Schmutz S.,University of Natural Resources and Life Sciences, Vienna |
Jurajda P.,Academy of Sciences of the Czech Republic |
Kaufmann S.,University of Natural Resources and Life Sciences, Vienna |
Lorenz A.W.,University of Duisburg - Essen |
And 4 more authors.
Hydrobiologia | Year: 2016
European rivers are highly degraded and restoration efforts are becoming more frequent. However, only few restoration projects have been rigorously evaluated so far. We investigated the response of fish assemblages to hydromorphological restoration measures including river widening, creation of instream structures, flow enhancement, remeandering and side-channel reconnection. We sampled 15 rivers with pairs of degraded and restored sites and calculated the effect sizes (i.e., restored–degraded) for species richness, species diversity, fish density and habitat traits. We analysed the following factors potentially affecting restoration success: (1) length of the restored river stretch, (2) time after restoration and (3) hydromorphological quality of restoration. While species diversity and density did not respond to restoration, proportion of small rheophilic fish increased and eurytopic decreased. Short-term (<3 years) and long-term effects (>12 years) of restoration measures have a stronger effect on fish assemblages than mid-term effects. Furthermore, the hydromorphological quality and the length of the restored section are relevant for the restoration effects on the fish community. Future restoration projects should focus on more dynamic, self-sustaining habitat improvements extending over several kilometres and should be coupled with other measures such as restoring the river continuity and species reintroductions. © 2015, The Author(s).
Albayrak I.,University of Aberdeen |
Nikora V.,University of Aberdeen |
Miler O.,UK Center for Ecology and Hydrology |
O'Hare M.,Leibniz Institute For Gewasserokologie Und Binnenfischerei
Aquatic Sciences | Year: 2012
The effects of leaf shape, serration, roughness and flexural rigidity on drag force imposed by flowing water and its time variability were experimentally studied in an open-channel flume at seven leaf Reynolds numbers ranging from 5 to 35 × 103. The study involved artificial leaves of the same surface area but with three shapes ('elliptic', 'rectangular' and 'pinnate'), three flexural rigidities, smooth-edge and sawtooth-like serration, and three combinations of surface roughness (two-side rough, one-side rough/one-side smooth, and two-side smooth). Shape was the most important factor determining flow-leaf interactions, with flexural rigidity, serration and surface roughness affecting the magnitude but not the direction of the effect on drag control. The smooth-edge elliptic leaf had a better hydrodynamic shape as it experienced less drag force, with the rectangular leaf showing slightly less efficiency. The pinnate leaf experienced higher drag force than the other leaves due to its complex geometry. It is likely that flow separation from 12 leaflets of the pinnate leaf prevented leaf reconfiguration such as leaflets folding and/or streamlining. Flexural rigidity strongly influenced the leaf reconfiguration and augmented the serration effect since very rigid leaves showed a strong effect of serration. Furthermore, serration changed the turbulence pattern around the leaves by increasing the turbulence intensity. Surface roughness was observed to enhance the drag force acting on the leaf at high Reynolds numbers. The results also suggest that there are two distinctly different flow-leaf interaction regimes: (I) regime of passive interaction at low turbulence levels when the drag statistics are completely controlled by the turbulence statistics, and (II) regime of active interaction at high turbulence levels when the effect of leaf properties on the drag statistics becomes comparable to the turbulence contribution. © 2011 Springer Basel AG.
Studies of water and mass fluxes to provide a basis for an Integrated Water Resources Management (IWRM) in the catchment of the River Kharaa in Mongolia [Untersuchung von Wasser- Und Stoffflüssen als Grundlage für ein Integriertes Wasserressourcen-Management im Kharaa-Einzugsgebiet, Mongolei]
Menzel L.,University of Heidelberg |
Hofmann J.,Leibniz Institute For Gewasserokologie Und Binnenfischerei |
Ibisch R.,Helmholtz Center for Environmental Research
Hydrologie und Wasserbewirtschaftung | Year: 2011
The paper first reports water-related problems In Mongolia that can be traced back both to adverse natural conditions and to the lack of structures to control the appropriate distribution and protection of water. This is followed by a description of studies in hydrology, mass fluxes, and freshwater ecology that are part of a project dealing with the development of an example of a system of Integrated Water Resources Management (IWRM) in a river basin in northern Mongolia.
