Communities of Freshwater Macroinvertebrate and Fish in Mountain Streams and Rivers of the Upper Dunajec Catchment (Western Carpathians) Including Long-Term Human Impact

Abstract

The study aimed to determine natural communities of invertebrates and ichthyofauna on the background of physiographic and geological conditions and water chemistry and to evaluate the influence of human pressure on these communities on the basis of the results of long-term studies carried out since the 1960s in the Upper Dunajec River and its Tatra tributaries (West Carpathians). Here, for the Dunajec River, we present a pattern of human impact on freshwater fauna communities in mountain streams and rivers with stony bottoms and rapid currents. The Tatra streams (tributaries of the Dunajec River) have mostly retained their natural character. The source of water pollution was mainly from the tourist shelter and tourism centre nearby. Discharge of untreated or partially treated sewage effluent affected invertebrate communities; however, this impact was only observed over a short river section. On the other hand, dam reservoirs completely changed the character of the Dunajec River. In the Czorsztyn Reservoir, communities of macroinvertebrates and fish developed, which are not typical of mountain rivers, replacing previous taxa with those characteristic of slow-flowing waters.