NHER 38490 (Monument record) - Undated submerged linear features, Blakeney Harbour Channel

March 2004. Norfolk NMP.
A group of possible submerbed and undated linear features are visible on aerial photographs within the Blakeney Harbour Channel (S1). These features appear to form 'L' or 'V-shaped' arrangements. It is possible that these are components of fish traps or mussel beds laid in the channel. The exact date of these features is not known, although it is possible that they be Anglo-Saxon, medieval or post-medieval or even modern in date. Similar shaped features have been identified nearby within the same channel (NHER 38487-9). Also to the west is a large complex of cobble and shingle built enclosures and structures relating to the post medieval mussel industry in the Blakeney Harbour channel (NHER 27739), although these may possibly relate to a different period of exploitation.

As these features are only partially visible within the water it is hard to discern the actual structure. From the available aerial photograph evidence these linear features are not as convincing as other identified in the channel, such as NHER 27739 and 38387. However it is possible that they are fish traps constructed from either wattle, posts or even low flint cobble walls. Similar intertidal structures in the channel have been provided to be constructed from flint cobbles, see NHER 27739. In this case the submerged 'enclosure' was interpreted as a modern mussel bed. However the 'V' shape is particularly reminscent of a fish trap. The V-shape design could have trapped fish as the tide receded along the channel. These structures often have a net or enclosure at the ‘eye’ of the 'V' to collect the fish, such as the fish trapped mapped during the Suffolk Coastal NMP in Holbrook Bay (Hegarty & Newsome, 2005, p61-2) (S2). Fish weirs and traps of this design are often Saxon in date, however, they can be much later, possibly Medieval to Post-medieval in date. In this case a post medieval or later date may be 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) (S3), 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 site is centred on TF 9856 4538. Although due to a lack of control points to aid the location of the feature from the aerial photographs, it is possible that this grid reference may be inaccurate. Hopefully the NAU Coastal Field Survey will provide further locational information for the site.

A clear L-shaped linear feature can be seen in the base of the channel running from TF 9854 4541 to TF 9850 4517, which is 38m in length. A comparable linear feature is visible to the east, although it is not as clear. Two other possible V-shaped features are centred on TF 9859 4534, the souther example is 59m and the northern is 30m.

Information has been provided by [1] concerning the modern and Nineteenth Century mussel industry in this part of the channel (NHER 27739). This included the construction of low flint walls and water breaks along the Blakeney Channel to create mussel beds. It is possible that these features are related to that activity.
(S1-3)
S.Massey (NMP), 03 March 2004.