Plant Pigments in Water and Bottom Sediments of the Tsimlyansk Reservoir

Abstract

In August of a low-water year (2018), the first correlated data on plant pigments in water column and bottom sediments (BS’s) in the Tsimlyansk Reservoir (Russia) were obtained. In the water column, chlorophyll (Chl) is represented mainly by the active form and its concentrations (16.7–415 µg/L) are characterized by a discrete distribution over the reservoir water area (Cv = 142%). The pigment pool of bottom sediments (4.6–264.0 µg/g of dry weight) contains a high percentage of pheopigments (Pheo) and is distributed over the bottom area more evenly (Cv = 78.9%). The concentrations of the pigments of two biotopes are weakly correlated with each other (r = –0.24), which reflects the complex multidirectional nature of the relationship between them. The average content of Chl in the water column (66.7 µg/L) characterizes the Tsimlyansk Reservoir as hypereutrophic; the average content of Chl + Pheo in BS (93.3 µg/g of dry weight) characterizes it as eutrophic.