6.4. Assessment of Adverse Effects of the Array in-Combination with other Plans and Projects

6.4.1. Plans and Projects Screened into the In-Combination Assessment for Annex II MArine Mammals

  1. The in-combination effects screening area for marine mammals initially focussed on projects within the regional marine mammal study area ( Figure 6.1   Open ▸ ), as agreed with SNCBs as part of the Ossian Array Scoping Opinion and LSE2 Screening step (MD-LOT, 2023). The spatial and temporal scale of impacts is critical in the in-combination assessment and has been considered on an impact-by-impact basis to ensure a proportionate approach to the in-combination assessment and is discussed in further detail in paragraph 763.
  2. Given the limited data about Tier 3 projects available at the time of writing, projects were screened in initially based on temporal and/or spatial overlap as a precautionary approach. There was limited/no information on the construction/operation dates, nor foundation types proposed, however, with which to undertake a detailed assessment. Therefore, for potential impacts arising from piling, for example, which require these more detailed parameters, there was insufficient information to carry out a full quantitative assessment. A qualitative assessment has been undertaken using the most recent publicly available information for each project.
  3. The plans and projects that have been identified as having the potential for in-combination effects are presented in Figure 6.13   Open ▸ and Table 6.57   Open ▸ .


Figure 6.13:
Location of Other Plans and Projects Considered for the In-Combination Effects Assessment on SACs with Annex II Marine Mammals Features

Figure 6.13: Location of Other Plans and Projects Considered for the In-Combination Effects Assessment on SACs with Annex II Marine Mammals Features


Table 6.57:
List of Other Plans and Projects with Potential for In-Combination Effects on Annex II Marine Mammal Features

Table 6.57: List of Other Plans and Projects with Potential for In-Combination Effects on Annex II Marine Mammal Features

 

  1. The in-combination effects screening area for marine mammals initially focussed on projects within the regional marine mammal study area ( Figure 6.1   Open ▸ ), as agreed with SNCBs during the Ossian Array Scoping Opinion and LSE2 screening process. The spatial and temporal scale of impacts is critical for the in-combination assessment and has been considered on an impact-by-impact basis to ensure a proportionate approach. For the purposes of this assessment, in-combination impacts have been screened in/out on the following basis per impact:
  • Underwater noise generated during piling (construction phase) – the ZoI for piling can extend beyond the boundaries of proposed offshore wind farms and therefore, adopting a precautionary approach, the assessment has screened in projects within the regional marine mammal study area whose construction phases overlap with the construction phase of the Array. As a precautionary approach, projects whose construction phase finishes in the two years preceding the commencement of construction phase at the Array (2031) were screened in as the sequential piling at respective projects could lead to a longer duration of effect (i.e. two years prior to 2031). Where a project finishes offshore construction prior to the two years before construction begins, animals are anticipated to recover fully to baseline levels and therefore these projects are screened out on the basis of no receptor impact pathway.
  • Underwater noise during UXO clearance (construction phase) – the ZoI for UXO clearance can extend beyond the boundaries of other proposed offshore wind farms. Therefore, adopting a precautionary approach, the assessment has screened in projects within 100 km of the site boundary (which is greater than the largest disturbance range of ~32 km for the Array alone) whose construction phases (which would include pre-construction UXO clearance) overlap with the construction phase of the Array. Projects with completed UXO clearance campaigns were screened out of the assessment. Projects whose construction phase finishes in the year preceding the commencement of the Array’s construction phase (i.e. one year prior to 2031) were screened in as the sequential UXO clearance at respective projects could lead to a longer duration of effect.
