Sulfate reducing bacteria which are known to promote corrosion, particularly of iron, in an anaerobic environment where they produce sulfuric acid and atomic hydrogen have been found in sea water under aerobic conditions. The sulfuric acid and hydrogen cause etching corrosion and hydrogen embrittlement respectively. Research was begun to investigate drastically short lifetimes of immersed equipment. Preliminary results indicate that these normally anaerobic bacteria are capable of adapting to life under aerobic conditions at depths as shallow as 20 m and possibly at the surface. -- AATA