High-level Workshop Discusses Ocean Acidification and Coral Reefs

Is it too late?

One of the resounding messages during the three-day workshop was a message of hope. It is not too late, and a variety of solutions exist. When faced with the choice of where to focus our efforts first, Ruth Gates summarised: “Do something, and do something now”. She stressed that solutions as simple as installing mooring buoys over coral reefs, as opposed to having people throw anchors, could have immediate positive impacts.

What are the solutions?

Several participants provided overviews of their work on coral reef restoration and rehabilitation. Frank Mars, member of the Board of directors of Mars Inc., known for its eponymous chocolate bars, and former Global President of Mars Symbioscience, discussed some of the organisation’s successes in coral reef rehabilitation in Indonesia. Their participative projects, which see the involvement of local populations, have already been successful on a small scale, and have seen two hectares rehabilitated between 2012 and 2017. Though small progress, this has had an impact on local populations who have seen fish catches from the reef increase, and Mr Mars argues that such projects are scalable and can be successful on a larger scale.

“Solutions exist, but we need to start seeing more involvement from policy-makers and private companies to enact change” said Mr Mars.

Beyond these solutions for adaptation and rehabilitation, one of the key messages from participants was that reducing greenhouse gases would effectively limit the pressure on coral reefs by curbing ocean acidification, and climate change impacts such as increase in temperature and rise in sea level. As Jean-Pierre Gattuso from the French National Center for Scientific Research (CNRS) summarised it “decreasing CO2 emissions is the best solution”. He added “if the Paris Agreement on Climate is fully and timely implemented, only 1% of the world ocean will exceed key thresholds of temperature and acidity. Otherwise, in a business-as-usual situation, 69% of the ocean will exceed these thresholds”.

While coral reefs represent less than 0.2% of the total surface of the oceans, they have major ecological importance as they provide habitats for over 30% of all marine fauna. They provide essential ecosystem services as a source of food/protein to human communities, a source of income from tourism, as well as costal protection against erosion and storms. Even a small alteration in the ecological functions of coral reefs could have a major impact on human societies.

Nuclear and isotopic techniques are powerful tools for studying ocean acidification and have contributed widely to investigating past changes in ocean acidity and potential impacts on marine organisms. Researchers at the IAEA Environment Laboratories use calcium-45 to examine the growth rates in calcifying organisms such as corals, mussels and other molluscs, whose skeletons and shells are composed of calcium carbonate. Tracers are also used to determine how ocean acidification is affecting the physiology of marine organisms, as well as the impact of a combination of stressors, such as ocean acidification, increases in temperature and contaminants.

David Osborn, director of the IAEA Environment Laboratories, highlighted the “need for new science in order to inform the decisions we make on ocean acidification”. He added that “it was important to address the multiple stressors which the oceans face, including pollution, overfishing and environmental changes”.