Infaunal Communities Associated with Deep-Sea Coral Habitats in the Western Atlantic

Deep-sea coral habitats support abundant and diverse sediment infaunal communities through the provision of highly complex three-dimensional structures that facilitate sediment accumulation and alter hydrodynamic regimes. While studies elsewhere (e.g. Gulf of Mexico, NE Atlantic) indicate that cold-water coral (CWC)-associated infauna are important contributors to deep-sea biodiversity and differ from the vast mud-dominated deep sea, little is known about infauna from CWCs in the Mid-Atlantic and Southeastern U.S. regions. Infauna provide several critical ecosystem functions and services and understanding this component of coral communities is vital in the light of potential offshore development and global change. Recent exploration in these regions has documented extensive coral provinces along the western Atlantic margin. With little known regarding the ecosystem function of these habitats, examination of historical samples provides the first insight into CWC sediment communities in this region. We investigated macrofaunal abundance, diversity, and community structure from sediments collected near Lophelia pertusa and Enallopsammia colonies at Cape Canaveral offshore of Florida, U.S (406-742 m). Infaunal communities near live coral structures were overall similar, but differed from those collected in coral rubble and background soft-sediments. Density of infauna was lower at Cape Canaveral and communities differed from those reported from similar habitats and depths in the Gulf of Mexico, suggesting different geophysical environments. Additional results on infaunal communities from newly investigated CWC found offshore Georgia to North Carolina will be included to provide a broader biogeographic context to these habitats. This study provides important baseline information on the connectivity of CWC sediment environments in the western Atlantic and the role of CWC in supporting biological diversity on shelf and slope environments in the region.