New insight into the macroinvertebrates of the Rawka River Nature Reserve (central Poland)

Abstract

This paper presents the results of a preliminary survey on macroinvertebrate communities of a pristine lowland river Rawka in central Poland. The whole river is protected by a nature reserve but its invertebrates haven’t yet been investigated extensively. This research has three main objectives: 1) to recognise preliminarily Rawka’s macrofauna, 2) to determine the dissimilarity pattern between macroinvertebrates from the riverbed and the local oxbow, 3) to compare the invertebrate assemblages occurring in different habitats. The material was collected at three riverbed sampling points and one oxbow study site. It was found that the oxbow of Rawka River has different aquatic invertebrate communities than the riverbed. Conducted preliminary studies indicate that Rawka and its oxbow reveal high invertebrate diversity that is still vastly underestimated. Seventy-seven invertebrate taxa were collected and twenty-seven of them are first-recorded for Rawka River. Some rare and protected species have been found in the river, e.g. Ophiogomphus cecilia − a dragonfly which remains under strict species protection in Poland. The composition of aquatic invertebrates indicates that water quality of Rawka at the investigated section is good, but this needs to be confirmed with more extensive studies.