Radioisotopes for monitoring the effects of Climate Change on marine Ecosystems: The REMO/ClimOcean project at SPES/LNL RIB facility

The industrial revolution released massive CO2 molecules to the atmosphere, starting from 170-280 parts per million in the XIX century up to 418 parts per million in 2023. Recent studies have shown that oceans absorbed about 22% of this anthropogenic CO2 between 2008-2017. Carbon dioxide re­acts with water producing carbonic acid (H2CO3), which lowers the pH, produc­ing the so-called ocean acidification. The latter, combined with global warming, has a vast anthropogenic effect on marine ecosystems and oceanic currents in­fluencing negatively the physiology and ecology of marine ecosystems. Coral communities are particularly affected by rapid changes in environmental con­ditions. As corals, bivalves and sea urchins build their skeletons and shells through the production of calcium carbonate (CaCO3), the influence of seawater acidification on the calcium uptake and growth of these organisms can be sig­nificant. The REMO/ClimOcean project focuses on the study of marine species heavily impacted by acidification. Calcification rates are determined using ra­diotracers for different species of corals, bivalves and sea urchins, comparing animals grown at present and projected pH values. Measurements have been performed at the Oceanografic, Valencia, Spain, at the Hydrobiological Station in Chioggia, Italy and at the island of Ischia, Italy.