In the Western Scheldt, pelagic fish stocks are sampled using tidal currents and traditional fishing methods.
The Western Scheldt is the only natural and open river mouth in the Delta region. The Eems Estuary in the Northern Netherlands is the only other natural fresh/brackish water transitional area in the whole country. Transitional areas from fresh to salt water are a scarce environment everywhere and, for this reason, the Western Scheldt has been designated as a European Natura 2000 area that has to be preserved in a good ecological condition.
The Western Scheldt is the access route to the ports of Vlissingen, Terneuzen and Antwerp; and to serve this function, the river has been widened and deepened to accommodate large ocean-going ships. The Western Scheldt is also the access route for fish migrating from freshwater to salt water and back as well as a spawning ground and nursery for several species of fish, some of which have a special status, including sea and river lamprey, twaite shad and anchovy. In order to assess how these fish species are faring, IMARES has set up and is running a monitoring programme that involves sampling pelagic fish stocks in a number of locations. Fishing with traditional methods every year gives an accurate impression of the trends in fish stocks in the Western Scheldt.
IMARES uses stow net fishing to take samples in the Western Scheldt, an old but ultra-efficient commercial fishing method. In this method, a fishing boat is held in position by a long anchor, while the tidal current flows through two large frame-nets attached to the side of the boat. All the fish swimming with the current are caught in the nets.