How METAL predicts oceanic shifts

Ocean warming has led to unprecedented marine biological changes on a global scale over the past decade – and a new study indicates that future temperature changes are set to have even more momentous effects on marine life.

Only a tiny fraction of the ocean is currently monitored for climate-change effects, which has until now limited scientists’ ability to predict their implications for marine biodiversity.

Now a European-led international research team, including scientists from the Marine Biological Association (MBA), University of Plymouth and Plymouth Marine Laboratory (PML), say that for the first time they are able to explain marine-life changes on a global scale.

Their METAL (Macro-Ecological Theory on the Arrangement of Life) computer model incorporates the preferred temperature ranges of marine species and can, they say, make “remarkably accurate” predictions of long-term fluctuations in marine eco-systems.

METAL has already identified an “unprecedented and massive shift” in ocean populations that occurred between 2010 and 2015, and which the scientists say could have substantial ecological consequences across the planet.

“Observations from marine-biological monitoring programmes and theoretical predictions from the METAL model exhibit similar patterns of change,” said lead author Grégory Beaugrand of Lille University and the MBA. “Our model can provide early-warning signals of change in the state of marine-biological systems in all oceans.”

“At the large time and space scales we examined, most of the variability in species abundances was explainable by environmental temperature, and its effects on the temperature tolerance of the individuals,” said co-author Angus Atkinson from PML.

“This provides a welcome degree of simplification to our understanding of complex food webs.”

The research paper, Prediction of Unprecedented Biological Shifts in the Global Ocean, is published in Nature Climate Change.