The northern part of the Florida Keys’ reef is shrinking faster than expected, according to a new study. This is because seawater has become more acidic presumably due to global warming. The acidic seawater is causing erosion in parts of the limestone framework for coral reef.

Researchers at the University of Miami (UM) say that oceans suffer from a process called ocean acidification. This means that each year, the ocean absorbs carbon dioxide from the atmosphere. Which in turn dissolves in seawater, therefore making oceans become more acidic. The study was published Monday in the journal Global Biogeochemical Cycles.

Florida Keys Reef
The coral erosion was projected to start between 2050 and 2060, but researchers claim it started earlier. The effects have begun in the northern parts of Florida, mainly because cold weathers fasten the carbon dioxide’s absorption. Credit:IBK News

The carbon dioxide absorbed by the ocean causes the pH to drop. And it’s worth noticing the pH of the seawater surface, which has fallen by 0.1 units worldwide has increased its acidity over 30 percent.

However, it’s not unusual for reefs to disappear and reappear throughout the year. There’s a natural cycle of limestone production on reefs, where it grows faster in the summer when the water becomes less acidic. Afterwards, life in the reef tends to die in both winter and fall. This is when the water becomes naturally more acidic, slowing and stopping limestone growth.

Chris Langdon, a biological oceanographer at the University of Miami was the author behind the study published on Monday. He says that man-made carbon dioxide in the atmosphere is being added to the regular ocean acidification. Therefore making it more acidic than it should be, said Langdon. As humans continue to pump carbon into the air, the oceans will continue to become more acidic, he added.

“We tend to think we have a lot of time and this study shows we have maybe 30 years less time,” said Chris Langdon at University of Miami.

Seawater’s pH levels surprised researchers 

According to the study, the coral erosion was projected to start between 2050 and 2060, but researchers claim it started earlier. The effects have begun in the northern parts of Florida, mainly because cold weathers fasten the carbon dioxide’s absorption. Nonetheless, the situation is already moving south and away from Miami’s dense coast.

Langdon also said the northern part of the Florida Keys reef has already lost about 14 pounds of limestone over the past six years. The acidic water eats away the nooks and crannies of the limestone foundation, making them more porous and weaker. This corrosion makes the reefs dissolve and become flatter. Therefore causing fish to leave or die. Also, the acidic water eats away the shells of the shellfish, making them easier prey for other fish and harder for humans to harvest.

Different opinions on the reef’s sudden shrinking 

Mark Eakin, reef watch coordinator at National Oceanic and Atmospheric Administration (NOAA) waged in despite of not being involved in the study. Eakin claims the vanishing of the Florida Keys’ reef is another climate change-related case. And people underestimate the damage caused by excess carbon dioxide in the atmosphere, according to Mark Eakin.

Derek Manzello, a scientist in the ocean acidification program at NOAA said that ocean acidification is not the only cause of damage. Manzello adds that long-term coral bleaching and death can cause the limestone to dissolve too.

Reefs in Florida provide $2.8 billion a year to its economy due to tourists who pay to dive and fish, as well as commercial fishing.

Source: University of Miami (Press Release)