Interpretation of the relationship between benthic fauna, geologic distributions, and methane seeps at Southern Hydrate Ridge, Oregon continental margin

Abstract

[author abstract] Deposits of methane and their associated seeps are found worldwide along continental margins. These seeps are of importance and increasing interest because their potential as an energy source, their contribution to greenhouse gases, and the unique community of chemosynthetic microorganisms and fauna that they host. One of the best-studied methane seep sites is Southern Hydrate Ridge, located ~90 km west of Newport, Oregon at a water depth of ~780 m. Despite extensive geophysical and biological research completed here, no studies have quantified the relationship of seep sites and seafloor geology to the spatial distribution and abundances of microbial and macrofaunal communities. High resolution, georeferenced photomosaics of the individual seeps and the associated biological communities at this site were collected in 2011, using the remotely operated vehicle ROPOS. Detailed analyses of these images has allowed for the quantification and characterization of the diversity and structure of the faunal community coregistered with seafloor substrate. Results show that both the distribution and abundances of seep organisms are highly variable.