Organic Matter in the Small Lakes of the Sikhote-Alin Biosphere Reserve

The carbon concentration and distribution in dissolved organic matter (DOM) and particulate organic matter (POM) in the lagoon lakes Blagodaty and Golubichnoe located in the Sikhote-Alin Nature Reserve and Lake Vaskovskoye оf the Dalnegorsk urban district of Primorsky Krai were analysed using data collected in July–August of 2011–2014. The content of DOM carbon ranged from 1.9 to 8.6 mg/l, representing 68–90% of the total organic carbon. Reductions in the POM carbon concentration and organic carbon percentage of the particulate matter in the sequence of the lakes Blagodaty–Golubichnoe–Vaskovskoye were determined. Analysis of the SUVA₂₅₄ dynamics and the fluorescence intensity revealed a trend of simplification of the molecular structure of DOM from the surface to a depth of 1 to 1.5 m in lakes Golubichnoe and Vaskovskoye as well as at the northern station in the brackish Blagodaty Lake.