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首页> 外文期刊>Estuarine Coastal and Shelf Science >Faunal shift in southern California's coastal fishes: A new assemblage and trophic structure takes hold
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Faunal shift in southern California's coastal fishes: A new assemblage and trophic structure takes hold

机译：加利福尼亚南部沿海鱼类的动物迁移：新的组合和营养结构得以确立

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Trends in coastal fish abundance indices were examined using a novel 39-year (1972-2010) time series recorded at southern California coastal power plants. Since 1972, the annual mean abundance index significantly declined (r~2 = 0.45, p < 0.001). The mean annual biomass index likewise declined but with a large interruption in 2005-2006 when an influx of large bodied, southern species increased the annual means. Ensemble mean abundance indices for fished and unfished species declined at similar rates. Two faunal shifts were identified, 1983-1984 and 1989-1990. The ensemble mean, annual entrapment rate abundance index during the current period (1990-2010) represents only 22% of that recorded during the first and most abundant period, 1972-1983. The mean biogeographic distribution of the assemblage was non-linear over time including a shift south during the 1980s through the 1990s before shifting north in recent years. The northern shift in recent years accompanied higher variability than previously recorded and was likely related to the overall low abundance. Since the early 1980s, the mean trophic level derived from abundance declined. The observed patterns were not correlated with commonly employed composite indices such as the Pacific Decadal Oscillation, but did show some sensitivity to changes in coastal seawater temperature and density over time. Timing of the observed faunal shifts in the fish assemblage was consistent with reported oceanographic shifts. These data suggested factors beyond fishing, such as oceanographic change, have substantially impacted the coastal fishes of southern California.
机译：使用在加利福尼亚南部沿海发电厂记录的新颖的39年（1972-2010年）时间序列，研究了沿海鱼类丰度指数的趋势。自1972年以来，年平均丰度指数显着下降（r〜2 = 0.45，p <0.001）。年均生物量指数同样下降，但在2005-2006年间出现了较大的中断，当时大量南方南方有名的物种增加了年均值。集合的平均可捕捞和未捕捞物种指数以相似的速度下降。确定了两个动物区系转移，分别是1983-1984年和1989-1990年。在当前时期（1990年至2010年）的总体平均年滞留率丰度指数仅占第一个也是最丰富的时期（1972年至1983年）记录的22％。该组合的平均生物地理分布随时间呈非线性变化，包括在1980年代至1990年代向南移动，然后在近年来向北移动。近年来的北方变化伴随着比以前记录的更高的变异性，可能与总体低丰度有关。自1980年代初以来，源自丰富度的平均营养水平下降了。观测到的模式与常用的综合指数（如太平洋年代际涛动）不相关，但确实显示出对沿海海水温度和密度随时间变化的敏感性。鱼群中观察到的动物区系变化的时间与所报告的海洋学变化相一致。这些数据表明，捕捞以外的其他因素，例如海洋学变化，已对加利福尼亚南部的沿海鱼类产生了重大影响。

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