Study

Assessment of the entering stock, migration dynamics and fish pass fidelity of European eel in the Belgian Meuse River

  • Published source details Nzau Matondo B., Benitez J.P., Dierckx A., Philippart J.C. & Ovidio M. (2017) Assessment of the entering stock, migration dynamics and fish pass fidelity of European eel in the Belgian Meuse River. River Research and Applications, 33, 292-301.

Actions

This study is summarised as evidence for the following.

Action Category

Install pool-and-weir fish passes

Action Link
Eel Conservation in Inland Habitats

Install vertical-slot fish passes

Action Link
Eel Conservation in Inland Habitats
  1. Install pool-and-weir fish passes

    A study in 2013 in a river near Visé, Belgium (Nzau Matondo et al. 2017) reported that a pool-and-weir pass at a hydropower dam was used by more European eels Anguilla anguilla to travel upstream than a vertical-slot pass. Unless stated, statistical significance was not assessed. Over six months, 271 eels (196–765 mm long) were captured in the pool-and-weir fish pass, whereas 164 eels (261–836 mm long) were captured in the vertical-slot fish pass. After tagging and releasing the captured eels downstream, there was no significant difference in the number of tagged eels passing through the two types of fish pass for a second time (pool-and-weir: 84 eels detected, 11 eels recaptured; vertical-slot: 60 eels detected, 16 eels recaptured). Alongside a dam at a hydropower station, a pool-and-weir fish pass (48 m long) was installed in 1980 and a vertical-slot fish pass (305 m long) in 1998. From April to September 2013, eels were captured in two cone traps in the-pool-and-weir pass and eight net traps in the vertical-slot pass. The vertical-slot pass had higher discharge, larger pools and deeper slots than the pool-and-weir pass (see paper for details). Captured eels were radio-tagged, released 0.3 km downstream of the dam and either recaptured or detected with an antenna upstream of each fish pass. 

    (Summarised by: Vanessa Cutts)

  2. Install vertical-slot fish passes

    A study in 2013 in a river near Visé, Belgium (Nzau Matondo et al. 2017) reported that a vertical-slot pass at a dam was used by fewer European eels Anguilla anguilla to travel upstream than a pool-and-weir pass. Unless stated, statistical significance was not assessed. Over six months, 164 eels (261–836 mm long) were captured in the vertical-slot fish pass, whereas 271 eels (196–765 mm long) were captured in the pool-and-weir fish pass. After tagging and releasing the captured eels downstream, there was no significant difference in the number of tagged eels passing through the two types of fish pass for a second time (vertical slot: 60 eels detected, 16 eels recaptured; pool-and-weir: 84 eels detected, 11 eels recaptured). Alongside a dam at a hydropower station, a pool-and-weir fish pass (48 m long) was installed in 1980 and a vertical-slot fish pass 305 m long) was installed in 1998. From April to September 2013, eels were captured in two cone traps in the-pool-and-weir pass and eight net traps in the vertical-slot pass. The vertical-slot pass had higher discharge, larger pools and deeper slots than the pool-and-weir pass (see paper for details). Captured eels were radio-tagged, released 0.3 km downstream of the dam and either recaptured or detected with an antenna upstream of each fish pass. 

    (Summarised by: Vanessa Cutts)

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