The influence of dredging of a lowland river (the Krąpiel in NW Poland) on water mite fauna (Acari: Hydrachnidia)
Zawal, Andrzej; Stępień, Edyta; Szlauer-Łukaszewska, Agnieszka; Michoński, Grzegorz; Kłosowska, Magdalena; Bańkowska, Aleksandra; Myśliwy, Monika; Stryjecki, Robert; Buczyńska, Edyta; Buczyński, Paweł
published: May 1, 2015
ArtNo. ESP141018603002, Price: 29.00 €
As a result of river engineering many rivers undergo very serious alterations. Many studies have been devoted to the influence of river engineering on invertebrate fauna. However, very little data are available on the influence of river dredging on recovering faunal structures. With regard to water mites, an important group for ecological and bioindicative reasons, no such data have been available at all. The present study researched the influence of dredging along a short, previously regulated stretch of a small lowland river (the Kr˛piel) on its water mite fauna, and indicated refugia which allowed for recolonization after the investment was completed. On the basis of species composition, abundance, dominance structure, distribution of synecological groups and biodiversity indicators the following conclusions were drawn: 1) dredging of the stretch of the river that had previously undergone regulation resulted in an increase in water mite species diversity; 2) after dredging the dominant species included the eurytopic Limnesia maculata and the psammophilous Mideopsis orbicularis; 3) the increase in species diversity affected both rheophilic and rheobiontic species, as well as stagnophilic species; 4) species diversity of water mites was only partially connected with the time lapse since the completion of the investment; 5) rheophilic and rheobiontic species were positively correlated with river current velocity and sandy bottoms, whereas stagnophilic species were positively correlated with silty and muddy bottoms, the extent of macrophyte vegetation coverage and the time lapse since the completion of the investment.