Salt

In the later 17th century, the salt production on Portsea Island was ranked second in the country. Although salt has always been an important local industry, with many pre Roman sites being known, and eleven salt works being mentioned in the Domesday Book, it was given a boost by the founding of the Great Salterns works in 1666. A local entreprenuer, Richard Alchorne, dug salt pans in approximately 100 acres of land that had been reclaimed at Gatcombe Haven.
Great Salterns and another large salt pan at Copnor supplied the Navy, providing refined salt that was more reliable at preserving meat by brining rather than dry-salting.