Hydrological exchange and sediment characteristics in a riverbank: relationship between heavy metals and invertebrate community structure

Abstract

The first metre of bed sediments of the Rhône River functions as a filter for fluxes of heavy metals and epigean organisms between surface and interstitial environments. To study the efficacy of this bank filtration, three sampling stations were established at increasing distances from pumping wells, resulting in a gradient of hydraulic characteristics. Station A, a permanent downwelling area with very high hydraulic gradients, low hydraulic conductivity, low oxygen content, and rather high metal concentrations contained a fauna exclusively composed of epigean organisms. At station B, intermediate hydraulic gradients, high hydraulic conductivity near the surface, and variable direction of water exchanges resulted in well-oxygenated pore water and a diversified fauna with hypogean and epigean species. Finally, at station C, low hydraulic gradient, low hydraulic conductivity, low water exchange, and high sediment metal concentrations resulted in low pore-water oxygen concentrations and low interstitial fauna density and diversity. At this site, low oxygen content and low biodiversity were related to the clogging of shallow sediments and low filtration efficiency. Thus, bank filtration efficiency, a property that depends mainly on natural or human-induced hydraulic gradients and sediment granulometry, determines pore-water chemistry, metal distribution, and faunal composition in the shallow interstitial environments of the Rhône River.

Land‐use effects on the hyporheic ecology of five small streams near Hamilton, New Zealand

“…Fewer species and taxa were found in the more hypoxic areas. Dissolved oxygen concentration has been suggested as a key determinant of processes occurring in the hyporheic zone (reviews in: Williams 1993;Brunke & Gonser 1997) and often correlates positively with the richness and abundance of the hyporheos (Boulton et al 1992;Gibert et al 1995). Many typically hyporheic taxaincluding nematodes, ostracods, harpacticoids, and cyclopoids-apparently can tolerate low levels of dissolved oxygen (Boulton et al 1992) and in this study were present at concentrations below 30% saturation.…”

“…31 The linkages between a stream and its valley have been recognised for decades (Hynes 1975), and studies on the impacts of catchment land use have usually focussed on fish and surface benthic invertebrates (Rosenberg & Resh 1993;Loeb & Spacie 1994). Although interstitial invertebrates have been suggested as likely sentinels for detecting pollution from heavy metals (Gibert et al 1995;Plenet et al 1996) and sewage (Creuze des Chatelliers et al 1992), little seems known about the possible impacts of land use upon ecological processes and fauna occurring in the hyporheic or parafluvial zones of streams.…”

Human-Driven Microbiological Contamination of Benthic and Hyporheic Sediments of an Intermittent Peri-Urban River Assessed from MST and 16S rRNA Genetic Structure Analyses

“…This filter effect will depend upon the nature of the river bed media including size of its physical components. These will affect the porosity of the bed and impact water flow in the hyporheic zone (Gibert et al, 1995; Maazouzi et al, 2013). Disturbance of these zones can lead to a decrease of the ecological quality of a river (Lafont et al, 2009).…”

Landscape topography and the distribution of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) in a high desert stream

“…The hyporheic zone has been defined as the region of mixing between surface and ground water (Orghidan 1959), but can also be thought of as the area of saturated subsurface sediments containing stream water (Kasahara and Wondzell 2003). Hyporheic exchange, or the movement of water between surface and hyporheic flows, occurs both vertically through the stream substrate in the form of upwelling and downwelling (Harvey and Bencala 1993), and horizontally by entering and exiting surface flows through the stream banks (Gibert et al 1995). Areas of hyporheic input (where hyporheic flows join surface flows) offer thermal refugia for fish because they are generally cooler in summer, warmer in winter and more thermally stable than surface waters (Williams 1984;Malard et al 2001).…”