Oyster farms in Virginia and beyond are suffering unexplained mass die-offs

When Bruce Vogt and his team at Big Island Aquaculture in Gloucester pull up their oyster cages from the water, they can instantly tell when some are dead. “We call them clunkers,” Vogt said. “Because it’s kind of a hollow sound the shell makes when they’re knocked together.” Since he opened Big Island about a decade ago, Vogt said they're seeing more and more clunkers. The company estimates they lost about four million oysters total – about four times the amount they plant each year. “You pull the bag up...