Zooplankton structure in two interconnected ponds: similarities and differences

Abstract

The research of zooplankton diversity, abundance and trophic structure was conducted during the summer period in pelagial zone on the longitudinal profile of the Sutla River Backwater. Investigated site consists of two interconnected basins: transparent Upper Basin with submerged macrophytes and turbid Lower Basin without macrophytes in the littoral zone. In the Upper Basin, abundance and diversity of zooplankton in the pelagial was higher in comparison to the Lower Basin, with prevailing species of genus Keratella as microfilter-feeder, and genera of Polyartha and Trihocerca as macrofilter-feeder rotifers. On the contrary, in the Lower Basin, crustaceans dominated in abundance. Microfilter-feeder cladoceran (Bosmina longirostris) and larval and adult stages of macrofilter-feeder copepod (Macrocyclops albidus) prevailed in the Lower Basin. Fish predation pressure was more pronounced in the pelagial of the Upper Basin, indicated by low cladoceran abundance in the surface layer. Although the studied basins were interconnected, results indicate significant (Mann-Whitney U test, p < 0.05) differences in the zooplankton structure as a potential result of the macrophyte impact on environmental conditions and fish predation pressure.

Impact of water level fluctuation in the shaping of zooplankton assemblage in a shallow lake.

“…Succession of the planktonic species was probably caused by competition for detritus and algae in the environment plentiful with food resources (Wallace et al, 2006). Cladocerans were present in both years with Bosmina longirostris and were completely exterminated, probably due to extended fish predation, which is in accordance with recent studies (González Sagrario et al, 2009;Špoljar et al, 2016). Copepod assemblage was significantly modified in transition from the low to the high water regime.…”

“…Namely, copepods are quick in response to water oscillations and to fish, as visual predators. Moreover, higher turbidity at higher water level and their abundant populations probably hindered fish efficiency (Estlander et al, 2009;Špoljar et al, 2016). It was presumed that at the higher water level, resuspended nutrients, due to macrophyte absence, affected positively phytoplankton biomass and successively enhanced zooplankton growth, and thus productivity of the entire oxbow biocoenosis, including fish.…”

The Effect of Hydrological Connectivity on the Zooplankton Structure in Floodplain Lakes of a Regulated Large River (the Lower Vistula, Poland)

“…According to many authors [18,46,47], Rotifera predominate in both standing and flowing waters owing to their tolerance to changing environmental conditions. Their dominance is believed to be connected with their small size and relatively short development time compared to crustaceans [48][49][50]. Rotifera display life history r-strategies and are more adaptable to environmental disturbances of lotic and semi-lotic habitats [18,50].…”

Disentangling food webs interactions in the littoral of temperate shallow lakes

“…The structural heterogeneity of habitats in the Sutla backwater related to the complex macrophyte architecture, significantly enhanced the biodiversity (Kuczyńska-Kippen, 2003;Špoljar et al, 2012a;Chaparo et al, 2015;Dražina et al, 2016), as different from the structural simplicity and biodiversity scarcity in Zajarki gravel pit (Špoljar et al, 2011, Špoljar, 2013). Snails, water mites and insect larvae are the main consumers of epiphyton (Liboriussen et al, 2005), maintain macrophyte light conditions i.e.…”