Assessment of the water quality of aquatic resources using biological methods

Abstract

Assessment of water quality at Radmilovac estate near Belgrade that is used for irrigation of cultures and as a water supply for experimental fish farm and hatchery was performed by using aquatic invertebrates (zooplankton and macrozoobenthos) and fish gill histology as bioindicators. Two open wells and a stream were monitored during a three year investigation. A total of 25 and 31 species of zooplankton were found in open wells and 11 and 12 taxa of macrozoobenthos at two sites of stream Sugavac. The saprobity index (S) was used to evaluate the water quality of these four sites. Statistical analysis showed that site S2 was the most polluted, with Oligochaeta and Chironomidae larvae dominating. Overall, beta mesosaprobic organisms have been prevailing at all four sites indicating that the water was polluted at moderate levels. All analyzed fish gills showed predominantly normal structure. Identified histopathological changes of gill structure indicated mild and reparable alterations. The results obtained imply that these water resources can be used as a supply for carp fish farm. We suggest that the type of biological water assessment depends on waterbodies characteristics.