The Food and Drug Administration said Friday that it will conduct further studies before implementing a plan to ban raw, untreated Gulf Coast oysters during months when they are most likely to be infected with a harmful bacterium.

The plan had sparked outcry from Southern politicians who feared it would devastate the regional industry.

The FDA proposal, set to take effect by summer 2011, was an attempt to prevent the 15 deaths on average that occur in the United States each year from the consumption of raw oysters infected with the bacterium Vibrio vulnificus.

A number of post-harvest treatments have been developed to kill Vibrio, but some aficionados say treatment defiles the taste of a classic and simple culinary experience.

Many in the oyster industry also said that the treatment equipment is prohibitively expensive for the mom-and-pop oyster processors that dot the Gulf Coast from Florida to Texas. Few companies are equipped with the treatment technology.

On Capitol Hill on Tuesday, the FDA came in for stinging criticism from Democrats and Republicans who said they worried about the effect the April-to-October ban would have on an industry that supports 3,500 jobs.

Sen David Vitter (R-La.), co-sponsor of a bill to cut off funding to the anti-bacterium push, hinted that he might find other ways to curtail FDA funding if his bill failed. Rep. Charlie Melancon (D-La.) -- who is challenging Vitter for his Senate seat -- said that 15 deaths a year was a "pretty reasonable" number, given the size of the United States.

FDA officials had argued that Gulf oyster businesses had been given years to work on an education campaign to lower the infection rate, but that it failed to meet its goals. At the same time, they noted, a California ban on untreated raw oysters wiped out occurrences of the disease in the state.

An FDA statement Friday said that the politicians and oystermen had "legitimate concerns" and that further study was needed to "address this important health goal."

The news came as a relief to Nick "Bez" Bezmalinovic, a small oyster supplier in Belle Chasse, La. His company sells about $1.3 million worth of oysters a year; a water-pressure treatment machine could set him back as much as $750,000.

"If I had that kind of money," he said with a chuckle, "I'd retire."

FDA officials plan to revisit the issue on a number of fronts. Among other things, they plan to speak with other federal agencies about establishing programs to help small oyster businesses afford the treatments.