Appropriate Assessment Report Assessment of the likely effects of dredging of the navigation channel in Sligo harbour on the integrity of the Cummeen Strand / Drumcliff Bay SAC and the Cummeen Strand SPA Project Description: Sligo County Council proposed to carry out capital and maintenance dredging works in a 5.3Km stretch of the navigation channel between Oyster Island and the Barytes Jetty in Sligo Harbour. The areas to be dredged are shown on Drawing No. IBE0440 Attachment 3(i), dated 8/10/2012 that accompanied the application.. For the Capital dredging element of the proposed works it is intended to dredge the channel to a depth of -3.0m CD and it is estimated that the total volume of material to be dredge will be 250,000m3. The dredging will be carried out using either a Suction Dredger or a Backhoe Dredger but the exact dredger type to be used will not be known until a Contractor has been appointed. It is intended that all the dredged material will be disposed of at sea, subject to a Dumping at Sea Permit being granted by the EPA, at a site located some 63 Km from the deep water jetty in Sligo Harbour, approximately 31.5 Km southwest of Malin More Head. Given the shallow water depths in the existing channel it is anticipated that the dredger will have to “dig its way upstream” and thus will only be able to carry out dredging during the upper half of the tidal cycle. It is estimated that the dredger will only be able to operate for a period of 70 – 80 minutes during each tide. The remainder of the time would be spent steaming to and from the dump site. It is anticipated that the dredging operation will take 4 – 8 months to complete. Capital dredging to -3.0m CD is proposed to give vessels with a draught of 5.9m a 3 hour window at high tide during which they could complete the passage through Sligo harbour into the Port. It is also intended to carry out maintenance dredging, using Water Injection Dredging (WID) of an area within the Sligo Port as shown on Drawing No. IBE0440 Attachment 3(i), dated 8/10/2012. This will involve the removal of some 5,500m3 of material from the area around the channel to the Deepwater jetty and berths at both Deepwater and Barytes Jetties. It is intended that WID will be carried out on an ebbing tide in order to ensure that suspended particles are transported away from the Port area and it is anticipated that the WID operation would be completed within 5 -6 tides. Details of the proposed works are shown the following Drawings submitted by the applicant in support of the application: o Drawing No IBE 0440-Attachment 3(i) ‘’A3 Overview Navigation Channel Dredging Areas(OS) o Drawing No IBE 0440 Attachment 3(ii) ‘’A3 Overview Navigation Channel Dredging Area(Admiralty Chart 2852) o Drawing No IBE 0440/500-Rev 0- ‘’Plan Overview of Dredging Cross Section Locations o Drawing No’s IBE 0440/500_1, IBE 0440/500_2 and IBE 0440/500_3-Rev 0- ‘’Dredging Cross Sections’’ The total area of foreshore involved is estimated to be 28.3Ha. The area of the proposed works is within the Cummeen Strand / Drumcliff Bay SAC (Site Code 000627) and the Cummeen Strand SPA (Site Code 004035). A Natura Impact Statement to inform Appropriate Assessment, dated October 2012 prepared by AquaFact International Services Ltd was submitted by the applicant. Cummeen Strand / Drumcliff Bay SAC This large coastal site extends from Cullamore in the north-west to Killaspug in the south-west, and from Sligo town in the south-east to Drumcliff village in the north-east. It encompasses two large, shallow bays (Drumcliff Bay and Sligo Harbour), Ardboline and Horse Islands, sand dunes and sand hills at Rosses Point, Killaspug, Yellow Strand and Coney Island, grassland at Ballintemple and Ballygilgan (Lissadell) and a variety of other habitats (woodland, salt marsh, sandy beaches, boulder beaches, shingle, fen, freshwater marshes, rocky sea cliffs, lakes). The dominant habitats on the site are estuaries and intertidal sand and mud flats. Sligo Harbour receives the waters of the Garavogue River, which flows from Lough Gill, while Drumcliff Bay receives the Drumcliff River which flows from Glencar Lough. At low tide extensive areas of intertidal flats are exposed in both of these sheltered estuarine bays. The intertidal flats support a diverse macrofauna, with invertebrate species such as lugworm (Arenicola marina), cockles (Cerastoderma edule), sand mason (Lanice conchilega), Baltic tellin (Macoma balthica), spire shell (Hydrobia ulvae) and mussels (Mytilus edulis) being frequent. Of particular note is the presence of eelgrass (Zostera noltii and Z. angustifolia) beds in both bays. Both estuaries and intertidal flats are of conservation significance and are listed on Annex I of the EU Habitats Directive. Areas of salt marsh fringe both bays in places. At least five species listed on Annex II of the EU Habitats Directive are found within this site. Drumcliff Bay is important for the presence of a breeding