ABSTRACT
Aquatic natural organic matter (NOM) is found in water systems of all types, oceans, and freshwaters, including groundwater areas. The clear evidence of its presence is the characteristic yellow-brown color of a bog or swamp water and many lakes and rivers. Even “clean” waters, such as those from certain deep lakes, open oceans, or even deep groundwaters, contain at least a small fraction of the aquatic NOMtypical concentrations being within the range of ca. 1-3 mg L−1. Accordingly, the aquatic NOM is one of the largest pools of carbon on the earth.
