EFFICIENCY OF A STANDARDIZED ARTIFICIAL SUBSTRATE FOR BIOLOGICAL MONITORING OF RIVER WATER-QUALITY

Before using macroinvertebrates in water quality assessment in the Chu sovaya River (Russia, the Urals, 50 degrees 55'N, 60 degrees E), preli minary results of three sampling methods were compared: handnet, circu lar shovel and a standardized artificial substrate sampler. The artifi cial substrate consisted of glass marbles (phi 20 mm). To compare the efficiency of these sampling methods the total numbers of taxa found a t each location per sampling data were considered to be 100%. The high est efficiency was reached with the artificial substrate sampler. 75-1 00% of the taxa at the different locations were collected with this sa mpler. Only 5-19% and 10-20% of the taxa at each location per sampling date were collected with the circular shovel in the sand and gravel s ubstrate respectively, being the lowest efficiency. Intermediate resul ts were obtained with the hand net. 23-38% of the taxa were collected with this net. Based on these results and requirements placed upon sam pling methods in general, the standardized artificial substrate sample r has been considered to be an optimal sampling device for macroinvert ebrates in biological monitoring.