  • Disturbance due to site-investigation surveys (including geophysical surveys) (Construction and operation and maintenance phase) – it is anticipated that the impacts will be of a similar scale to that described for the Array alone (i.e. metres; see section 6.3.3), with the potential for marine mammals to experience disturbance expected to be localised to within the boundaries of the respective projects. Therefore, the in-combination assessment has focussed only on site-investigation surveys for those projects within the close vicinity (up to 50 km) of the site boundary, and whose construction phase temporally overlaps with that of the Array. For pre-construction phase, where surveys are known to have been completed, this potential impact has been screened out.
  • Effects on marine mammals due to altered prey availability (construction phase) – potential in-combination effects on fish and shellfish assemblages, as identified in volume 2, chapter 9 of the Array EIA Report, may have indirect effects on marine mammals. For the purposes of the fish and shellfish ecology assessment of effects, in-combination effects have been assessed within a representative 50 km buffer of the fish and shellfish ecology study area. This 50 km buffer applies to all impacts considered in the EIA, except underwater noise, where a larger buffer of 100 km has been used to account for the larger ZoI. Therefore, only the projects considered in volume 2, chapter 9 of the Array EIA Report (and section 5.4 by default) are considered in the assessment of in-combination indirect impacts due to changes in fish and shellfish communities affecting prey availability.
  • Entanglement (operation and maintenance phase) – this potential impact is included for projects which have operations and maintenance phases that overlap with the operations and maintenance phase of the Array. However, the potential for entanglement would be expected to be localised to within the close vicinity of the respective projects and as such the assessment has focussed only on floating offshore wind projects within a 50 km buffer of the Array as a conservative but proportionate approach.
  • Injury and disturbance from underwater noise generated during the operation of floating wind turbines and anchor mooring lines (operation and maintenance phase) – this potential impact is included for projects which have operations and maintenance phases that overlap with the operations and maintenance phase of the Array. However the potential to experience disturbance by marine mammal receptors would be expected to be localised to within the close vicinity of the respective projects (for example the maximum TTS range for the Array was 50 m) and as such the assessment has focussed only on floating offshore wind projects within a 50 km buffer of the Array as a conservative but proportionate approach. Risch et al. (2023b) highlighted the importance of considering the in-combination noise output of large floating offshore wind turbine arrays, particular where boundaries overlap, and therefore the wider 50 km buffer captures this wider spatial scale of effect.
  1. The assessment of in-combination effects with relevant projects has focussed on information available in the public domain (e.g. where the potential impact has been identified in the Scoping Report (Tier 2 projects) or the EIA Report and/or RIAA (Tier 1 projects)). In this regard, where an potential impact has been identified and screened in, there is considered to be a potential for in-combination effects and therefore will be considered further in the in-combination assessment. Where impacts have been scoped out from individual assessments of respective projects, they have not been considered further.
  2. It should be noted that the in-combination assessment on Annex II marine mammals has been undertaken on the basis of information presented in the EIA Reports for the other plans and projects, which is based upon the respective MDSs.

