Ocean acidification due to climate change is dissolving limestone along the Florida Reef Tract much faster than previously thought, reports a new study.
As the ocean absorbs carbon dioxide from the atmosphere, the oceans become more acidic. But lab studies hadn't predicted a pH low enough to make reefs dissolve until 2050 or later, according to researchers at the University of Miami's Rosensteil School of Marine & Atmospheric Science.
It was widely believed that the reefs would reach a point where they lost more limestone than they were gaining. But the study, published in the in the journal Global Biogeochemical Cycles, [/i ]reports that the limestone forming the foundation for the coral reefs is already dissolving.
"We don't have as much time as we previously thought," said Chris Langdon, professor of marine biology and ecology at the University of Miami and a senior author of the study. "The reefs are beginning to dissolve away."
The damage could the reefs is expected to reduce habitat for fish species important for recreation and commercially. The Florida Keys reefs have an estimated worth of $7.6 billion, the researchers report.
Two years of collecting samples suggests reefs to the south are reaching the point where their growth cycle doesn't create more limestone than is dissolving during fall and winter.
"Only the two southern-most reefs were net depositional year-round," the researchers wrote in the study. "These results indicate that parts of the (Florida Reef Tract) have already crossed the tipping point for carbonate production and other parts are getting close."
"This is one more reason why we need to get serious about reducing carbon dioxide emission sooner rather than later," Langdon said.