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The trouble with salmon

机译：三文鱼的麻烦

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Among the issues are deciding which salmon are in trouble, and in describing just what the trouble is. For decades the Pacific Northwest has been immersed in debate regarding the state of salmon runs in general -- and lately, of wild salmon runs inparticular. Since enactment of the Northwest Power Act in 1980, an estimated 4 billion dollar has been spent to restore diminished Columbia River fish runs. Most observers consider the results disappointing. Except for a spasmodic burst of record-level runs last year and this year, many species of wild fish continue to decline or remain significantly below target levels of recovery. Columbia River salmon runs once were reckoned the largest in the world. Before 1850, an estimated 10-16 million wild adultsalmon returned from the ocean tO the Columbia Basin each year. Today's runs are significantly reduced, something on the order of one-fifth to one-eighth of historic levels. Furthermore, only 20 percent or so of the present diminished runs are considered "wild fish;" the remainder come from hatcheries. Declining fish runs in the Columbia Basin are not a recent phenomenon. Estimates indicate that 60 to 90 percent of the decline in salmon runs since the mid-19th Century occurred before the 1930s when Bonneville Dam, the first major dam across the Columbia River, was constructed.
机译：其中的问题是确定哪种鲑鱼遇到了麻烦，以及在描述问题出在什么方面。几十年来，西北太平洋地区一直在围绕鲑鱼运行状况进行辩论，最近，野生鲑鱼运行尤其如此。自从1980年颁布《西北电力法》以来，估计已花费40亿美元来恢复减少的哥伦比亚河鱼道。大多数观察者认为结果令人失望。除了去年和今年的创纪录水平的突飞猛进之外，许多野生鱼类物种继续减少或仍大大低于恢复的目标水平。哥伦比亚河鲑鱼曾经一度被认为是世界上最大的鲑鱼。 1850年之前，每年大约有10-16百万只野生成年鲑从海洋返回哥伦比亚盆地。今天的运行大大减少，大约是历史水平的五分之一到八分之一。此外，在目前减少的游程中，只有20％左右被认为是“野生鱼”;其余的来自孵化场。哥伦比亚盆地的鱼类游走下降不是最近的现象。据估计，自19世纪中叶以来，鲑鱼数量下降了60％至90％，发生在1930年代之前，即横跨哥伦比亚河的第一座主要水坝Bonneville大坝。

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