Freshwaters: which NOM matters?

One of the difficulties encountered in the study of natural organic matter (NOM) in aquatic environments concerns terminology: a large number of different names and acronyms are used. In fact, this diversity merely reflects the variety of approaches applied to the study of NOM, leading to the definition and measurement of different operationally-defined fractions. As a result, the choice of the ‘best’ method to use and of the ‘best’ fraction to work on in a particular case is far from straightforward. This has as a consequence that often very simple methods for NOM characterisation are used in applied environmental studies and surveys. This study includes, first, a review of the most widely applied terminology, as described in over 500 articles, and, second, a first attempt at assessing how the panoply of methods available is really used in applied environmental studies.