Fishing through (and up) Alaskan food webs
Fishing through (and up) Alaskan food webs
复制标题
通过（及向上）阿拉斯加食物网捕鱼
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
D. Urban
中科院分区：
文献类型：
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作者：
Michael A. Litzow;D. Urban
我们使用了112年的阿拉斯加渔业渔获量的时间序列来测试竞争的假设，平均渔获量的趋势，营养级，渔业可持续性的一个广泛使用的指标。我们发现，平均营养级一般保持稳定或增加，在最近几十年在阿拉斯加州范围内和区域尺度上，表明稳定的渔获量高营养级类群。在平均营养级下降的历史时期，上层营养级类群的渔获量增加或保持稳定，与“沿食物网捕鱼”假说的预测相反。此外，在20世纪40年代和70年代，气候指数与平均营养级和（或）相关渔业平衡（FIB）指数在气候制度转变中高度相关（r = 0.69-0.97），这表明气候影响，特别是对高营养级类群的影响，可以作为这些参数变化的主要驱动因素。这些结果提供了一个对比的看法，普遍下降的平均营养级的渔业渔获量，…
We used a 112-year time series of Alaskan fishery catches to test competing hypotheses concerning trends in mean catch trophic level, a widely used indicator of fisheries sustainability. We found that mean trophic level has generally remained steady or increased in recent decades on Alaska-wide and regional scales, indicating stable catches of high trophic level taxa. During historical periods of declining mean trophic level, catches of upper trophic level taxa either increased or remained steady, contrary to the predictions of the “fishing down the food web” hypothesis. Further, a climate index was highly correlated (r = 0.69–0.97) with mean trophic level and (or) the related fisheries in balance (FIB) index across climate regime shifts in the 1940s and 1970s, indicating that climate effects, particularly on high trophic level taxa, can act as the major driver of variability in these parameters. These results provide a contrast to the view of ubiquitous declines in mean trophic level of fishery catches, ...