Island shellfish constables issued advisories this week after two cases of vibrio were confirmed to come from shellfish harvested in Lagoon Pond.

Oak Bluffs and Tisbury sent notices out to shellfishermen and placed advisories at landings and popular shellfishing areas Tuesday. The notices reiterate the proper protocols for recreational harvest. Donovan McElligatt, the Oak Bluffs shellfish constable, said that the cause of the illness is being investigated by the state Department of Public Health.

Vibrio bacteria replicate more quickly in warm temperatures and symptoms of infection include nausea, abdominal cramps, and diarrhea.

“The big risk of vibrio this time of year is exposure of the shellfish to what is called temperature abuse,” said Mr. McElligatt. 

Temperature abuse includes leaving shellfish in a hot car or under direct sunlight.

Mr. McElligatt stressed the three Cs of safe recreational harvesting: check to make sure the shellfishing area is open, chill shellfish after catching, and cook the catch. He added that cooking shellfish to an internal temperature of 145 degrees for 15 seconds will destroy vibrio bacteria.

Danielle Ewart, the Tisbury shellfish constable, said she also sent a similar notice to permit holders in her town this week. She said that signs are being put out at popular locations like the opening of Tashmoo Lake. Ms. Ewart added that no cases of vibrio infection have been tied to Tisbury. 

There are no closures in either town due to the vibrio bacteria. 

“We know that due to record high water temperatures and record high air temperatures, it creates the conditions for the vibrio to grow if there’s improper handling,” said Mr. McElligatt. “It’s just too warm to play with letting them sit underneath the sun or even at the tideline.”