FISHGUARD: Impact assessment and remediation of anthropogenic interventions on fish populations



Habitat fragmentation and its threat to biodiversity, the core of this project, have risen to high prominence on the (inter)national agenda. Hence, the number of conventions, agreements and amendments has grown steadily. In these agreements, the emphasis is put on the need for preserving biodiversity, at the species, subspecies, variety and population levels, because of their ecological, genetic, social, economic, scientific, educational, cultural, recreational and aesthetic value. More specifically concerning freshwaters, the restoration of water quality and hydromorphology of water courses, and the maintenance or restoration of longitudinal and lateral connectivity are central themes of two international directives and decree: the European Water Framework Directive and the Benelux Decree M 96, with deadlines set for 2015 and 2010 respectively.

Project description


The disruption of longitudinal connectivity by man-made obstacles and the stocking of fish communities with non-indigenous species or genotypes may threaten the fish fauna of Belgian rivers to various extents. Obstacles impede migrations between habitats that are vital for populations and they may restrict the gene flow between populations, thereby reducing the effective size and genetic diversity of populations and increasing the risk of local extinction. Stocking programmes often involve the introduction of non-indigenous genotypes in native populations. It frequently leads to accidental introductions of non-indigenous fish species and may as such enhance the expansion of alien species. Although stocking programmes lead to the temporal and superficial enrichment of local fish communities or gene pools, they generally result in a loss of biodiversity on a regional or international scale through the homogenisation of communities and the breakdown of genetic differentiation between populations.

This project aims at assessing the impact of these factors and provide tools for priorisation and remediation, through a three-step approach:

(1) a descriptive field survey including genetic analysis,
(2) a study investigating the swimming and leaping capacities of local fish species,
(3) and a study of actual migration of fish in the field.


A descriptive field survey of fish diversity in the vicinity of various types of artefacts that are representative of the southern, upland and northern, lowland parts of Belgium will be conducted. It comprises analyses at the fish community level and at the genetic level for target species (brown trout, bullhead, roach, three-spine stickleback) that are representative of river systems and have undergone contrasting histories of restocking. Genetic analyses with hypervariable microsatellites will be conducted on specimens from the field and on stocks used for restocking in order to measure the impact of the stocking and of obstacles on the gene flow.

The ecophysiology of movement (swimming and leaping capacity of fish) will be determined under controlled conditions in the laboratory. The critical swimming speed of fish will be measured in respiratory swimming chambers. Theoretical leaping curves will be produced and evaluated in a large flume mimicking a culvert. Energy expenditure associated with swimming and leaping will be determined. Experimental data will be used to develop species-specific predictive models to be validated and evaluated in field situations.

Capacities of fishes to cross man-made obstacles will be measured with telemetry (PIT and radio telemetry) in actual field conditions in a section of the river systems under study, both to test the predictions of laboratory models, and to cast light on how the obstacles eventually affect the gene flow. Fishes implied in the telemetry and energy studies will be genotyped to assess their origin and their status in the genetic structure of the population.

Interaction between different partners

The different partners are very dependent on each others performance and interact during the whole duration of the project. For example, IBW-IN and ULg are responsible for the analysis of fish populations in the chosen model systems in the field: presence, size, condition and sex ratio will be determined and analysed. The physical properties of the barriers will be assessed by RUCA-AWZ. During these same field trips samples will be taken for the genetic analysis, research to be conducted by the KULeuven and the UCL. Fish will also be tagged or provided with telemetry tags which allows to follow fish migration in the field (IBW-IN and ULg), and fish will be taken to the laboratory to assess their swimming and leaping capacities (RUCA-AWZ). The outcome will be a model predicting the capacity of fish species to cross barriers (RUCA-AWZ), which can then be validated by both the results from the tagging expeditions (IBW-IN and ULg) and the genetic analysis (KULeuven and UCL).

Expected results and/or products

Laboratory and field results will be integrated in order to produce user-friendly tools for predicting the severity of obstacles and stocking practices, and determining the priorities for preservation and remediation. The project will result in (1) extensive datasets that can be used for future research, (2) user-friendly tools (a manual and software) that allow end-users and other stakeholders to assess, mitigate and prevent problems related to fish migration and stocking programmes, and (3) a policy document, where general as well as specific suggestions and advices are formulated to the address of managers, political authorities and decision-makers.



