Department of Arctic and Marine Biology, University of Tromsø, Tromsø, Norway.
PLoS One. 2010 May 28;5(5):e10869. doi: 10.1371/journal.pone.0010869.
To investigate reasons for the decline of an endangered population of coho salmon (O. kisutch), 190 smolts were acoustically tagged during three consecutive years and their movements and survival were estimated using the Pacific Ocean Shelf Tracking project (POST) array. Median travel times of the Thompson River coho salmon smolts to the lower Fraser River sub-array were 16, 12 and 10 days during 2004, 2005 and 2006, respectively. Few smolts were recorded on marine arrays. Freshwater survival rates of the tagged smolts during their downstream migration were 0.0-5.6% (0.0-9.0% s.e.) in 2004, 7.0% (6.2% s.e.) in 2005, and 50.9% (18.6% s.e.) in 2006. Overall smolt-to-adult return rates exhibited a similar pattern, which suggests that low freshwater survival rates of out-migrating smolts may be a primary reason for the poor conservation status of this endangered coho salmon population.
为了探究濒危银大麻哈鱼（Oncorhynchus kisutch）种群数量下降的原因，我们在连续三年中对 190 尾幼鱼进行了声学标记，并利用太平洋大陆架追踪项目（Pacific Ocean Shelf Tracking project，简称 POST）的数组来估计它们的洄游和生存情况。2004 年、2005 年和 2006 年，汤普森河银大麻哈鱼幼鱼到达弗雷泽河下游亚数组的平均洄游时间分别为 16 天、12 天和 10 天。在海洋数组中记录到的幼鱼数量很少。在 2004 年、2005 年和 2006 年，标记幼鱼在洄游过程中的淡水存活率分别为 0.0-5.6%（0.0-9.0%标准误）、7.0%（6.2%标准误）和 50.9%（18.6%标准误）。总体上，幼鱼到成鱼的回游率表现出相似的模式，这表明洄游幼鱼的淡水存活率低可能是导致这种濒危银大麻哈鱼种群保护状况不佳的主要原因。