6.4.2. Underwater Noise Generated During Piling

  1. The LSE2 assessment during the HRA Stage One process identified that LSE2 could not be ruled out for underwater noise generated during piling in the construction phase of the Array in-combination with other plans and projects. This relates to the following sites and relevant Annex II marine mammal features:
  • Berwickshire and North Northumberland Coast SAC;

–           grey seal.

  • Southern North Sea SAC; and

–           harbour porpoise.

  • Moray Firth SAC;

–           bottlenose dolphin.

  1. The MDS considered for this in-combination assessment is shown in Table 6.58   Open ▸ . The designed in measures are presented in Table 6.8   Open ▸ for the assessment of the Array alone.
Table 6.58:
MDS Considered for the Assessment of Potential Impacts to Annex II Marine Mammals due to Underwater Noise Generated during Piling at the Array In-Combination with other Plans and Projects

Table 6.58: MDS Considered for the Assessment of Potential Impacts to Annex II Marine Mammals due to Underwater Noise Generated during Piling at the Array In-Combination with other Plans and Projects

 

                        In-combination assessment

  1. There is the potential for in-combination impacts from underwater noise generated during piling in the construction phases of the Array and other plans and projects. For the purposes of this assessment, this potential impact has been assessed using the tiered approach outlined in section 4.6. The plans and projects screened into the in-combination assessment for this potential impact and their respective tiers are outlined in Table 6.58   Open ▸ .
                        Tier 1
  1. There were three Tier 1 projects identified with potential for in-combination effects associated with this impact:
  • the construction and operation and maintenance phases of the Proposed offshore export cable corridor(s);
  • the construction and operation and maintenance phases of Berwick Bank; and
  • the construction and operation and maintenance phases of Hornsea Project Three ( Table 6.58   Open ▸ ).
  1. Whilst the construction phase at Green Volt Offshore Wind Farm is anticipated to be completed in 2029, the Green Volt Offshore Wind Farm EIA (GreenVolt, 2023) states offshore construction is anticipated to take approximately 24 months from quarter four of 2025 to the end of quarter three of 2027 and therefore there is no temporal overlap in piling between Green Volt Offshore Wind Farm and the Array. There will be a period of three years between offshore construction at Green Volt Offshore Wind Farm and the Array and therefore animals are anticipated to recover fully in this period and Green- Volt Offshore Wind Farm will not contribute to the in-combination effect with the Array and is therefore excluded from further assessment.
  2. There is no offshore piling during the construction of the construction and operation and maintenance phases of the Proposed offshore export cable corridor(s) and therefore will not contribute to the in-combination effect with the Array and is excluded from the CEA for piling.
  3. Piling at each of these Tier 1 projects will occur as a discrete stage within the overall construction phase and therefore the periods of piling may not coincide. These timelines are, however, indicative and may be subject to change, although the realistic worst-case scenario has been considered in this in-combination assessment. Where numbers of animals potentially disturbed are presented, the calculations consider the timelines of respective projects. Given that Hornsea Project Three completes the construction prior to the commencement of construction activities at the Array (see paragraph 776), animals are likely to recover from the disturbance between piling events and therefore the numbers of animals potentially disturbed at respective projects are not added together. If construction timelines directly overlap (such as between Berwick Bank and Hornsea Project Three), animals could be disturbed during piling for both projects simultaneously and therefore numbers of animals potentially disturbed during piling are summed. Nevertheless, to ensure the most precautionary approach, in-combination iPCoD modelling incorporates numbers of animals affected by all Tier 1 projects throughout construction phases.
  4. The potential to experience auditory injury in terms of PTS by marine mammal receptors as a result of underwater noise due to piling would be expected to be localised to within the boundaries of the respective projects (assuming similar ranges of effect as presented for the Array). It is also anticipated that standard offshore wind industry construction methods (which include soft starts and visual and acoustic monitoring of marine mammals as standard) will be applied, thereby reducing the magnitude of the potential impact with respect to auditory injury occurring in marine mammals. Therefore, there is no potential for significant in-combination impacts for injury from elevated underwater noise during pilling and the in-combination assessment focuses on disturbance only.
