Carbon of Dissolved Organic Matter in the Ocean

Organic matter is present in the world ocean in diverse dispersive and phase states. Because of methodological limitations of isolation and quantitative analysis, OM is classified at present in the majority of works only as dissolved and particulate (suspended). Definition of the term “dissolved organic matter” (DOM) means distinguishing between these two arbitrarily identified forms of organic compounds in natural waters. No uniform opinion prevails on this point. However, the majority of research workers in the field of geochemistry and ecology share the opinion that DOM includes the sum of organic compounds passing through filters with 0.45 – 1 µm pore size. Owing to colmatage, i.e., washing of finely-dispersed particles into filter pores, all of them retain particles of a lesser diameter. This form of OM includes the truly dissolved (particle size below 0.001 µm) and colloidal (0.001 – 0.1 µm) OM, as well as a small proportion of larger particles.