The effect of flocks of anseriform birds on seston and phytoplankton of lakes in Taimyr Peninsula
M. I. Gladyshev1,2, S. B. Rosenfeld3, T. N. Anufrieva1,2, G. V. Kirtaev3, E. S. Kravchuk1, A. V. Ryabitsev4, A. A. Kolmakova1, E. A. Ivanova1,2, O. V. Anishchenko1
1Institute of Biophysics, Siberian Branch, Russian Academy of Sciences, Federal Research Center “Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences”, Krasnoyarsk, Russia
2Siberian Federal University, Krasnoyarsk, Russia
3Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
4Institute of Plant and Animal Ecology of Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russia
Keywords: guanotrophication, C : N : P stoichiometry, seston, phytoplankton, Taimyr, anseriform birds
Abstract
An effect of molting anseriform birds on structure and elemental composition of phytoplankton (seston) was evaluated in 20 Arctic lakes of the Taimyr Peninsula. In lakes (lake area) inhabited with ~50-700 birds of 6 species, an average stoichiometric ratio N : P (mol: mol) was statistically significantly lower, than in lakes without anseriforms: 15.8 ± 1.4 и 22.4 ± 2.7, respectively. Besides, there was a tendency of higher average specific electrical conductivity in lakes with the birds, 113 ± 32 µS/cm, compared with those without anseriforms, 60 ± 18 µS/cm. The differences observed could be likely explained by an effect of guanotrophication, namely by a flow in water of metabolites of molting anseriforms. Total biomass of phytoplankton and proportions of algal taxa and cyanobacteria in the total biomass did not differ statistically significantly in lakes with and without molting anseriforms. Thereby, under the guanotrophication, the main threat of eutrophication was absent: an increase of biomass of cyanobacteria causing nuisance “bloom” of water. Moreover, an opposite tendency occurred: in lakes with molting anseriforms, the proportion of cyanobacteria in total biomass of phytoplankton was on average lower, than that in lakes without the birds, 16.2 ± 5.3 and 30.8 ± 9.3 %, respectively. Thus, a hypothesis was confirmed, that an artificial guanotrophication should be regarded as a suitable ecotechnology for an increase of productivity of oligotrophic Arctic lakes.
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