  5. Each project screened in has a slightly different approach to assessing behavioural disturbance of cetaceans and pinnipeds. For many years since it was published, Southall et al. (2007) along with Lucke et al. (2009) was widely used to assess the effects of noise on marine mammals, and was used in the assessment of disturbance for Dogger Bank Creyke Beck A, Dogger Bank Creyke Beck B (Forewind, 2014). This represents a fixed-threshold value approach, where it is assumed that all animals within the predicted impact area are to display a behavioural reaction, while none of the animals outside this area will react. However, since then a dose-response curve derived using received noise level and harbour porpoise presence data (Graham et al., 2017) was used to determine the proportion of animals present likely to be displaced in assessments for projects such as Inch Cape (Inch Cape Offshore Limited, 2018), Moray West (Moray West OWF Limited, 2018c) and Hornsea Project Three (Ørsted, 2018a), Hornsea Project Four (Ørsted, 2021) and the Array. Given that respective projects used different criteria and noise thresholds modelled for marine mammal receptors in their assessments, it is necessary to exercise considerable caution if attempting any comparison between results of these appraisals. There are also variations between projects in the way results are presented. Some projects present the range of area from which animals are excluded and numbers of animals disturbed, whilst others only present number of animals disturbed and no ranges. Various densities were used to derive these numbers of animals (e.g. data from the integrated cetacean analysis (Mackenzie et al., 2012) and combined site-specific density surface and SCANS III Block data at Hornsea Project Three). As these values come from different sources, density details may reflect various densities of respective species throughout the year (i.e. seasonal versus average across the year). Respective projects may also use different reference populations. Therefore, assessment of the potential effects on marine mammals predicted by other wind farms is not always directly comparable to those presented the Array due to different approaches to assessment taken by other offshore developers, different noise criteria and thresholds used, and differing levels of detail presented in associated EIAs.
  6. The construction phase of Berwick Bank Offshore Wind Farm is expected to run from 2025 to 2032 with the final piling phase in 2031 (SSE Renewables, 2022c), therefore offshore construction may overlap with the construction phase of the Array by two years, and an overlap of piling for one year and therefore lead to in-combination effects from piling. Located 56.84 km south-west from the site boundary, the MDS for piling at Berwick Bank Offshore Wind Farm assumed that 5.5 m diameter piled jacket foundations will be installed using a maximum hammer energy of 4,000 kJ. The EIA states piling will be required at up to 179 wind turbine foundations and ten OSP/Offshore convertor station platform foundations, with the MDS based on concurrent piling at wind turbine foundations with the largest separation between piling locations as this leads to the MDS for disturbance (piling could occur concurrently at a wind turbine and OSP/Offshore convertor station platform foundation but these locations would be closer together compared to two wind turbine foundations). The maximum number of days (24 hours) within which piling could occur on the basis of two piling operations was 287 piling days (concurrent vessel) for the 179 wind turbines and 85 piling days (single vessel) for the ten OSPs/Offshore convertor station platforms. Piling activity at Berwick Bank Offshore Wind Farm will take place in three campaigns, and an indicative piling schedule was presented in the iPCoD report which gives a realistic installation programme (SSE Renewables, 2022a), and this was carried forward to population modelling presented in volume 2, chapter 10 of the Array EIA Report. With mitigation measures in place (MMO2, PAM, ADD for 30 minutes, low hammer initiation, soft start and ramp up, such as those in Table 6.7   Open ▸ for the Array alone), the residual number of individuals potentially affected by PTS was zero for all species. Numbers of animals disturbed for marine mammal IEFs, as presented in the Berwick Bank Offshore Wind Farm EIA (SSE Renewables, 2022c), is given in Table 6.59   Open ▸ .
Table 6.59:
Numbers of Animals Predicted to be Disturbed as a Result of Underwater Noise During Piling for Berwick Bank Offshore Wind Farm (SSE Renewables, 2022c)

