Florida and 14 other states face big economic losses from global warming-induced "ocean acidification" that could gut commercially valuable shellfish populations, according to a new study.

The highest vulnerability in Florida resides in the Panhandle, home to most of state's shellfish industry. But off Florida's east coast, little is know about the long-term effects of lower pH in the ocean or the Indian River Lagoon.

"We're monitoring very little coastal waters," said Lisa Suatoni, senior scientist at Natural Resources Defense Council, a nonprofit group that lead the study. "We have no information about the ocean chemistry for most of the east coast and west coast of Florida."

Nationally, the counties in the Florida Panhandle ranked 11th in economic dependence on shelled mollusks, according to the study, published online this week in the journal, Nature Climate Change.

The study included researchers from NRDC, Duke University, University of Miami, Oregon State University, and several other universities.

The research was funded by the National Science Foundation.

The researchers studied oyster, clam and scallop harvests because those are likely to be the first harmed by ocean acidification. They then mapped coastal communities most vulnerable to declining harvests. Maine, Connecticut, Louisiana and the Carolinas were among the most vulnerable.

But lower pH also could hamper efforts to restore oysters in the Indian River Lagoon. That's because excess nitrogen from fertilizer, sewage and other sources could heighten acidification, by triggering algae blooms. Bacteria that consume rotting algae release more CO2 in the water, Suatoni said. "It makes the problem even worse," she said.

Oceans absorb about a third of the carbon dioxide from the fossil-fuel fallout and other sources. As CO2 reacts with seawater, it slows the rate sea life can calcify to form shells and skeletons.

Although dubbed "acidification," seas won't actually become acidic, just less "basic" in pH.

Shellfish harvest generated an average of $6 million annually over the past decade in Florida, the study said. But the state's coral reefs generate more than $300 million a year, according to federal studies.

"We didn't include coral reef in this study, even though they are incredibly vulnerable," Suatoni said. "Anytime they're hit by diseases or a storm, they rebound much slower. It's like osteoporosis: once you break your bone, it's very hard to repair it."

Seagrass might thrive in CO2-rich conditions, but coral might not form skeletons fast enough to replace itself. Starfish, snails, urchins and lobster could be impacted, too. Biologists also speculate that carbonic acid also might buildup in body fluids of fish and other marine organisms, weakening their respiratory and immune function.

The researchers call for water pollution reductions from farms, development and sewage. They also urge more investment in shellfish aquaculture, especially to cultivate acidification-resistant shellfish.

Source - http://www.floridatoday.com/