Ocean Acidification Projected To Weaken Coral Skeletons

Feb 25, 2018

Scientists at the Woods Hole Oceanographic Institution have released a study that found ocean acidification could weaken coral skeletons by up to 20 percent by the end of the century.


PH levels in the ocean have been dropping because of climate change, which causes the water to become more acidic. An international team of researchers looked at how this chemical change could impact a coral skeleton’s growth and density.

They found that over time, vertical growth was unaffected, but the skeletons weren’t as thick.

Corals need carbonate ions to thicken their skeletons, and ocean acidification reduces the amount of those ions available in the ocean. Researchers have projected by the year 2100, up to half of the carbonate ions could be gone. 

Weifu Guo, lead investigator and associate scientist at Woods Hole Oceanographic Institution, said it’s important to have strong coral reefs that can withstand waves and storms.

"Organisms living in coral reefs rely on the skeleton of the corals to be their habitat, their food source," Guo said. 

Guo added corals help sustain coastal economies around the world. 

The National Oceanic and Atmospheric Administration estimates coral reefs pump more than $3.4 billion into the U.S. economy each year, including contributing more than $100 million to U.S. fisheries. 

Scientists predict coral skeletons in the waters around Indonesia, Malaysia, the Philippines, Papua New Guinea, Timor Leste and the Solomon Islands could be up to 20 percent thinner by the year 2100. However, coral reefs in the Caribbean, Hawaii and northern Red Sea could fare better with less than 10 percent reductions in coral skeletal density. 

In addition to ocean acidification, warming ocean temperatures and rising sea levels have been shown to threaten the health of coral reefs.

To better protect corals, Guo said it’s important to reduce carbon emissions. 

The study was published late last month in the scientific journal Proceedings of the Natural Academy of Sciences.