Biological assessment of stream water quality - the example of the Reka river (Slovenia)
Tanja Pipan - (29/1,2000)
Investigations of macroinvertebrate communities in the Reka, a karst river, were carried out at three sampling sites. We used the so-called "kick sampling" semi-quantitative method, sampling every three months from July 1995 to June 1996. This method proved to be a suitable sampling procedure for identifying macroinvertebrate community structures and for their further analysis. The differences in physical and chemical factors, which indicated seasonal changes, affected the changes in the living communities of macroinvertebrates and were evaluated using diversity, saprobic and biotic indices. The Chandler biotic score changed in proportion to the saprobic value and qualitative classes, and proved to be the best index for assessing water quality in the Reka. Assessments made using the Shannon-Wiener diversity index corresponded with those made using a modified saprobic index and the average Chandler biotic score. The river, with an actual biological optimum, does not exert any substantial negative impact on the underground streams of Škocjanske Jame, into which it flows.