Diurnal variations of trace metals and heterotrophic bacterioplankton concentration in a small boreal lake of the White Sea basin

Abstract

-This work represents a concerted effort aimed at understanding the microbiological and chemical evolution of a small boreal lake during the diurnal cycle of photosynthesis. We studied diurnal variation of y 40 dissolved macro-and trace elements, organic carbon and bacterial population dynamics in the surface and bottom water layer of the shallow Vilno Lake in the White Sea basin. Four-days continuous measurements with 6 h sampling steps both at the surface (0.5 m) and on the bottom (4.0 m depth) during no-bloom periods revealed constant concentrations (within ¡ 20-30%) of all major elements (Na, Mg, Si, K, Ca), organic and inorganic carbon and most trace elements (B, V, Cr, Fe, Cu, Ga, As, Rb, Sr, Y, Zr, Sb, Cs, Ba, all REEs, Hf, Pb, Th, U). At the same time, the concentration of some biologically important trace metals (Mo, Mn, Co, Cd) was subjected to variations partially reflecting the change of bacterioplankton concentration. This work enables two types of element behavior to be distinguished during photosynthesis in the water column -constant concentration and sinusoidal variations -depending on their speciation in solution and their affinity to aquatic microorganisms.

Diurnal variations of dissolved and colloidal organic carbon and trace metals in a boreal lake during summer bloom

“…The studied area can be considered as weakly influenced by local agricultural activity. The concentration level of most major and trace elements is within the range of other pristine lakes of the region (e.g., Shirokova et al, 2010). The watershed lithology is represented by glacial moraine (products of graniteegneisses erosion) and carbonate rocks.…”

Small Boreal Lake Ecosystem Evolution under the Influence of Natural and Anthropogenic Factors: Results of Multidisciplinary Long-Term Study

“…Active bacteria number count (Colony forming units, CFU/mL) was done using Petri dishes inoculation (0.1 to 1.0 mL of lake water in three replicates) performed in a specially organized microbiological field laboratory (i.e., refs. [15][16][17]). All manipulations were performed in the vicinity of open flame on thoroughly alcohol-and detergent-treated and UV-sterilized microbiological table.…”

Size Distribution, Surface Coverage, Water, Carbon, and Metal Storage of Thermokarst Lakes in the Permafrost Zone of the Western Siberia Lowland

“…For this, water samples were collected from the lake surface (0.3 to 0.5 m) in pre-cleaned polypropylene containers and filtered on-site or within 4 h after sampling through disposable acetate cellulose filter units (0.45 µm poresize, 33 mm diameter), using sterile plastic syringes and vinyl gloves. An ultraclean sampling procedure was used [78]. The filtered samples were stored at 4-5 • C in the dark, before analysis.…”