Modelling the migration opportunities of diadromous fish species along a gradient of dissolved oxygen concentration in a European tidal watershed
Maes, J.; Stevens, M.; Breine, J. (2007). Modelling the migration opportunities of diadromous fish species along a gradient of dissolved oxygen concentration in a European tidal watershed. Est., Coast. and Shelf Sci. 75(1-2): 151-162. dx.doi.org/10.1016/j.ecss.2007.03.036
In: Estuarine, Coastal and Shelf Science. Academic Press: London; New York. ISSN 0272-7714; e-ISSN 1096-0015, more
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| Keywords |
Aquatic sciences > Freshwater sciences > Ecology > Freshwater ecology
Behaviour > Migration
Behaviour > Migrations
Chemical elements > Nonmetals > Atmospheric gases > Oxygen > Dissolved gases > Dissolved oxygen
Diadromy
Dissolved chemicals
Perturbations > Tidal perturbation
Pollution > Water pollution
Products > Animal products > Products > Fish products > Products > Fish
Watersheds
ANE, Netherlands, Westerschelde [Marine Regions]; Belgium, Zeeschelde [Marine Regions]
Marine/Coastal; Brackish water; Fresh water |
| Author keywords |
fish migration; logistic model; dissolved oxygen; water pollution; freshwater tidal reach; anadromy; River Scheldt |
| Abstract |
The relationship between poor water quality and migration opportunities for fish remains poorly documented, although it is an essential research step in implementing EU water legislation. In this paper, we model the environmental constraints that control the movements of anadromous and catadromous fish populations that migrate through the tidal watershed of River Scheldt, a heavily impacted river basin in Western Europe. Local populations of sturgeon, sea lamprey, sea trout, Atlantic salmon, houting and allis shad were essentially extirpated around 1900. For remaining populations (flounder, three-spined stickleback, twaite shad, thinlip mullet, European eel and European smelt), a data driven logistic model was parameterized. The presence or absence of fish species in samples taken between 1995 and 2004 was modelled as a function of temperature, dissolved oxygen concentration, river flow and season. Probabilities to catch individuals from all diadromous species but three-spined stickleback increased as a function of the interaction between temperature and dissolved oxygen. The hypoxic zone situated in the freshwater tidal part of the estuary was an effective barrier for upstream migrating anadromous spawners since it blocked the entrance to historical spawning sites upstream. Similarly, habitat availability for catadromous fish was greatly reduced and restricted to lower brackish water parts of the estuary. The model was applied to infer preliminary dissolved oxygen criteria for diadromous fish, to make qualitative predictions about future changes in fish distribution given anticipated changes in water quality and to suggest necessary measures with respect to watershed management. |
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