Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Beginning in the 1980s, return rates of Atlantic salmon (Salmo salar) to the Penobscot River, Maine, USA, declined and have persisted at low levels. This downturn coincided with similar declines in North American and European Atlantic salmon stocks and with changes in the Northwest Atlantic ecosystem. Previous studies investigated whether early marine growth explained the declines, but results varied, with decreased growth associated with declines in European stocks but not North American stocks. In this study, we evaluate whether growth over the entire marine stage is related to Atlantic salmon marine survival. We constructed a growth time series from scales of returned Penobscot River Atlantic salmon spanning periods of varying marine survival. We used analysis of variance (ANOVA) and post hoc tests to quantify seasonal growth increment differences and principal component analysis to characterize variability among the suite of growth increments. We observed reduced growth during the second winter and second marine year starting in the 1990s, with compensatory seasonal growth relationships. These results indicate that diminished growth during late marine stages is associated with low return rates in this population.

中文翻译：

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佩诺布斯科特河大西洋鲑鱼海洋生长及其与回归率关系的回顾性分析

加拿大渔业和水生科学杂志，印刷前。
从 1980 年代开始，大西洋鲑鱼（Salmo salar）返回美国缅因州佩诺布斯科特河的比率下降并一直保持在低水平。这种低迷与北美和欧洲大西洋鲑鱼种群的类似下降以及西北大西洋生态系统的变化相吻合。以前的研究调查了早期海洋生长是否解释了下降，但结果各不相同，增长下降与欧洲种群的下降有关，但与北美种群的下降无关。在这项研究中，我们评估了整个海洋阶段的生长是否与大西洋鲑鱼的海洋生存有关。我们从跨越不同海洋生存期的归来的佩诺布斯科特河大西洋鲑鱼的规模构建了一个生长时间序列。我们使用方差分析 (ANOVA) 和事后检验来量化季节性增长增量差异，并使用主成分分析来表征增长增量套件之间的变异性。我们观察到从 1990 年代开始的第二个冬季和第二个海洋年的增长减少，具有补偿性季节性增长关系。这些结果表明，晚期海洋阶段的生长减少与该种群的低回归率有关。