Cardiff Bay fish pass
Cardiff Bay fish pass
The Cardiff Bay barrage incorporates a fish pass to allow salmon and sea trout to return to the rivers Taff and Ely. It is one of the most advanced of its kind in Europe. Underwater cameras and motion and audio equipment record the passage of fish through the Pass.
The river Taff has been stocked with salmon since the 1980s. For decades the river had been polluted by the coal and other industries. Abstraction of water for industrial uses also made the river inhospitable to fish such as salmon and sea trout. The river has become cleaner with the decline of heavy industry and intervention to improve water quality.
The barrage across the mouths of the rivers Taff and Ely cut off the route mature salmon were starting to use to return to their nurseries up the river. To overcome this, a channel with a series of pools was constructed. Freshwater from the lagoon behind the barrage flows from one pool to the next, providing a route for salmon to return home to spawn. Salmon can jump considerable heights over natural weirs. Some Taff salmon are tagged as juveniles so that scientists can record how many fish return.
Website of Cardiff Harbour Authority