Most traces of historical fishing infrastructure have long since rotted away or been swallowed by silt, which makes the survival of this post structure, still legible in the channel, quietly remarkable.

A stake weir works by guiding fish into a confined space as the tide drops, using closely spaced upright posts driven into the riverbed or estuary floor, sometimes with wattle or netting woven between them. What remains here, documented by Aidan O'Sullivan in 2001, is a substantial example: the principal alignment of posts runs north to south, set at right angles to the tidal channel, and stretches some 35 metres in length. Flanking it are four further alignments, one to the east and two to the west running parallel to the main structure, and a fifth running east to west across its southern end, giving the whole arrangement an overall width of about 15 metres. O'Sullivan assessed the structure as probably dating from the nineteenth century, placing it in the post-medieval tradition of intertidal fishing that was once widespread along the Shannon but is now largely invisible to anyone not looking closely at the foreshore at low tide.

The structure sits on a muddy shoal roughly 50 metres to the south of Bush Island, and is only accessible to view at or near low water mark. The combination of tidal timing and the unremarkable appearance of wooden posts in estuary mud means this kind of feature tends to go unnoticed, which is part of why documented examples carry real value as evidence of how communities once worked the river.