The study – by the University of Exeter and Queen Mary University of London, and published in the journal Nature – found that 4°C of warming reduced energy transfer in the plankton food webs by up to 56%.
Warmer conditions increase the metabolic cost of growth, leading to less efficient energy flow through the food chain and ultimately to a reduction in overall biomass.
"These findings shine a light on an under-appreciated consequence of global warming," said Professor Gabriel Yvon-Durocher, of the Environment and Sustainability Institute on Exeter's Penryn Campus in Cornwall.
"Phytoplankton and zooplankton are the foundation of food webs that support freshwater and marine ecosystems that humans depend on.
"Our study is the first direct evidence that the cost of growth increases in higher temperatures, limiting the transfer of energy up a food chain."
Professor Mark Trimmer, of Queen Mary University of London, said: "If the effects we find in this experiment are evident in natural ecosystems, the consequences could be profound.