Re-establishing regionally extinct or endangered species in the German Baltic Sea - The example of the Baltic grey seal (Halichoerus grypus balticus) and the Baltic sturgeon (Acipenser oxyrinchus) [Wiederaufbau ausgestorbener oder gefährdeter Arten in der deutschen Ostsee am Beispiel der Ostseekegelrobbe (Halichoerus grypus balticus) und dem Ostseestör (Acipenser oxyrinchus)]
Maschner K.,Deutsches Meeresmuseum DMM |
Gessner J.,Leibniz Institute For Gewasserokologie Und Binnenfischerei
Natur und Landschaft | Year: 2011
In the German coastal and marine waters biodiversity is declining as a result of large-scale anthropogenic impacts. Several marine species are extinct or considered endangered. The paper summarizes positive examples of the re-establishment and conservation of endangered species. Typically this group comprises species that are long-lived or have a low reproductive efficiency, and have suffered massively from human impact - either direct or on the habitat. The examples presented focus on the Baltic grey seal and the Baltic sturgeon. The two examples highlight different approaches. For the grey seal the planned project for its reintroduction was based upon relocation but succeeded by natural colonization, while for the sturgeon the approach includes the development of an ex-situ stock as the basis for stocking. As an important aspect of the project, options for cooperation with coastal fisheries are discussed in order to increase their acceptance of the measures.
Bruggemann R.,Leibniz Institute For Gewasserokologie Und Binnenfischerei |
Wittmann J.,HTW Berlin University of Applied Sciences |
Carlsen L.,Awareness Center
Multi-indicator Systems and Modelling in Partial Order | Year: 2014
"Multi-indicator Systems and Modelling in Partial Order" contains the newest theoretical concepts as well as new applications or even applications, where standard multivariate statistics fail. Some of the presentations have their counterpart in the book; however, there are many contributions, which are completely new in the field of applied partial order. © 2014 Springer Science+Business Media New York. All rights are reserved.
Gessner J.,Leibniz Institute For Gewasserokologie Und Binnenfischerei |
Tautenhahn M.,Gesellschaft zur Rettung des Stors |
Spratte S.,Gesellschaft zur Rettung des Stors |
Arndt G.-M.,Gesellschaft zur Rettung des Stors |
And 2 more authors.
Journal of Applied Ichthyology | Year: 2011
Since the European sturgeon (Acipenser sturio) is one of the most highly endangered fish species worldwide with only one population known to still exist in the Gironde River, France, it is attempted to facilitate in-situ and ex-situ protection of the species through coordinated efforts within the former range. To increase the collaborative approach in safeguarding and restoration of the species' population the Bern Convention has adopted an Action Plan (AP) at the Standing Committee meeting in November 2007. Based on this agreement, the member states to the Bern Convention are requested to develop national APs addressing the critical issues for its conservation. This paper discusses in detail the prerequisites for the development of such a national AP, thus focusing on the complex structures in the German Federal and Regional governance system, the stakeholder involvement required, as well as the dynamics of a process unprecedented in any fish species under this convention. For the national AP the governmental agencies for nature conservation and for fisheries, the regional and national stakeholders such as commercial and recreational fisheries, inland navigation administration, port authorities, river catchment management units, recreational water users and environmental conservation NGO's have to be brought together, overcoming major barriers to allow a constructive dialogue leading towards a common problem analysis. As a result, the German national AP is intended to provide a common basis for the future protection attempts, outlining the main focal points for necessary activities. As such it also serves as the framework for the management plans for the river systems considered suitable for the attempts to remediate populations of the European sturgeon in German and other European Rivers in a joint effort with the French partners. © 2011 Blackwell Verlag, Berlin.
