IMIS | Flanders Marine Institute

Flanders Marine Institute

Platform for marine research



Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ] Printer-friendly version

Impact assessment and remediation of anthropogenic interventions on fish populations

More:  Institutes | Dataset 
Dutch title: Invloed en herstel van antropogene ingrepen op vispopulaties
Parent project: Research action SPSD-I: Sustainable management of the North Sea, more
Reference no: EV/31; 526
Period: January 2003 till April 2006
Status: Completed

Thesaurus terms: Fish; Man-induced effects
Taxonomic terms: Gasterosteus aculeatus Linnaeus, 1758 [WoRMS]; Rutilus Rafinesque, 1820 [WoRMS]; Salmo trutta fario Linnaeus, 1758 [WoRMS]
Geographical term: Belgium [Marine Regions]

Institutes (7)  Top | Dataset 

  • Context

    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

    • Objectives

      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.

    • Methodology

      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 differe

Dataset  Top | Institutes 
  • FISHGUARD: Fishguard Fish Migration Data, more

 Top | Institutes | Dataset