Data from: Highly unsaturated fatty acids in nature: what we know and what we need to learn

The supply and demand of omega-3 highly unsaturated fatty acids (ω-3 HUFA) in natural ecosystems may lead to resource limitation in a diverse array of animal taxa. Here, we review why food quality in terms of ω-3 HUFAs is important, particularly for neural tissue, across a diversity of animal taxa ranging from invertebrate zooplankton to vertebrates (including humans). Our review is focused on ω-3 HUFAs rather than other unsaturated fatty acids because these compounds are especially important biochemically, but scarce in nature. We discuss the dichotomy between ω-3 HUFA availability between aquatic primary producers, which are often rich in these compounds, and terrestrial primary producers, which are contain little to none of them. We describe the use of fatty acids as qualitative and quantitative tracers for reconstructing animal diets in natural ecosystems. Next, we discuss both direct and indirect ecological implications of ω-3 HUFA limitation at the individual, population, food web, and ecosystem scales, which include: changes in behavior, species composition, secondary production rates, trophic transfer efficiency, and cross-ecosystem subsidies. We finish by highlighting future research priorities including a need for more research on ω-3 HUFAs in terrestrial systems, more research their importance for higher order consumers, and more research on the food web and ecosystem-scale effects of ω-3 HUFA limitation.

自然生态系统中ω-3高度不饱和脂肪酸（omega-3 highly unsaturated fatty acids, ω-3 HUFA）的供需状况，可能会在多样的动物类群中引发资源限制。本文综述了为何以ω-3 HUFA为衡量标准的食物质量至关重要——尤其对于神经组织——其覆盖范围涵盖从无脊椎浮游动物到脊椎动物（包括人类）的各类动物类群。本综述聚焦ω-3 HUFA而非其他不饱和脂肪酸，原因在于这类化合物在生化层面尤为关键，但在自然界中却相对稀缺。我们探讨了水生初级生产者（通常富含此类化合物）与陆生初级生产者（几乎不含或完全不含此类物质）之间，ω-3 HUFA可获得性的二元差异。本文阐述了脂肪酸作为定性与定量示踪剂，用于重建自然生态系统中动物食性的应用方式。随后，我们讨论了ω-3 HUFA限制在个体、种群、食物网以及生态系统尺度下的直接与间接生态影响，其中包括：行为变化、物种组成、次级生产力、营养传递效率以及跨生态系统补贴。本文最后强调了未来的研究重点，包括需开展更多针对陆生生态系统中ω-3 HUFA的研究、更多关于其对高阶消费者重要性的研究，以及更多关于ω-3 HUFA限制对食物网与生态系统尺度影响的研究。