Federal officials plan to ban sales of raw oysters harvested from the Gulf of Mexico unless the shellfish are treated to destroy potentially deadly bacteria.

Opponents say the requirement could deprive diners of a delicacy cherished for generations.

The proposal would take effect in 2011 for fresh Gulf Coast oysters harvested during warm months. Those oysters would have to be treated with low-dose radiation, a process that would kill them before they get to market.

Industry officials argue that the procedure is too costly. They say adequate measures already are being taken. The Gulf supplies about two-thirds of U.S. oysters.

About 15 people die each year in the United States from raw oysters infected with Vibrio vulnificus, which typically is found in warm coastal waters between April and October.