Biogeochemistry of particulate organic matter in the oceans: results from sediment trap experiments

Abstract

Abstract Particulate organic matter collected in sediment traps from various oceanic regimes— Sargasso Sea, equatorial North Atlantic, central North Pacific, California Current, and Peru coastal upwelling—have been analyzed for their lipid and amino acid composition and flux. Despite rapid settling of the large particles through the water column and a relatively small depth gradient for total organic carbon flux, there are major changes in the composition and flux of lipids and amino acids associated with the particles. The rapid disappearance of the more labile compounds, such as amino acids and polyunsaturated fatty acids, with increasing depth indicates that the major sources of such compounds are in the upper part of the water column and that they are readily degraded as the particles sink. On the other hand, the intermittent appearance of large amounts of wax ester, along with the changing fatty acid composition of the particles, points to deep-water sources for some of these compounds.