Whilst boating in Chichester Harbour you may have noticed diggers and heavy equipment operating on the shore at West Itchenor. This is part of an exciting project by the the Chichester Harbour Conservancy to restore saltmarsh in our harbour which has been contracting due to sea rise and the inability for the plant to retreat inland because of man-made defences. Saltmarsh is important within our coastal ecosystem as it stores carbon, helping to counter climate change, and acts as a natural flood and coastal defence as well as helping to improve water quality.
The project began in February this year and piloted a new technique, the ‘Saltmarsh Restoration Dragbox’ (SRDB). Designed by the company Land and Water, the drag box pulls sediment dredged elsewhere in the harbour higher up the intertidal area to a level where it is hoped that the saltmarsh can become established and colonise the area without being washed away.
The sediment itself came from a routine maintenance dredge at the entrance to Chichester Marina with around 1,600 cubic meters of dredged sediment being deposited at West Itchenor. Each load was delivered at high tide as far up the intertidal area as water depths would allow. When the tide had retreated far enough, all the sediment was transferred to the top of the shore by the SRDB and moulded into shape. Once in place the sediment settled relatively quickly, drying out, and seemingly unaffected by tides or weather conditions. A survey of the trial site shows that the placed sediment is at heights which should be suitable for saltmarsh plant colonisation. The total area measures around 0.25 hectares.
In the last couple of weeks the first shoots have been spotted on the site. This is great news for the trial and we hope other areas will be identified to restore more saltmarsh to our harbour.
There is a informative fifteen minute video link on this saltmarsh restoration project HERE
Find out more about similar Chichester Harbour Conservancy initiative’s by visiting their dedicated website at www.chapron.org.uk.
