Investigation of East Bay Oyster Die-Off Mystery Underway

Dale Rooks says his customers are "crying" for East Bay oysters.

But the large, palm-sized oysters, renowned for their sweetness, are not showing up on his Marina Oyster Barn's menu as the seasonal dish customers expect this time of the year.

"We're finding very few alive," said Pasco Gibson, a main supplier of the East Bay oysters. "This time of the year, we should be catching 500 to 1,000 pounds per boat a day. We're not even catching a hundred pounds."

Oyster season opened on Oct. 1, and oystermen were expecting great hauls. Instead, they were alarmed when they dipped their long, wooden tongs with metal jaws into beds that had been teaming with large, juicy and healthy oysters at the end of last season, on June 30, and pulled up mostly dead ones.

"Something happened in August, and it had to be massive because some of these beds are 10 miles apart," Gibson said of the beds scattered near the shorelines of East Bay.

Depending on what's killing the oysters, once they start growing back, it could take up to three years to grow them large enough to harvest, he said.

To solve the mystery, scientists from the Department of Agriculture's Division of Aquaculture will be in town this week to check on the oyster beds.

Oyster die-offs are not unusual. And in the absence of scientific evidence, the cause of this one would be purely speculation, said Leslie Palmer, director of the Aquaculture Division in Tallahassee.

"A variety of causes could potentially be responsible for the deaths of adult oysters," she said.

Drought, extreme heat, warmer than normal water temperatures, high salinity and low oxygen in the water are suspect and could upset the delicate balance oysters thrive on, she said. Diseases and parasites also can wipe out an oyster bed.

Even though some local scientists say the effects of the April 2010 BP oil spill can't be ruled out, Palmer is doubtful the oil spill is to blame.

Robert Turpin, Escambia County's marine resources manager, said without data to support it, he, too, is hesitant to blame the oil spill. But it can't be ignored, he said.

Turpin believes stormwater runoff from Tropical Storm Lee's rain, which hit the area Labor Day weekend, could have pushed silt over the beds, smothering the oysters.

"That could be easily confirmed by jumping into the water and checking out the beds to see if it is silt or something else," he said.

Silting is a common occurrence. In the 1980s, Turpin was an oyster diver and said he saw a similar die-off following a hurricane.

Ecological effects

Oysters are very efficient spawners. They produce millions and millions of eggs, Turpin said.

"Unless all the oysters in the system had died off, and I don't have any way of knowing, then I would say oyster bed restoration projects would be able to reverse the trend," Turpin said. "If something out there is persistently killing the oysters, then restoration is not going to have an effect."

What troubles Turpin is how the die-off may be affecting the ecology and water quality of the bay.

"When you lose oysters, you lose a natural filtration system," he said.

The one agency that might have been able to shed light on what's going on, the Northwest Florida Aquatic Preserve office, was shut down by Gov. Rick Scott on July 1, amid state budget cuts.

The Garcon Point aquatic office was responsible for the restoration and preservation of salt marshes, seagrass beds and oyster beds, as well as shoreline stabilization and water quality monitoring of submerged lands from Perdido Key to St. Andrews Bay.

Since its closure, no one has taken over the monitoring of those preserves, a Florida Department of Environmental Protection agency spokeswoman said.

Troubling signs

Even before the start of the East Bay oyster harvest, there were signs that something was wrong with the oysters.

Carl and Ann Jeffcoat live in Gulf Breeze on Escambia Bay. They are self-professed oyster connoisseurs who have dined on raw oysters in France, Australia, Thailand, New York and in cities all along the Gulf Coast.

Hands down, East Bay oysters are their favorite and they occasionally pluck a few from the rocks on their seawall.

"I had noticed a really good crop of little oysters had come back a year or so ago after hurricanes Ivan and Dennis in 2004 and 2005 had killed them off," said Carl Jeffcoat, as he and Ann ate two dozen Apalachicola oysters at the Marina Oyster Barn last week. "Weeks ago, I noticed that it looked like there was some silting again, and it looked like many of the oysters were gone and many were opened. And I thought, 'Gee. That's puzzling.' "

Oysters on Gulf Breeze's Deadman's Island artificial reef in Pensacola Bay began dying off in July 2010. At the time, Deadman's Island restoration project manager Heather Reed thought it was an isolated incident related to the oil spill.

The reef was built in 2009 to protect the historically and environmentally significant isthmus from rapid erosion. It is only a few miles down current from Pensacola Pass, an area slicked with BP oil in the summer of 2010. Pockets of submerged oil remain in the pass.

