Comparative investigation of chemical and biological characteristics in waters and trophic state of Mongolian lakes

Abstract

The objective of this study is to describe the biogeochemical characteristics in the waters of Mongolian lakes, particularly those related to parameters limiting phytoplankton growth and the trophic state. Investigations into the distribution of chemical and biological parameters were carried out in the following 18 lakes: Har Us, Har, Hovsgol, Achit, Dalai, Bayan, Tolbo, Holboo, Bust, Sangiyn Dalai, Tunamal, Dorgon, Uureg, Telmen, Hyargas, Uvs, Erkhel and Oygon, all of which showed a wide range of salinity between 0.16 and 24.9 g l -1 . Lake water was classified into four types: six fresh (less than 0.5 g l -1 salinity), three subsaline (0.5-3 g l -1 ), seven hyposaline (3-20 g l -1 ) and two mesosaline (20-50 g l -1 ) lakes. Predominant cations and anions in the order of dominance were Ca, Mg [ Na [ K and HCO 3 [ SO 4 , Cl in freshwater lakes, Na [ Mg [ Ca, K and HCO 3 , Cl [ SO 4 in subsaline lakes, and Na [ Mg [ K, Ca and Cl, SO 4 [ HCO 3 in hyposaline and mesosaline lakes. Nitrogenous and phosphorus nutrients in the waters were low, seemingly caused by the low loads from their watersheds, where the ground was free of vegetation with an extremely low level of human activity. The present investigations revealed some 234 taxa of phytoplankton and 38 of zooplankton. The PC:PN:PP stoichiometric ratio by weight was (22-202):(3-27):1. Phosphorus was assessed as the potential limiting parameter in eight lakes, nitrogen in six and both nutrients in four others. Twelve lakes showed an oligotrophic character, while six were mesotrophic type.The six oligotrophic lakes seemed to be subject to phosphorus limiting phytoplankton growth, four to nitrogen and two to both limitations. In the mesotrophic lakes, on the other hand, phosphorus limitation was verified in two lakes, nitrogen in two others and both in two lakes.

Assessing the impact of wildfires on water quality using satellite remote sensing: the Lake Baikal case study

“…In fact, in the period 2003-2011 Chl-a showed a decreasing trend in the southern basins (Barguzin and Selenga), while Turbidity showed an increasing trend in Barguzin These findings suggest that the different areas investigated of Lake Baikal are still oligotrophic with average Chl-a ranging from 1.7 to 3.0 mg m -3 (OECD, 1982;Poikane et al, 2011) with clear waters (average Turbidity below 1 NTU). Similarly low values are present in other lakes in this region, with Chl-a ranging from 0.2 to 3.2 mg m -3 , attributed to large catchments with low vegetation and human activity (Mitamura et al, 2010). We can speculate that this deep lake shows resilience in the medium-long term to ongoing climate change effects and anthropogenic pressures.…”

Increasing Spring Insolation in the Late Holocene Intensified Aeolian Activity in Dryland Asia

“…Here, we present high‐resolution grain size data from the lake sediment at Tolbo Lake in the arid regions of western Mongolia (Figures 1b and 1c, Text S1 in Supporting Information ). The lake is open with low‐salinity (Mitamura et al., 2010), and has inflow from the Tolbo River at the southeastern corner of the lake (Figure 1d). The vegetation of the Gobi Desert in the Tolbo Lake basin is sparse.…”

Bacterial Communities of Three Saline Meromictic Lakes in Central Asia

“…The limnological characteristics of Lakes Shira and Shunet, including ecological modeling, characterization of environmental factors, elemental cycles with temporal and spatial variations, and surveys of flora and fauna, have been reported [ 9 , 20 , 21 , 28 – 30 ]. Physicochemical properties, water color, etc., were direct evidence for stratification.…”