Rehabilitation efforts for Atlantic salmon in the Meuse basin area : Synthesis 1983-1998

In the 1950's, Atlantic salmon had become extinct in the river Meuse basin, mainly owing to the construction of navigation weirs. In 1987, started a rehabilitation program of Atlantic salmon in Belgium. Stockings are being performed in six tributaries of the river Meuse, using eyed eggs, parr and pre-smolt obtained from foreign eggs reared in a hatchery of the 'Service de la Pêche'. By the end of 1998, 896033 young salmon have been released in the wild, especially in the river Ourthe basin. In most of the cases, the evaluation of stocking operations indicates good adaptation of parr in the tributaries where they are stocked, with autumnal 0+ parr density up to 20-30 ind. /100 m2. However, fish mortality may occur when smolts pass through the turbines of the hydropower stations in the river Meuse (5% per power plant), and most of the fish passes located downstream of Namur are not suitable for anadromous fish migration. The paper reports the results of stocking experiments, the evaluation of mortality rates in turbines and the advancement of programmes aiming at the rehabilitation of downstream and upstream migration (construction of fish migration facilities).