Monument record SUE 054 - Probable Post Medieval oyster beds and sluice earthworks on the Sudbourne bank of the River Alde

Probable Post Medieval Oyster pits and sluice eathworks are visible on aerial photographs as earthworks in the inter-tidal salt-marsh of the River Alde, centred on circa TM46075538. The oyster pits are visible as square or rectangular pits cut into the saltmarsh, connected by channels that allowed the flow of tidal water between the pits to encourage the growth of shellfish. The pits are visible on aerial photographs from 1941 onwards and are not marked on the first or second edition Ordnance Survey maps of 1884 of 1904 (S1-S4). A number may therefore be modern in date, and indeed, on the 1945 photographs a number of the pits appear to be very well defined suggesting a relatively recent date for their construction. However, the majority are eroded to varying degrees, and the remains of more pits are undoubtedly visible but are not discernible from the saltmarsh with any level of confidence. A Post Medieval date for most of the oyster pits is therefore likely. By 1975 even the clearest pits on the 1945 photographs are completely silted or have begun to silt up (S5). The sluice earthworks are visible flanking a sluice channel in the saltmarsh at circa TM64725476. They are clearly visible at hight tide on aerial photographs of 1943 (S6). The sluice probably post dates the reclamation of Sudbourne marshes and is therefore likely to be Post-Medieval in date.