The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Juergen Geist - One of the best experts on this subject based on the ideXlab platform.
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do we know enough to save european riverine fish a systematic review on autecological requirements during critical life stages of 10 Rheophilic Species at risk
Sustainability, 2019Co-Authors: Nicole Smialek, Joachim Pander, Melanie Mueller, Christian Wolter, Ruben Van Treeck, Juergen GeistAbstract:Modeling of fish population developments in the context of hydropower impacts and restoration planning requires autecological information on critical life stages (especially on juvenile stages and reproduction). We compiled and examined the current data availability in peer-reviewed and grey literature on autecological requirements of ten Rheophilic fish Species at risk, belonging to the salmonid, cyprinid, and cottid families. In total, 1725 data points from 223 sources were included. Economically important salmonids and the common nase were the most studied Species. Grey and peer-reviewed data showed similar dispersion and variance and contributed nearly equally to the data pool of the specific Species. An in-depth analysis on seven ecological parameters revealed no significant differences between both sources in terms of data availability and quality. We found substantial deficits in the data for about a quarter of the reviewed ecological parameters, in particular on individual densities in the habitats, egg development and information about juvenile stages despite the necessity of such data for more advanced population analyses. To secure fish populations in the long term, more data on basic autecological parameters is needed and grey literature might add valuable information, particularly if it relies on standardized methodologies.
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Do We Know Enough to Save European Riverine Fish?—A Systematic Review on Autecological Requirements During Critical Life Stages of 10 Rheophilic Species at Risk
Sustainability, 2019Co-Authors: Nicole Smialek, Joachim Pander, Melanie Mueller, Christian Wolter, Ruben Van Treeck, Juergen GeistAbstract:Modeling of fish population developments in the context of hydropower impacts and restoration planning requires autecological information on critical life stages (especially on juvenile stages and reproduction). We compiled and examined the current data availability in peer-reviewed and grey literature on autecological requirements of ten Rheophilic fish Species at risk, belonging to the salmonid, cyprinid, and cottid families. In total, 1725 data points from 223 sources were included. Economically important salmonids and the common nase were the most studied Species. Grey and peer-reviewed data showed similar dispersion and variance and contributed nearly equally to the data pool of the specific Species. An in-depth analysis on seven ecological parameters revealed no significant differences between both sources in terms of data availability and quality. We found substantial deficits in the data for about a quarter of the reviewed ecological parameters, in particular on individual densities in the habitats, egg development and information about juvenile stages despite the necessity of such data for more advanced population analyses. To secure fish populations in the long term, more data on basic autecological parameters is needed and grey literature might add valuable information, particularly if it relies on standardized methodologies.
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can fish habitat restoration for Rheophilic Species in highly modified rivers be sustainable in the long run
Ecological Engineering, 2016Co-Authors: Joachim Pander, Juergen GeistAbstract:Abstract As a result of the ongoing loss of freshwater biodiversity, restoration of riverine habitats is high on the agenda. However, it remains controversial if commonly used instream fish habitat restoration techniques have sustainable effects in highly modified waterbodies. This study compared the effects of introducing four different instream structures (bank rip-rap, benched bank rip-rap, successively grown riparian wood and introduced dead wood, nine replicates each) on the fish community distribution in the river Gunz in Germany. To assess the sustainability of the restoration measures, different time points (seven and two years after the restoration) and seasons were considered. Out of all measures, the introduction of dead wood had strongest effects on fish aggregation (biomass and density) as well as on Species richness and diversity. Even seven years after restoration, no alterations in the density and demography of target Species in conservation was detectable. These results suggest that instream habitat restoration measures are unlikely to fully mitigate deficiencies in highly modified rivers. Consequently, the investment of resources for aquatic restoration may have greater effects in systems that are closer to an optimal state, unless greater effort into restoration beyond the main channel is made.
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ecological functions of fish bypass channels in streams migration corridor and habitat for Rheophilic Species
River Research and Applications, 2013Co-Authors: Joachim Pander, Melanie Mueller, Juergen GeistAbstract:The introduction of weirs into stream ecosystems resulted in modifications of serial continuity and in the decline of riverine fish Species. Successful river restoration requires information on the ecological functionality of fish bypass channels that are considered an ecological improvement according to the European Water Framework Directive. In this study, we compared the functionality of three nature-oriented fish passes as compensatory habitats and migration corridors for fishes. Fish passes differed significantly from upstream and downstream reaches of the weirs, revealing higher current speed, lower water depth, smaller channel width and greater habitat variability. Following these structural differences, they provided key habitats for juvenile, small and Rheophilic fishes that are typically underrepresented in highly modified water bodies. All fish passes were used as migration corridors, with increased fish movements during high discharge and at spawning periods. Because river stretches with high variability of current speed and water depth are scarce in highly modified water bodies, fish passes can play an important role as compensatory habitats and should thus be considered more intensively in habitat assessments and river restoration. Ideally, fish bypasses should mirror the natural discharge dynamics and consider all occurring fish Species and sizes. Copyright © 2011 John Wiley & Sons, Ltd.
