NHER 27739 (Monument record) - Post medieval to modern date intertidal structures and enclosures

September 2002 & November 2004. Norfolk NMP.
A series of post medieval to modern date intertidal structures and enclosures associated with mussel farming are located within the Blakeney harbour channel are visible on aerial photographs (S1-5).The site is centred on TF 9885 4533, although see below for potential positional inaccuracy. The main component of the group is a large trapezoidal mussel bed and possible associated weir. A further submerged rectilinear enclosure is also visible and this appears to be connected to the larger structures by a series of linear features. This site was first identified from aerial photographs and has since been visited on the ground. Further intertidal structures are located in close proximity within the Blakeney Harbout channel and some of these may be part of the same complex of mussel beds (NHER 27740, 38487-90). However it is possible that some of these structures relate to earlier exploitation of the channel, see NHER 38487-90.

The large trapezoidal enclosure and possible associated weir were identified in the Blakeney harbour channel on aerial photographs from 2000-2 (S1-3). Subsequent aerial photography taken in 2005 revealed the site to be more extensive and complex (S4-5). These structures were initially interpreted as a fish trap and weir of potential saxon to medieval date. However a post medieval date was considered the most likely due to recorded change to the course of the Blakeney channel, which is known to have altered significantly in the last few centuries. This channel has lengthened and shifted almost 3km to the west since the late sixteenth century (Hooton, 1996,13-22) (S6), taking in the location of the structures. The changes were caused by the shifting formation of a large shingle spit to the north, plus a reduced tidal discharge and scour caused by the reclamation of the surrounding saltmarsh.

The largest structure is approximately centred on TF 9882 4537 and is roughly trapezoidal in shape. It measures 58m by 50.5m and the diagonal measurement is 67m. From initial inspection of the aerial photographs the structure was thought to be timber, with a possible wicker or wattle component, although stone construction is possible. Unfortunately the site was largely obscured by silt and the reflection of the water in the aerial photographs. A site visit would be necessary to ascertain the actual construction method. ( See below for details of field visit indicating that the structure is cobble built)

The sides of the structure appear to be less than 1m thick. The south-western side appears to be complete. The south-eastern side has one possible 3m gap to the south. The north-eastern side has two gaps, the largest being 2.5m across. The north-western side has two 1.5m gaps and both of the corner joints are open. It is possible that these gaps are due to later damage to the structure, however, they seem fairly clear and are probably part of the original design. It seems likely due to the structure’s position in the harbour channel that this feature is a fish trap or similar site. However the shape of it and the location of the gaps does not seem to work with the flow of the channel. It is hard to see how this structure would have caught fish effectively, presumably nets would have had to be involved. It is also very large for such a feature. It is therefore possible that this is a storage enclosure for fish, oysters or mussels. The photography taken in 2004 (S4-5) has subsequently revealed that there were additional conjoined enclosures to the immediate south east of the main structure.

To the immediate S. W. is a linear feature running from TF 9879 4535 to TF 9873 4526 for 110m. It was thought that this may represent a line of posts or a low wall. The line of this linear kinks out to the west to form a point, from which a perpendicular linear structure runs from TF 9874 4530 to TF 9877 4529, measuring 24m long. The majority of the structure is approximately 2m across, although much silting appears to have taken place against the structure, particularly around this central perpendicular feature, where it measures as much as 7m across. Along the north-eastern end of the structure from TF 9815 4532 to TF 9877 4533, the linear splits into two forked sections, 2m across and 23m in total. These appear to be separated by a gap on either side up to 6m across. This area may have been netted and acted as a fish trap. The whole structure with its slightly ‘arrow’ shaped design would appear to be a fish weir. These structures are often Saxon in date, however, the large size of these two constructions may indicate that they are later, possibly medieval to post medieval in date.

To the east, centred on TF 9895 4535, a further rectilinear submerged structure can be seen emerging on the edge of the present channel. This measures at least 30m by 20m.This appears to be linked to the larger trapezoidal enclosure to the east by a series of linear structures or banks (S4-5).

Due to a lack of sound control points to aid the location of the feature from the aerial photographs, it is possible that the locations of these features may be marginally inaccurate. Hopefully the future NAU Coastal Field Survey will provide further locational information for the site.
(S1-6)
S. Massey (NMP), 26 September 2002 & November 2004.

January 2004.
Site visited by John Wright of Blakeney Historical Society. The structure of the main trapezoidal enclosure is identified as being 'walls' constructed from narrow lines of flint cobbles (c. 4-6 inches in diameter) mostly clean on their undersides. The linear feature extending to the south from the southwestern corner of the enclosure, previously referred to a possible weir, was visible only as a discontinuous line of stones. In the area of the eastern enclosure and associated linears, a line could be identified at an angle to the shore extending out into deeper water. This linear appeared to be a narrow ridge of small flints, resembling a shingle bank. This feature along with the other inter-tidal sites in the area were interpreted as being relatively recent (20th century) and relating to the mussel industry. The enclosure was interpreted as a relatively recent (20th century) mussel bed, created to form a lagoon during the ebb of the tide to give the mussels a longer time under water.
Comp. S. Massey (NMP), 10 May 2004.

June 2008. Norfolk NMP.
Letter sent to Eastern Daily Press in May 2006 (S7) stating that some of these mussel beds or 'lays' are still in use and were created in the twentieth century.
S. Massey (NMP), 17 June 2008.