Ecological effects of sediment bypass tunnels

Different techniques, including Sediment Bypass Tunnels (SBTs), are used to reestablish sediment regimes downstream of dams. Our goal was to evaluate the ecological effects of a new SBT in an alpine stream in Switzerland. Sediment respiration (SR), fine particulate organic matter (FPOM), periphyton biomass and macroinvertebrate density and richness were analysed along a 5 km stretch of the river. Sampling was conducted upstream and downstream of sediment input sources, including the SBT and major tributaries, to determine the ecological impact of SBT high flow events. Our results showed that SR, periphyton biomass and macroinvertebrate density and richness decreased after SBT events due to water and sediment scouring/deposition. These results suggest SBT events act as short-term disturbances, but may potentially enhance sediment regimes downstream of dams in the long term.

[1]  C. F. Rabeni,et al.  Stream invertebrate community functional responses to deposited sediment , 2005, Aquatic Sciences.

[2]  Maria Cristina Bruno,et al.  Impact of hydropeaking on hyporheic invertebrates in an Alpine stream (Trentino, Italy) , 2009 .

[3]  W. Schlesinger,et al.  Soil CO2 dynamics, acidification, and chemical weathering in a temperate forest with experimental CO2 enrichment , 2001 .

[4]  Gerald J. Niemi,et al.  Application of Ecological Indicators , 2004 .

[5]  F. James Rohlf,et al.  Biometry: The Principles and Practice of Statistics in Biological Research , 1969 .

[6]  Tetsuya Sumi,et al.  RESERVOIR SEDIMENTATION MANAGEMENT WITH BYPASS TUNNELS IN JAPAN , 2004 .

[7]  J. Mount,et al.  The influence of relative sediment supply on riverine habitat heterogeneity , 2006 .

[8]  C. Revenga,et al.  Fragmentation and Flow Regulation of the World's Large River Systems , 2005, Science.

[9]  Laura E. McMullen,et al.  Are large‐scale flow experiments informing the science and management of freshwater ecosystems? , 2014 .

[10]  M. Wolman,et al.  Downstream effects of dams on alluvial rivers. , 1984 .

[11]  U. Uehlinger,et al.  Ecosystem Metabolism, Disturbance, and Stability in a Prealpine Gravel Bed River , 1998, Journal of the North American Benthological Society.

[12]  C. Robinson,et al.  Spatial patterns in macroinvertebrate assemblages in surface-flowing waters of a glacially-influenced floodplain , 2013, Aquatic Sciences.

[13]  Dong-sheng Wang,et al.  Seasonal variations of chemical and physical characteristics of dissolved organic matter and trihalomethane precursors in a reservoir: a case study. , 2008, Journal of hazardous materials.

[14]  E. Castelli,et al.  Effects of suspended sediments from reservoir flushing on fish and macroinvertebrates in an alpine stream , 2009, Aquatic Sciences.

[15]  D. Lytle.  Biotic and abiotic effects of flash flooding in a montane desert stream , 2000 .

[16]  V. Acuña,et al.  Flow regulation by dams affects ecosystem metabolism in Mediterranean rivers , 2014 .

[17]  U. Uehlinger,et al.  Contribution of the Hyporheic Zone to Ecosystem Metabolism in a Prealpine Gravel-Bed-River , 1997, Journal of the North American Benthological Society.

[18]  U. Uehlinger,et al.  Spatiotemporal heterogeneity of soil and sediment respiration in a river-floodplain mosaic (Tagliamento, NE Italy) , 2011 .

[19]  J. Newbold,et al.  Contributions of microbial biofilms to ecosystem processes in stream mesocosms , 2003, Nature.

[20]  S. Anders Brandt,et al.  Classification of geomorphological effects downstream of dams , 2000 .

[21]  U. Uehlinger,et al.  The physico-chemical habitat template for periphyton in alpine glacial streams under a changing climate , 2009, Hydrobiologia.

[22]  S. Fisher,et al.  A heterotrophic desert stream? The role of sediment stability , 2002 .

[23]  M. Monaghan,et al.  Effects of a multi-year experimental flood regime on macroinvertebrates downstream of a reservoir , 2003, Aquatic Sciences.

[24]  M. Monaghan,et al.  Stream ecosystem response to multiple experimental floods from a reservoir , 2004 .