Methane Ice Worm
Date: 1 Jul 1997
Scientists discovered this new kind of centipede-like worm in 1997 living on and within mounds of methane ice on the floor of the Gulf of Mexico, about 150 miles south of New Orleans. Methane ice, a gas hydrate, 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 bottom. Occasionally this seeping, solid methane bursts through in mounds, often six to eight feet across.
Although scientists had hypothesized that bacteria might colonize methane ice mounds, this is the first time animals have been found living in the mounds.
The discovery of dense colonies of these one-to-two-inch-long, flat, pinkish worms burrowing into a mushroom-shaped mound of methane seeping up from the sea floor raises speculation that the worms may be a new species with a pervasive and as yet unknown influence on these energy-rich gas deposits.
The worms were observed using their two rows of oar-like appendages to move about the honeycombed, yellow and white surface of the icy mound. The researchers speculate that the worms may be grazing off chemosynthetic bacteria that grow on the methane or are otherwise living symbiotically with them.
The scientists have also managed to keep a number of the exotic worms alive in shoreside laboratories for further study.
The expedition was carried out aboard the Harbor Branch Research Vessel Edwin Link and sponsored by the NOAA National Undersea Research Center at the University of North Carolina at Wilmington and the Minerals Management Service of the U.S. Department of the Interior. In addition to Chief Scientist Charles Fisher, principal investigators included Ian MacDonald of Texas A&M University, Robert Carney of Louisiana State University, Steve Macko of the University of Virginia, and Alissa Arp and David Julian of San Francisco State University.
Last Update: 5 Jul 2011 (AMB)