ENVIRONMENTAL STATEMENT BARDOLINO DEVELOPMENT

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Bardolino Development Environmental Statement operations in the area. Restrictions for access to shipping and fishing will be limited to a safety radius 500 m centred on the vessel. 6.5.2 Impact on sensitive receptors and proposed or designated sites In 2007, Shell commissioned an anchoring conditions survey centred on the Bardolino well location and encompassing the proposed Bardolino to Howe pipeline route. This survey obtained detailed information on the bathymetry and seabed conditions. Seabed sediments comprise a veneer of sand with outcrops of clay and scattered cobbles and small boulders (Gardline Geosurvey Limited, 2007). No regions of potential Annex I habitats or habitats of potential importance were identified during the survey. Once the trenching, backfilling and/or rock dumping have been completed, natural sediment redistribution and re-colonisation by benthic organisms would begin. This would occur as a result of organisms migrating from adjacent areas into the displaced sediments, the reestablishment of organisms that survived the displacement, and the settling out of eggs and larval stages from the water column. Given the dynamic nature of the seabed sediments in the area, the infauna would quickly re-colonise the physically disturbed area and re-establish a community similar to that in adjacent undisturbed areas. The completion of rock dumping over the pipeline, either blanket cover or spot rock dumping, would introduce a different substrate to the predominantly sandy clay substrate in this localised area, although the seabed at the Bardolino location has been found to contain occasional gravel (Gardline Geosurvey Limited, 2007). The blanket cover of the pipelines would be not extend above the level of the adjacent natural seabed and could be expected to be re-covered by surrounding sediments following rock dumping. The spot rock dumping will result in areas of gravel above the existing level of the seabed. These areas would be minimised as far as possible, and result in a change to only a very small area of substrate in comparison with the available existing habitat in the region surrounding Bardolino. The introduction of this material would not be expected to result in a significant change to the benthic communities in the area due to the localised nature of the spot rock dumping and the predominance of unperturbed natural habitat in areas adjacent to the pipeline. Fish species may move away from the immediate area during trenching and rock dumping, but it is anticipated that they would rapidly return to the area once pipeline installation operations have ceased. There could, however, be some very localised disturbance to species that spawn on the seabed. The proposed development area coincides with spawning areas for mackerel, lemon sole, Norway pout and Nephrops. Although the Bardolino development lies within a large area in which Nephrops have been noted to spawn, the Bardolino site and pipeline route comprise sandy clay (Section 4.2.6), rather than the muddy sediments that Nephrops prefer. Consequently it is not thought likely that the Bardolino location is a significant Nephrops area. However, the pipeline and umbilical installation are planned to commence in June 2009 and this would coincide with the peak spawning period for Nephrops (Section 4.4.3). Nephrops is widely distributed in the North Sea, however, and the area of seabed that would be affected by the installation of the pipelines would be very small in comparison to the area inhabited by the wider population. It is therefore anticipated that the operations to install the pipelines and umbilical would have no effect on the size or viability of Nephrops populations. Mackerel, lemon sole and Norway pout have a widespread distribution over the North Sea and release their eggs into the water column to be fertilised. The effects of installing the pipelines and umbilical are therefore not considered to be significant. Trenching, installation, backfilling and rock dumping operations would last approximately 6 weeks, and during this time there would be restrictions on commercial shipping and fishing in the immediate area of the pipeline route. These are not considered to be significant as the restrictions would be short-term, fishing effort in the area (Section 4.5.1) is very low to low, Page 6-14 April 2008
Bardolino Development Environmental Statement and shipping activity in the area (Section 4.5.2) is moderate overall for this area of the central North Sea. Guard boats would be used to monitor vessel activity in the area during the pipeline operations. Once buried by rock dump or natural sediment infill, the physical presence of the pipelines and umbilical would pose no threat to bottom-towed fishing gear; the pipelines and umbilical would be trenched so that the top of the pipe is a minimum of 1.0 m below the natural seabed. Areas at either end of the pipelines that are not trenched, such as the tie-in spools, would be designed so as to prevent the snagging of fishing gear and shall be protected from dropped objects using concrete protection mats. In addition, the transition zones would lie within the statutory 500 m exclusion areas at Bardolino and the Howe subsea manifold. It is therefore concluded that the very local, temporary disturbance to the benthic community would be outweighed by the benefits gained by trenching, backfilling and/or rock dumping the pipelines to eliminate potential interactions with fishing gear. The location and profile of the spot rock dump material would be made available to fishermen and fishing interests. The blanket rock dump rock dump would be below the level of the trench. The tie-in spools and concrete mattresses protecting them would create new habitats for benthic organisms that live on hard surfaces. Such organisms typically include tubeworms, barnacles, hydroids, tunicates and bryozoans, which are commonly found on submerged rocky outcrops, boulders and offshore structures. These structures could also provide habitats for crevice-dwelling fish (e.g. ling) and crustaceans (e.g. squat lobsters and crabs). The overall disturbance would be negligible, as these structures will cover only a small area of the seabed. 6.5.3 Contribution to transboundary, cumulative or global impacts The installation of the pipelines and umbilical would cause localised temporary disturbance and interference along corridors of seabed estimated to cover a total area of approximately 0.02 km 2 . The pipeline and umbilical installation operations would all be within UK waters, so there would be no transboundary impacts. Over the past decade, several pipelines have been installed in this area of the North Sea, but the installation of the proposed 2km long buried Bardolino pipelines and umbilical is unlikely to result in any cumulative impacts. The concrete mattresses that would be placed to protect the untrenched ends of the pipelines would be located within the 500 m safety exclusion zones, and would therefore not represent a cumulative impact on fishing. Spot rock dumping the pipelines would alter the character of a very small proportion of the seabed; sediment movement would begin to re-establish the natural seabed surface at these areas. There would be no global impacts. 6.5.4 Consultee concerns JNCC advised that survey data for the pipeline should ideally be presented within the ES. However, as the planned pipeline is only 2 km long, and 1 km of it will be within the 500m zones of Howe and Bardolino, JNCC suggested that, on this occasion, if the data were not available the ES should describe the survey work to be undertaken, with the complete results being included in the subsequent PON 15s. 6.5.5 Adequacy of proposed mitigation measures A 3 km by 3 km rig site survey was undertaken for the Bardolino well location, which encompasses the planned pipeline route corridor between Howe and Bardolino, to gain detailed information on bathymetry (Gardline Geosurvey Limited, 2007). No unusual seabed April 2008 Page 6-15
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ENVIRONMENTAL STATEMENT BARDOLINO D
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Page 181 and 182: 13 th March 2008 Dear Sir or Madam,
Page 183 and 184: To: Paul Wood Shell U.K Limited, Se
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What risks to marine mammals do pil
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Noise propagation modelling. Noise
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If, for any reason, piling operatio
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APPPENDIX 1 MARINE MAMMAL RECORDING
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ENVIRONMENTAL STATEMENT BARDOLINO DEVELOPMENT

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