Hydrothermal Field consists of some 30 large vents made up of carbonate minerals, which range from 10 to 60 meters in height, and hundreds of smaller structures. Microbial life in and around the vents thrives in the absence of carbon dioxide, which is the key energy source for life at better-known black-smoker hydrothermal vents. Instead, Lost City microbes appear to live off of methane and hydrogen. In addition, the fluid percolating through the site reaches just 170 degrees Fahrenheit, compared to the scorching 700 degrees F emitted by black smokers. A month-long excursion to the Lost City, described in the current issue of the journal Science, found large numbers of microorganisms in the vicinity as well as translucent crabs, shrimp and fish.