A team of scientists on board the research vessel Falkor have just finished surveying the largely unexplored Mariana Back-Arc in the western Pacific Ocean for life at depths greater than 13,000 feet (4,000 meters). The team studied the area with the new remotely operated vehicle (ROV) SuBastian.
They found spectacular chimneys made of sulfide minerals, some up to 30 meters (100 feet) tall. The chimneys were belching smoky vent fluid at temperatures up to 365°C (690°F) and were covered with vent animals including “hairy snails,” shrimp, crabs, mussels, limpets, squat lobsters, anemones and worms.
The newly discovered vent sites have an ecosystem that is characteristic of the Mariana Back-Arc, with some animal species found nowhere else on Earth. The similarity between vents occurs despite the fact that each vent site is relatively small and isolated, being separated from the others by up to 100 miles. This suggests that the Back-Arc vent sites are relatively long-lived and that each site has biological “connectivity” with the others despite the long distances.
The study also confirmed that the Back-Arc ecosystems are distinct and different from the nearby Volcanic Arc hydrothermal ecosystems, supporting the idea that geological and chemical environment play a key role in determining animal community composition at hydrothermal vents.
Dr David Butterfield of the University of Washington and Dr William Chadwick of NOAA-PMEL and Oregon State University led the group to the Back-Arc; returning for the second phase of a two-part exploration of the region. In 2015, the team of scientists located new hydrothermal vents in the Back-Arc region, including evidence of recent lava flows.