1. The impacts of non‐native species are hypothesised to be proportional to the functional distinctiveness of invaders in their invaded ecosystems. Throughout the Patagonia region of southern South America, Chinook salmon (Oncorhynchus tshawytscha) have recently established non‐native populations, and their anadromous, semelparous life cycle could be functionally unique such that marine‐derived nutrients are delivered to streams which have historically lacked such a resource linkage with the ocean.
2. We tested the hypothesis that salmon subsidise biofilm‐associated algae in streams throughout the Aysén province of southern Chile. Using spatial and temporal variation in the presence of salmon among multiple streams and across two spawning seasons, we found strong evidence of salmon‐subsidised algae in three out of four streams examined that have spawning salmon populations.
3. The biofilm of subsidised streams had enriched stable isotopic ratios of nitrogen and carbon, indicating that marine‐derived nutrients were incorporated by biofilms. This nutrient uptake translated into increased algal biomass and percent of total biofilm biomass composed of algae, indicating that the incorporation of marine‐derived nutrients stimulated autotrophic production of biomass.
4. In one stream, the incorporation of marine‐derived nutrients by biofilm occurred in only one of the two studied spawning seasons. Incorporation occurred in a year with low flows of water throughout salmon spawning (4.59 m³/s) and did not occur in a year with much higher flows (41.6 m³/s), suggesting that inter‐annual variation in discharge can mediate the subsidising effect of salmon.
5. These results indicate that Chinook salmon have bridged the historical gap between productive marine ecosystems and nutrient‐poor stream ecosystems in Patagonia. Anadromous salmon can be a significant source of nutrients in nutrient‐limited catchments, and their ongoing expansion in southern South America is likely to entail ecological impacts in stream and riparian food webs.

中文翻译：

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非本土的奇努克鲑鱼为巴塔哥尼亚河流增加了营养补贴和功能新颖性

1. 假设非本地物种的影响与入侵者在其入侵的生态系统中的功能独特性成正比。在整个南美南部的巴塔哥尼亚地区，奇努克鲑鱼（Oncorhynchus tshawytscha）最近建立了非本地种群，它们的无性，同生的生命周期在功能上可能是独特的，因此海洋来源的养分被输送到历来缺乏这种养分的河流中。与海洋的资源联系。
2. 我们检验了以下假设，即鲑鱼补贴了智利南部艾森省整个河流中生物膜相关藻类的生长。利用鲑鱼在多个溪流之间以及两个产卵季节中存在的时空变化，我们发现在有鲑鱼种群的四分之三溪水中，有三分之二有鲑鱼补贴的藻类证据。
3. 补贴流的生物膜富含氮和碳的稳定同位素比，表明生物膜吸收了海洋来源的养分。这种养分的吸收转化为藻类生物量的增加和藻类组成的生物膜总生物量的百分比，表明海洋来源养分的掺入刺激了生物量的自养生产。
4. 在研究的两个产卵季节之一中，只有一股流被生物膜吸收了海洋来源的养分。掺入发生在整个鲑鱼产卵期水流量低的年份（4.59 m ³ / s），而没有发生在流量高得多的年份（41.6 m ³ / s），这表明年际流量变化可以调节鲑鱼的补贴作用。
5. 这些结果表明，奇努克鲑鱼弥合了巴塔哥尼亚生产性海洋生态系统和营养贫乏的河流生态系统之间的历史鸿沟。食盐鲑鱼可能是养分有限的流域中重要的养分来源，其在南美洲南部的持续扩张很可能对河流和河岸食物网产生生态影响。