SANTA CRUZ, CA--Observations at submarine springs found along the coast of Mexico's Yucatan Peninsula are giving scientists a preview of the possible fate of coral reef ecosystems in response to ocean acidification.
The naturally low pH (a measure of acidity) in the water around the springs creates conditions similar to those that will result from the widespread acidification of surface waters that scientists expect to occur as the oceans absorb increasing amounts of carbon dioxide from the atmosphere. Ecological surveys around the springs found small, patchily distributed colonies of only a few species of corals, without the structurally complex corals that compose the framework of the nearby Mesoamerican Barrier Reef, one of the Caribbean's largest coral reef ecosystems.
A team led by scientists at the University of California, Santa Cruz, has been studying the submarine springs at Puerto Morelos near the Mesoamerican reef for the past three years. The researchers reported their findings in a paper published in the journal Coral Reefs (published online Nov. 20).
"This study has some good news and some bad news for corals," said coauthor Adina Paytan, a research professor in the Institute of Marine Sciences at UC Santa Cruz. "The good news is that some species of corals are able to calcify and grow at very low pH. The bad news is that these are not the ones that build the framework of the coral reefs. So if this is an indication of what will happen with future ocean acidification, the reefs will not be as we know them today."
The submarine springs, known as "ojos," occur along the eastern coast of the Yucatan Peninsula. Limestone "karst" landforms near the coast feature underground drainage systems that discharge brackish water at the ojos. The discharged water has lower pH than the surrounding seawater, and these conditions have existed for thousands of years. Lowering the pH affects the chemical equilibrium of se
|Contact: Tim Stephens|
University of California - Santa Cruz