Size‐spectral approaches quantify the efficiency of energy transfer through food webs, but theory and field studies disagree over how changes in temperature, nutrients, and extreme weather impact on this efficiency. We address this at two scales: via 6 years of weekly sampling of the plankton size spectrum at the Plymouth L4 shelf sea site, and via a new, global‐scale, meta‐analysis of aquatic size spectra. The time series showed that with summertime nutrient starvation, the energy transfer efficiency from picoplankton to macroplankton decreased (i.e., steepening slopes of the size spectra). This reflected increasing dominance by small cells and their microbial consumers. The extreme storms in winter 2013/2014 caused high metazoan mortality, steep size‐spectral slopes, and reduced plankton biomass. However, recovery was within months, demonstrating an inbuilt resilience of the system. Both L4 and our meta‐analysis showed steep slopes of normalized size spectra (median −1.11). This reflects much lower values, either of trophic transfer efficiency (3.5%) or predator–prey mass ratio (569), compared to commonly quoted values. Results from the meta‐analysis further showed that to represent energy transfer faithfully, size spectra are best constructed in units of carbon mass and not biovolume, and span a mass range of > 10⁷. When this range is covered, both the meta‐analysis and time series show a dome‐shaped relationship between spectral slopes and plankton biomass, with steepening slopes under increasingly oligotrophic and eutrophic conditions. This suggests that ocean warming could decrease the efficiency of energy transfer through pelagic food webs via indirect effects of increasing stratification and nutrient starvation.

中文翻译：

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营养物压力的增加降低了通过浮游式尺寸谱传递能量的效率

尺寸光谱方法量化了通过食物网的能量转移效率，但是理论和现场研究在温度，营养成分和极端天气的变化如何影响能量效率上存在分歧。我们用两个尺度来解决这个问题：通过每周6年在普利茅斯L4陆架海站点采样浮游生物，并通过新的，全球尺度的水生尺寸谱的荟萃分析。时间序列显示，随着夏季养分的匮乏，从微微浮游生物到大型浮游生物的能量转移效率下降（即，尺寸谱的斜率变陡）。这反映出小细胞及其微生物消费者的优势日益增强。2013/2014年冬季的极端风暴造成了后生动物的高死亡率，陡峭的光谱范围和减少的浮游生物量。但是，恢复在数月之内，展示了系统的内在弹性。L4和我们的荟萃分析均显示出归一化尺寸谱的陡峭斜率（中值-1.11）。与通常引用的值相比，这反映了营养传递效率（3.5％）或捕食者－猎物质量比（569）更低的值。荟萃分析的结果进一步表明，为了忠实地表示能量转移，尺寸谱最好以碳质量而不是生物体积的单位构建，并且质量范围应大于10⁷。当覆盖该范围时，荟萃分析和时间序列都显示出光谱斜率与浮游生物量之间呈圆顶状关系，并且在日益贫营养和富营养的条件下，斜率会变陡。这表明海洋变暖可能通过增加分层和营养饥饿而间接影响通过远洋食物网的能量转移效率。