Table 6.59 Numbers of Animals Predicted to be Disturbed as a Result of Underwater Noise During Piling for Berwick Bank Offshore Wind Farm (SSE Renewables, 2022c)

 

  1. The construction of Hornsea Project Three is anticipated to occur until 2030 ( Table 6.57   Open ▸ ), one year prior to the construction of the Array. Therefore, whilst the construction of Hornsea Project Three will be completed prior to commencement of piling at the Array, it could lead to a longer duration of piling operations (i.e. sequential rather than concurrent piling). It must be noted however that Hornsea Three is at the furthest extent of the regional marine mammal study area (a very small overlap therefore was screened in), located 319.38 km from the Array, and therefore in-combination effects are highly unlikely at this distance. The regional marine mammal study area is a precautionary screening area for assessment to account for the mobile nature of marine mammals and does not account for the levels of precaution in each respective projects MDS assessment (see paragraph 462 et seq for examples of conservatism in underwater noise modelling). The in-combination assessment of Hornsea Project Three is based upon the EIA submitted alongside the application for Development Consent Orders to the Planning Inspectorate (Ørsted, 2018a). As detailed in the EIA, piling at Hornsea Three is likely to occur in two short phases (each of approximately one year and a half), with a maximum duration of three years between phases where no piling will occur, and it is expected animals will recover in this period.
  2. The MDS for marine mammals for Hornsea Project Three included both a maximum spatial scenario and maximum temporal scenario. The maximum spatial scenario consisted of concurrent piling of 319 monopiles (300 turbine foundations and 19 foundations for other infrastructure and platform foundations) installed over 193.8 days, which comprises 189 days for monopiles over a 2.5 year period (divided into two phases and a gap of up to three years between phases), and 4.8 days for offshore High Voltage Alternating Current (HVAC) booster (over eight months within the 2.5 year piling period, single piling only), with a maximum hammer energy of up to 5,000 kJ (although Ørsted (2018a) noted typically the maximum hammer energy will be considerably less than this and would not be required at all locations). The MDS states concurrent piling will occur only for infrastructure located within the Hornsea Three Array Area and not for infrastructure located within the offshore HVAC booster station search area in which only a single vessel scenario is possible.
  3. The maximum temporal scenario for Hornsea Project Three consisted of single piling of 1,848 pin piles (1,200 for jacket foundations and 648 for other infrastructure and platform foundations) over 554.4 days, over a 2.5 year period with two phases and a gap of up to three years between phases, and 28.8 days for offshore HVAC booster over eight months within the 2.5 year piling period), with an absolute maximum hammer energy of up to 2,500 kJ.
  4. The assessment in Hornsea Three was based on the definition of MDS piling parameters for each turbine foundation type (i.e. 5,000 kJ hammer energy for the monopiles and 2,500 kJ for the pin piles), however both a ‘most likely’ ramp up scenario (i.e. maximum hammer energy for most of the piling events = 3,500 kJ hammer energy for monopiles and 1,750 kJ for pin piles) and an overall ‘average’ hammer energy were defined (i.e., average typical hammer energy = 2,000 kJ for monopiles and 1,500 kJ for pin piles). Ørsted (2018a) stated the number of animals disturbed under the maximum design scenario is highly precautionary as these hammer energies will not be representative of most of the actual piling activity. Whilst five representative locations were modelled, the highest impact ranges were found at the north-east modelling location within the Hornsea Three array (Hornsea Three NE) and at the south modelling location within the HVAC search area (HVAC S) and therefore used in the assessment for cetaceans. For grey seal, the Hornsea Three north-west (NW) location overlapped with higher seal density areas and therefore used for the assessment for grey seal. For concurrent scenarios, the MDS was modelled for monopiles at locations Hornsea Three NE and NW.
  5. A range of density estimates were used for the assessment of disturbance at Hornsea Three, as presented in Table 6.60   Open ▸ , alongside the dose-response method (Graham et al. (2017) for harbour porpoise and Russell et al. (2016) for grey seal (bottlenose dolphin were not included in the assessment)). It should be noted that dose-response is not an area-based approach (see paragraphs 446 et seq.), and numbers of animals potentially impacted cannot be accurately attributed to the populations of specific SACs. Numbers of animals potentially disturbed from Hornsea Project Three are discussed for their respective SACs below in paragraphs 797 et seq.

