River Clyde Fisheries Management Trust Ltd.
 

Blockages


Blockages natural/man-made. Salmonids need to migrate to spawn, adult trout or salmon will migrate upstream to the spawning grounds or redds. If their passage is obstructed it can quickly lead to a massive decrease in the numbers of juveniles which would normally be found above the barrier/blockage. Man-made obstacles such as weirs and dams can be bypassed by means of a fish ladder etc. Natural blockages such as fallen trees need to be removed manually. It is important to keep as much of the river (open to fish) if it is to remain healthy. Loss of fish populations lead to loss of predators such as otters, kingfishers and herons etc.