Natural analogues of the future ocean to understand and protect marine ecosystems under climate change and ocean acidification

Natural analogues of the future ocean allow us to identify the impacts and associated mechanisms of ocean warming, ocean acidification and oxygen loss on marine organisms from effects on species right up to an ecosystem scale. This is improving understanding about how ongoing rapid changes to the structure and functioning of marine systems are and will continue to affect human society. Strong marine gradients in temperature, pH, alkalinity and oxygen provide test beds to show the practical real-world advantages to society of complying with the UN SDGs, the Paris Agreement, and the CBD, demonstrating what ecosystem services are secured as ecosystems are ‘dialed-back’ from business-as-usual emissions and poor ocean management scenarios.

The International CO2 Natural Analogue (ICONA) network, an ocean decade action endorsed under the “Ocean Acidification Research for Sustainability' programme, brings together experts, local communities, and stakeholders to use futuristic marine test bed environments, spanning temperate, sub-tropical and tropical regions. Our findings are showing the varieties of responses to future ocean conditions from molecules to ecosystems. They highlight that reducing CO2 emissions and limiting ocean warming, acidification, and oxygen loss brings tangible benefits to society by restoring ecosystem services that have been degraded. Moreover, resistant species and populations of marine organisms found in these futuristic environments have been selected through chronic exposure to end of the century levels of heatwaves, CO2 and reduced oxygen. These can be a source of genes of resilience for the development of adaptation strategies such as assisted evolution and assisted gene flows. Finally, the microbial diversity found at this global network of study sites has proven its potential for the development of carbon sequestration techniques which can help achieve a carbon neutral society. The ICONA network aims to expand to engage more partners, scientists and diverse stakeholders to unlock the ways in which these systems can benefit humanity, through novel hidden biodiversity and as demonstration sites for how our societies can best adapt to near-future CO2 levels, and to co-design conservation strategies around these ecosystems.