Comparison of the ecological status and water quality of lakes inhabited by and devoid of Dreissena polymorpha (Pallas)

• Published in: Russian journal of biological invasions 2015, Vol.6 (3), p.184-196
• Main Authors: Razlutskij, V. I, Sysova, E. A, Buseva, Z. F, Feniova, I. Y
• Format: Article
• Language: English
• Subjects: aquatic communities; biomass; Biomedical and Life Sciences; Cladocera; cooling; Developmental Biology; Dreissena polymorpha; ecological invasion; Ecology; environmental impact; European Union; Freshwater & Marine Ecology; lakes; Life Sciences; molluscs; phytoplankton; Plant Sciences; surface water; water quality
• ISSN: 2075-1117; 2075-1125
• DOI: 10.1134/S2075111715030042

Dreissena polymorpha is one of the bivalve species having a great impact on the environment, composition, and structure of aquatic communities, thereby acting as an efficient driver of changes in the ecological state of water bodies. We studied five Belarusian lakes in order to compare the water quality between lakes inhabited by and devoid of D. polymorpha, as well as to reveal the reasons for the observed differences. Lake Obsterno with a natural thermal regime and cooling reservoir Lake Lukolmskoe were invaded by this mollusk. Lakes Gorushka and Nobisto with a natural thermal regime, as well as cooling reservoir Lake Beloe, were devoid of D. polymorpha. The water quality classes were determined using the indices based on the physical and chemical parameters and characteristics of phytoplankton and Cladocera communities in line with the requirements of the EU Water Framework Directive and the saprobity index calculated by the Pantle–Buck method in Sladechek’s modification. It is commonly accepted that transparency is a good indicator of the ecological state of lakes. According to the data on transparency, Obsterno and Lukolmskoe lakes have the highest ecological status. However, the estimates obtained with the help of biotic indices did not differ as significantly as transparency in these lakes. The calculations demonstrate that the discrepancies in transparency of lakes inhabited by and devoid of D. polymorpha were not in accordance with those found with the saprobity index (mismatch above 70%) and other biotic indices (above 50%). This allows us to conclude that introduction of D. polymorpha does not improve the ecological water quality through changes in the planktonic communities, regardless of higher transparency values and reduction of the phytoplankton biomass.