European silver eel (Anguilla anguilla L.) migration behaviour in a highly regulated shipping canal

• Published in: Fisheries Research
• Main Authors: Verhelst, Pieterjan, Bayens, Raf, Reubens, Jan, Benitez, Jean-Philippe, Coeck, Johan, Goethals, Peter, Ovidio, Michaël, Vergeynst, Jenna, Moens, Tom, Mouton, Ans
• Other Authors: FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège, AFFISH-RC - Applied and Fundamental FISH Research Center - ULiège
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2018
• Subjects: Diadromous; Canal; Migration; Water regulation; shipping locks; Life sciences; Environmental sciences & ecology; Sciences du vivant; Sciences de l’environnement & écologie; Anguilla anguilla
• Online Access: https://orbi.uliege.be/handle/2268/223921; https://doi.org/10.1016/j.fishres.2018.05.013

peer reviewed Among the many man-made structures that facilitate shipping, navigable canals take an important position. These canals may offer energetically favourable migration routes for diadromous fish, but they may also obstruct fish migration, for instance at shipping locks. Because the use of shipping canals by, and their effects on, mi- grating fish remain unknown, we assessed whether these canals can play a significant role in the migration of the critically endangered European eel. Only one third of 70 acoustically tagged silver eels completed migration through a shipping canal, and did so at a very low pace (average < 0.06 m s−1) due to delays at shipping locks and most likely also due to the disruption of water flow. These delays may come at an energetic cost, hampering the chances of successful migration. Knowledge on the impact of shipping canals on diadromous fish is crucial for proper management regulations. For instance, the observation that eels mostly migrated at night and during spring and autumn can support water managers to define adequate measures to improve eel migration in shipping canals.