Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Recent decline in abundance of Atlantic salmon (Salmo salar) and concomitant changes in life history may result from a decline in the growth conditions during marine migration. Available literature suggests the existence of a sex-specific reaction norm linking maturation with environmental growth conditions at sea. However, the extent to which this mechanism explains variations in age at maturity remains unclear. Using a historical collection of scales (1987–2017) from the Sélune River, France, we showed that marine growth declined over the first summer and remained stable during the subsequent periods at sea among returning salmon. Results support the hypothesis of a sex-specific probabilistic reaction norm, with individual probability to return after 1 year at sea increasing when growth increases. Females may require higher growth than males to attain their maturation threshold. This mechanism is a good candidate to explain temporal variability in sea-age at return at both the individual and population level in the Sélune population and in many other southern European populations.

中文翻译：

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第一个夏季海上的生长调节了大西洋鲑鱼特定性别的成熟时间表

《加拿大渔业和水生科学杂志》，印刷前。
近来大西洋鲑鱼（Salmo salar）的丰度下降以及生活史的随之变化，可能是由于海洋迁移过程中生长条件的下降所致。现有文献表明，存在着一种性别特异性反应规范，该规范将成熟度与海上环境生长条件联系起来。但是，该机制解释成熟期年龄变化的程度仍不清楚。我们使用法国塞鲁纳河（SéluneRiver）的历史规模（1987-2017）进行收集，结果表明，在返回的鲑鱼中，海洋生长在第一个夏季下降，并在随后的海上保持稳定。结果支持了针对性别的概率反应规范的假设，随着增长的增加，在海上航行1年后返回的个体概率也随之增加。为了达到成熟阈值，女性可能需要比男性更高的生长速度。该机制是解释塞伦岛人口和许多其他南欧人口在个人和人口水平上返回时海域时间变化的很好的候选者。