Telemetry tags are increasingly used in management to monitor the migration timing of Atlantic salmon smolts (Salmo salar L.). It has been postulated that (1) effects from tagging and handling may alter migration behaviour, and (2) that the selection of fish during sampling is not representative of all migrating smolts, yielding bias in migration timing estimates. In the River Dale (Vestland, Norway), five groups of wild Atlantic salmon smolts (N = 385) were tagged in April–May and recaptured in a wolf trap. Migration timing was then compared to the untagged population. Migration timing differed between tagged (12 mm PIT) and untagged fish for 4/5 groups. Only fish tagged at the first time point did not have significantly different timing of migration from untagged counterparts. The relationship between length and the timing of migration was different for initial length and length at recapture; initial length suggested earlier migration of longer fish, but the extra time spent in the river prior to migrating for smolts that were initially smaller compensated for the size difference. The tagging protocol is crucial to obtaining representative migration timing results. Smolts should be tagged as early as possible and include the entire size distribution.

中文翻译：

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验证通过遥测研究获得的鲑鱼小鲑鱼的运行时间

遥测标签越来越多地用于管理监测大西洋鲑鱼 ( Salmo salar L.)的迁移时间。据推测，(1) 标记和处理的影响可能会改变迁移行为，以及 (2) 采样期间对鱼类的选择不能代表所有迁移的小鲑鱼，从而导致迁移时间估计存在偏差。在河谷（挪威韦斯特兰），五组野生大西洋鲑鱼（N = 385) 在 4 月至 5 月被标记并在狼陷阱中重新捕获。然后将迁移时间与未标记的种群进行比较。4/5 组的标记 (12 mm PIT) 和未标记鱼的迁移时间不同。只有在第一个时间点标记的鱼与未标记的对应物没有显着不同的迁移时间。初始长度和重新捕获长度的长度与迁移时间之间的关系不同；初始长度表明较长的鱼较早洄游，但在洄游之前在河流中度过的额外时间，最初较小的小鱼弥补了大小差异。标记协议对于获得具有代表性的迁移计时结果至关重要。应尽早标记小鲑鱼并包括整个尺寸分布。