Joachim Pander - One of the best experts on this subject based on the ideXlab platform.
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do we know enough to save european riverine fish a systematic review on autecological requirements during critical life stages of 10 Rheophilic Species at risk
Sustainability, 2019Co-Authors: Nicole Smialek, Joachim Pander, Melanie Mueller, Christian Wolter, Ruben Van Treeck, Juergen GeistAbstract:Modeling of fish population developments in the context of hydropower impacts and restoration planning requires autecological information on critical life stages (especially on juvenile stages and reproduction). We compiled and examined the current data availability in peer-reviewed and grey literature on autecological requirements of ten Rheophilic fish Species at risk, belonging to the salmonid, cyprinid, and cottid families. In total, 1725 data points from 223 sources were included. Economically important salmonids and the common nase were the most studied Species. Grey and peer-reviewed data showed similar dispersion and variance and contributed nearly equally to the data pool of the specific Species. An in-depth analysis on seven ecological parameters revealed no significant differences between both sources in terms of data availability and quality. We found substantial deficits in the data for about a quarter of the reviewed ecological parameters, in particular on individual densities in the habitats, egg development and information about juvenile stages despite the necessity of such data for more advanced population analyses. To secure fish populations in the long term, more data on basic autecological parameters is needed and grey literature might add valuable information, particularly if it relies on standardized methodologies.
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Do We Know Enough to Save European Riverine Fish?—A Systematic Review on Autecological Requirements During Critical Life Stages of 10 Rheophilic Species at Risk
Sustainability, 2019Co-Authors: Nicole Smialek, Joachim Pander, Melanie Mueller, Christian Wolter, Ruben Van Treeck, Juergen GeistAbstract:Modeling of fish population developments in the context of hydropower impacts and restoration planning requires autecological information on critical life stages (especially on juvenile stages and reproduction). We compiled and examined the current data availability in peer-reviewed and grey literature on autecological requirements of ten Rheophilic fish Species at risk, belonging to the salmonid, cyprinid, and cottid families. In total, 1725 data points from 223 sources were included. Economically important salmonids and the common nase were the most studied Species. Grey and peer-reviewed data showed similar dispersion and variance and contributed nearly equally to the data pool of the specific Species. An in-depth analysis on seven ecological parameters revealed no significant differences between both sources in terms of data availability and quality. We found substantial deficits in the data for about a quarter of the reviewed ecological parameters, in particular on individual densities in the habitats, egg development and information about juvenile stages despite the necessity of such data for more advanced population analyses. To secure fish populations in the long term, more data on basic autecological parameters is needed and grey literature might add valuable information, particularly if it relies on standardized methodologies.
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can fish habitat restoration for Rheophilic Species in highly modified rivers be sustainable in the long run
Ecological Engineering, 2016Co-Authors: Joachim Pander, Juergen GeistAbstract:Abstract As a result of the ongoing loss of freshwater biodiversity, restoration of riverine habitats is high on the agenda. However, it remains controversial if commonly used instream fish habitat restoration techniques have sustainable effects in highly modified waterbodies. This study compared the effects of introducing four different instream structures (bank rip-rap, benched bank rip-rap, successively grown riparian wood and introduced dead wood, nine replicates each) on the fish community distribution in the river Gunz in Germany. To assess the sustainability of the restoration measures, different time points (seven and two years after the restoration) and seasons were considered. Out of all measures, the introduction of dead wood had strongest effects on fish aggregation (biomass and density) as well as on Species richness and diversity. Even seven years after restoration, no alterations in the density and demography of target Species in conservation was detectable. These results suggest that instream habitat restoration measures are unlikely to fully mitigate deficiencies in highly modified rivers. Consequently, the investment of resources for aquatic restoration may have greater effects in systems that are closer to an optimal state, unless greater effort into restoration beyond the main channel is made.
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ecological functions of fish bypass channels in streams migration corridor and habitat for Rheophilic Species
River Research and Applications, 2013Co-Authors: Joachim Pander, Melanie Mueller, Juergen GeistAbstract:The introduction of weirs into stream ecosystems resulted in modifications of serial continuity and in the decline of riverine fish Species. Successful river restoration requires information on the ecological functionality of fish bypass channels that are considered an ecological improvement according to the European Water Framework Directive. In this study, we compared the functionality of three nature-oriented fish passes as compensatory habitats and migration corridors for fishes. Fish passes differed significantly from upstream and downstream reaches of the weirs, revealing higher current speed, lower water depth, smaller channel width and greater habitat variability. Following these structural differences, they provided key habitats for juvenile, small and Rheophilic fishes that are typically underrepresented in highly modified water bodies. All fish passes were used as migration corridors, with increased fish movements during high discharge and at spawning periods. Because river stretches with high variability of current speed and water depth are scarce in highly modified water bodies, fish passes can play an important role as compensatory habitats and should thus be considered more intensively in habitat assessments and river restoration. Ideally, fish bypasses should mirror the natural discharge dynamics and consider all occurring fish Species and sizes. Copyright © 2011 John Wiley & Sons, Ltd.
