Surprising Discovery Provides Insight on Reef’s Resistance to Climate Change

 

Scuba divers over the reefs of Palau

Scuba divers over the reefs of Palau

On January 16, 2014 an article was published in Geographical Research Letters which reported diverse reef communities in Palau which thrive, rather than suffer, while the ocean’s acidity naturally increases. Kathryn Shamberger and her team of researchers at Woods Hole Oceanographic Institution made unexpected discoveries that could provide insight into a plan to protect coral reefs across the world, as well as provide understanding of corals’ resistance to ocean acidification.

Ocean acidification is occurring because the increased levels of carbon dioxide (CO2) are absorbed into the ocean, which reacts with the seawater and lowers the pH levels, making the water increasingly acidic. During this process, carbonate ion levels, which are essential for coral reef growth, are decreased and many organisms generally struggle to gather enough to form their shells.

The team of researchers was surprised to find that contrary to previous findings from coral reef communities elsewhere, the diversity and size of the reefs in Palau were greater than neighboring reefs with lower acidity levels. It is not clear what exactly allows these corals to survive so well in these acidic conditions, but it is believed that it could be a combination of biological and environmental factors that enable these communities to thrive.

Shamberger and her colleagues believe that the Palau reefs could be unique because their acidity levels might be high due to respiration, which puts CO2 into the water, as well as shell building which decreased carbonate ion levels. Elsewhere in the world ocean acidification results from fossil fuel emissions which increase the amount of CO2 in the atmosphere.

The scientists predict that the organisms had time to evolve due to acidic conditions that have been present for thousands of years in this area. Ocean acidification due to humans is happening over a much shorter time scale, so it has not allowed affected reefs to evolve and adjust to the acidity levels. By comparing reef community responses among the full spectrum of naturally acidified sites, the team hopes to gain insight into the factors that enable healthy coral communities to persist under relatively acidic conditions.

 

For more information, please visit the article here

Journal Reference:

  1. Kathryn E. F. Shamberger, Anne L. Cohen, Yimnang Golbuu, Daniel C. McCorkle, Steven J. Lentz, Hannah C. Barkley. Diverse Coral Communities in Naturally Acidified Waters of a Western Pacific ReefGeophysical Research Letters, 2013; DOI:10.1002/2013GL058489

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