Phenology and biological traits of migrating eels sampled by trapping in the Oir river (France).

Study Extent

Elvers have been monitored since 2017.The trap is surveyed in the morning every day throughout the year on the River Oir, a tributary of the Sélune in Normandy. Silver eels have been monitored since 1983.The trap is surveyed in the morning every day throughout the year on the River Oir, a tributary of the Sélune in Normandy.

Sampling

Elvers are monitored by trapping at the Cerisel Mill, upstream trap operating the whole year. Trap configuration allows only partial capture depending on the flow which requires to estimate the effectiveness of the traps Silver eels have been monitored by trapping at the Cerisel Mill, downstream trap operating the whole year. Trap configuration allows only partial capture depending on the flow which requires to estimate the effectiveness of the traps.

Method steps

1. Since 2017, trapping of upstream-migrating elvers to the upstream parts of the Oir River has been carried out by using an eel climbing ramp, which provides the eels with a substrate (brushes) that allows them to climb a 40% slope.
2. Silver eels have been monitored since 1983 by trapping at the Cerisel Mill, downstream trap operating the whole year. Trap configuration allows only partial capture depending on the flow which requires to estimate the effectiveness of the traps.

1. Anguilla anguilla (Linnaeus, 1758)
   rank: species

Coastal river in Normandy (France) http://services.sandre.eaufrance.fr/Courdo/Fiche/client/fiche_courdo.php?CdSandre=I9280600