Agricultural activity permanently affected ecosystems – agroecosystems are particularly in terms of ensuring of nutrition for human society, very important functional units of the biosphere. Represent economically important organisms and their environment. Very often are surrounded by natural ecosystems, which are usually very closely linked. Although their relationship is two-sided, agroecosystems can induce not only reduce the heterogeneity of the country but also may affect the biodiversity of the surrounding terrestrial and aquatic habitats. In order to assess the impact of agricultural activities on the water quality characteristics, as well as on the biodiversity and the structure of communities of aquatic organisms, we carried out sampling of water from six sampling sites at regular quarterly intervals, 24 water samples was collected, in the year 2007 in the Nnature reserve Alluvium Žitavy located in the southwestern part of Slovak Republic, in the geomorphologic unit of Podunajská rovina,. As the basic biological material we used organisms of macrozoobenthos living at the bottom of the aquatic habitats. This group of individuals is an important indicator of water quality, based on their species and numerical representation can be evaluated the water quality of monitored biotopes. Analysis of samples of water we obtained 9920 individuals, deterministic as 110 species of fourteen systematic groups of invertebrates. Of them, the largest proportion in the structure of benthic macrozoobenthos had Gastropoda (24.01%), Isopoda (13.47%), Ephemeroptera (10.60%), Heteroptera (9.33%), Coleoptera (8.49%), individuals of family Chironomidae (8.25%) and Diptera(7,40%). The species with the smallest proportion in the structure of zoobenthos of monitored wetlands (ranging from 1.61% to 4.32%) included representatives of systematic groups Turbellaria, Odonata, Hirudinea, Trichoptera, Amphipoda, Bivalvia and Oligochaeta. The most of species that formed monitored community of aquatic organisms belongs to the good indicators of water quality. Therefore, not only based on the structure of community of macrozoobenthos but also based on the calculated saprobic index (Si), the water which is used by this community as their habitat corresponds to β-mezosaprobic zone, slightly polluted water. Between sampling sites the significant differences in the quality and purity of water was recorded, even not only in the numerous represented of benthic fauna. Some differences in representation of species were observed, because each of the representatives of zoobenthos has different requirements for water quality characteristics. Despite this, agriculture fertilizer application, spillage of the oil substances and their floating could result in deterioration of water quality of monitoring wetlands and thus the structure and biodiversity of benthic invertebrates.

Slovak Republic, Alluvium Žitavy, agroecosystems, water, zoobenthos

Presentation: oral