Until recently, the main reason for removing dams was to restore salmon runs, but it is now recognized that a more important reason to remove dams is that they are no longer safe.

直到近期，拆除大坝主要还是为了恢复鲑鱼的数量，但现在人们认识到，拆除大坝的一个更重要的原因是这些大坝已不再安全了。