Disappearing oysters could spell trouble for environment, economy

Oysters are a common menu option at restaurants, but researchers at the University of South Florida found they are disappearing from the Gulf Coast, negatively impacting the environment and economy. 

USF researchers said wild oysters in Crystal River are shrinking – now a third smaller than before compared to oyster shells from hundreds of years ago.

“Whenever these oyster populations are decreasing in size, that tells us that they're close to collapse and they won't take much more,” said Greg Herbert, an associate professor at USF’s School of Geosciences.

Herbert worked on a study published Wednesday in Biology Letters that shows how oysters in the Big Bend area, once thought to be pristine, and are disappearing.

“What our study does is that it tells us the Big Bend is in much more dire condition than previously realized,” said Herbert.

Oysters create habitats for marine life and help humans on land.

“The oyster reefs are like a natural sea wall. So, if we lose those reefs, our coastlines become less stable,” said Herbert. “We could lose property and that's also bad for Florida.”

A potential collapse would also impact those who harvest wild oysters for the restaurant industry. Brian Rosegger of Lost Coast Oyster Company hopes to help as an oyster farmer.

“With every farmed oyster out there that hits a dinner plate, that's one less oyster that's harvested from the wild,” said Rosegger, who runs the company with his wife. 

He buys the shellfish when they are the size of a fingernail and places them in bags for a water column farm. 

“While they're out at the farming location, they're filtering the water, getting the free food that's abundant in the water,” said Rosegger. “And as they grow we move them up into larger and larger size mesh bags.”

Then he spends months tending to them off the coast of Manatee County before taking them to a wholesaler for Tampa Bay area restaurants to buy the half shell oysters.

While Rosegger works to take the stress off the environment right now, USF researchers said the decline spans centuries.

“It's hard for humans to understand that time scale. We can only see changes over just a few years, and so we may have lost a lot more than we realize,” said Herbert.

While doing the study in 2014, researchers said the Apalachicola oyster industry collapsed. 

Herbert said some factors contributing to the loss of the oyster industry include sea level rise and the amount of water being drained from estuaries for development. 

Researchers hope their findings in the study will give more insight into conservation efforts needed to restore oyster reefs.