It’s been bad news for shellfishing on Martha’s Vineyard and beyond in recent days, from a state-ordered closure to the discovery last week of a heavy algae bloom in the Tisbury Great Pond.

While a new study on Vibrio looks at possible causes, from warming seas to increased demand, Vineyard growers are using various techniques to combat the bacteria during the hottest months.

Under a silvery gray sky this week, brothers Dan and Greg Martino motored out from Lagoon Pond to their oyster farm off Eastville.

Charles Dickens had two out of three right when he spoke of oysters as “secret, and self-contained, and solitary.”

Katama Bay oyster farms reopened for business Thursday morning after a two-week closure because of Vibrio illness traced to consumption of raw oysters harvested from the water. The 12 aquaculture farms operating on the bay were back up and running early Thursday.

As Katama Bay oyster farms remain closed because of Vibrio illness tied to raw oysters, scientists are using the bay as a testing ground to understand more about the bacteria and how it interacts with oysters.