Weir removal in salmonid streams: implications, challenges and practicalities

Leániz, Carlos García de

doi:10.1007/s10750-008-9397-x

Cited by 149 publications

(80 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The restoration rationale was to remove anthropogenic obstructions where possible and where not, to use nature-like passage approaches, so as to facilitate natural river processes and support dispersal of aquatic biota (Jungwirth 1996;Garcia de Leaniz 2008). Obstructions located at S4, S5 and S6 were removed by conversion to single span, full-channel width bridges with natural substrate.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach

Tummers

Hudson

Lucas

2016

Science of The Total Environment

View full text Add to dashboard Cite

. (2016) 'Evaluating the eectiveness of restoring longitudinal connectivity for stream sh communities : towards a more holistic approach.', Science of the total environment., 569-570 . pp. 850-860. Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractA more holistic approach towards testing longitudinal connectivity restoration is needed in order to establish that intended ecological functions are achieved. We illustrate the use of a multi-method scheme to evaluate the effectiveness of 'nature-like' connectivity restoration for stream fish communities in the River Deerness, NE England. Electric-fishing, capture-mark-recapture, PIT telemetry and radio-telemetry were used to measure fish community composition, dispersal, fishway efficiency and upstream migration respectively. For measuring passage and dispersal, our rationale was to evaluate a wide size range of strong swimmers (exemplified by brown trout Salmo trutta) and weak swimmers (exemplified by bullhead Cottus perifretum) in situ in the stream ecosystem. Radiotracking of adult trout during the spawning migration showed that passage efficiency at each of five connectivity-restored sites was 81.3-100%. Unaltered (experimental control) structures on the migration route had a bottle-neck effect on upstream migration, especially during low flows.However, even during low flows, displaced PIT tagged juvenile trout (total n = 153) exhibited a passage efficiency of 70.1-93.1% at two nature-like passes. In mark-recapture experiments juvenile brown trout and bullhead tagged (total n = 5303) succeeded in dispersing upstream more often at most structures following obstacle modification, but not at the two control sites, based on a Laplace kernel modelling approach of observed dispersal distance and barrier traverses. Short-term post-restoration data (2-3 years) showed that the fish assemblage remained similar at five of six connectivity-restored sites and two control sites, but at one connectivity-restored headwater site previously inhabited by trout only, three native non-salmonid species colonised. We conclude that stream habitat reconnection should support free movement of a wide range of species and life stages, wherever retention of such obstacles is not needed to manage non-native invasive species. Evaluation of the effectiveness of fish community restoration in degraded streams benefits from a similarly holistic approach.

show abstract

Section: Methodsmentioning

confidence: 99%

“…The preferred method of reinstituting effective longitudinal connectivity is physical removal of obstructions where possible (Poff and Hart 2002;Garcia de Leaniz 2008). Obstruction removal is sometimes not feasible due to budgetary constraints, flood risks or cultural history reasons.…”

Section: Introductionmentioning

confidence: 99%

Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach

Tummers

Hudson

Lucas

2016

Science of The Total Environment

View full text Add to dashboard Cite

show abstract

“…Damming is probably one of the greatest stressors affecting the integrity of running waters (Heinz Center 2002;Garcia de Leaniz 2008), because it can interfere or even stop the transport of sediment and nutrients along waterways and eventually disturb ecological connectivity, which underpins the transfer of materials and products of ecological functions and processes (Jenkins and Boulton 2003). Additionally, impounded waters can trigger important changes in the composition of stream fauna, favoring lentic over lotic species (Raymond 1979;Lewis 2001;Shao et al 2007;Zhou et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Impacts of cascade run-of-river dams on benthic diatoms in the Xiangxi River, China

Tang

et al. 2009

Aquat. Sci.

View full text Add to dashboard Cite

The ecological effects of small run-of-river dams on aquatic ecosystems are poorly understood, especially on downstream benthic algal communities. We examined impacts of such dams on the benthic diatom community at a regional scale in the Xiangxi River, China. A total of 90 sites were visited, which were divided into five habitats (H1-H5) according to impact extent of each dam. Using partial least squares (PLS) modeling, we developed two predictive models (diatom species richness and total diatom density) based on environmental variables of an unregulated habitat (H1). These models were then used to predict species richness and total densities at impacted habitats (H2-H5) and residuals, i.e. the differences between observed and predicted values, were used to evaluate impact strength of flow regulation. Significant impacts of flow regulation on diatom species richness were detected at three impacted habitats (H3-H5), where observed species richness were significantly higher-70.6, 63.9 and 46.6%, respectively-than predicted values. Then, possible mechanisms for observed impacts were discussed. Further research is necessary to address the potential negative impacts of cascade run-of-river dams on other aquatic organisms in different seasons, and to explore more appropriate mechanisms for such impacts, which may lead to sustainable management strategies and help to determine the optimal ecological water requirement for the Xiangxi River.

show abstract

“…The impact of delay, acting through increased energetic expense, may be exacerbated for those eels already compromised through infection with the invasive parasite Anguillicoloides crassus (Höglund et al 1992) which may be present in up to 90% of the eel population in most European systems (Lefebvre and Crivelli 2004). Further, due to accumulation of fish delayed at structures, the potential for parasite disease transfer is also enhanced (Garcia de Leaniz 2008), as is the risk of predation by species such as cormorants, Phalacrocorax carbo, Keller 1995) and otters, Lutra lutra, (Jenkins and Harper 1980) both of which are known to frequent the study site.…”

Section: Discussionmentioning

confidence: 99%

Impact of Tide Gates on the Migration of Adult European Eels, Anguilla anguilla

Wright

Kemp

2015

Estuaries and Coasts

View full text Add to dashboard Cite

Tide gates form a temporal barrier to fish migration, closing during the flood tide and opening during the ebb, primarily for flood prevention and land reclamation. Their impact on downstream adult migration of the critically endangered European eel, Anguilla anguilla, is unknown. The River Stiffkey, UK, has three top-hung tide gates (one counterbalanced, two not) through which it discharges into the North Sea. Adult eels of silver appearance (n = 118) were caught between 0.5 to 6.0 km upstream from the tide gates in Autumn 2011 and implanted with 23 mm half-duplex passive integrated transponder (PIT) tags. Tagged individuals were detected by PIT antennae located near the tide gates. Of the eels tagged, 80 were detected actively migrating downstream to the gates.Escapement past the gates was 98.3%. Speed of migration was slower near the gates than for an unimpeded upstream reach, and was positively and negatively related to mean degree of gate opening and mean light intensity, respectively. When the largest gate was modified through installation of an orifice intended to improve upstream passage of sea trout and juvenile eels, downstream migration was more rapid when it was operating. However, video analysis revealed that eels did not pass through the orifice, meaning that faster migration may have been a result of the gates being open on more occasions when eels initially approached them, or the lower tides and upstream saline intrusion that occurred during these periods. Top-hung tide gates in the River Stiffkey delayed eel migration, potentially increasing the risk of predation and energy expenditure immediately prior to a 5000 -6000 km migration to spawning grounds in the Sargasso Sea.

show abstract

Weir removal in salmonid streams: implications, challenges and practicalities

Cited by 149 publications

References 65 publications

Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach

Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach

Impacts of cascade run-of-river dams on benthic diatoms in the Xiangxi River, China

Impact of Tide Gates on the Migration of Adult European Eels, Anguilla anguilla

Contact Info

Product

Resources

About