BOSTON (CBS) – The state says the waters of Cape Cod Bay are getting warmer, which is raising the risk for bacteria that infects raw oysters.

Five people got sick last year eating raw oysters contaminated not from polluted beds, but from naturally occurring bacteria called Vibrio.

WBZ NewsRadio 1030′s Laurie Kirby reports

State Marine Fisheries Chief Shellfish Biologist Mike Hickey says starting this summer, oyster growers and harvesters will be required to get their oysters onto ice or a refrigerator within five hours.

The plan comes with some challenges during the evening tides, but Hickey says its better than the extreme option suggested of allowing raw oysters in the summer to be sold only for cooking.