Home – Home – Jornals – Contemporary Problems of Ecology 2012 number 3

Threshold concentrations of elements in fresh water necessary for the survival of Spirogira sp. were determined.
The concentrations of sodium, potassium, calcium, magnesium in the algae was maintained at a level of (84,3 ± 0,8), (23,9 ± 0,5), (3,5 ± 0,2), (8,5 ± 0,2) mmol/kg of dry mass, respectively, and water (92,5 ± 0,21) %. It was shown that the threshold concentrations of sodium, potassium, calcium, magnesium in water, determining the boundaries of the range of Spirogyra sp. in fresh water reservoirs are equal to 0,003-0,007, 0,002-0,003, 0,0017-0,0022, 0,0012-0,0018 mmol/l, respectively. A decrease in water mineralization was accompanied by a substantial increase in the gradient of cation concentration between the algae and the environment, thus enhancing the load on the systems maintaining water-salt metabolism. It was shown on the basis of comparative analysis that Spirogyra sp., being the primary link of the trophic chain, possesses a more efficient ability to extract ions from water in comparison with freshwater animals.