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Enterprise Energy Ireland Ltd Corrib Offshore EIS 7. FLORA AND FAUNA 7.1 Introduction An assessment has been made of the offshore and coastal areas of the proposed Corrib Field and pipeline route (to the high water mark), in terms of the likely impact on the habitats present, together with constituent flora and fauna species. Information provided is based on a review of the existing literature, consultation with a number of conservation organisations, and fieldwork in the Corrib Field and along the pipeline route. The offshore fieldwork was undertaken by Gardline and Aqua-Fact Ltd in 2000, and by EcoServe in 2001. The Corrib Field is located some 65 km west of County Mayo (see Figure 1.1) in approximately 350 m water depth. The proposed pipeline route runs east from the Field through Broadhaven and Sruwaddacon Bay to the proposed Terminal site at Bellanaboy Bridge. This section has been divided into offshore (defined as the waters outside Broadhaven Bay), nearshore (defined as coastal areas and waters within Broadhaven Bay) and the landfall area, including Sruwaddacon Bay (which is crossed twice by the pipeline). The pipeline and umbilical routes are described as one, except where the pipeline and umbilical are being referred to specifically. Maps contained in this section cover the offshore section of the pipeline route. The onshore section of the pipeline between the landfall and the Terminal is described in Section 19. 7.2 Study Methods The aim of the literature review, consultation exercises and surveys was to: • identify habitats or species on, or close to, the proposed Field and pipeline route, which are likely to be of commercial or scientific interest and/or conservation value; and • investigate the presence of protected species of flora or fauna. These findings have been used to identify mitigating measures to reduce the impacts during construction and operation. The methods and objectives of the Corrib Field and offshore pipeline route surveys were discussed and agreed with the Petroleum Affairs Division (PAD) of the Department of the Marine and Natural Resources (DOMNR). 7.2.1 Literature Review and Consultation Information was obtained from the following sources: RSK/H/P/P8069/03/04/01rev01 7-1 Corrib Offshore EIS Enterprise Energy Ireland Ltd • benthic communities: baseline surveys carried out in the general area of the Corrib Field and pipeline route, and existing marine biological survey data; • fisheries: ICES fisheries data, Irish catch data, the Central Fisheries Board and from Jee Associates (2000); • plankton: published sources; • seabirds: surveys conducted by the Cetacean and Seabirds at Sea teams of the Coastal Research Centre at University College Cork (CRC), on behalf of the Rockall Studies Group (RSG) and the Porcupine Studies Group (PSG) (Petroleum Infrastructure Programmes II and III), counts of wintering wildfowl and waders in the Sruwaddacon by Dúchas; and • cetaceans: stranding data recorded in the Irish Naturalists' Journal, sighting data supplied by the Irish Whale and Dolphin Group, survey carried out by CRC, a survey carried out by Gordon et al. in 1993 (Gordon et al., 2000), data collated by Berrow (2000), and two papers published by Clark and Charif (1998 and 2000). 7.2.2 Baseline Marine Studies and Surveys 7.2.2.1 Offshore and Nearshore Area Enterprise commissioned physico-chemical and macrofaunal sampling, and a seabed video and photograph survey in the vicinity of the Corrib Field and along the proposed pipeline route. The details of these surveys are provided below: Macrofaunal grab samples were taken from 27 sites within the Corrib Field during summer 2000. The locations of these sites within the Field are shown on Figure 7.1. A further 12 stations were sampled along the pipeline route between the Field and the landfall, their locations are shown in Figure 7.2. The samples were sieved over a 1 mm mesh. The surveys were designed to identify any changes in fauna in the Corrib Field which could be attributable to historic drilling activities, and to establish the main changes in benthic communities with depth along the pipeline route. Some of the stations sampled will also be useful as future baseline reference points, as they were outwith any potential impacts from drilling and pipelay operations. In most cases three replicate grab samples were obtained from each of the Corrib Field sites, however there were some sites where only two were retrieved. Two replicates were analysed from each of the pipeline route stations. In order to have comparable data on density of individual organisms for the Corrib Field sampling locations, the numbers were multiplied up to give a number of individuals that would be found in 0.5 m2 (for example, where 3 samples were taken the total was multiplied by 1.66, and where only 2 were 7-2 RSK/H/P/P8069/03/04/01rev01 Enterprise Energy Ireland Ltd Corrib Offshore EIS taken the total was multiplied by 2.5). A further sample from each site was taken for physico-chemical analysis (the physico-chemical results are presented in Section 8). The sampling was carried out using a 0.1 m2 Day grab, which is standard equipment for this type of survey. 