Amino acid and chlorin based degradation indicators in freshwater systems

Lakes cover a global area that is about 35 times smaller than the oceans, but carbon burial in lakes and oceans are on same order of magnitude. Hence, understanding processes for such high organic lacustrine systems essential. We applied proxies typically used marine environments including amino acid (AA) content their nitrogen stable isotope composition to water columns sediments three differ trophic states depositions rates sedimentary terrestrial matter. Additionally, we fingerprinting AAs characterise sources fates. show this set tracks degradation eutrophic with total content. Those also have hydrolysable (THAA) as well higher pigment concentrations. While Chlorin Index (CI) showed increasing values depth, patterns were less consistent Degradation (DI). In general, all parameters failed describe most oligotrophic lake due very low sediment. mostly autochthonous origin AA contribute 5–45% material plankton, POM, Proxies based bacterial reworking (ΣV) or level (TL) column relatively sediments. Furthermore, methanotrophic bacteria led increased proxy extraordinarily δ13C (−30 −60‰).