Seasonal and spatial bank habitat use by fish in highly altered rivers – a comparison of four different restoration measures

Abstract

River regulations have resulted in substantial modifications of the characteristics and the diversity of stream ecosystems. Fish habitat use in the context of species life histories and temporal habitat dynamics are crucial for the development of sustainable measures of habitat restoration in degraded rivers. The objective of this study was to compare the effects of introducing four different in-stream structures (bank ripprapp, benched bank ripp-rapp, successively grown riparian wood and artificial dead wood, nine replicates each) on the seasonal fish community distribution in a heavily modified stream ecosystem. Species richness and diversity, fish biomass and density showed strong variation (i) between habitat types, (ii) among replicates of the same habitat type, and (iii) in different seasons. The current low abundance of historical widespread rheophilic and migratory fish species in the study stream suggests that technical bank habitat restoration measures are only of limited use for the restoration of highly specialised target species in conservation such as Barbus barbus and Chondrostoma nasus. However, introduction of particular artificial stream structures (in particular of artificial dead-wood fascines) was found to concentrate biomass and density of none-specialised fish species like Squalius cephalus, Alburnus alburnus, Gobio gobio or Rutilus rutilus.

Effects of flow regulation on the establishment of alien fish species: A community structure approach to biological validation of environmental flows

“…Its principle relies on the knowledge and basic description of the physical habitat requirements of stream biota and how the amount of suitable physical habitat changes with flow. The river littoral habitats (riparian zone and wetted area adjacent to the banks) play an important role in the ecological functioning of rivers, providing suitable habitat for fish (Cummins, 1993;Growns et al, 2003;Pander and Geist, 2010). In large rivers, this habitat becomes even more important due to its function of shelter (shade and coverage) (Pander and Geist, 2010) and feeding ground (Platts, 1983;Moring et al, 1985).…”

“…The river littoral habitats (riparian zone and wetted area adjacent to the banks) play an important role in the ecological functioning of rivers, providing suitable habitat for fish (Cummins, 1993;Growns et al, 2003;Pander and Geist, 2010). In large rivers, this habitat becomes even more important due to its function of shelter (shade and coverage) (Pander and Geist, 2010) and feeding ground (Platts, 1983;Moring et al, 1985). Hydromorphological alterations that may occur in rivers' littoral zones have a direct impact on the fish community structure (Hawkins et al, 1983;Growns et al, 1998;Maridet et al, 1998;Lyons et al, 2000).…”

Model-Based Evaluation of the Effects of River Discharge Modulations on Physical Fish Habitat Quality

“…Furthermore, the slope of the river bed has changed dramatically due to an accelerated incision [85]. Morphological restoration, namely the removal of the channelization, meandering and slope reduction, increases the diversity of physical habitats [87,88], and the investigated river reach was hydro-morphologically restored. However, morphological restoration in urban areas, namely of heavily modified water bodies [16], remains difficult because of physical limitations [89].…”

Young-of-the-year fish assemblages as indicators of anthropogenic disturbances in large tributaries of the Seine River Basin (France)

“…Moreover, using YOY fish assemblages could help to improve or complement the biotic indices previously developed for adult fish assemblages since these indices suffer some important limitations: (1) a poor ability to establish cause-effect relationships (Roche et al, 2005), mostly because of the relatively long time response of adult populations to disturbances (Jurajda et al, 2010); (2) problems in sampling efficiencies for adult fishes in large rivers (De Leeuw et al, 2007); (3) problems linked to fish stocking (Schmutz et al, 2000); and (4) weak efficiency in evaluating river rehabilitation works which are often done at very small grain (few hundred meters) (Adam et al, 2007;Pander & Geist, 2010).…”