The first records of the occurrence of a North American invader Gammarus tigrinus Sexton, 1939 in the tributaries of the upper Vistula River

The amphipod species Gammarus tigrinus, Sexton 1939 is native to the Atlantic coast of North America. The native range of its occurrence includes oligo- and mesohaline brackish waters with salinity of up to 14‰. Our survey was carried out in the tributaries of the upper Vistula River in Upper Silesia that is the most urbanised and industrialised region in Poland and constitutes one of the largest coal basins in the world. This survey uncovered the first occurrence of G. tigrinus with the maximum density of 1040 individualsm 2 in the tributaries of the upper Vistula River that have been polluted by coal mine water discharge. The occurrence of the invasive alien gastropod species, i.e. Potamopyrgus antipodarum (Gray, 1843) was also recorded in such salinised water. Our results showed that the anthropogenically salinised tributaries of the upper Vistula River constitute new habitats for euryhaline species and create new migration routes for alien and invasive species

The importance of the mining subsidence reservoirs located along the Trans-Regional Highway in the conservation of the biodiversity of freshwater molluscs in industrial areas (Upper Silesia, Poland)

The objectives of the survey were to analyse the structure of the mollusc communities in the mining subsidence reservoirs that were created as a result of land subsidence over exploited hard coal seams and to determine the most predictive environmental factors that influence the distribution of mollusc species. The reservoirs are located in urbanised and industrialised areas along the Trans-Regional Highway, which has a high volume of vehicular traffic. They all have the same sources of supply but differ in the physical and chemical parameters of the water. In total, 15 mollusc species were recorded including four bivalve species. Among them Anodonta cygnea is classified as Endangered according to the Polish Red Data Book of Animals and also as Near Threatened according to the European Red List of Non-marine Molluscs. Eleven of the 15 mollusc species are included on the European Red List of Nonmarine Molluscs as Least Concern. Conductivity, pH and the concentration of calcium were the parameters most associated with the distribution of mollusc species. Canonical correspondence analysis showed that Potamopyrgus antipodarum, Radix balthica, Physella acuta, Gyraulus crista and Pisidium casertanum were associated with higher conductivity and lower pH values. A. cygnea, Anodonta anatina and Ferrissia fragilis were negatively influenced by these parameters of the water. The results of this survey showed that the mining subsidence reservoirs located in urbanised and industrialised areas provide refuges for rare and legally protected species and that they play an essential role in the dispersal of alien species as well

Response of the mollusc communities to environmental factors along an anthropogenic salinity gradient

Anthropogenic salinisation of freshwater ecosystems is frequent across the world. The scale of this phenomenon remains unrecognised, and therefore, monitoring and management of such ecosystems is very important. We conducted a study on the mollusc communities in inland anthropogenic ponds covering a large gradient of salinity located in an area of underground coal mining activity. A total of 14 gastropod and 6 bivalve species were noted. No molluscs were found in waters with total dissolved solids (TDS) higher than 17.1 g L−1. The share of alien species in the communities was very high in waters with elevated salinity and significantly lower in the freshwaters. Canonical correspondence analysis (CCA) showed that TDS, pH, alkalinity, nitrate nitrogen, ammonium nitrogen, iron, the content of organic matter in sediments, the type of substrate and the content of sand and gravel in sediments were the variables that were significantly associated with the distribution of molluscs. The regression analysis revealed that total mollusc density was positively related to alkalinity and negatively related to nitrate nitrogen. The taxa richness was negatively related to TDS, which is consistent with previous studies which indicated that a high salinity level is a significant threat to freshwater malacofauna, causing a loss of biodiversity and contributing to the colonisation and establishment of alien species in aquatic ecosystems

Triggers for the Impoverishment of the Macroinvertebrate Communities in the Human-Impacted Rivers of Two Central European Ecoregions

Human activity triggers negative alternations in river habitats, including changes to the physical and chemical parameters of thewater, its hydromorphological features and the introduction and spread of invasive alien species. These modifications are expected to be intensified by climate change. Eight rivers in one of the most urbanised and industrialised regions in Europe, i.e. the Upper Silesian Coal Basin, were surveyed in order to explain the impact of anthropopressure on the distribution of macroinvertebrates. Conductivity, altitude, hydromorphological transformations, hardness, the organic matter content and certain fractions of benthic sediments significantly affect (p < 0.01) the occurrence of macroinvertebrates in Central European rivers. Our results proved that the hydromorphological transformation of watercourses, which is expressed by the relevant indices, is one of the most predictive factors that contribute to the distribution of macroinvertebrates. Anthropogenic inland waters that have been salinised by the discharge of hard coal mine waters create new habitats for brackish and marine species that replace native freshwater species. An increase in salinity causes an impoverishment of macroinvertebrate biodiversity therefore all possible actions should be taken to reduce the anthropogenic salinity of inland waters. Secondary saline rivers may prove to be prescient for climateinduced changes to river macroinvertebrates

Impact of anthropogenic transformations on the vegetation of selected abiotic types of rivers in two ecoregions (Southern Poland)

