Use of dredged material to recreate sand or mud flats - management options

Using maintenance and other dredged material for restoring tidal flats and providing sediment for saltmarsh growth has been extensively employed in wetland re-creation in the USA. However its use can be problematic due to the contaminated nature of estuarine and other tidal sediments. Some of the other pitfalls associated with the impact on the dredged sites are provided by a study of the situation in Holland . Timing, frequency and location of dumping sites are all important to finding ways of mitigating adverse impacts, especially in relation to filter-feeding organisms and on benthic fauna (Essink 1999).

Its use in the UK is restricted though recent experiments have been undertaken in Essex from material dredged from Harwich Haven for the Felixstowe docks. In the Conwy Estuary, north Wales dredged material has been placed to landward to create new coastal habitats which have developed considerable interest in a relatively short space of time.

Comment: There are relatively few examples of the use of dredged material for re-creating sand or mud flats in the UK. However a very useful source of information can be found on the English Nature web site http://www.english-nature.org.uk/ where two reports are available (Research Report No 7, Capital and maintenance dredging. A pilot case study to review potential benefits for nature conservation, available in 4 parts to download and Research Report No 13, An experimental study on the impact of clam dredging of soft sediment macroinvertebrates. Contact the Enquiry Service to get your free copy of the Research Report.), enter publications and search on 'Dredging'.

References

Essink, K. 1999. Ecological effects of dumping of dredged sediments: options for management. , 69-80. Abstract...