The Ecophysiology, Biochemistry and Toxicology lab (RUCA) performs fundamental and applied research in environmental and adaptational biology. The Hydraulic Laboratory (AWZ) is specialised in hydraulic research. The Institute for Forestry and Game Management (IBW) is responsible for scientific research and services in greenery, forests, fauna, fish stock and their management in Flanders. They co-operate with the Institute of Nature Conservation (IN). The Laboratory of Aquatic Ecology (KULeuven) focuses community-ecology of aquatic organisms, population ecology and population genetics. The Unit in Genetics (UCL) is specialised in statistical genetics i.e. application of statistical and model-based approaches to genetical data. The Laboratory of Fish Demography and Hydroecology (ULg) is specialised in the study of fish populations and migrations.

Contact Information


Ronny Blust and Gudrun De Boeck
Universiteit van Antwerpen (RUCA)
Ecophysiology, Biochemistry and Toxicology
Groenenborgerlaan 171
B-2020 Antwerp
Tel: +32 (0)3 218 03 47
Fax: +32 (0)3 218 04 97


Hilde Verbiest and Daniel De Charleroy
Institute for Forestry and Game Management (IBW)
Duboislaan 14
B-1560 Hoeilaart
Tel: +32 (0)2 657 03 86
Fax: +32 (0)2 657 96 82

Filip Volckaert
Katholieke Universiteit Leuven (KULeuven)
Laboratory of Aquatic Ecology
Ch. De Bériotstraat 32
B-3000 Leuven
Tel: +32 (0)16 /32 37 17
Fax: +32 (0)16 32 45 75

Philippe Baret
Université Catholique de Louvain (UCL)
Unit in Genetics, Faculty of Bio-engineering, Agronomy and Environment
2, croix du Sud, box14
B-1348 Louvain-la-Neuve
Tel: +32 (0)10 47 37 23
Fax: +32 (0)10 47 37 28

Jean-Claude Philippart
Université de Liège (ULg)
Laboratory of Fish Demography and Hydroecology
10, chemin de la Justice
B-4500 Tihange
Tel: +32 (0)85 27 41 55
Fax: +32 (0)85 23 05 92


Peter Viaene
Hydraulic Laboratory and Hydrological Research Division (AWZ)
Berchemlei 115
B-2140 Borgerhout
Tel: +32 (0)3 224 60 35
Fax: +32 (0)3 224 60 36

Johan Coeck
Institute for Nature Conservation (IN)
Kliniekstraat 25
B-1070 Brussels
Tel: +32 (0)2 558 18 11
Fax: +32 (0)2 558 18 05

Users Committee

J.P. Heirman - Ministry of Flanders (AMINAL)
K. De Smet - Fisheries Fund
P. Gerard - Ministry of the Walloon Community (Nature, Game and Fisheries)
W. Graré & L. Meyvi s - Ministry of Flanders (Sea Scheldt)
E. Dupont - Ministry of the Walloon Community
V. Van Den Langenbergh - Flemish Environmental Company
P. Symen - Natuurpunt


ecophysiology, fish, freshwater, genetics, model, obstacles, population, SPSD II, PODO II, PADD II, EV31


National {Cooperation status}
Belgium {Geographical scope}
Inland Waters {Habitat type}
Ecosystem Services {Tags}


Name Role Amount
Science for Sustainable Development unknown


Name Role Start End
De Charleroy, Daniel member 2003-01-01 2006-04-01
Verbiest, Hilde member 2003-01-01 2006-04-01
Volckaert, Filip member 2002-01-01 2006-04-01
Baret, Philippe member 2003-01-01 2006-04-01
Philippart, Jean-Claude member 2003-01-01 2006-04-01
De Boeck, Gudrun co-promotor 2003-01-01 2006-04-01
Blust, Ronny co-promotor 2003-01-01 2006-04-01


Name Role Start End
Ecophysiology, Biochemistry and Toxicology leader 2003-01-01 2006-04-01
Biotoopherstel member 2003-01-01 2006-04-01
Behoud en bescherming van autochtone vissoorten member 2003-01-01 2006-04-01
Unité de génétique member 2003-01-01 2006-04-01
Laboratoire de démographie des poissons et hydroécologie member 2003-01-01 2006-04-01
Laboratory of Aquatic Ecology and Evolutionary Biology member 2002-01-01 2006-04-01

created:2011-12-14 14:18:59 UTC, source:web

© 2012 by the Belgian Biodiversity Platform