Because of their long‐term listing under the Endangered Species Act, much interest has been placed on estimating population vital rates for Bull Trout Salvelinus confluentus, but the biotic and abiotic factors that influence the interannual variability in those vital rates have rarely been evaluated. We used mark–recapture data to estimate fish growth, survival, and trends in abundance for fluvial adult Bull Trout in the East Fork Salmon River, Idaho. Over an 8‐year period, a total of 1,205 individual Bull Trout were collected at a weir on the East Fork Salmon River (29 km upstream of its confluence with the Salmon River) during June–September, of which 420 were recaptures from prior years. Bull Trout varied in length from 215 to 756 mm and achieved a slightly larger asymptotic length and a slightly lower rate of growth relative to other fluvial and adfluvial Bull Trout populations. Apparent survival averaged 0.42 across all years, which was similar to previous studies estimating apparent survival for Bull Trout. The number of emigrating anadromous salmonid smolts in the upper Salmon River basin positively influenced East Fork Salmon River Bull Trout growth and survival, and survival was higher in years with lower annual discharge. Assessment of population growth via linear regression analysis indicated that the Bull Trout population was increasing during the study period (λ = 1.08; 95% confidence interval = 1.03–1.14). Our findings highlight the ecological link between the abundance of wild and hatchery Chinook Salmon Oncorhynchus tshawytscha, Sockeye Salmon O. nerka, and steelhead O. mykiss smolts and growth and survival of adult Bull Trout in systems where these species occur in sympatry.

中文翻译：

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爱达荷州东叉鲑鱼河上的鳟鱼种群动态和时间趋势

由于根据《濒临灭绝物种法》长期列入清单，因此人们对估算鳟鱼Salvelinus confluentus的人口生命率备受关注。，但很少评估影响这些生命率年际变化的生物和非生物因素。我们使用了标记捕获数据来估算爱达荷州东叉鲑鱼河中成年成年公鳟鱼的鱼类生长，存活率和丰度趋势。在8年的时间里，在6月至9月期间，在东叉鲑鱼河（与鲑鱼河汇合处上游29公里处）的一条堰处收集了1,205头单独的红鳟鱼，其中有420头是前几年的捕获物。鳟鱼的长度从215到756毫米不等，相对于其他河流和非河流鳟鱼种群，其渐近线长度稍大，生长速率略低。所有年份的表观存活率平均为0.42，这与之前的研究估计牛鳟的表观存活率相似。鲑鱼河上游流域的迁徙性鲑科鲑鱼数量对东叉鲑鱼河鳟鱼的生长和存活产生积极影响，并且年存活率较高，年排放量较低。通过线性回归分析对人口增长的评估表明，在研究期间，鳟鱼种群正在增加（λ= 1.08； 95％置信区间= 1.03-1.14）。我们的发现强调了野生和孵化场奇努克鲑鱼之间的生态联系 通过线性回归分析对人口增长的评估表明，在研究期间，鳟鱼种群正在增加（λ= 1.08； 95％置信区间= 1.03-1.14）。我们的发现强调了野生和孵化场奇努克鲑鱼之间的生态联系 通过线性回归分析对人口增长的评估表明，在研究期间，鳟鱼种群正在增加（λ= 1.08； 95％置信区间= 1.03-1.14）。我们的发现强调了野生和孵化场奇努克鲑鱼之间的生态联系Oncorhynchus tshawytscha，Sockeye Salmon O. nerka和steelhead O. mykiss的软体动物以及成年公鳟鱼在这些物种共生的系统中的生长和存活。