Schrittwieser J.,Bundesministerium fur Land und Forstwirtschaft |
Uberwimmer F.,Abt. Anlagen |
Venohr M.,Leibniz Institute For Gewasserokologie Und Binnenfischerei
Osterreichische Wasser- und Abfallwirtschaft | Year: 2014
A pressing management question in the Danube river basin is how to reduce nutrient emissions so as to improve the status of the Danube and the Black Sea. This article describes the fundamentals and goals of nutrient management, presents the current level of nutrient load and input pathways, and offers insights into efforts to reduce nutrient emissions. With the help of the simulation model MONERIS we have been able to quantify the nutrient emissions from household and industrial wastewater, from atmospheric deposition and from agriculture, and to analyze the temporal and spatial effects of various management scenarios. Major investments have been and are being made in wastewater treatment plants in the Danube countries, and the EU-wide limit on the phosphate content in household detergents marks a major success. Through European environmental policy and the EU's Common Agricultural Policy (CAP), efforts are being made to more quickly arrive at agricultural methods that are safer for our waters. At the same time, awareness campaigns and a "greening" of the CAP are already underway. © 2013 Springer-Verlag Wien.
Ferreira-Rodriguez N.,University of Vigo |
Gessner J.,Leibniz Institute For Gewasserokologie Und Binnenfischerei |
Pardo I.,University of Vigo
Journal of Fish Biology | Year: 2016
This pilot study explored the potential of juvenile European Atlantic sturgeon Acipenser sturio to feed on two invasive bivalve species, the Asian clam Corbicula fluminea and the Eurasian zebra mussel Dreissena polymorpha. Preliminary results indicate that native A. sturio were feeding on D. polymorpha at a very limited rate and their potential to prevent the establishment of invasive bivalve species, in new and previously invaded areas, is considered limited. © 2016 The Fisheries Society of the British Isles
PubMed | University of Vigo and Leibniz Institute For Gewasserokologie Und Binnenfischerei
Type: Journal Article | Journal: Journal of fish biology | Year: 2016
This pilot study explored the potential of juvenile European Atlantic sturgeon Acipenser sturio to feed on two invasive bivalve species, the Asian clam Corbicula fluminea and the Eurasian zebra mussel Dreissena polymorpha. Preliminary results indicate that native A. sturio were feeding on D. polymorpha at a very limited rate and their potential to prevent the establishment of invasive bivalve species, in new and previously invaded areas, is considered limited.
Brothers S.M.,University of Quebec at Montréal |
Brothers S.M.,Leibniz Institute For Gewasserokologie Und Binnenfischerei |
del Giorgio P.A.,University of Quebec at Montréal |
Teodoru C.R.,University of Quebec at Montréal |
Prairie Y.T.,University of Quebec at Montréal
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2012
Surface carbon dioxide (CO 2) emissions exhibit a high degree of spatial heterogeneity in the young boreal Eastmain- 1 hydroelectric reservoir, located in northern Quebec, Canada. Estimates of the individual components of net CO 2 production within the reservoir (benthic respiration, water column respiration, and primary production) furthermore provide a link between the heterogeneity in surface CO 2 emissions and the flooded landscapes below. Specifically, the preflood carbon stock and soil-sediment respiration rates of flooded landscapes were found to influence benthic CO 2 production, the rate of decline of hypolimnetic dissolved organic carbon (DOC), and the estimated rate at which flooded landscapes release DOC, further influencing water column respiration rates. Estimates of the individual components of net CO 2 production in Eastmain- 1 are supported by a positive relationship (t test, r 2 = 0.64, P < 0.01) between measured surface CO 2 emissions (mean ± SE = 1540 ± 145.4 mg C·m -2·day -1) and independently derived estimates of total net CO 2 production (mean ± SE = 1230 ± 162.4 mg C·m -2·day -1). Our findings emphasize the utility of fundamental landscape characterization prior to construction in predicting reservoir greenhouse gas emissions.