Regional synchrony in return rates of chum salmon (Oncorhynchus keta) in Japan in relation to coastal temperature and size at release
Regional synchrony in return rates of chum salmon (Oncorhynchus keta) in Japan in relation to coastal temperature and size at release
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DOI：
10.1016/j.fishres.2008.07.004
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发表时间：
2009-01-01
影响因子：
2.4
通讯作者：
Nagasawa, Kazuya
中科院分区：
文献类型：
--
作者：
Saito, Toshihiko;Nagasawa, Kazuya
在日本，大麻哈鱼（Oncorhynchus凯塔）的种群已经通过人工繁殖维持了30多年。自1980年代初以来，每年的鲑鱼释放量基本保持不变，而成年鲑鱼的返回量在各区域之间差异很大。为了更好地了解这种变异性及其原因，我们比较了1976-1998年育雏年鲑鱼在日本的七个地区之间的回报率。返回率的同步变化被发现在两个耦合区域：鄂霍次克和根室（OH-NE）地区，和西北海道太平洋和本州太平洋（WP-HP）地区。由于每一对区域在地理上相邻，沿海温度在早期的海洋生活和鱼苗从该地区释放的大小进行了测试，作为潜在的因素，调节在每一对的回报率。返回率为OH-NE的朋友在研究期间增加，与鱼苗的大小增加，从孵化场在这两个地区。相反，WP-HP诱饵的返回率与释放时的大小无关。另外，在他们的沿海居住的后期（6月至7月）的年际温度变化是最有影响力的因素，造成每年的回报率的差异。这项研究表明，日本大麻哈鱼成年返回的地区差异与早期海洋生活的存活率有关。虽然在释放增加大小提高早期海洋生存，生存的大小效应不同的区域之间，在区域范围内的海洋环境条件决定死亡率在沿海居住的少年鲑鱼。(C)2008 Elsevier B. V.保留所有权利。
In Japan, the population of chum salmon (Oncorhynchus keta) has been sustained for over 30 years by artificial propagation. Annual chum salmon releases have remained approximately constant since the early 1980s while the number of adult returns has varied greatly among regions. To better understand this variability and its cause, we compared return rates for 1976-1998 brood-year chum salmon among seven regions of Japan. Synchronous changes in the return rates were found in each of the two coupled regions: Okhotsk and Nemuro (OH-NE) regions, and West Hokkaido Pacific and Honshu Pacific (WP-HP) regions. As each pair of regions is geographically adjacent, coastal temperature during the early ocean life and size at release of fry from the regions were tested as potential factors regulating the return rates in each pair. Return rates for OH-NE chum increased during the study period, associated with an increase in the size of fry released from hatcheries in both regions. In contrast, the return rates for WP-HP chum were not related to size at release. Alternatively, inter-annual temperature variability during the late season of their coastal residency (June-July) was the most influential factor causing year-to-year differences in return rates. The study indicates that regional difference in adult returns of chum salmon in Japan is related to survival rates during early ocean life. Although increased size at release improves early ocean survival, the size effect on survival varies between the different regions, where ocean environmental conditions at a regional scale determine mortality during the coastal residency of juvenile salmon. (C) 2008 Elsevier B.V. All rights reserved.