Medieval to post-medieval oyster pits at Cindery Island, Brightlingsea (EHER 16951)

A salt marsh island, 1km long and 200m at its widest, which is largely covered in rectangular oyster pits and sluice gates, cut into the salt marsh in an irregular pattern.

Aerial photography and cropmark evidence. This salt marsh island, 1km long and 200m at its widest, is largely covered in rectangular oyster pits, cut into the salt marsh in an irregular pattern. These are visible on various sources of aerial photographs. <1>-<4> June 2010. Field Survey. Cindery island comprises saltmarsh, commonly described as ‘salting’, the survival of which will be aided by depositing material onto the island during a programme of replenishment. The saltmarsh island is divided in two by a small channel called The Folly and this survey was undertaken on the Westernmost part of the island. Rills (saltmarsh creeks) lace the island, which is inundated with man-made oyster pits. During the medieval period, and until the early 20th century, the main local industry was oysters. The early industry revolved around oyster dredging and dredging passes were granted at the Admiralty courts to people from Colchester, Brightlingsea and surrounding towns and villages. By the 16th century, the natural stock of oysters had been over-fished to the point of destruction, following an Act of 1562 allowing the free sale and export of fish which inadvertently created a massive increase in the number of oyster dredgers. The oyster shortages of the 16th and 17th centuries led to the introduction of oyster husbandry, which eventually largely replaced the method of controlled gathering. Oyster pits were used to overwinter the growing oysters and enabled full-grown oysters to be stored prior to sale. Most small growers required at least two pits, which were usually haphazardly excavated in any convenient area of level saltmarsh. The pits were of varying size and usually three feet (0.75m) deep, so that they were submerged at spring tides. The bottoms of the pits were floored and the edges sometimes boarded, while an outlet channel and dam were necessary to allow for cleaning. Later a wooden shutter was introduced, set in an angle-iron frame and acted as a sluice. A site visit undertaken in June 2010 showed that the preservation of the surviving oyster pits varies considerably. Some are only visible as shallow depressions, silted up and grassed over, while others are still recognisable as square and rectangular open pits. The survival of a small number of sluice gates may represent management of the island by the oyster men, though they may also represent various attempts to manage and maintain the salt marsh island over the years. The aerial photography shows that several pits overlap, indicating that over time such was the high demand for pits that new ones were cut, at least in part, into older, disused pits that had silted up or been deliberately infilled. <7> See also <8> <9>