Marinas in the harbour are dredged regularly to maintain safe navigational depth. Dredged sediments are presently disposed of outside the harbour, thus losing valuable mud from the harbour's ecosystem. In the new trial, which took place recently, fine mud from the Chichester Marina approach channel was released at a point near the harbour entrance and the fast flowing flood tide redistributed it throughout the harbour.

The research model showed that more than 50% of the mud would stay within the harbour to regenerate eroding mudflats and saltmarsh which are the most valuable habitats for wintering waders and wildfowl. The research also shows that there is no danger of the mud depositing on oyster beds or other sensitive sub-tidal communities and it will not settle in the navigable channels of the harbour. The trial was closely monitored by the Conservancy and by lead consultants HR Wallingford.

In addition to the benefits for wildlife, the ability to dispose of dredged material in the harbour may reduce dredging time and cost, to the benefit of harbour users.

The results of the trial will be published later this year.

The research is being funded by the Chichester Harbour Conservancy, the marinas in the harbour, English Nature, and the Standing Conference on Problems Associated with the Coast (SCOPAC).

MJ Information No: 19411