Patch scale response of hyporheic invertebrates to fine sediment removal in two chalk rivers
Pacioglu, Octavian; Shaw, Peter; Robertson, Anne
published: Dec 1, 2012
ArtNo. ESP141018104003, Price: 29.00 €
Groundwater-fed permeable catchments are very susceptible to fine sediment infiltration into the stream bed (colmation), leading to potential reductions in hydraulic conductivity and therefore modification of oxygen and nutrient exchange between hyporheic and surface waters. We investigated the effect of fine sediment (< 2 mm) removal on invertebrate assemblages in the shallow hyporheic zones of two chalk rivers using a field experimental approach. we used colonization chambers containing one of two treatments: control and unclogged sediments. anions, cations and dissolved oxygen did not differ significantly between treatments suggesting good connectivity between surface and hyporheic waters. total organic carbon differed significantly between treatments (p < 0.01) and was higher in the control. in the hyporheic assemblage only oligochaeta abundance differed significantly between treatments (p < 0.01) and was higher in the control. Overall our study suggests that patch-scale restoration of sediments does not alter hyporheic invertebrate community composition in chalk rivers.