The list of shallow—water molluscs: chitons (2 species), gastropods (33 species) and bivalves (36 species) of Isfjorden is presented. Distribution, frequency and domination structure are discussed and zoogeographical analysis is presented.
Assemblages of molluscs have been used for stratigraphy of Late Glacial and Holocene deposits in Poland. Changes of the climate as well as migration of species are main factors which control the recompositions of molluscan communities in this time. Thirteen malacostratigraphical zones have been definied. Eight of them corresponds with land environments, while the remaining ones (five) with water habitats. The succesions of these zones gives the malacostratigraphical subdivisions, which can be compared with similar schemes proposed in some other countries of Central Europe. They supplement palynostratigraphical zones or even can be used as main way of stratigraphical intrepretations.
This paper presents the impact of salinisation on the aquatic mollusc fauna in flooded mine subsidences in the Karvina region (Czech Republic). The results of the previous research on salinity in flooded mine subsidences show that some of them contain a high content of dissolved inorganic substances (above 1000 mg·l-1). These substances can affect the vegetation and animals occurring in the water and the surrounding area. The phylum of Mollusca was selected as a model group for the fieldwork as it includes species with the proven bioindication potential.
The occurrence of aquatic mollusc species was studied at 10 sites. The sites were selected based on the content of dissolved substances (the salinity gradient from <500 to >1000 mg·l-1. A total of 12 aquatic mollusc species were found, including one species identified as a potential bioindicator of the negative effect of salinisation on aquatic biota.
The analysis showed statistically significant positive correlations between the content of dissolved inorganic substances and the presence of alien species Potamopyrgus antipodarum (J.E. Gray, 1843). The gradient of salinity significantly affects the species composition of the mollusc fauna in flooded mine subsidences and may affect the biodiversity of this group.
This malacological analysis was conducted at a site with peat and calcareous tufas in Łapsze Niżne, Podhale
(southern Poland). The study was carried out in 6 main and several complementary sections, in which 37 mollusc
species were recognized represented by almost 11 000 specimens. The study enabled the reconstruction of
environmental changes during the accumulation of the Holocene deposits (from the Boreal Phase till present).
Conclusions drawn from these reconstructions were compared with results of malacological and palynological
studies from other sites in Podhale. As a result, regional environmental reconstructions for the Holocene of the
area were made. The specific composition, ecological structure and succession of molluscan assemblages from
Łapsze Niżne indicate a significant role for local factors, thus demonstrating the variability of environmental
conditions within a geographic region.