How to prepare our oceans for one of climate change’s silent killers

In a paper published today in the journal Environmental Research Letters, an international research team composed of scientists affiliated with more than a dozen institutions, including the University of Portsmouth, propose a first-of-its-kind framework for governments around the world to evaluate their preparedness for—and guide future policies to address—ocean acidification, among the most dire threats to marine ecosystems. 

Ocean acidification is when the ocean becomes more acidic as a consequence of absorbing carbon dioxide emissions in the atmosphere.

Professor Steve Fletcher, one of the authors and Director of the Global Plastics Policy Centre at the University of Portsmouth says: “Ocean acidification is a looming threat that has flown under the radar in discussions about climate change. While coral bleaching captures headlines, ocean acidification is just as dangerous, with the potential to devastate marine ecosystems on a global scale within the next decade. 

Professor Fletcher and his colleagues have taken a proactive approach by proposing a comprehensive plan to policymakers that addresses the risks of ocean acidification and outlines strategies to protect the environment and society from its harmful effects. Professor Fletcher says: “With time running out, it is vital that we act urgently and decisively to confront this silent killer and safeguard our planet's future.”

Ultimately, the researchers identified six aspects of effective ocean acidification policy, along with specific indicators for each, that policymaking bodies, from local governments to federal agencies, can use to evaluate and guide their own policies. 

As a case study, the researchers used the framework to evaluate the current state of ocean acidification preparedness in Australia, which is home to the world’s largest system of coral reefs and has vibrant ecosystems that support the livelihoods of more than a billion people worldwide but are uniquely susceptible to acidification. 

They found that while Australia is generally well prepared with a deep understanding of the adaptive capacity of vulnerable socioeconomic sectors and management strategies that explicitly address ocean acidification, the country is lacking in policy coherence and broader climate protection measures which may hinder its ability to lower greenhouse gas emissions which are the main contributor to ocean acidification. 

“Ocean acidification is not an isolated issue, but rather one that is closely linked to other anthropogenic hazards—in Australia and elsewhere—such as warming, sea level rise, oxygen loss, and eutrophication,” says University of Queensland coral biologist Ove Hoegh-Guldberg, PhD. “Therefore, any policy designed to address ocean acidification either locally or globally must consider the many interconnected factors and their impacts on both ecosystems and society.”

By providing a baseline for countries to assess their preparedness for ocean acidification, the researchers say their framework will also enable researchers, conservationists, and governing bodies at all levels to identify areas for investment or collaboration to ensure their environments and societies are better protected. 

“After governments self-assess their readiness for ocean acidification, they’ll have a better sense of where gaps may exist,” says Sarah Cooley, PhD, Director of Climate Science at the Ocean Conservancy. “Gaps will be different for every government—some governments might need to increase fundamental research just to understand how their marine systems will respond to acidification, while others might need to bump up adaptation to safeguard people and ecosystems most likely to be affected by acidification. This self-test will help governments focus future efforts to make sure they are emphasising the most essential areas for them and can take the necessary steps to address the salient threats from acidification.”