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The contamination of freshwater ecosystems with microfibres has not yet been studied in Poland. We analysed samples from a river and three lakes located in central and northeastern Poland. A significantly higher number of fibres were reported in the river, which runs through large cities, compared with the lake situated within the Landscape Park. Fibres smaller than 1.0 mm dominated, especially in the river where they constituted 39% of all fibres detected. We found more microplastics (⩽ 4930 fibres·m−3) by using a mesh size of 20 µm compared with other studies of inland waters. The use of Raman spectroscopy allowed us to identify conventional plastic polymers: polyethylene terephthalate, polyester and polyurethane. We estimated that up to 25 g of microplastic in the form of fibres might be in the lake water under the surface. We found microplastic fibres in Majcz Lake situated within the Masurian Landscape Park. This suggests that microfibres are carried by the wind and rain and enter freshwater isolated from sewage outlets. By using the control sample and an air-test of microfibres in the laboratory, we observed that there is a high probability of contamination with microplastic in the field samples (up to 30% of all fibres detected). The contamination risk noted from the samples cannot be ignored; this could be particularly important for analysis of microplastic in remote freshwater ecosystems.

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This contribution presents the first record of ornamental shrimp epibiont, Scutariella japonica (Platyhelminthes: Temnocephalida) in European waters. The species lives on freshwater Atyidae shrimp from temperate, subtropical and tropical zones of South-East Asia. In total, 120 individuals of Neocaridina davidi shrimp were caught in thermally polluted canal of Oder river, near the city of Gryfino, in the northwest part of Poland. In that group, 5.83% were infected with scutariellids. Among shrimp, females were mostly infected (85.71%). Since ornamental shrimp released into thermally polluted water bodies have been also noticed in surrounding waters of natural temperature regime in Europe, S. japonica may spread further following potential expansion of the Neocaridina shrimp in Oder river. It is possible that other crustaceans, both native and alien which are present at this location, may also become vectors of this epibiont.

The aim of our study was to determine the current distribution, habitats, ecology, and possible dispersal routes of three species of the Rudny Altai (East Kazakhstan): Eisenia tracta, E. nana, and E. ventripapillata. We found that these species dispersed far beyond their original distribution into the flatland part of western Siberia (Russia) up to the central forest steppe of the Omsk oblast. E. tracta, E. nana, and E. ventripapillata were found in both floodplains and interfluvials. Hydrochory was the most plausible way of northward dispersal, while on interfluvials, they were probably introduced by humans. The studied species showed no preference for a particular habitat or river bank. The habitats were diverse and significantly different from the original ones in Rudny Altai. The factors that allowed E. tracta, E. nana, and E. ventripapillata to colonize western Siberia were probably their wide tolerance range to soil pH, temperature, density, and humidity, along with the decrease of winter soil freezing in recent decades. This is the first information about the occurrence of these species of earthworms in Siberia.