Although the global mapping of reservoir trophic status (and associated upscaling of CH4 emissions) is beyond the scope of this article, recent progress in the mapping of chlorophyll a in medium and large - sized
lakes and reservoirs shows that about 60 % of systems have more than 10 micrograms per liter chlorophyll a (Sayers et al. 2015), and would therefore be considered
eutrophic by most classification schemes (Cunha et al. 2013).