Changes in the benthic fauna composition in the Upper Vistula over the last 50 years – the consequences of the water pollution reduction and alien species invasion

Abstract

The organic pollution of the Upper Vistula waters has been significantly reduced since the mid-20th century. Also salinity has gradually decreased, following an increase observed until the 1990s. Furthermore, the number of alien species has systematically increased. The above-mentioned changes have affected the richness and composition of the benthic fauna. They are particularly remarkable in the river stretch between the town of Oświęcim and the city of Kraków. The improvement of water quality has resulted in the increased number of taxa, mainly those characteristic of moderately polluted water, and the disappearance of taxa typical of strongly polluted or deoxygenated water. Despite the increased salinity level persisting for many years, only three benthic species of brackish waters (Gammarus tigrinus, Paranais frici and P. litoralis) were found in the Upper Vistula. Taxa considered to be euryhaline or halophilous were more numerous. In the 1960s, only one alien species (Physa acuta) was found, but the increased number of non-indigenous species in the last decades is visible, particularly among gammarid crustaceans (Amphipoda, Gammaroidea). The presence of alien species has not caused any visible changes in the species abundance of oligochaetes and mollusks.

Distribution pattern of the brackish Apocorophium lacustre (Vanhoffen, 1911) (Amphipoda: Corophiidae) and the structure of the amphipod assemblages in the upper Oder River catchment

“…In contrast, our study revealed that in two localities on the Oder, the native A. lacustre had successfully colonized and outnumbered alien amphipod species such as C. curvispinum , D. haemobaphes , D. villosus and G. tigrinus . Similar findings regarding the occurrence of the native brackish oligochaete species Paranais litoralis (Müller, 1780) in anthropogenically saline inland waters were observed by Dumnicka et al (2018) and Sowa et al (2018). This species amounted to almost 100% of the oligochaete fauna in the strongly saline Gostynka River (Dumnicka et al, 2018) and in a coal mine settling pond (conductivity up to 42,400 µS cm −1 ) in Knurow, Poland (Sowa et al, 2018).…”

“…Similar findings regarding the occurrence of the native brackish oligochaete species Paranais litoralis (Müller, 1780) in anthropogenically saline inland waters were observed by Dumnicka et al (2018) and Sowa et al (2018). This species amounted to almost 100% of the oligochaete fauna in the strongly saline Gostynka River (Dumnicka et al, 2018) and in a coal mine settling pond (conductivity up to 42,400 µS cm −1 ) in Knurow, Poland (Sowa et al, 2018). The aforementioned results suggest that secondary saline inland waters can be inhabited by both alien and native species that are mainly associated with primary saline or brackish coastal habitats.…”

Impact of secondary salinisation on the structure and diversity of oligochaete communities

“…Gillett et al (2007) recorded only this species in the Malind and Okatie Creeks (South Carolina, USA). Similar as in the investigated hypohaline water bodies (ponds 8 and 9), P. litoralis was the dominant oligochaete species or commonly found in naturally saline environments such as estuaries, salt marshes, spring streams, rivers, mangrove biotopes, and tidal flats (e.g., Sardà et al, 1996;Timm, 1999;Kolbe and Michaelis, 2001;Erséus, 2003;Moseman et al, 2004;Giere, 2006;Fujii, 2007;Gillett et al, 2007;Moreno et al, 2010;Capítulo et al, 2014) as well as in the Gostynka River, which is strongly contaminated with salt (Dumnicka et al, 2018); the Bolina River (Halabowski et al, 2019); and in salt marsh clay pits (Vöge et al, 2008). Therefore, these findings suggest that euryhaline P. litoralis could be considered as a good indicator of anthropogenically saline aquatic habitats.…”

The diversity of annelids in subterranean waters: a case study from Poland

“…Groundwater fauna consists of: stygobionts À organisms reproducing exclusively in this habitat, stygophiles À species completing their life cycle in both subterranean and surface waters, and stygoxens À species that can accidentally be found in underground water (Pacioglu 2010). These groups have different degrees of adaptation to groundwaters (Gibert et al, 1994b), but even stygobionts can be found occasionally in surface waters (Krzanowski et al, 1965;Dumnicka et al, 2018). Composition of invertebrate benthic fauna in surface and subterranean waters differs significantly: non-insect species (mainly crustaceans, water mites and annelids) are the most abundant and diverse in underground waters (e.g., Sket, 1999;Ko sel, 2009;Martin et al, 2009;Chertoprud et al, 2016), while insect fauna is usually rich in the benthos of nonpolluted stagnant and running surface waters of Europe (Starmach et al, 1976;Dijkstra et al, 2014).…”

“…A few data sets available from artificial subterranean spaces such as adits or quarries (Moszyński 1936;Dumnicka 1996) are included with data from caves in this paper. The studies on annelid fauna of interstitial waters began in the second half of the 20th century, but this habitat was intensively investigated in following years (Kasprzak, 1973a,b,c;1975, 1976, 1979aDumnicka, 2000;Dumnicka et al, 2018). In Poland, very few studies dealing with annelids were conducted in the waterworks systems (Moszyński, 1934;Pawłowski, 1951) directly connected with underground waters, which are sometimes inhabited by numerous and diverse invertebrates (Łuczak et al, 1980).…”