Littoral benthic primary production is considered the most important energy source of consumers in subarctic lakes. We analyzed essential fatty acid (EFA) and amino acid (EAA) content of 23 littoral benthic macroinvertebrate taxa as well as cladocerans and copepods from pelagic and littoral habitats of 8–9 subarctic lakes to compare their nutritional quality. Pelagic crustacean zooplankton had significantly higher EFA and total FA content (on average 2.6‐fold and 1.6‐fold, respectively) than littoral macroinvertebrates in all our study lakes. Specifically, docosahexaenoic acid (DHA), one of the most important EFA for juvenile fish, was almost exclusively found in pelagic copepods. In littoral macroinvertebrates, only Lymnaea (Gastropoda), Eurycercus (Cladocera), and Gammarus (Amphipoda) contained a low amount of DHA, whereas most littoral invertebrate taxa contained moderate amounts of eicosapentaenoic acid (EPA). The difference in DHA content may explain why so many generalist fish shift their diet to pelagic zooplankton at their peak abundance in mid/late‐summer. Meanwhile, the differences in EAA content between pelagic zooplankton and littoral invertebrates were much lower than for EFA suggesting a wider availability of EAA in subarctic lakes, except for methionine. In the studied subarctic lakes, EFA and EAA variation in consumers was more related to taxon‐specific than lake‐specific characteristics. This indicates that climate‐induced changes in the abundance and community structure of zooplankton vs. littoral macroinvertebrates will be important parameters in determining the availability of EFA and EAA to juvenile fish, and potentially fish production.

中文翻译：

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亚北极湖泊滨海大型无脊椎动物和浮游浮游动物的营养质量

沿海底栖初级产品被认为是北极湖中消费者最重要的能源。我们分析了8-9个亚北极湖泊中上生和沿海生境的23个滨海底栖大型无脊椎动物类群以及枝角类和co足类动物的必需脂肪酸（EFA）和氨基酸（EAA）含量，以比较其营养质量。在我们所有研究的湖泊中，中上层甲壳类浮游动物的EFA和总FA含量均显着高于沿海大型无脊椎动物（分别为平均2.6倍和1.6倍）。具体而言，二十二碳六烯酸（DHA）是幼鱼最重要的全民教育之一，几乎仅在远洋co足类动物中发现。在滨海大型无脊椎动物中，仅Lymnaea（Gastropoda），Eurycercus（Cladocera）和伽玛鲁斯 （两栖动物）的DHA含量低，而大多数沿岸无脊椎动物类群的中度二十碳五烯酸（EPA）含量适中。DHA含量的差异可能解释了为什么这么多的通才鱼在中/夏高峰时将其饮食转向浮游性浮游动物。同时，远洋浮游动物和沿海无脊椎动物之间的EAA含量差异远低于EFA，表明除蛋氨酸外，亚弧形湖泊中EAA的利用率更高。在研究的北极湖中，消费者中的EFA和EAA变化与特定分类群相关，而不是特定于湖泊的特征。这表明气候引起的浮游动物数量与群落结构的变化