March 1 (UPI) – As the planet gets warmer, a new study shows that food chains are becoming less efficient, producing less energy and less energy from the bottom to the top.
For the study, researchers at the University of Exeter and Queen Mary University of London measured the effect of temperature on the transfer of energy from single-celled algae, or phytoplankton, to the microscopic organisms – called zooplankton – that eat them.
The findings, published Monday in the journal Nature, showed that a 4 degree Celsius increase in energy transfer from phytoplankton to zooplankton increased by 56 percent.
“These findings shed light on the effects of less global warming,” study co-author Gabriel Yvon-Durocher said in a press release.
“Phytoplankton and zooplankton form the basis of food webs that support human-dependent freshwater and marine ecosystems,” said Yvon-Durocher, a professor of biology at the Exeter Institute for Environment and Sustainability.
Over seven years, researchers consistently measured the efficiency of nitrogen transfer – a surrogate for total energy transfer – among plankton that was gradually exposed to warmer and warmer water.
According to Yvon-Durocher, the new study is the first to measure the metabolic costs of higher temperatures within a food chain base.
“If the effects we find in this experiment are obvious in natural ecosystems, the results could be profound,” said co-author Mark Trimmer.
“The impact on larger animals at the top of the food chain – which is dependent on energy provided from being lower down the food chain – could be very severe,” said Trimmer, senior. professor of biochemistry at QMUL.
Previous studies suggest that around one-tenth of the energy produced on one stage of a food chain is transferred to the next. That’s because most of the energy an organism consumes is consumed throughout its life. Only a fraction is converted into biofuels that can be eaten and converted into energy by a predator.
“Warmer temperatures can accelerate metabolic rates faster than growth rates, reducing the energy available to predators in the next stage up the food web,” said co-author Diego Barneche, a researcher at the Australian Institute of Marine Science and Oceans Institute at the University of Western Australia.
The authors of the new study said more research is needed to determine how slow the movement of energy within real food chains is.