国外洄游性鱼类(鲑、鳟、鳗、鲟等)经济价值较高。他们都按一定的规律在河海之间洄游、繁殖、生长。在河流中修建水利枢纽就会截断这些鱼类的洄游通道而造成严重减产,甚至绝迹。下面简单介绍美国、加拿大、苏联、日本等国解决这个问题的技术措施和发展趋向。一、过鱼建筑物美国、加拿大位于北美,西临太平洋。西海岸河流中的洄游性鱼类主要有鲑、铜头 Foreign migratory fish (salmon, trout, eel, sturgeon, etc.) higher economic value. They all migrate, multiply and grow in rivers and seas according to certain rules. The construction of a water control hub in a river will cut off the migratory routes of these fish species and cause serious cuts or even extinctions. The following brief introduction of the United States, Canada, the Soviet Union, Japan and other countries to solve this problem technical measures and development trends. First, over the fish buildings in the United States, Canada is located in North America, west Pacific. Migratory fish in the West Coast rivers are mainly salmon and copper heads