The Role of Dissolved Organic Matter in the Nutrition of Deep-Sea Benthos

SYNOPSIS. Deep-sea sediments contain less particulate organicmatter and lower biomass than shallow-water sediments, but thedissolved organic matter in pore water varies less with depthand may provide a significant food source for deep-sea benthos.Pogonophora are a phylum of predominantly deep-sea animals,all without an internal digestive system. Experiments show thatone or two species ought to be able to live by uptake of dissolvedorganic matter from pore water in deep-sea deposits: some otherspecies may need local enrichment of the habitat for such uptaketo be useful. Less is known about nutrition of other deep-seaanimals, but dissolved organic matter may supplement a conventionaldiet in several groups. Chemoautotrophy, using endosymbioticbacteria, may be important for the large vestimentiferan Pogonophorain the high-sulfide conditions of the hydrothermal vents.