Belfast Lough: from heavy industry to mariculture • The Belfast Lough Special Protection Area (SPA); – • The Belfast Lough Open Water SPA; – • designated for overwintering (non breeding) Redshank. designated for overwintering (non breeding) Great Crested Grebe. 25 licensed aquaculture sites of which 21 are active Aquaculture • Subtidal aquaculture sites for blue mussel (Mytilus edulis) culture within Belfast Lough • The total area of Belfast Lough occupied by aquaculture is approximately 1,270 hectares – a third of the inner lough • Cultivation began in 1989. Belfast Lough is the largest production area for bottom grown mussels in NI • The production of bottom grown mussels varied between 5177 t (2010) to 3458 t (2012). • In NI, aquaculture is now worth over €7.5 million annually, and the regulating department is aiming to increase this sector by 30% by 2020. • Co-location with Natura 2000 sites • Beds are licensed and regulated by Department of Agriculture and Rural Development • Activity is monitored and cumulative impact assessment undertaken for Natura 2000 sites • Import/export to beds and dredging activity monitored via vessel “black box” • Ecosystem modelling used to assess impact of blue mussel cultivation on wild species and optimal stocking levels Sustainable management Activity Seeding Equipment Modified Dutch Dredge Maintenance Starfish mop and Modified Dutch Dredge Harvesting Modified Dutch Dredge Timing Usually Spring and Autumn but is dependent on seed availability. Throughout the year. Market dependant as stock is harvested to order. Unprocessed filtered data Black Box data • Black box data is filtered in ArcGIS for: – Speed; – Location; – Month . • Provides estimate of intensity (number of logged positions per km²) Processed filtered data • Used to ensure activity is restricted to licensed beds and assess impact of activity on conservation designations (Natura 2000 sites) • Application in the MSFD indicator “physical damage” (part of Descriptor 6 – seabed integrity), to provide information on physical abrasion. This requires ongoing validation. Bathymetry data Multibeam echosounder survey • EM3002 dual head data processed by British Geological Survey to yield 1m horizontal resolution and <10cm vertical resolution bathymetry and backscatter imagery • Backscatter provides information on seabed texture, with seabed features evident including dredge scars • Use to validate black box data and assess persistence of dredge marks on seabed Backscatter data BGS – White Ribbon survey (EM3002) Backscatter mosaic (1m resolution) BGS – White Ribbon survey (EM3002) Backscatter mosaic (1m resolution)
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