population of Common Seal. Ardboline and Horse Islands on the western side of the site are also important as haul-out areas for this species. Sea Lamprey and River Lamprey have been recorded in the Garavogue River, and River Lamprey are also known from further upstream in the tributaries of Lough Gill. The Marsh Fritillary butterfly is found at Rosses Point, while the rare snail, Vertigo angustior has recently been recorded from sand dunes at Killaspugbrone. Cummeen Strand/Drumcliff Bay (Sligo Bay) is an important site of high conservation significance, which includes a wide variety of habitat types, including several listed on Annex I of the EU Habitats Directive, several species listed on Annex II of this directive, large and important populations of waterfowl and seabirds, and several rare plant species. As set out in the NPWS (2013)1 the key Conservation Objectives for this site are : To maintain the favourable conservation condition of Estuaries in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To maintain the favourable conservation condition of Mudflats and sandflats not covered by seawater at low tide in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To maintain the favourable conservation condition of Embryonic shifting dunes in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To restore the favourable conservation condition of Shifting dunes along the shoreline with Ammophila arenaria ('white dunes') in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To restore the favourable conservation condition of Fixed coastal dunes with herbaceous vegetation ('grey dunes') in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To restore the favourable conservation condition of Juniperus communis formations on heaths or calcareous grasslands in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To maintain the favourable conservation condition of Petrifying springs with tufa formation (Cratoneurion) in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To maintain the favourable conservation condition of Narrow-mouthed Whorl Snail in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To restore the favourable conservation condition of Sea Lamprey in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To maintain the favourable conservation condition of River Lamprey in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC To maintain the favourable conservation condition of Harbour Seal in Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC Impact of Project on key species and key habitats Considering the location, nature and scale of the proposed works it is considered that no direct or indirect effects are likely on the following species / habitats o Embryonic shifting dunes along the shoreline with Ammophila arenaria ('white dunes') o Fixed coastal dunes with herbaceous vegetation ('grey dunes') o Juniperus communis formations on heaths or calcareous grasslands o Narrow-mouthed Whorl Snail Noise associated with the works could result in the disturbance and displacement of Harbour seal and other marine mammals. Noise and resuspension of sediments during the dredging operation, could impact on the passage of migratory fish including river lamprey and sea lamprey. 1 NPWS (2013) Conservation Objectives: Cummeen Strand/Drumcliff Bay (Sligo Bay) SAC 000627. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht. Resuspension of sediments during dredging with subsequent resettlement could have an indirect effect on Mudflats and sandflats not covered by seawater at low tide The dredging operation, both capital and maintenance, as proposed will have a direct impact on circa 28.3 Ha of the following habitats “Estuaries” habitat. Harbour seal (Phoca vitulina), is a species listed in Annex II of the EU Habitats Directive and is a qualifying feature/interest for the Cummeen Strand/Drumcliff Bay Special Area of Conservation. Drumcliff Bay is important for the presence of a breeding population of Common Seal while Ardboline and Horse Islands on the western side of the site are also important as haul-out areas for this species. There are, however, no known seal breeding or haul-out areas in the areas to be dredged. Other marine mammal species, including the cetacean species Bottle nose dolphin and Harbour porpoise have been sighted in the Sligo area but are not known to be resident within the Sligo Harbour area. All cetaceans are listed under Annex IV the Habitats Directive. The interaction with marine mammals will be mitigated by the employment of a Marine Mammal Observer and the use of “soft start” procedure. The Marine Mammal Observer will undertake 30 minutes of survey prior to commencement of the soft-start procedure to ensure that no marine mammals are within 50m of the works area. The noise producing works will not be continuous. Any increase in water column turbidly will be temporary, localised and within the natural range of variability caused by current induced sediment resuspension.