Influence of Fish Ponds on the Benthic Invertebrate Composition in Hydrological Networks of Selected Fish Farms in Southern Poland

Fish production can generate high amounts of wastewater containing compounds such as suspended solids, nitrogen and phosphorus. On the other hand, fish ponds provide a range of ecological functions including biocenotic, physiocenotic, hydrological and microclimatic functions as well as landscape shaping. The aim of this study was to determine the taxonomic composition of the bottom invertebrate fauna in selected watercourses on chosen carp fish farms and to assess the influence of fish farming on the taxonomic composition of the zoobenthos of the watercourses associated with such ponds. The research was conducted in four channels on two semi-intensive aquaculture fish farms located in Zaborze and Kraków (Poland). Sampling of the benthic fauna was carried out once a month between May and September 2018. The results showed that the mean monthly number of zoobenthos families in the inflow canal in Zaborze was higher than those in the outflow canal. Moreover, a decrease of the BMWP-PL index in the aforementioned farm may indicate a deterioration of the water quality resulting from its flow through the ponds. It can therefore be concluded that semi-intensive carp farming may affect the diversity of benthic invertebrate fauna in the watercourses connected to these ponds.