A model of navigation-induced currents in inland waterways and implications for juvenile fish displacement

Rezensierter Artikel

The likely extension of commercial inland navigation in the future could increase hazards directly impacting on the nurseries of freshwater fish, especially for smaller individuals with limited swimming abilities. One limitation of the evaluation of inland navigation on fish assemblages is the lack of suitable hydraulic models. This article presents a hydraulic model to assess the increase of navigation-induced physical forces due to higher vessel speed, length, and drought in alow-flowing waterway related to maximum swimming performance of fish to (1) fore see hazards of enhancement of inland navigation, (2) derive construction measures to minimize the hydraulic impact on small fish, and (3) improve fish recruitment in waterways. The derived model computed current velocities induced by passing commercial vessels in inland waterways experimentally verified and parameterized in a German lowland waterway. Results were linked with a model of maximum fish swimming performance to elucidate consequences for freshwater fish populations. The absolute magnitude of navigation-induced current limits the availability of littoral habitats for small fish. Typical navigation-induced current velocities of 0.7–1 m/s in the straight reaches of waterways will be maintained by fish longer than 42 mm only. Smaller juveniles unable to with stand those current scould become washed out, injured, or displaced. In contrast, in small local bays, the navigation-induced current declined significantly. According to our model, in a 20-m extended bay, the return current drops below 0.11 m/s, corresponding to the maximum swimming speed of a 9-mm-long fish. Thus, enhancing shoreline development by connecting oxbows, tributaries, and especially by purpose-built bays limits the impact on fish recruitment without restricting navigation resulting in more precautionary and sustainable inland navigation.

Wolter, C., Arlinghaus, R., Sukhodolov, A., Engelhardt, C. (2004). A model of navigation-induced currents in inland waterways and implications for juvenile fish displacement. Environmental Management, 34, 656-668


Veröffentlicht : 2004
Erschienen in : Environmental Management, 34, 656-668