The influence of industrial environment on the distribution of freshwater snails in Uppersilesian industrial region

Abstract

The gastropod fauna of man-made reservoirs of the Upper Silesian Coal Basin (4 sinkhole ponds, 7 sand pits, 4 storage reservoirs) was studied. The author found the occurrence of 19 species. The most important environmental disturbances of the sinkhole ponds effected in the qualitative impoverishment of their gastropod fauna (10 species found), whereas the fauna of the sand pits and storage reservoirs, due to their more favourable water chemistry and physical conditions, was richer (15 and 17 species respectively). In all the types of reservoirs only certain species were observed to occur in mass. The analysis of influence of some environmental factors has shown that the total water hardness and the contents of calcium, iron, sulphates, chlorides, ammonia nitrogen, as well as age, size, and kind of bottom of the reservoirs do not affect the diversity of their malacofauna, what differs industrial reservoirs from natural ones. Excess of Mg++ ions in water seems a considerably limiting factor for most of the gastropod species found, this being especially distinct in sinkhole ponds.