Summary of Progress in Fish-Passage Research 1964

The development of a river system for power and flood control produces sudden, enormous changes in the environment for anadromous fish: Great dams bar passage to the sea; huge lakes replace swift-flowing rivers; spawning gravels are inundated; water temperatures are modified; predator, competitor, and disease relationships are upset; food supplies are affected. The necessity for providing safe passage of fish over the physical obstruction of dams is an obvious reality. Of equal importance is the need to protect the fish where the changes made by dams in the basic environment are too severe. All of the factors that affect the survival of anadromous fish during migration must be considered if safe passage is to be provided. The need for information is particularly critical in four major areas; progress in research in these areas are outlined