ABSTRACT
The dissolved organic matter (DOM) pool in the ocean is equivalent to that of the atmospheric CO2 and is measured at ~1018 g (McCarthy et al., 1996). Net oxidation of only 1% of the oceanic DOM pool within 1 year would be sufficient to generate a CO2 flux larger than that produced annually by fossil fuel combustion (Hedges, 2002). The great size and dynamics of the DOM pool have brought it within focus of global proportions. The DOM pool provides a large reservoir of substrates for life, a source for nutrient regeneration, ion exchange capacity, binding capacity of contaminants, light, and heat absorption. The carbon pool drives the microbial loop in the ocean, and therefore the marine food web. Overall, accurate quantification of DOM pools, fluxes, and their controls is critical to understanding oceanic carbon cycling and how the oceans will respond to increasing concentrations of atmospheric CO2 and climate change. However, knowledge of the marine carbon cycle, including production, recycling, and burial of organic matter, is still limited, and so is the precise estimation of its reservoirs.
