The end of Callis Wharf Road is not the end of the world; it just feels like it is.

From the careful-where-you-step pier at the dilapidated dock house, the protected waters of Milford Haven sprawl out, vast and rough in a brisk wind. To the west is the Piankatank River; to the north, the rocky Rappahannock. They all meet in the mainstem of the Chesapeake, just on the other side of an outbuilding barely holding its own against the wind and waves.

Only a small sign at the other end of the complex announces there is life within: Oyster Seed Holdings.

It is here, on Gwynn’s Island, that a young, one-time graduate student from Hampton Roads named Mike Congrove and a third-generation Deltaville waterman named Rufus Ruark Jr. have built the hatchery that is fueling the state’s fast-growing oyster aquaculture industry.

Oyster Seed Holdings has helped transform Virginia’s Middle Peninsula into a cottage industry of oyster growers, employing dozens of workers and supp...