Throughout their life-cycle, fish use different types of habitats. A healthy fish stock is the result of excellent habitats and a proper interchange between the main habitats. Wageningen Marine Research carries out research into fish migration in Dutch waters. Our expertise in fish behaviour enables us to advise on what alterations in sluices, dams and water power plants are most effective in promoting fish migration.
Barriers for fish
Migration between habitats is crucial to all species of fish, from salmon to bream and from eel to zander. Fish migration is often hindered by artificial barriers such as dams and pumping stations. Fish are often not, or only with great difficulty, able to pass these artificial constructions, which may lead to the following issues:
- Closing of migration routes, preventing fish from reaching needed habitats
- Fish injured or killed through pumping stations
- Compartmentalising of habitats, resulting in areas too small for the fish population
- Too little interchange between fish populations, which negatively impacts the vitality of the fish population.
Focus on unhindered fish migration
Water, nature and fish stock management agencies focus on fish migration. This includes the European Water Framework Directive, Natura 2000 and the European Eel Plan, which all call for more focus on fish's unhindered migration. Fish migration facilities are constructed in an increasing number of places, ranging from fish stairs in creeks and rivers to a fish migration river in the Afsluitdijk.
- Advanced equipment and infrastructure to study fish behaviour, such as telemetry systems (transmitters and receivers: VEMCO, PIT) and acoustic equipment (DIDSON)
- Extensive expertise on fish behaviour
- Monitoring of, and data on, fish migration
- Expertise on the role of fish migration in the natural recovery of fish populations