Guest essay by Eric Worrall
Anyone who thinks that keeping the swimming pool green in summer is a struggle is wrong. According to a recent study, warming is slowing the rate of plankton growth and starving animals in the food chain.
Global warming is putting the food chains at risk
MARCH 2, 2021 04:14 AEDT
Scientists have measured the energy transfer from unicellular algae (phytoplankton) to the small animals that eat them (zooplankton).
The study – by Queen Mary University of London and the University of Exeter – published in the journal Nature – found that 4 ° C warming reduced energy transfer in the plankton food webs by up to 56 percent.
“These results shed light on an underrated 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 form the basis 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 at higher temperatures and limits the transfer of energy in a food chain. “
Read more: https://www.miragenews.com/global-warming-poses-threat-to-food-521387/
The abstract of the study;
The warming affects the efficiency of trophic transmission in a long term field test
Diego R. Barneche, Chris J. Hulatt, Matteo Dossena, Daniel Padfield, Guy Woodward, Mark Trimmer and Gabriel Yvon-Durocher
Published: March 01, 2021
In natural ecosystems, the efficiency of energy transfer from resources to consumers determines the biomass structure of food webs. Typically about 10% of the energy generated in one trophic level reaches the next 1-3. Recent theories suggest that this energy transfer could be further restricted if rising temperatures increase metabolic growth costs4, although experimental confirmation is lacking across ecosystems. We quantified the efficiency of nitrogen transfer (a proxy for total energy transfer) in freshwater plankton in artificial ponds that were exposed to 7 years of experimental warming. We provide the first direct experimental evidence that an increase in temperature of 4 ° C compared to ambient conditions can decrease trophic transmission efficiency by up to 56%. In addition, both phytoplankton and zooplankton biomass were lower in the warmed ponds, indicating significant shifts in energy uptake, conversion and transmission5,6. These new findings reconcile observed heat-related changes in growth costs at the individual level and the efficiency of carbon use in various taxa4,7–10 with an increase in the ratio of total respiration to gross primary production at the ecosystem level11–13. Our results suggest that an increasing proportion of the carbon fixed by photosynthesis is lost to the atmosphere as the planet warms, impairing the flow of energy through the food chains, negatively affecting larger consumers and the functioning of entire ecosystems.
Read more: https://www.nature.com/articles/s41586-021-03352-2
I would like to know what your secret is. Because the only thing that annoys me about living in the tropics is the annual battle in summer to keep the swimming pool from turning bright green. I bet my tropical swimming pool on the biological battlefield is much warmer than any gently heated pool in the UK.