The Massachusetts Division of Marine Fisheries (DMF) and Department of Public Health (DPH) ordered that Katama Bay oyster beds in Edgartown be closed to commercial harvesting for an additional seven days, beginning at sunrise on Wednesday, Sept. 2, due to three more confirmed cases of illnesses caused by eating raw oysters from Katama Bay. The original seven-day closure began on August 26, and was to have ended Thursday, Sept. 3.
“Should more cases be confirmed, an extended U.S. FDA–enforced closure could be issued,” the state agencies said in a joint press release issued Tuesday. “This is the first time a specific harvest area in Massachusetts has been closed due to Vibrio this year.”
The decision to issue a precautionary closure was made jointly between DPH and DMF officials, “in response to warming waters in Katama Bay, anticipated high air temperatures forecast for the coming days,” and additional confirmed cases of Vibrio tied to the Katama Bay harvest area. Six confirmed cases have been reported.
Vibrio is a bacteria that occurs naturally in coastal waters in the United States and Canada. It has caused illnesses in the Gulf Coast and West Coast of the United States for a number of years. It is not related to pollution of Massachusetts shellfish.
“It thrives in warmer temperatures, multiplying as water and ambient air temperatures increase. The more Vibrio present in oysters, the greater the risk of infection. Current water temperatures in Katama Bay are consistent with water temperatures and environmental conditions that were associated with an increased occurrence for Vibrio illnesses in 2013 and 2014,” according to a press release.
The Vibrio season in Massachusetts runs from May to October. Health officials are reminding all persons who are at high risk, especially those who are elderly or immune-compromised, to avoid eating any raw shellfish.
Due to the increase in Vibrio cases in 2012, and continued reports of Vibrio among people reporting consumption of raw oysters in waters beyond Eastern Cape Cod Bay, the FDA advised Massachusetts to expand Vibrio controls to all oyster harvest areas in 2013.