Natural Environment Blog

Three separate investigations from three different parts of the world have drawn the same conclusion; that rising carbon dioxide (CO₂) levels will have a far greater impact on the world’s coral reefs than previously thought.

In particular, it is the CO₂ derived from human activities that will cause this greater impact and is likely to cause the death of coral reefs around the world. 

The Three Studies

The three different studies were carried out by:

• A team in Australia, led by Dr Ken Anthony of the ARC Centre of Excellence for Coral Reef Studies and the University of Queensland
• A team in Taiwan, led by Allen Chen, an associate researcher at the Research Center for Biodiversity, Academia Sinica
• A team in the United States, involving oceanographers Long Cao and Ken Caldeira from the Carnegie Institution’s Department of Global Ecology at Stanford University in California

The Findings

All three studies concluded that anthropogenic CO₂ - carbon dioxide derived from human activities - causes increased ocean acidification, which in turn, leads to coral bleaching and eventually, the death of coral reefs.

Cao and Caldeira from the U.S. study said that the main contributor of anthropogenic CO₂ is the burning of fossil fuels.

Dr Anthony from the Australian study said “Every time you start your car or turn on the lights, half the CO₂ you emit ends up in the oceans, turning them just a tiny bit more acidic, as well as causing the climate to warm. What is new is an understanding of how these two effects interact to affect the corals and reef building algae.”

Caldeira issues a bleak forecast, “If current trends in CO₂ emissions continue unabated, in the next few decades, we will produce chemical conditions in the oceans that have not been seen for tens of millions of years. We are doing something very profound to our oceans. Ecosystems like coral reefs that have been around for many millions of years just won’t be able to cope with the change.”

Chen, from the Taiwanese study says, “Coral ecosystems could disappear completely by the end of the century if measures are not taken to reduce carbon emissions.” 

Chen also said, “The disappearance of the coral ecosystem would produce a ripple effect and be detrimental to human survival.”

Scientists who wrote the “Honolulu Declaration on Ocean Acidification and Reef Management” have presented key findings and recommendations of the report to delegates of the World Conservation Congress being held in Barcelona this week.

The Honolulu Declaration was first presented to the U.S. Coral Reef Task Force meeting in Kona, Hawaii back in August. The report provides recommendations in dealing with the issue of acidification of the oceans, and managing coral reefs around the world.

Ocean acidification is believed to be the biggest threat to our oceans today, and could virtually wipe out the world’s coral reefs before the end of the century.  

Some of the recommendations in the report include:

• Stabilize CO2 emissions and reduce marine pollution across multiple channels;
• Mandate the inclusion of climate change actions into marine protected area management plans;
• Increase appropriations to improve the science and actions addressing ocean acidification impacts on coral reefs;
• Reduce all stresses on coral reefs as much as possible to enhance their health and resilience;
• Protect reefs that are less vulnerable to the impacts of ocean acidification by creating new marine protected areas and through zoning plans in existing ones;
• Develop, test and implement innovative interventions to reduce damage to weakened reefs and replenish species loss caused by ocean acidification; and
• Develop a collaborative international program on ocean acidification that includes a coordinated network of monitoring stations.

Governments around the world are starting to realize the threat that our coral reefs are under. Only a few days ago, the Queensland government of Australia agreed to step up efforts to save the Great Barrier Reef,  following the ,release of a new report on water quality surrounding the reef.