Evidence for size-selective mortality after the first summer of ocean growth by pink salmon
Evidence for size-selective mortality after the first summer of ocean growth by pink salmon
复制标题
DOI：
10.1577/t05-054.1
复制
发表时间：
2005-09-01
影响因子：
1.4
通讯作者：
Helle, JH
中科院分区：
文献类型：
--
作者：
Moss, JH;Beauchamp, DA;Helle, JH
2001 年，威廉王子湾孵化场放归的粉红鲑鱼 Onchorhynchus gorbuscha 带有可识别的热耳石痕迹，用于检验这样的假设：在海洋中的第一个夏天，生长较快的鱼比生长较慢的鱼有更高的存活率。每月在威廉王子湾和阿拉斯加湾对带有标记的幼年粉红鲑鱼进行采样，并于次年在孵化场释放地点回收存活至成熟的成体。与在第一个海洋夏季期间在海上收集的幼鱼相比，幸存的鱼类在早期海洋居住期间形成的鳞片区域表现出明显更宽的环间距，这表明第一个生长季节后的海洋生存与早期海洋生长的增加有关。在相同的循环中，返回的成鱼的平均尺度半径明显大于来自同一孵化场的幼鱼，这表明较大、生长较快的幼鱼具有较高的存活率，并且在对幼鱼进行取样后发生了显着的尺寸选择性死亡率。根据不同孵化场释放组之间的圆环间距推断出的生长模式各不相同，这表明密度依赖过程在释放组之间存在差异，并且发生在威廉王子湾和阿拉斯加沿海湾。这些观察结果支持了其他研究，这些研究发现体型较大、生长速度较快的鱼类更有可能存活到成熟。
Pink salmon Onchorhynchus gorbuscha with identifiable thermal otolith marks from Prince William Sound hatchery release groups during 2001 were used to test the hypothesis that faster-growing fish during their first summer in the ocean had higher survival rates than slower-growing fish. Marked juvenile pink salmon were sampled monthly in Prince William Sound and the Gulf of Alaska, and adults that survived to maturity were recovered at hatchery release sites the following year. Surviving fish exhibited significantly wider circuli spacing on the region of the scale formed during early marine residence than did juveniles collected at sea during their first ocean summer, indicating that marine survival after the first growing season was related to increases in early marine growth. At the same circuli, a significantly larger average scale radius for returning adults than for juveniles from the same hatchery would suggest that larger, faster-growing juveniles had a higher survival rate and that significant size-selective mortality occurred after the juveniles were sampled. Growth patterns inferred from intercirculi spacing on scales varied among hatchery release groups, suggesting that density-dependent processes differed among release groups and occurred across Prince William Sound and the coastal Gulf of Alaska. These observations support other studies that have found that larger, faster-growing fish are more likely to survive until maturity.