Mining is a relatively highly monitored industry. While chemical pollutants (toxic ions, radionuclides, etc.) have mostly been eliminated from mining waters, other types of environmental pollution (temperature regime alterations, high concentrations of various anions, etc.) can affect benthic invertebrates. In this study, we focused on the effect of mining water effluent on the diversity and density of aquatic Clitellata. Four sampling sites were selected. Three sites in a natural stream (the Nedvědička River, Czech Republic), one upstream and two downstream from the mining effluent, and one site on the mining waters were sampled monthly during [2008][2009]. Environmental variables were recorded in and samples were collected from two types of habitats -riffles and pools. The response of clitellate assemblages was evaluated using principal component analysis and generalised estimating equations. The results indicated that the mining effluent caused partial species exchange and had negative effects on clitellate taxa richness and abundance. These responses were specific to both the habitat (riffle/pool) and species sampled. In each of the different taxa studied, we observed one of four typical clitellate responses: (a) elimination of stenotherm species; (b) reduction of clitellate species followed by quick recovery; (c) neutral response; or (d) positive influence. We found that aquatic clitellates, which are considered to be eurytopic with broad ecological valences, are also sensitive to even slight environmental pollution.

The main aims of this study were to analyse the effect of a mineralized heated water inflow from a uranium ore processing plant on the abundance and diversity of epilithon and macroinvertebrate herbivores as well as to identify changes in functional feeding groups. In total, four sampling sites were selected. One site was on the mining water tributary and three sites in a recipient natural stream (the Nedveˇdicˇka River, Czech Republic): one of them upstream and two downstream from the mining effluent. Samples were taken monthly during the period 2008-2009. The number of species in the epilithon was higher downstream from the tributary and we also recorded a small increase in density. We observed significant changes in the taxonomical composition of epilithon and macroinvertebrate communities downstream from the tributary. Taxa richness of macroinvertebrates was similar between sampling sites. A small drop in macroinvertebrate abundance immediately downstream from the tributary was followed by a significantly elevated number of herbivores, especially scraper-collectors, at the more downstream site. Alteration of the species composition and abundance of herbivorous macroinvertebrates in the Nedveˇdicˇka River could be explained by a combination of a change in food availability and the physico-chemical properties of the water.