By Sean Henahan, Access Excellence

A team of  scientists has been exploring mounds of methane ice found on the ocean floor in the Gulf of Mexico. Methane ice forms naturally at the high pressure and low temperature of the deep sea, but is usually buried deep in marine sediment. The Gulf of Mexico is one of the few places where hydrate can be found exposed on the ocean floor. In some cases, the methane forms into yellow and white mounds as much as sixteen feet across.

Caption: Close-up photo shows a dense colony of one-to-two inch-long polychaete worms living on and in the surface of the methane hydrate. (Photo credit: Charles Fisher, Penn State)

While scientists have suspected that bacteria might colonize these ocean-floor ice mounds, known as gas hydrates, the discovery of the worms came as quite a surprise. Scientists believe they may discovered a new species with a unique interrelationship with these methane deposits.

The scientists observed dense colonies of the 1-inch-long flat, pink worms- called polychaetes- living on the mounds. The blind creatures use two rows of oar-like appendages to move throughout the honeycombed, yellow and white surface of the hydrate mound.

The worms were first spotted only two weeks ago by Dr. Charles Fisher of Pennsylvania State University, chief scientist of the expedition. The worms were discovered during an 1,800- foot-dive in the deep-sea submarine known as the Johnson Sea Link.

"These are not just another common worm in the mud," says Fisher. "These are higher order organisms that can live right on methane hydrates. If these animals turn out to be ubiquitous on shallow sea-floor gas deposits, they could have a significant impact on how we go about mining or otherwise harvesting this natural gas as a source of energy."

Another team member, Dr. Alissa Arp, director of SF State University's Romberg Tiburon Center for Environmental Studies, is now studying live specimens in her lab in order to determine how the animals can thrive in such inhospitable conditions.

"Biologists are always thrilled to find a new organism that has such an intricate strategy for inhabiting such a remote and hostile environment. We've discovered that the worms have a fully developed digestive tract. This means they are either grazing off chemosynthetic bacteria living directly on the methane, or, the relationship may be more symbiotic. They may be farming this type of bacteria on their appendages," Arp reports.

A second leg of the expedition is now underway.