Aerobic Microbial Respiration in 86-Million-Year-Old Deep-Sea Red Clay

Abstract

Deep Breathing Living microbes have been discovered many meters into marine sediments. On a cruise in the North Pacific Gyre, Røy et al. (p. 922 ) discovered that oxygen occurred for tens of meters into the sediment. The bacteria living in these sediments were respiring the oxygen but at a slower rate than the supply of organic material dropping out of the water column, allowing these ancient deep marine sediments to remain oxygenated. Modeling showed that the rate of respiration of specific carbon decreased as a function of sediment depth, that is, its age. Thus aerobic metabolism can persist in deep marine sediments.