Active Eruption of NW Rota-1 Submarine Volcano

Three years ago scientists visited NW Rota-1, an erupting submarine volcano near the....

Three years ago scientists visited NW Rota-1, an erupting submarine volcano near the Island of Guam. Upon returning they found that the volcano had been in near continuous eruption and that large numbers of shrimp, crab, limpets and barnacles now inhabit the volcanos. Many of these creatures are adapting to life on the volcano and some are new-to-science species only observed here. The pressures of the ocean deep significantly reduces the strength of volcanic blasts and that enabled the scientists to observe the volcano closely with Jason, their remotely-operated vehicle. Scientists who have just returned from an expedition to an erupting undersea volcano near the Island of Guam report that the volcano appears to be continuously active, has grown considerably in size during the past three years, and its activity supports a unique biological community thriving despite the eruptions. An international science team on the expedition, funded by the National Science Foundation (NSF), captured dramatic new information about the eruptive activity of NW Rota-1. "This research allows us, for the first time, to study undersea volcanoes in detail and close up," said Barbara Ransom, program director in NSF’s Division of Ocean Sciences, which funded the research. "NW Rota-1 remains the only place on Earth where a deep submarine volcano has ever been directly observed while erupting." Scientists first observed eruptions at NW Rota-1 in 2004 and again in 2006, said Bill Chadwick, an Oregon State University (OSU) volcanologist and chief investigator on the expedition. This time, however, they discovered that the volcano had built a new cone 40 meters high and 300 meters wide"That’s as tall as a 12-story building and as wide as a full city block," Chadwick said. "As the cone has grown, we’ve seen a significant increase in the population of animals that lives atop the volcano. We’re trying to determine if there is a direct connection between the increase in the volcanic activity and that population increase." Animals in this unusual ecosystem include shrimp, crab, limpets and barnacles, some of which are new species. "They’re specially adapted to their environment," said Chadwick, "and are thriving in harsh chemical conditions that would be toxic to normal marine life. "Life here is actually nourished by the erupting volcano." Verena Tunnicliffe, a biologist from the University of Victoria, said that most of the animals are dependent on diffuse hydrothermal venting that provides basic food in the form of bacterial filaments coating the rocks. "It appears that since 2006 the diffuse venting has spread and, with it, the vent animals," Tunnicliffe said. "There is now a very large biomass of shrimp on the volcano, and two species are able to cope with the volcanic conditions." The shrimp reveal intriguing adaptations to volcano living. "The ’Loihi’ shrimp has adapted to grazing the bacterial filaments with tiny claws like garden shears," said Tunnicliffe. "The second shrimp is a new species--they also graze as juveniles, but as they grow to adult stage, their front claws enlarge and they become predators." The Loihi shrimp was previously known only from a small active volcano near Hawaii--a long distance away. It survives on the fast-growing bacteria and tries to avoid the hazards of the volcanic eruptions. Clouds of these shrimp were seen fleeing volcanic bursts. The other species attacks the Loihi shrimp and preys on marine life that wanders too close to the volcanic plumes and dies. "We saw dying fish, squid, etc., raining down onto the seamount, where they were jumped on by the volcano shrimp--a lovely adaptation to exploiting the noxious effects of the volcano," Tunnicliffe said. The new studies are important because NW Rota-1 provides a one-of-a-kind natural laboratory for the investigation of undersea volcanic activity and its relation to chemical-based ecosystems at hydrothermal vents, where life on Earth may have originated.