Barlaup Bjørn T, Rund Hans, Normann Eirik S, Stranzl Sebastian, Mahlum Shad, Vollset Knut W
Unit Research Environment, LFI - Freshwater Biology, Bergen, Norway.
University of Natural Resources and Life Sciences, Vienna.
J Fish Biol. 2018 Sep;93(3):455-464. doi: 10.1111/jfb.13648.
Floating passive-integrated transponder (PIT) antennae and smolt traps were used to study the time of sea entry and relative recapture of wild and hatchery-reared Atlantic salmon Salmo salar smolt released below and above a lake formed in the Vosso River. In total, 8.4 and 4.1% of the tagged wild and hatchery fish, respectively, were detected leaving the river (i.e. sea entry). Wild smolts released below the lake were detected leaving the river 16 days before smolts released above the lake, which also showed a 52% lower probability of detection during out-migration. Hatchery smolts were out of sync with the wild smolts and were detected approximately 2 months later than the wild smolts from both release locations, with an 84% lower likelihood of detection than wild fish. Size selection was evident for wild fish released above the lake, but not below the lake, with an overall likelihood of detection increasing by 2.6% per cm total length (L ). Wild fish caught in the tributaries and transported to the main river had a 64% lower likelihood of detection than fish caught and released in the main river. This study demonstrates that floating PIT antennae out-performed the traditional rotary screw trap in the ability to detect tagged smolts and that it is an efficient tool for evaluating the time of sea entry of S. salar smolts in a large river system.
使用漂浮式无源集成应答器（PIT）天线和银大麻哈鱼诱捕器，研究了野生和孵化养殖的大西洋鲑（Salmo salar）银大麻哈鱼在沃索河形成的湖泊上下游放流后进入海洋的时间和相对回捕情况。总共分别检测到8.4%的带标记野生鱼和4.1%的带标记孵化养殖鱼离开河流（即进入海洋）。在湖泊下游放流的野生银大麻哈鱼比在湖泊上游放流的银大麻哈鱼提前16天被检测到离开河流，并且在洄游期间被检测到的概率也低52%。孵化养殖的银大麻哈鱼与野生银大麻哈鱼不同步，比来自两个放流地点的野生银大麻哈鱼晚约2个月被检测到，被检测到的可能性比野生鱼低84%。对于在湖泊上游放流的野生鱼，存在明显的大小选择，但在湖泊下游则没有，总体被检测到的可能性随全长每厘米（L）增加2.6%。在支流中捕获并运输到主河道的野生鱼被检测到的可能性比在主河道中捕获并放流的鱼低64%。这项研究表明，漂浮式PIT天线在检测带标记银大麻哈鱼的能力方面优于传统的旋转螺旋诱捕器，并且它是评估大型河流系统中大西洋鲑银大麻哈鱼进入海洋时间的有效工具。
