University of Washington, School of Aquatic and Fishery Sciences, 1122 N.E. Boat Street, Box 355020, Seattle, WA 98195-5020, U.S.A.
J Fish Biol. 2014 Jul;85(1):31-51. doi: 10.1111/jfb.12433. Epub 2014 May 28.
This study provides evidence of the importance of tributary tidal wetlands to local coho salmon Oncorhynchus kisutch populations and life-history diversity. Subyearling and, to a lesser extent, yearling O. kisutch life histories utilized various estuary habitats within the Grays River, a tidal freshwater tributary of the Columbia River estuary, including restoring emergent wetlands and natural forested wetlands. Migration timing data, size distributions, estuary residence and scale patterns suggest a predominance of subyearling migrant life histories, including several that involve extended periods of estuary rearing. Estuarine-rearing subyearling O. kisutch exhibited the greatest overall growth rates; the highest growth rates were seen in fish that utilized restoring emergent wetlands. These results contrast with studies conducted in the main-stem Columbia River estuary, which captured few O. kisutch, of which nearly all were hatchery-origin yearling smolts. Restoration and preservation of peripheral and tributary wetland habitats, such as those in the Grays River, could play an important role in the recovery of natural O. kisutch populations in the Columbia River and elsewhere.
本研究证明了支流潮滩湿地对当地银大麻哈鱼 Oncorhynchus kisutch 种群和生活史多样性的重要性。亚成体和（在较小程度上）幼体大麻哈鱼利用哥伦比亚河口格雷斯河（潮汐淡水支流）内的各种河口栖息地，包括恢复挺水湿地和自然森林湿地。洄游时间数据、体型分布、河口居留和规模模式表明，亚成体洄游生活史占主导地位，其中包括一些涉及河口育肥的生活史。在河口育肥的亚成体银大麻哈鱼表现出最大的总体生长率；在利用恢复挺水湿地的鱼类中，生长率最高。这些结果与在哥伦比亚河干流进行的研究形成对比，在干流捕获的银大麻哈鱼很少，几乎都是由人工养殖的幼鱼组成。外围和支流湿地栖息地的恢复和保护，如格雷斯河的湿地，可能在哥伦比亚河和其他地区自然银大麻哈鱼种群的恢复中发挥重要作用。
