Large quantities of material are moved annually from the ocean to freshwater systems by migrating Pacific salmon. Previous studies have focused on nitrogen and phosphorus provided by spawning salmon but largely ignored micronutrients essential to aquatic productivity. We collected salmon tissue, water, and biofilm from seven southeast Alaskan streams both before and during the salmon run to test for potential micronutrient provision by salmon and uptake by biofilm. To examine temporal patterns, one stream was also sampled with high frequency. Samples were analyzed using ICP-OES for boron (B), calcium (Ca), cobalt (Co), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), molybdenum (Mo), sodium (Na), selenium (Se), silicon (Si), and zinc (Zn). Arrival of salmon increased stream water loads for Ca, Fe, Mg, and Na and the concentration of Co in biofilm across the seven study streams. Stream loads of B and biofilm Cu and Na content decreased in the presence of salmon. By examining one stream at finer temporal resolution, biofilm increased in Ca, Fe, and Mn concentrations near the end of the salmon run, indicating possible lag effects between peak salmon densities and biofilm micronutrient uptake. The increase in stream water micronutrient loads across space for four elements and uptake of three elements in biofilm through time suggest that salmon are a potential source of essential micronutrients for freshwater ecosystems, as has been repeatedly demonstrated for macronutrients. This study expands our understanding of resource subsidies by identifying potential micronutrients important to those ecological dynamics.

中文翻译：

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除了氮和磷补贴：太平洋鲑鱼（Oncorhynchus spp.）作为微量营养素的潜在载体

通过迁徙太平洋鲑鱼，每年有大量物质从海洋转移到淡水系统。以前的研究主要关注产卵鲑鱼提供的氮和磷，但在很大程度上忽略了对水生生产力至关重要的微量营养素。我们在鲑鱼运行之前和期间从阿拉斯加东南部的七个溪流中收集了鲑鱼组织、水和生物膜，以测试鲑鱼潜在的微量营养素供应和生物膜的吸收。为了检查时间模式，还对一个流进行了高频采样。使用 ICP-OES 分析样品中的硼 (B)、钙 (Ca)、钴 (Co)、铜 (Cu)、铁 (Fe)、钾 (K)、镁 (Mg)、锰 (Mn)、钼 ( Mo)、钠 (Na)、硒 (Se)、硅 (Si) 和锌 (Zn)。鲑鱼的到来增加了钙、铁、镁、和 Na 以及七个研究流中生物膜中 Co 的浓度。在鲑鱼的存在下，B 和生物膜 Cu 和 Na 含量的溪流负荷降低。通过以更精细的时间分辨率检查一条河流，在接近鲑鱼运行结束时，生物膜的 Ca、Fe 和 Mn 浓度增加，表明鲑鱼峰值密度与生物膜微量营养素吸收之间可能存在滞后效应。随着时间的推移，河流水中四种元素的微量营养素负载增加以及生物膜中三种元素的吸收表明，鲑鱼是淡水生态系统必需微量营养素的潜在来源，正如大量营养素所反复证明的那样。这项研究通过确定对这些生态动态很重要的潜在微量营养素，扩展了我们对资源补贴的理解。