BENTHIC COMMUNITY STRUCTURE AT NEWLY INVESTIGATED HYDROCARBON SEEPS ON THE CONTINENTAL SLOPE OF THE WESTERN NORTH ATLANTIC
Hydrocarbon seeps support distinct benthic communities capable of utilizing reduced chemical compounds for nutrition. Until recently only three chemosynthetic communities were known from the U.S. Atlantic margin. In 2012 and 2013, seeps were investigated in this region: a shallow site near Baltimore Canyon (410-450 m) and a newly discovered deep site near Norfolk Canyon (1600 m); both sites exhibited extensive mussel beds and microbial mats. In 2013, in situ sediment cores, grab samples, and ROV video were collected from both sites to quantitatively assess abundance, diversity, and community structure of benthic macrofauna and megafauna. Macrofaunal abundance in microbial mats was four times greater than infauna in mussel beds and slope sediments. Community composition also differed between the two seep environments, where mussel bed sediments contained a greater proportion of crustaceans while microbial mat and slope communities were dominated by polychaetes. The chemosynthetic mussel Bathymodiolus childressi was the dominant species at both seeps, but associated invertebrate and fish communities differed between the sites. Patterns of community structure related to depth, habitat heterogeneity, and geochemical differences between habitats will be discussed.
Demopoulos, A. W., USGS-Southeast Ecological Science Center, USA, email@example.com
Bourque, J. R., Cherokee Nation Technology Solutions, Contracted to the USGS-Southeast Ecological Science Center, USA, firstname.lastname@example.org
Brooke, S., Florida State University, USA, email@example.com
Ross, S. W., UNCW, USA, firstname.lastname@example.org
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