Effect of hydropower peaking flow fluctuations on community structure and feeding guilds of invertebrates colonizing artificial substrates in a large impounded river

Abstract

Artificial substrates were used to monitor the invertebrate communities below a power peaking impoundment and a flow re-regulating impoundment on the Missouri River on northeastern Nebraska, USA. Invertebrate communities on shallow samplers subjected to exposure from diel fluctuations in flow averaged 3 taxa per sampler and 91 organisms per square meter. In the absence of diel fluctuations, number of taxa per sampler increased to 12 and mean densities increased to 743 per square meter. Fluctuating discharges had no significant effect on numbers of taxa or densities on continually submerged artificial substrates. However, greater numbers of taxa and total densities were observed on deep (107 cm) versus shallow (30 cm) samplers below both impoundments.Polycentropodidae (Trichoptera), Chironomidae (Diptera) and Oligochaeta were observed to tolerate diel fluctuations and exposure below Fort Randall Dam while Hydropsychidae (Trichoptera) and Heptageniidae (Ephemeroptera) were extremely intolerant.Collector-gatherers and predator-engulfers were the predominant functional groups colonizing samplers below both impoundments. Higher numbers of collector-gatherers, collector-filterers and scrapers were observed from samplers in the absence of diel flow fluctuations.This study corroborates results from a number of other investigations, separated in space and time. Examined collectively, these studies provide the framework for understanding power peaking as a stress to benthic stream communities.

Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam

“…Increased Hydropsychidae density with increased flow fluctuations in the wet season confirms the results of Elliott (1968), Troelstrup and Hergenrader (1990), and Boon (1993). Unlike Hydropsychidae, Simuliidae densities were reduced with increased flow fluctuations in the wet and dry seasons.…”

“…Chance and Craig (1986) also reported that Simuliidae larvae had a lower risk of being displaced by moderate flow changes because of their hydrodynamic and morphological adaptations to cling to the substrate, which is much less true for Hydropsychidae. Chironomidae drift densities increased with increased flow fluctuations in both wet and dry seasons, corroborating the results of Irvine and Henriques (1984) but differing from the results of Gislason (1985) and Troelstrup and Hergenrader (1990).…”

“…Macroinvertebrate drift is very important to aquatic ecosystem function, because it is a primary mechanism for the redistribution and colonisation of aquatic macroinvertebrates (Hay et al, 2008) and offers prey for predators such as fish (Flecker, 1992). Invertebrates downstream are affected by constant changes resulting from plant operations and may have different behaviours in the drift (Troelstrup and Hergenrader, 1990). Invertebrate drift can be stimulated by flow reductions (Cushman, 1985;Minshall and Winger, 1968) and increases (Scullion and Sinton, 1983;Lauters et al, 1996).…”

Effects of flow fluctuations on the daily and seasonal drift of invertebrates in a tropical river

“…During the period of highest energy demand, power is generated and water is rapidly released producing much higher and faster flows that fluctuate daily (Jones, 2013). These fluctuating discharges below impoundments may alter benthic invertebrate assemblages downstream, as a result of higher velocities, increased bed instability, and altered water temperature and quality, leading to higher invertebrate drift rates (Troelstrup and Hergenrader, 1990;Bruno et al, 2009;Smokorowski et al, 2011). Flows created by dam operations modulate natural seasonal extremes, and reduce flood frequency, duration and predictability (Poff et al, 1997;Bunn and Arthington, 2002), affecting aquatic biological conditions downstream of dams (Poff and Zimmerman, 2010).…”

Downstream effects of hydropower production on aquatic macroinvertebrate assemblages in two rivers in Costa Rica

“…Large dams reduce river connectivity (Pringle, 2001; Finer & Jenkins, 2012), cause habitat loss (Dudgeon et al, 2006;Freeman, Pringle & Jackson, 2007;Rodrigues & Silva, 2012), alter water temperature and oxygen (Ward & Stanford, 1983;Viana, 2002;Foto Menbohan, Koji, Ajeagah, Bilong Bilong & Njiné, 2012), and interrupt water flow, movement of sediments, nutrients and fauna (Ward & Stanford, 1983;Pringle, 1997;Bunn & Arthington, 2002;Greathouse, Pringle & Holmquist, 2006a;Williams, Armstrong, Katopodis, Lariniere & Travade, 2012). Streams affected by large dams can have decreased macrophyte total biomass, as well as macroinvertebrate abundance, richness, and biomass (Troelstrup & Hergenrader, 1990;Dejalon & Sanchez, 1994;Vinson, 2001). Additionally, due to changes in food sources and substrate, the composition of macroinvertebrate functional groups changes downstream from hydroelectric dams, favoring functional groups that can exploit plankton drifting from the reservoir, and that prefer habitats with low sediment deposition (Dejalon & Sanchez, 1994;Doi et al, 2008;Katano, Negishi, Minagawa, Doi, Kawaguchi & Kayaba, 2009).…”