Influence of Chemoautotrophic Organic Carbon on Sediment and Its Infauna in the Vicinity of the Rainbow Vent Field

Hydrothermal vents have been recognised as isolated islands of productivity in the deep sea, but very little is known about transport and export chemoautotrophic produced organic carbon to vent surrounding habitats. Here, we investigate its influence on benthic food webs sediments at Rainbow (RB) field Mid Atlantic Ridge ~2200 m water depth. Two sites were considered along dispersal direction RB plume for sample collection: close vicinity ~30-100 (“near-vent”); 4 km distance (“off-vent”) nearest venting area. At both sites, box corers used their fauna. A turbidity sensor mounted a CTD/Rosette provided data presence fluid column. Niskin bottles suspended particulate matter (SPOM) from plume, well surface waters 75 SPOM, fauna analysed nitrogen stable isotopes. Carbon derived situ chemoautotrophy, characterised by depleted δ 13 C, was taken up infauna area main nutrition source, while off-vent site showed less C with signature more typical photosynthetic- material. Nematodes most abundant faunal taxon. Their abundance biomass variable not different two studied sites. In traced back web The connectivity non-vent habitats should be appropriately into account when designing future spatial management plans regard deep-seabed mining hydrothermal vents.