The Role of Streams of Different Sizes in Recovery of Fish Fauna in the Pilica River Catchment

Abstract

Fish and lampreys were sampled by electrofishing in the Pilica River tributaries (the Vistula catchment, Poland) in 1992–1994 and 2003–2005. The patterns in fish assemblages were recognized on the basis of fish biomass using Kohonen's self‐organizing map (SOM) technique, combined with the indicator values (IndVal) for assessment of associations of fish species with particular SOM regions (and respective environmental conditions). Although the fish samples were clustered mostly according to the stream features (size, regulation, and pollution), a weaker temporal gradient indicated a recovery of the ichthyofauna in some smaller streams. The larger tributaries served as sources of colonisers for both the Pilica and the smaller streams. The differences between SOM subclusters in the quality of the aquatic environment were effectively presented with certain biological measures, including the dominances of potentially large species and non‐psammophilous rheophils, which are proposed as good bioindicators. It is worth mentioning that some closely related species (ide and dace, silver bream and bream, golden loach and spined loach, and Ukrainian lamprey and brook lamprey) were significantly associated with different SOM regions (and respective environmental conditions), perhaps in this way avoiding competition. Copyright © 2013 John Wiley & Sons, Ltd.

Disturbed fish fauna zonation as an indicator of large-scale human impact: A case study (2011-2012) of the large, lowland Warta River, Poland

“…The usefulness of ISA (IndVal index with Monte‐Carlo test) lies in the ability of statistical verification of the relationships of fish occurrence and biomass at a larger spatial scale (Lasne et al., ; Penczak et al., ). Because this analysis refers to the entire sections of the river (homogenous groups of sampling sites), and not just individual sampling sites, it seems that it is free of many of the above‐mentioned limitations (encountered when analysing abiotic‐biotic relationships), especially those resulting from fish movements and using different habitats.…”

“…These differences are also apparent in the indicator species analysis, as much fewer species were significantly associated with S3 compared with S2 and S4 (Table 3). The number of species significantly associated with the given group of samples of organisms (i.e., exhibiting the significantly highest values of the IndVal index) is considered a good measure of the quality of the environment from which these samples come from (Adamczyk, Kruk, Penczak, & Minter, 2012;Penczak et al, 2012Penczak et al, , 2014Szczepko, Kruk, & Bartos, 2012;Szczepko, Kruk, Bartos, & Wiśniowski, 2013). The worse state of the fish fauna in section S3 in comparison with S2 and S4 is a manifestation of the disturbed natural downstream gradient (zonation) of fish assemblages along the river and an indicator of human pressure (compare with Aarts & Nienhuis, 2003;Ibarra et al, 2005;Lasne, Bergerot, Lek, & Laffaille, 2007).…”

“…according to their location along the river) Additionally, the indicator species analysis (ISA; Dufrêne & Legendre, 1997) was used in order to identify species of fish and lampreys significantly associated with each river section. It is based on the indicator value (IndVal), which is calculated independently for each species and can be considered as a measure of the strength of preferences for habitat conditions prevailing in particular river sections (Kruk & Penczak, 2013;Penczak, Kruk, Głowacki, & Galicka, 2014). The index was calculated for each species i in each river section (i.e.…”

“…The usefulness of ISA (IndVal index with Monte-Carlo test) lies in the ability of statistical verification of the relationships of fish occurrence and biomass at a larger spatial scale (Lasne et al, 2007;Penczak et al, 2014). Because this analysis refers to the entire sections of the river (homogenous groups of sampling sites), and not just individual sampling sites, it seems that it is free of many of the above- The applied methodological approach (ISA preceded by the cluster analysis) made the explanation of fish assemblage condition and species occurrence and/or biomass with the use of some general information available in the literature easier ( Figure 6, Table 4).…”

Status and Trends in Biotic Integrity in a Sub‐Tropical River Drainage: Analysis of the Fish Assemblage Over a Three Decade Period

“…Absence or low numbers of fish species in streams located at the headwaters of a drainage network has been reported from other places (Fausch et al ., ; Oberdorff et al ., ; Magalhães et al ., ; García‐Melo et al ., ). However, because the ichthyofauna in small streams often depends on recolonization from springs or larger streams after droughts or other stressful periods (Gorman, ; Osborne and Wiley, ; Penczak et al ., ), the lack of fish in the Duero River headwaters could be the result of pollution barriers further downstream caused by the lack of wastewater treatment. In addition, some traditional activities, such as clothes washing in the river, introduce nutrients and other chemicals that may form more localized barriers.…”