Mapping an aggregate extraction site off the Eastern English Channel: a methodology in support of monitoring and management

Each year approximately 23–28 million tonnes of sand and gravel are removed from offshore sediments around England and Wales. This study was located in a licensed marine aggregate extraction site off Shoreham in the Eastern English Channel (EEC thereafter). Results from the multibeam survey showed the presence of dredged pits created by suction hopper dredging and elongated furrows created by trailer suction hopper dredging in the area where sand and gravel had been excavated. Electronic Monitoring System (EMS) contained the dredging intensity recorded annually at the site; this information was combined with particle size data providing interpreted maps, which informed the status of the sediments at the site.The aim of the current study was to explore the presence of marine habitats over a smaller area known as the ‘Shoreham Box’ in the EEC. Results showed some differences in the community composition produced by the two methods of extraction. There was also indication of enhanced number of species in the area dredged by suction hopper method. Notably, slipper limpets were also observed inhabiting dredged pits and creating permanent habitats in areas cratered by the dredging activity.This study has generated ecological information on the status of species and habitats inhabiting the dredged and undredged area. Management considerations are also discussed to ensure that sound aggregate extraction practices are in place to minimised the effects of aggregate dredging over licensed areas