Talk #59, 9/29/10

Oases of the deep: chemical-based microbial life and methane cycling in the deep-sea

Victoria Orphan

The deep-sea has been described as one of the last unexplored frontiers on Earth, representing 90% of the global ocean volume. Previously portrayed as a dark, life-less desert, recent findings, aided by advanced submersible technologies, have begun to illuminate a much richer environment, home to thousands of new animal species and an even greater number of microorganisms (bacteria and archaea) living in and far below the seafloor. Some of this microbial life relies on the delivery of photosynthetically-derived carbon from sunlit surface waters, while others flourish on reduced chemical energy, such as methane and sulfide, forming unique oases of life in the abyss. This presentation will explore the nature of this hidden biosphere, cooperative partnerships formed between its microbial residents, and their impact on global biogeochemical cycles.