The quality of water in rivers is declining worldwide due to anthropogenic activities. This phenomenon may be exacerbated by climate change and population growth. We hypothesised that both physical and chemical parameters of water, which reflect the differences in the underlying geology and anthropogenic transformations, are the most important characteristics to explain the distribution of macrophytes in rivers. In the present study, we analysed the effect of anthropogenic transformation on the structure of macrophytes in eight rivers within the river basins of the Vistula and Oder Rivers (Southern Poland). A canonical correspondence analysis showed that conductivity, altitude, natural features of rivers and adjacent land use, which are indicated by the values of the Hydromorphological Diversity Index (WRH), and medium sand were the most important factors that affected the distribution of macrophytes. The eurytopic species, including invasive alien species, were negatively correlated with the WRH index and positively correlated with high conductivity. An increase in the conductivity led to a loss of vegetation diversity and caused the replacement of freshwater species with brackish or salt-resistant species. Salinity of 2.96–5.16 PSU decreased the number of macrophyte taxa by over 30% in the rivers as compared to salinity of 0.45–0.64 PSU. Because very few studies have investigated the effect of salinity on macrophytes, further research is needed to explain this phenomenon. We therefore suggest extensive use of hydromorphological indices in studies on the distribution of macrophytes in rivers

Applying the methods to assess the ecological status of flowing waters in the monitoring of natural habitats on the example of rivers with water crowfoot communities (Ranunculion fluitantis)

tekst w j. pol. i ang.Zastosowanie metod oceny stanu ekologicznego wód płynących w monitoringu siedliska przyrodniczego 3260: Nizinne i podgórskie rzeki ze zbiorowiskami włosieniczników (Ranunculion fluitantis) zgodnie z założeniami Ramowej Dyrektywy Wodnej Unii Europejskiej i Dyrektywy Siedliskowej (rzeka Korzenica, Ekoregion 14)

Distribution and ecology of two interesting diatom species Navicula flandriae Van de Vijver et Mertens and Planothidium nanum Bąk, Kryk et Halabowski in rivers of Southern Poland and their spring areas

In this paper, we report new records of rare diatoms that have recently been found in Southern Poland. Planothidium nanum was found only in the upper reaches of the Centuria River, which is not exposed to human influence, while Navicula flandriae was found in two rivers (the Bolina and the Mleczna) affected by salt mine water from hard coal mines. The impact of anthropogenic salinity on diatom communities is as yet poorly documented. Therefore, we conducted a survey on this phenomenon. We surveyed seven sampling sites for diatom assemblages and habitat characteristics, including three sampling sites impacted by mine water. Navicula flandriae was recorded at both sampling sites affected by salt mine water and in two other rivers (the Centuria and the Mitręga), indicating its wide preference for salinity. We confirmed the occurrence of P. nanum at the same site where this species was found and described in our previous paper. In addition, we recorded the occurrence of this species at two other sites in habitats with similar characteristics (lower reaches of the Centuria and Wiercica rivers). Our results indicate a more common occurrence of N. flandriae and P. nanum, which means that further monitoring of diatoms is necessary

Development of comprehensive river typology based on macrophytes in the mountain-lowland gradient of different Central European ecoregions

The aim of the study was to identify the vegetation pattern in the different types of watercourses basing on survey in reference conditions in a wide geographical gradient, including mountain, upland and lowland rivers. We tested relationship between composition of macrophytes to environmental variables including: altitude, slope, catchment area, geology of valley, land use, hydromorphological sfeatures, water physical and chemical measurements. Analysis based on 109 pristine river sites located throughout major types of rivers in Central Europe. Qualitative and quantitative plant surveys were carried out between 2005 and 2013. Based on TWINSPAN classification and DCA analysis, six macrophyte types were distinguished. The lowland sites were divided into the following three types: humic rivers and two types of siliceous rivers depending on the catchment area, including medium-large and small rivers. The mountain and upland rivers were divided into three geological types: siliceous, calcareous and gravel. We found that the variation of macrophyte communities was determined by several habitat factors (mainly altitude, flow type, riverbed granulometry, conductivity and alkalinity), whereas the spatial factor was rather limited; further, the plant diversity was not reflected accurately by the European ecoregion approach

Biological indices applied to benthic macroinvertebrates at reference conditions of mountain streams in two ecoregions (Poland, the Slovak Republic)

The study was carried out from 2007 to 2010 in two ecoregions: the Carpathians and the Central Highlands. The objectives of our survey were to test the existing biological index metric based on benthic macroinvertebrates at reference conditions in the high- and mid-altitude mountain streams of two ecoregions according to the requirements of the EU WFD and to determine which environmental factors influence the distribution of benthic macroinvertebrates. Our results revealed statistically significant differences in the values of the physical and chemical parameters of water as well as the mean values of metrics between the types of streams at the sampling sites. RDA analysis showed that the temperature of the water, pH, conductivity, the stream gradient, values of the HQA index, and altitude were the parameters most associated with the distribution of benthic macroinvertebrate taxa and the values of the metrics. The values of biological indices should be considered according to the stream typology including altitude and geology. At the reference conditions, the suggested border values of biological indices are very harsh. The values of the biological indices of most sampling sites did not correspond to the requirements of the high status in rivers. The streams at altitudes above 1,200 m a.s.l. should be treated as another river type and new reference values should be established

Effet de l'eau souterraine de mines de sel sur les communautés de rotifères dans la rivière Bolina (Haute Silésie, Sud de la Pologne)

The research was carried out in the Bolina River, which is the most anthropogenically saline river in Europe, from 2017 to 2018. This river flows through the highly industrialised and urbanised part of Upper Silesia (Poland). The aims of our survey were to analyse the structure of the rotifer communities and to determine the most important environmental factors that have a significant impact on their structure in a river under the influence of underground salty mine water discharge. According to a canonical correspondence analysis (CCA), the rotifer communities in the Bolina River are affected by electrical conductivity, the temperature of the water and the concentration of phosphates. An increase in the electrical conductivity (salinity) in the lower course, which was the result of salty mine water discharge into the Bolina River, was reflected by a decrease in the median density, the number of rotifer taxa and the Shannon–Wiener index H0. The Bolina River is a unique habitat for halophilic rotifers as well as a site of the occurrence of rotifers that can also develop in winter