"In April 2010, we did a survey of the reef, and everything was fine," said Reed, who served as the City of Gulf Breeze oil spill adviser.

By July 2010, an algae bloom overwhelmed the reef, the fish began disappearing and the oysters began dying. The algae bloom persisted through February of this year, she said.

By March, oyster drills, a tiny snail that eats oysters, took over the reef. Only a handful of live oysters remain.

Reed blames hydrocarbons, one of the chemicals found in crude oil, for feeding the algae bloom that may have killed the oysters and lowered the oxygen levels in the water.

"(Hydrocarbons) act like a fertilizer (for algae)," Reed said. "We saw the algae in the Gulf and all the way up to Garcon Point in Escambia Bay. And that takes oxygen out of the water."

Research by scientists at the Environmental Protection Agency's Gulf Ecology Division's research lab on Pensacola Beach measures water quality in the Pensacola Bay system. James D. Hagy, a research ecologist, confirmed low oxygen levels (hypoxia) have been detected in the water system.

"Adult oysters are relatively tolerant of low oxygen," Hagy said. "We do not have any data to show that any mortality that may be occurring right now was caused by hypoxia."

The lab does not monitor oyster beds, and the EPA offered no speculation on the cause of the hypoxia.

Now that Reed has learned the oyster die-off is more widespread, she is worried there won't be enough baby oysters spawning from East Bay this year to reseed Deadman's reef, something she was depending on. She is convinced the oyster die-off, similar to the mass die-off of sea stars and sand dollars in Santa Rosa Sound earlier this year, is an example of the long-term effects of the oil spill.

BP's Florida District spokesman Craig Savage said the oil company is working "cooperatively" with state and federal agencies, as part of the Natural Resource Damage Assessment process, to collect hundreds of field observations and thousands of oyster samples with a goal of further understanding all the potential factors that can affect oyster production.

"These results will help to guide the agencies and public in order to make informed decisions for future oyster management," he said. "We understand from federal, state, and academic scientists and fisheries experts that many factors can affect the population of oysters, which are independent of any potential impacts related to the Deepwater Horizon accident."

Waiting for answers

While he waits for answers, Gibson's worried.

"We have a real dilemma," he said. "They are vital to our bay."

His six oyster boats at his marina on Blackwater Bay are mostly idle. Some of his freelance oystermen are heading to Apalachicola, hunting for work. Gibson is losing 40 percent of his income because the meager harvest barely provides oysters for his restaurant, Nichols Seafood on Avalon Boulevard, and his customers, including Marina Oyster Barn, Atlas Oyster Bar, The Fish House and The Grand Marlin.

Jim Shirley, executive chef and co-owner of The Fish House, is disappointed he can't get East Bay oysters, which are favored among his customers.

"It's a great loss," he said. "They've been touted in Southern Living and Florida Life magazines and all kinds of places as the best oysters in America."

When Shirley first heard of the shortage, he had hoped it just meant one bad oyster bed in the bay.

"But this sounds like something else," Shirley said. "Those are our babies, one of our great claims to fame. We have so many fans of East Bays. Everyone will be sad not to have them."

Shellfish Experts Checking on East Bay Oysters

Scientists with Florida Division of Aquaculture began assessing the oyster beds in East Bay today.

The visit is part routine and partly in response to reports of the oyster die-off.

John Gunter, a shellfish biologist, spoke to the News Journal as he made his way to Pensacola from Tallahassee this morning.

The team will be doing routine “resource enhancement” of oyster beds, which calls for blowing new oyster shells onto the beds to create a shell base on which baby oysters can attach, he said.

Based on the reports he’s received about the die-off, his speculates the disease perkinsosis, commonly called dermo, is responsible.

Dermo is a prevalent pathogen of oysters that causes massive mortality.

Gunter said Galveston, Texas is dealing with a similar die-off in its bays. But he knows of no other areas along the Gulf Coast experiencing a mass die-off.

“Dermo has to play out,” he said of about the cycle of the disease. “It begins to reduce itself after it contributes to a high mortality.”

Dermo is prevalent when the weather is the hottest and there’s an imbalance in the salinity of the water.

But Gunter said he will know more once he’s able to assess beds.

Meanwhile, he, too, said it could take more than a year for the oysters to begin recovering.







© Copyright 2010 Save Our Gulf All rights reserved.