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ABPmer
Quayside Suite
Medina Chambers
Town Quay
Southampton
SO14 2AQ
2020
Unmanaged realignment
United Kingdom
Langstone Harbour
-0.9899497
50.839118
Lagoon
Mudflat
Saltmarsh
5 Hectares
Create a More Natural Shoreline
Other
The seawall at Southmoor was breached by the tide in September 2020. Following a pattern that is common in such 'unmanaged realignment' sites, there was a relatively small amount of seepage through the wall on the larger tides over the first days. Over time the breach matured and the site become more frequently and fully inundated (see photos taken in 2021 nearly one year later).
The poor condition of the wall was recognised well in advance and the Environment Agency developed plans for a managed realignment back in 2017 (see links below). In the design of that planned project, the breach would have been located at the weakest point on the wall which is where the tide did eventually break though.
This deliberate and ‘managed’ realignment was not progressed due to concerns about the underground services to Hayling Island that run across the site. In the end however, the failure of the sea wall essentially created the wetland that had been planned anyway.
As is typical for such newly formed coastal wetlands, the habitat developed relatively quickly. After two years the environment was already looking relatively mature. This can be seen in photos taken by the RSPB at the end of 2022 and into early 2023. There was little if any formal monitoring of the site in its first few months/years. But, based on visual/photographic evidence alone, the mudflat looks rich in invertebrates after two years with active signs of foraging by waterbirds, fish and foxes. Several Little Egret were found at the site and were seen roosting in the trees at the back. Their presence here may well signal a richness of fish prey species.
The RSPB photos include an excellent aerial/drone view of the whole site taken in October 2022.
ABPmer
Quayside Suite
Medina Chambers
Town Quay
Southampton
SO14 2AQ