Energy Flow through Marine Ecosystems: Confronting Transfer Efficiency

T. D. Eddy, J. Bernhardt, J. Blanchard, W. W. L. Cheung, M. Colléter, H. D. Pontavice, E. A. Fulton, D. Gascuel, K. Kearney, P. C.M., T. Roy, R. R. Rykaczewski, R. Selden, C. A. Stock, C. C. C. Wabnitz, R. A. Watson, (2020). Trends in Ecology and Evolution,

trophic ecology, food web, trophic efficiency, energy transfer, climate change, fishing impacts,

Transfer efficiency is the proportion of energy passed between nodes in food webs. It is an emergent, unitless property that is difficult to measure and responds dynamically to environmental and ecosystem changes. Because the consequences of changes in transfer efficiency compound through ecosystems, slight variations can have large effects on food availability for top predators. We review processes controlling transfer efficiency, approaches to estimate it, and known variations across ocean biomes. Both process-level analysis and observed macroscale variations suggest that ecosystemscale transfer efficiency is highly variable, impacted by fishing, and will decline with climate change. It is important that we more fully resolve the processes controlling transfer efficiency in models to effectively anticipate changes in marine ecosystems and fisheries resources.