Michèle Trémolières - One of the best experts on this subject based on the ideXlab platform.
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Vegetation dynamics in side-channels reconnected to the Rhine River: what are the main factors controlling communities trajectories after restoration?
Hydrobiologia, 2013Co-Authors: Albin Meyer, Isabelle Combroux, Laurent Schmitt, Michèle TrémolièresAbstract:The hydraulic management of large rivers led to a disconnection of side-channels. Restoration works were to reconnect these side-channels to the main course in order to recover hydrological and ecological functions. The aim of the study was to analyze the vegetation dynamics after restoration and to link it to the change in chemical and hydro-geomorphological characteristics. Changes in Species richness, cover and composition of the macrophytes communities were studied in nine side-channels of the Rhine river (France) after reconnection which occurred between 1998 and 2006. Vegetation dynamics was surveyed between 2007 and 2011 and compared to the ones of three target side-channels (never disconnected). Three vegetation communities were identified: one characterized by Rheophilic Species, a second one by mesotrophic Species, and a third one by eutrophic Species. Distribution of communities depended mainly on the flow velocity and the sediment texture of the side-channels. The floristic composition of communities evolved rapidly and remained stable a few years after restoration. Changes in Species richness and cover remained relatively low in all side-channels over the study period. Time after restoration did not affect the dynamics of colonization. Reconnection allowed the restored side-channels to exhibit vegetation dynamics similar to those of the target side-channels.
Piet H. Nienhuis - One of the best experts on this subject based on the ideXlab platform.
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Fish zonations and guilds as the basis for assessment of ecological integrity of large rivers
Hydrobiologia, 2003Co-Authors: Bram G.w. Aarts, Piet H. NienhuisAbstract:Longitudinal zonation concepts describe the downstream changes in chemico-physical and biological properties of rivers. Including information on ecological fish guilds can enhance the usefulness of fish zonation concepts, in a way that they can be used as tools for assessment and management of the ecological integrity of large rivers. We present an ecological characterization of fish zones and fish communities in near-natural and in regulated large rivers in Europe (the River Doubs in France and the Rivers Rhine and Meuse in the Netherlands), using guild classifications of several life-history traits of fish and national Red Lists of threatened Species. The Doubs data set was also analyzed using indices of the sensitivity of fish Species to environmental degradation and indices for eurytopy. In these rivers, the number of ecological guilds per zone increases downstream, and there are clear shifts in the structure of the guilds. Flow preference and reproduction ecology of river fish are closely linked. The proportion of Rheophilic Species in the fish community decreases downstream, and the proportions of limnophilic and eurytopic Species increase. Lithophilic and psammophilic spawners are dominant in the upper zones, whereas the lower zones are dominated by phytophilic and phytolithophilic spawners. The proportion of zoobenthivorous and periphytivorous Species decreases downstream, and the proportion of zooplanktivorous and phytivorous Species increases. However, because the European fish fauna mainly consists of feeding generalists, the discriminative abilities of simplistic feeding guild classifications are not very high. Guilds of sensitive, stenoecious Species that share life history strategies that are highly adapted to specific riverine conditions (rheophils and limnophils) have declined far more than generalist Species that can survive in a wide range of habitats that are not characteristic of natural river ecosystems. Because of the subsequent over-abundance of the eurytopic Species the original longitudinal fish zonations are hardly recognizable anymore in heavily impacted large rivers such as the River Rhine. Hence these rivers do not meet the criteria for ecological integrity. Within a specific fish region, a suitable way of analyzing and monitoring the impact of human disturbance on the structure of the fish community is by comparing the guild structure of the present state of a fish zone with that of the reference situation.
L. Füreder - One of the best experts on this subject based on the ideXlab platform.
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Fish fauna and fisheries of large European rivers: examples from the Volga and the Danube
Hydrobiologia, 2018Co-Authors: Martin Schletterer, V. V. Kuzovlev, Y. N. Zhenikov, J. A. Tuhtan, G. Haidvogl, T. Friedrich, K. Górski, L. FürederAbstract:Globally, multiple stressors acting on large rivers strongly influence their ecosystem functions. They do so by altering both their biodiversity and integrity, which may in turn degrade the available ecosystem services. We present the catchment characteristics and discuss different management strategies for the two longest European rivers, the Volga (3531 km) and the Danube (2850 km). Subsequently, we analyze patterns and characteristics of fish fauna of the two rivers based on a review of historical and recent fish surveys. The native fish community of the Danube is characterized by Rheophilic Species, whereas the Volga has a similar proportion of Rheophilic and eurytopic fish, with increasing portions of Rheophilic Species in the Lower Volga and the Volga Delta. We analyzed the Species composition of certain regions of the Volga and the Danube and found a range of 0.515–0.667 for the Jaccard distance. Our review and comparison of fish communities and fisheries between these two largest river systems in Europe indicate that the additive effects of multiple stressors cause impacts on their fish communities. Integrated management taking into account these stressors is needed in order to preserve riverine fish diversity and enhance sustainable fisheries.