The relationship between migration speed and release date for chum salmon Oncorhynchus keta fry exiting a 110-km northern Japanese river
The relationship between migration speed and release date for chum salmon Oncorhynchus keta fry exiting a 110-km northern Japanese river
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DOI：
10.1007/s12562-013-0615-8
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发表时间：
2013-07-01
影响因子：
1.9
通讯作者：
Irvine, James R.
中科院分区：
文献类型：
--
作者：
Kasugai, Kiyoshi;Torao, Mitsuru;Irvine, James R.
研究人员对从日本北部北海道东部西别河排出的孵化场鲑鱼鱼苗的释放日期和洄游速度之间的关系进行了研究，以便安排未来的释放，以便鱼苗在有利于高存活率的时期到达海洋。 2008年4月初、4月中旬和5月初、2009年3月下旬和4月中旬以及2010年4月中旬释放的单独标记的鲑鱼群在河口上方12公里处用旋转螺旋捕集器重新捕获。较晚放归群体中的鲑鱼往往比较早放归群体中的鱼类更快地向下游洄游。 4月中旬之后释放的，平均释放后9天到达下游，4月中旬之前释放的，平均释放后26-28天到达下游。大多数有标记的鱼在四月下旬至五月中旬抵达下游河流。这些结果表明，鲑鱼适应了调整其洄游速度，以便在相对离散的时期到达海洋，大概是在有利于良好生存的高生产力时期。
The relationship between release date and migration speed was examined for hatchery chum salmon Oncorhynchus keta fry exiting the Nishibetsu River in eastern Hokkaido, northern Japan so that future releases might be scheduled so that fry arrive at the ocean during periods favoring high survival. Separate marked groups of chum salmon released in early April, mid-April, and early May in 2008, late March and mid-April in 2009, and mid-April in 2010 were recaptured with a rotary screw trap 12 km above the river mouth. Chum salmon in later release groups tended to migrate downstream faster than fish in earlier release groups. Those released after mid-April arrived in the lower river on average 9 days after release, while those released before mid-April arrived on average 26-28 days after release. Most marked fish arrived in the lower river during late April to mid-May. These results suggest that chum salmon are adapted to adjust their migratory speed so as to arrive at the ocean during a relatively discrete period, presumably during a time of high productivity favoring good survival.