Shepherd vent on the CASM vent field was sampled for microbial mat and limpets on dive R628.

NOAA Ship Ron Brown/ROV ROPOS
Science News

Science Report - Thursday, July 26, 2001
Bill Chadwick
Ship's position: 45 55.4'/-130 01.4'

ROPOS dive R628 returned to the CASM vent area to investigate geologic features on the seafloor that were mapped on dive R626 with the scanning sonar. The new map covers part of the caldera floor (where the vents are located) and part of the caldera rim (where the north rift zone intersects the caldera), but not the caldera wall itself so some additional dive time was used to survey that feature today. Suction sampling is currently being done at the CASM vents to collect microbial mat samples. Molecular analyses from one 1999 sample showed that the mat community at CASM is much different than found at other vent sites throughout the entire Pacific (including other sites at Axial, and even Guaymas Basin in the Sea of Cortez and Loihi seamount south of Hawaii)! In other words, the microbial mat community at Loihi is more similar to the one at ASHES than the one at CASM, only 3 miles away. Additional samples will help to investigate why the CASM microbes are so different and why.