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人类为了充分利用河流,不断地修建大坝,用它来蓄水、灌溉、发电……但这些大坝却成为了鲑鱼迁徙路上的障碍。人们试过很多种办法,比如修建鱼专用楼梯、请鱼坐电梯,甚至动用直升机来帮助它们。但这些方法费时费力又费钱。有没有更好的办法呢?逆流而上鲑鱼在淡水中生活1~5年后,会游向大海中生活2~4年,之后再从大海逆流而上回归故乡,到达上游平静的湖水中产卵。在逆游途中,它们不仅要克服水流的阻力,闯过逐渐增高的地形,还要跳过小型瀑布和堤坝。这一路上
In order to make full use of rivers, human beings continue to build dams that use it for water storage, irrigation and electricity generation. However, these dams have become barriers to the salmon migration. People tried many kinds of methods, such as building fish-only staircases, asking fish to take the elevator and even using helicopters to help them. However, these methods are time-consuming and expensive. There is no better way to counter-current upstream salmon freshwater life in 1 to 5 years, will swim to the sea for 2 to 4 years, and then return home from the sea upstream, reaching the upper reaches of the quiet lake in the middle class egg. On the reverse journey, they not only overcome the resistance of the water flow, pass through the gradually increasing topography, but also skip small waterfalls and dikes. This way