Increased Population Density and Suppressed Prey Biomass: Relative Impacts on Juvenile Atlantic Salmon Growth
Increased Population Density and Suppressed Prey Biomass: Relative Impacts on Juvenile Atlantic Salmon Growth
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DOI：
10.1577/t08-128.1
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发表时间：
2009-01-01
影响因子：
1.4
通讯作者：
Folt, C. L.
中科院分区：
文献类型：
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作者：
Ward, D. M.;Nislow, K. H.;Folt, C. L.
鱼类的个体生长率往往取决于种群密度和资源的可获得性。这两者都受到人为的影响，并呼吁被操纵，以恢复或增加鱼类种群的利益。然而，对这些因素的相对贡献的直接测试对于大多数群体来说是缺乏的，并且迫切需要10指导管理。我们使用它的大规模的现场试验，以评估相对影响的增加人口密度和抑制猎物生物量油的生长的幼年大西洋鲑鱼萨尔莫salar。我们直接操纵鲑鱼种群密度释放新孵化的鲑鱼鱼苗从统一的初始条件下，在三个密度处理在自然流（18个站点，重复2年以上）。我们排列的密度治疗站点，包括一个超过10倍的范围内的生物量的底栖无脊椎动物猎物鲑鱼，低猎物生物量与重阴影前河岸林冠层。这种控制方法清楚地表明了巨大的生长可塑性的幼年大西洋鲑鱼，他们的平均体重范围前1.2至14克跨越网站后一个生长季节。生物量对油鱼生长的影响最大。无论种群密度如何，鱼在猎物生物量高的地点生长得更快。和猎物的生物量单独占71%的解释变化，在他们的增长。只有在考虑到猎物生物量解释的变化是显而易见的，研究鱼类生长速度更快的网站，低放养密度和高损失减少大西洋鲑鱼种群密度的网站。维持鲑鱼的生长和大小依赖的生活史。恢复和管理工作显然需要考虑抑制猎物丰富度的人为因素。
Individual growth rates of fish often depend oil both population density and resource availability. both of which are subject to anthropogenic impacts and call be Manipulated in the interest of restoring or enhancing fish populations. However, direct tests of file relative contribution Of these factors 10 growth variation are lacking for most populations and are critically needed 10 guide management. We used it large-scale field experiment to evaluate the relative effects of increased population density and Suppressed prey biomass oil the growth of juvenile Atlantic salmon Salmo salar. We directly manipulated salmon population density by releasing newly hatched salmon fry from uniform initial conditions at three density treatments in natural streams (18 sites total, repeated over 2 years). We arrayed the density treatments across sites that encompassed a more than 10-fold range in the biomass of benthic invertebrate prey for salmon, it low prey biomass being associated with heavy shading front riparian forest canopy. This controlled approach clearly demonstrated the enormous growth plasticity of juvenile Atlantic salmon their mean body mass ranging front 1.2 to 14 g across sites after one growing season. Variation in file), biomass had the strongest effects oil fish growth. The fish grew faster at sites with high prey biomass regardless (if population density. and prey biomass alone accounted for 71% of the explained variation in their growth. Only after taking the variation explained by prey biomass into account was it apparent that the study fish grew faster in sites with low stocking density and at sites where high losses reduced Atlantic salmon population density. To maintain salmon growth and size-dependent life histories. restoration and management efforts clearly need to consider anthropogenic factors that Suppress prey abundance.