Topics include: Organic matter (C,N,P) composition, reactivity and budgets within, and fluxes through, major ocean reservoirs; microbial recycling pathways for organic matter; models of organic matter degradation and preservation; role of anoxia in organic matter burial; relationships between dissolved and particulate (sinking and suspended) organic matter; methods for characterization of sedimentary organic matter; and application of biological markers as tools in oceanography. Both structural and isotopic aspects are covered.