to a research team led by a Texas A&M University scientist.

A coral bed in about 1,200 feet of water studied by researchers in a submersible vehicle included the species Leiopathes, which carbon-dating technology has put at 4,265 years old, Brendan Roark, an assistant professor in the A&M College of Geosciences, said yesterday.

That age rivals the nearly 5,000-year-old bristlecone pine trees growing in the mountains of Northern California as among nature's longest-living continuously growing organisms.

A second coral species, Gerardia, also studied in the coral beds off Hawaii, is believed to be 2,742 years old.

It was previously thought the coral beds were no more than a few hundred years old, said Roark, who headed the team that included scientists from Stanford University, the University of California-Santa Cruz and Australian National University in Canberra. “;To find out that they are thousands of years old is a very exciting time for us.”;

The team's results are published in the current Proceedings of the National Academy of Sciences.

Roark described Leiopathes (pronounced Lee-oh-PATH-eez) as a tree- or shrub-like black skeleton with an orange tissue layer. A typical specimen is about a meter tall and a meter wide.

Coral for the study was collected in 2004 off Makapuu and Lanikai on Oahu, Keahole Point on the Big Island, and Cross Seamount, a 1,200-foot-deep peak about 180 miles south of Oahu. The scientists used the Pisces V submersible, owned by the Hawaii Undersea Research Laboratory at the University of Hawaii.

His research team has been collecting data since 2002 and believed the coral had been living longer than deep-sea coral, with a typical lifespan that reaches to 200 or 300 years. Their initial results had been questioned in some scientific circles, so they retested and expanded the research, Roark said.

“;We proved in no uncertain terms what we knew to be correct,”; he said, although the 4,200 years was longer than anybody suspected. “;That was a bit surprising, even to us.”;

The Leiopathes' longevity makes it a contemporary of the pyramids of Egypt, completed around 2200 B.C., and sections of Stonehenge.

Roark said the coral beds off Hawaii, one of them covering several hundred square feet, are under duress from fishermen's trawling nets and long lines, and from poachers who take coral for jewelry, despite international laws that protect the beds from harvesting.

“;The extreme age of the coral beds and their very slow growth, combined with the high levels of biodiversity surrounding the coral beds, means that protecting these reefs from further damage has to be a top priority,”; Roark said.

The Gerardia, coveted for its gold color, can grow much larger than Leiopathes — as 3 to 4 meters wide — and be lined up “;like a picket fence.”;

“;They're very beautiful,”; he said. “;Any kind of fishing activity that contacts the bottom is a threat to deep-sea coral beds and obviously to these species. ... You could compare the situation to that of the Amazon rainforest areas, where huge tracts of land are disappearing because of man-made activities.”;