Microbes, macrofauna, and methane: A novel seep community fueled by aerobic methanotrophy

• DOI: 10.4319/lo.2013.58.5.1640
• Publication Date: 2013-08-21T20:21:43Z
• Authors: Andrew R. Thurber; Lisa A. Levin; Ashley A. Rowden; Stefan Sommer; Peter Linke; Kerstin Kröger
• Keywords: Cold seep; Petroleum seep; Biogeochemical Cycle

During the discovery and description of seven New Zealand methane seep sites, an infaunal assemblage dominated by ampharetid polychaetes was found in association with high seabed emission. This ampharetid‐bed had a mean density 57,000 ± 7800 macrofaunal individuals m −2 maximum wet biomass 274 g , both being among greatest recorded from deep‐sea seeps. We investigated these questions: Does species present within beds form distinct community on margin? What type chemoautotrophic microbes fuel this heterotrophic community? Unlike other macro‐infaunal assemblages, composition homogeneous, independent location. Based mixing model species‐specific mass isotopic composition, combined published respiration measurements, we estimated that consumes 29–90 mmol C d −1 methane‐fueled biomass; is > 290 times carbon fixed anaerobic oxidizers beds. A fatty acid biomarker approach supported finding community, unlike those previously known, primarily aerobic methanotrophic bacteria. Due to novel microbial fueling flux rates, Zealand's provide system study influence metazoan grazing microbially mediated biogeochemical cycles, including involve greenhouse gas emissions.