6029000 6028000 REF1 6024400 C1 6027000 6024200 C2 18/20-3 6026000 6024000 C3 6025000 F7 C4 6023800 18/20-1 Z1 18/20-3 Northing 6024000 F1 F2 367400 367600 367800 Z2 F8 18/20-2z F6 6023000 18/20-4 REF2 Z7 F4 F3 6023500 6022000 Z8 Z3 Z4 18/20-2z Z12 Z11 Z10 Z9 F9 18/20-4 6021000 18/25-1 Z5 F5 6023000 Z6 366000 366500 6020000 363000 364000 365000 366000 367000 368000 369000 370000 371000 372000 Easting Key Existing Physico-chemical 18/20-4 Well & invertebrate sample location Figure 7.1: Benthic sampling locations in the Corrib Field RSK/H/P/P8069/03/04/01rev01 7-3 Corrib Offshore EIS Enterprise Energy Ireland Ltd 6030000 REF1 6025000 41A 38A 36 35 17 12 33A 10 REF2 32A 18 30A 21 20 28 27 15 6020000 15A 26 25C 6016000 8 Northing 25B 6015000 25A 25 JN336 6015500 STN 1 T1 HS T1 LS T1 MS JN336 JN336 JN336 STN 3 6010000 STN 4 STN 2 6015000 444000 445000 446000 447000 T6 MS 365000 370000 375000 380000 385000 390000 395000 400000 405000 410000 415000 420000 425000 430000 435000 440000 445000 450000 Easting Key Existing Sealine Coastline Physico-chemical Invertebrate Location Well 18/20-2z Route Location Figure 7.2: Benthic sampling stations along the proposed pipeline route 7-4 RSK/H/P/P8069/03/04/01rev01 Enterprise Energy Ireland Ltd Corrib Offshore EIS In addition to the intrusive sampling, sediment photography was also undertaken. The sediment surface was photographed at all sites, and at several sites in the Corrib Field, sediment profile imagery (SPI) was also undertaken. SPI photographs show a vertical profile of the sediment, taken by equipment which penetrates a few inches below the sediment surface. Corrib Field photos (including SPI) are provided in Figure 7.3, along with the numbers of species found at each site. Pipeline route photos are provided in Figure 7.4, along with the numbers of species found at these sites (Figures 7.3 and 7.4 are provided in plastic folders at the back of this chapter). The aim of the surface photography was to provide a record of the fauna and flora which is present on the seabed, but not easily sampled using the Day grab. In addition to the stills photography, video of the seabed along the proposed route was taken at a number of places. The objective of this videography was to determine whether or not cold-water corals (e.g. Lophelia pertusa) were present. Lophelia tends to grow in deep water on hard substrates. The Corrib pipeline route has been designed to avoid rocky areas. However, historic ‘ice-berg’ scour marks do exist on the seabed close to the Corrib Field, and it was considered possible that the consolidated sediment at the edges of the scour marks could present a suitable substrate for Lophelia. From the videos there is no evidence of Lophelia along the pipeline route or in the Corrib Field itself. It should be noted that Lophelia has been recorded in deeper water to the south and west of the Corrib Field, but within the Erris and Slyne troughs (IOOA, 1998). 7.2.2.2 Landfall and Sruwaddacon Bay A walkover survey was carried out by Aqua-Fact in July 2000, of the intertidal zones at the upper and lower pipeline crossings, and at the landfall location, as shown in Figure 7.5. In addition, cores (0.01 m2) were taken along transects from a number of tidal heights (where the substrate was soft) at these crossing points. The samples were sieved over a 1 mm mesh, and the invertebrates found were identified and counted. The sampling points from the 2000 survey are shown in Figure 7.5. An additional marine ecological study of the Sruwaddacon Bay crossing points and pipeline landfall was undertaken by EcoServe in June 2001, to build on the information collected in the previous survey. The upper and lower pipeline crossings and the pipeline landfall were all sampled from the shore at low water during spring tides. Upper Crossing Point In 2001 littoral habitats and communities (biotopes) and fauna and flora on the upper shore were mapped, in order to provide an assessment of the marine/estuarine fauna, flora and habitats present. Particular attention was paid to the site of the proposed pipeline crossing and to adjacent shores. Here transects down the shore on both sides of the Sruwaddacon were examined and quantitative samples taken from each of the main biotopes.