Revealing the influence of hyporheic water exchange on the composition and abundance of bottom-dwelling macroinvertebrates in a temperate lowland river

Abstract

We studied distributions and abundances of macroinvertebrates in relation to hyporheic water exchange (HWE) patterns of the upper Biebrza − a small, lowland, low dynamic European river located in Northeast Poland. On a 6-km stretch of the river; we determined the variability of water exchange in the hyporheic zone by using direct field measurements of the pressure gradient to determine groundwater–surface water interactions. We identified locations with upwelling and downwelling fluxes of HWE as well as ambiguous hydraulic contact between groundwater and surface water along the river. In these locations, we sampled bottom-dwelling macroinvertebrates. In total, 627 individuals of benthic macroinvertebrates of 34 taxa were identified. We revealed that bottom-dwelling macroinvertebrate fauna is more abundant and diverse in river stretches where water from the river infiltrates the hyporheic zone. Results also show higher taxonomic richness and abundances of benthic macroinvertebrates in stretches with diagnosed infiltrating conditions (downwelling flux in a hyporheic zone) compared to in stretches where the river drained groundwater (upwelling flux in a hyporheic zone), but the recorded differences were not statistically significant.

Detailed analysis of habitat suitability curves for macroinvertebrates and functional feeding groups

“…Habitat suitability criteria were determined for water flow velocities, depths, and substrate types. Although other environmental variables within the river channel (such as water quality, hyporheic water exchange) also tend to play significant roles in determining habitat quality for macroinvertebrates 32 , 72 , these three parameters are considered to be good predictors of macroinvertebrate distribution 34 , 46 . The analysis of the HPCs and HUCs determined separately for the data collected in 2018 and 2019 proved to be an important step in determining the final HSCs.…”

Effects of Fires on Microbial and Metazoan Communities in Peatlands

“…Nematodes respond much more slowly to sudden environmental disturbances. According to Grygoruk et al [48], in the Biebrza wetlands located in eastern Poland, the most abundant were Daphnia sp., Nematoda, and Chironomidae.…”

Differences in hyporheic water exchange in habitats of different aquatic Ranunculus species – case study in Poland

“…Hyporheic water exchange remains an important factor shaping habitats for a range of riverine biota, including macrophytes (Braun et al, 2012;Grygoruk et al, 2021;Ling et al, 2020;Magliozzi et al, 2019).…”