With coral reefs under threat worldwide, a new report examines and provides a framework to assess novel intervention options that could provide a way forward to protect them.
In the face of threats including habitat destruction, pollution, and climate change, the aim of these interventions is “to increase the ability of these coral reefs to persist in these rapidly degrading environmental conditions,” according to the report, A Decision Framework for Interventions to Increase the Persistence and Resilience of Coral Reefs, which was released on 12 June by the National Academies of Sciences, Engineering, and Medicine (NASEM).
The tools themselves, which also were detailed by NASEM in 2018, include genetic and reproductive interventions such as managed selection and breeding; physiological interventions including pre-exposure of corals to increase their tolerance to stress factors; environmental interventions such as marine and atmospheric shading; and managed relocations of coral populations.
Seven of the 23 examined tools already have been field-tested in specific locations, and all of the interventions have potential risks that need to be carefully weighed against perceived benefits, according to the report, which was requested and funded by the National Oceanic and Atmospheric Administration (NOAA), with additional support provided by the Paul G. Allen Family Foundation. For instance, different types of managed selection present the risk of a decrease in genetic variation. Genetic manipulation could alter the wrong genes and result in unknown risks. Another tool, shading, would alter light regimes.
“These new tools are needed because established approaches for managing coral reefs are neither sufficient, nor designed, to preserve corals in a changing climate,” the report states. “Coral interventions that address the impacts of ocean warming and ocean acidification are part of a three-pronged approach for coral reef management that crucially also includes the mitigation of greenhouse gas emissions and the alleviation of local stressors.”
Managers and decision makers “are faced with the task of evaluating the benefits and risks of a growing number of interventions, separately and in combination,” the report continues. “The interventions have different risks, benefits, and feasibilities in different regions.”
Because there is “no single generalizable approach” for coral reef interventions, the report recommends a structured and adaptive management framework that engages a wide range of stakeholders and that is tailored to local environmental and ecological settings, management objectives, and preferred intervention options.
A Bridge to the Future
“Mitigating [greenhouse gas] emissions is the only way that corals are going to be able to thrive into the far, far future,” Stephen Palumbi, chair of the NASEM committee that produced the report, said at a 12 June briefing. Palumbi, a coral scientist, is a professor of marine sciences and a senior fellow with the Woods Institute for the Environment at Stanford University. “But in this century, when we are hopefully getting a handle on mitigation of the emissions, and things will eventually be getting better by the century, it will take coral interventions now in order for those coral systems to bridge between now and the end of the century.”
In an interview with Eos, Palumbi summed up the report: “Coral reefs are in trouble, there are some things we can do about them, and we now have the tools to begin to be able to make that work in the future.”
“Corals are not just pretty things that we’d like to have around,” Palumbi said. “They support hundreds of millions of people.”
Shallow-water coral reefs, which cover less than 1% of the Earth’s surface, conservatively provide an estimated $172 billion per year in benefits to people in the form of food production, property protection, and tourism, according to NOAA’s Coral Reef Conservation Program Strategic Plan.
Moment of Opportunity
Marissa Baskett, a member of the NASEM committee that produced the report, told Eos that there is “a moment of opportunity” to help protect coral reefs if these interventions are managed properly and are ready for deployment when needed.
“We have a variety of potential interventions that can increase coral persistence in the future,” said Baskett, an associate professor of environmental science and policy at the University of California, Davis. “All come with uncertainties and risks. But if we leverage that uncertainty, we can learn from the process to mitigate risk, maximize learning, and improve the future.”
Baskett said that there needs to be a stakeholder-driven and scientifically driven process for understanding the potential risks and benefits of these interventions. “We have an extraordinary opportunity right now to be ready to deploy them when they are necessary” and to be proactive rather than reactive, she said.
Committee members also have briefed Congress, the White House, and NOAA about the report. NOAA, which received the report about a week ago, currently is developing its response, according to Tali Vardi, a coral scientist with ECS, a federal contracting company, who is NOAA’s point person to the NASEM study.
“There is a lot of work to do” to protect coral reefs, she told Eos. “Reefs are disappearing while we sit here and chat.”
Palumbi told Eos that he wants this report to make a real difference for the future of coral reefs.
“Everybody I know who has worked on reefs for the last 20 or 30 years knows places that were fabulous and are virtually dead now. How do we turn that around? How do we stop just cataloging those declines and start putting our energy into doing things?” Palumbi said. “That’s what I want this report to be. I want it to be the foundation on which people say, there are things to do, there’s energy to do it. There’s a goal. We have to wrap it into climate mitigation. We have to wrap it into the local stressors thing. But there is a way forward. Let’s take it, because what are we going to do if we don’t take it?”
—Randy Showstack (@RandyShowstack), Staff Writer