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首页> 外文期刊>San Francisco Estuary and Watershed Science >Delta Flow Factors Influencing Stray Rate of Escaping Adult San Joaquin River Fall-Run Chinook Salmon ()
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Delta Flow Factors Influencing Stray Rate of Escaping Adult San Joaquin River Fall-Run Chinook Salmon ()

机译：影响逃离成年圣华金河秋千奇努克鲑鱼杂散率的三角洲流量因子（）

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Adult salmon that stray when they escape into non-natal streams to spawn is a natural phenomenon that promotes population growth and genetic diversity, but excessive stray rates impede adult abundance restoration efforts. Adult San Joaquin River (SJR) Basin fall-run Chinook salmon (Oncorhynchus tshawytscha) that return to freshwater to spawn migrate through the San Francisco Bay and Sacramento–San Joaquin River Delta (Delta). The Delta has been heavily affected by land development and water diversion. During the fall time-period for the years 1979 to 2007 Delta pumping facilities diverted on average 340% of the total inflow volume that entered the Delta from the SJR. The hypothesis tested in this paper is that river flow and Delta exports are not significantly correlated with SJR salmon stray rates. Adult coded-wire-tagged salmon recoveries from Central Valley rivers were used to estimate the percentage of SJR Basin salmon that strayed to the Sacramento River Basin. SJR salmon stray rates were negatively correlated (P = 0.05) with the average magnitude of pulse flows (e.g., 10 d) in mid- to late-October and positively correlated (P = 0.10) with mean Delta export rates. It was not possible to differentiate between the effects of pulse flows in October and mean flows in October and November on stray rates because of the co-linearity between these two variables. Whether SJR-reduced pulse flow or elevated exports causes increased stray rates is unclear. Statistically speaking the results indicate that flow is the primary factor. However empirical data indicates that little if any pulse flow leaves the Delta when south Delta exports are elevated, so exports in combination with pulse flows may explain the elevated stray rates. For management purposes, we developed two statistical models that predict SJR salmon stray rate: (1) flow and export as co-independent variables; and (2) south Delta Export (E) and SJR inflow (I) in the form of an E:I ratio.
机译：成年鲑鱼在逃入非幼体河流产卵时会流浪，这是自然现象，可促进种群增长和遗传多样性，但流浪率过高会阻碍成年鲑鱼丰度的恢复。成年的圣华金河（SJR）流域秋季运行的奇努克鲑鱼（Oncorhynchus tshawytscha）回到淡水中产卵，穿过旧金山湾和萨克拉曼多-圣华金河三角洲（Delta）迁移。三角洲受到土地开发和引水的严重影响。在1979年至2007年的下降期间，三角洲的抽水设施平均转移了从SJR进入三角洲的总流入量的340％。本文检验的假设是，河流流量和三角洲出口与SJR鲑鱼杂散率没有显着相关。从中央河谷河流中采集的成年带编码标签的鲑鱼被用来估算流向萨克拉曼多河流域的SJR盆地鲑鱼的百分比。 SJR鲑流浪率与10月中下旬脉冲流的平均幅度（例如10 d）呈负相关（P = 0.05），与平均三角洲出口率呈正相关（P = 0.10）。由于这两个变量之间存在共线性，因此无法区分10月的脉冲流和10月和11月的平均流对杂散率的影响。 SJR减少的脉冲流或出口增加是否会导致杂散率增加尚不清楚。从统计学上讲，结果表明流量是主要因素。但是，经验数据表明，当南部三角洲的出口增加时，几乎没有脉冲流离开三角洲，因此，出口与脉冲流结合可以解释杂散率升高。为了管理目的，我们开发了两个统计模型来预测SJR鲑鱼的流浪率：（1）流量和出口作为共同独立变量; （2）南部三角洲出口（E）和SJR流入（I）以E：I比率的形式。

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