 

Table 6.60:
Density Estimates used in Hornsea Project Three Assessment of Piling (Ørsted, 2018a)

Table 6.60 Density Estimates used in Hornsea Project Three Assessment of Piling (Ørsted, 2018a)

 

                        Tier 2
  1. There were 20 Tier 2 projects identified with potential for in-combination effects associated with this impact:
  • Broadshore Hub Offshore Wind Farms
  • Buchan Offshore Wind Farm;
  • Caledonia Offshore Wind Farm;
  • Buchan Offshore Wind Farm;
  • Dogger Bank South East – RWE Renewables;
  • Dogger Bank South West – RWE Renewables;
  • Marram Offshore Wind Farm;
  • Morven Offshore Wind Farm;
  • Muir Mhor Offshore Wind Farm;
  • Salamander Offshore Wind Farm;
  • Stromar Offshore Wind Farm;
  • Nordsren I;
  • Nordsren II;
  • Nordsren II vest;
  • Nordsren III;
  • N-10.1’;
  • Nordsren III vest;
  • N-10.2;
  • N-9.4; and
  • Ten Noorden van de Waddeneilanden ( Table 6.58   Open ▸ ).
  1. Broadshore Hub Offshore Wind Farms are located 148.14 km from the Array and includes areas of seabed as part of INTOG leasing rounds to develop the 900 MW Broadshore Offshore Wind Farm Project (the Broadshore Project), the 99.5 MW Sinclair Offshore Wind Farm Project (the Sinclair Project) and the 99.5 MW Scaraben Offshore Wind Farm Project (the Scaraben Project), collectively known as the Broadshore Hub Offshore Wind Farms (Broadshore Offshore Wind Farm Limited et al., 2024). All projects will comprise wind turbines, station keeping systems and inter-array cables. The Broadshore Project will comprise up to 60 wind turbines, whilst the Sinclair and the Scaraben Projects will comprise up to six wind turbines. The Broadshore Hub Offshore Wind Farms Scoping Report (Broadshore Offshore Wind Farm Limited et al., 2024) scoped in underwater noise during impact piling (using hydraulic hammer or vibropiling) of anchors of fixed bottom substructures and/or floating substructures. Anchor driven piles may have up to 12 anchor driven piles per floating substructure estimated at 3.5 m diameter with hammer energy of up to 3,000 kJ. Fixed bottom substructures may comprise either jacket (tripod or quadruped) up to 4 m pile with hammer energy of up to 4,000 kJ, either impact or drill piled, or cable supported monopile with pile diameter of 16 m. The construction phase is expected to begin in 2028 until 2029 and therefore piling will be completed a year prior to the start of the Array, allowing some recovery before piling begins at the Array. Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  2. Buchan Offshore Wind Farm is located 151.62 km from the Array and is a floating offshore wind farm with up to 70 wind turbines and associated supporting structures, including floating foundations, mooring systems and anchors, inter-array cables, up to three OSPs and export cable corridor (Buchan Offshore Wind Limited, 2023). The Buchan Offshore Wind Farm scoped in increased underwater noise from pile driving for floating wind turbines, OSPs and Intermediate Reactive Compensation (IRC) platform (if piled foundations are used). The construction phase is expected to begin in 2028 until 2030 and therefore piling may be sequential with the start of the construction of the Array, however the large distance means cumulative effects are unlikely. Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  3. The Caledonia Offshore Wind Farm is located in the Moray Firth, 157.49 km north from the site boundary, indicatively 75% of the Caledonia Offshore Wind Farm’s Array Area could be constructed using fixed foundations, and is considering the use of floating foundations for remaining sites (Ocean Winds, 2022). Fixed-foundation types currently being considered include: monopile; fully restrained platform; jacket with pin piles; jacket with suction caissons; Gravity Based Structure (GBS). Floating foundation types include semi-submersible and tension leg platform. A maximum of 150 wind turbine generators will be located within the Array Area, with an estimated split of up to 111 fixed foundations and 39 floating foundations. An indicative spatial distribution on fixed foundations (an area approximately 307 km2 across the north of the Caledonia Array Area) and floating foundations (approximately 122 km2 across the south of the Caledonia Array Area) is presented within the Offshore Scoping Report. The MDS considers up to six OSPs. The final type and design for the foundations will be subject to further site investigations, however jacket with pin piles, jacket with suction caissons, monopile and GBS currently under consideration. The construction phase is expected to begin in 2028 until 2029 and therefore piling will be completed a year prior to the start of the Array, allowing some recovery before piling begins at the Array. Information on the numbers of animals potentially affected is not available at this time to undertake a quantitative assessment.
  4. Cenos Offshore Wind Farm is located 91.70 km from the Array and is a proposed floating offshore wind farm (part of the INTOG leasing process) with up to 1.4 GW and footprint of 333 km2. The Cenos Offshore Wind Farm Scoping Report (Flotation Energy, 2023) gives potential development size of 70 to 100 turbines with floating substructures with 3 to 6 mooring lines/anchor substructures. The Cenos Offshore Wind Farm scoped in underwater noise from percussion piling as a potential impact on marine mammals, but stated no significant effects on marine mammals due to noise are expected (Flotation Energy, 2023). The Cenos Offshore Wind Farm Scoping Report details an indicative schedule from 2027 to 2030 with installation of all the turbines expected to take two to three years, and therefore piling may be sequential with the start of the construction of the Array. Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  5. Dogger Bank South Offshore Wind Farms comprise Dogger Bank South East (located 363.35 km south from the site boundary) and Dogger Bank South West (located 499.03 km south from the site boundary). The Project Description allows for up to 150 turbines for each project, and the Scoping Report details a range of foundation options, including monopiles, jackets on pin piles; and jackets on suction buckets (RWE Renewables UK, 2022). Construction of the Dogger Bank Offshore Wind Farms is expected to begin no earlier than 2026, however the programme for construction will depend on the final confirmation of the grid connection date and there is no indication currently of a construction timeline (therefore on a precautionary basis it is considered there may be some overlap with the Array’s construction phase). It is anticipated that the two Dogger Bank projects will be built concurrently and sequentially (RWE Renewables UK, 2022). The large distance between the Dogger Bank South Offshore Wind Farms and the Array means in-combination effects are unlikely.
  6. The Morven Offshore Wind Farm is a proposed large scale fixed-foundation offshore wind farm located 5.50 km west from the site boundary. The Offshore Scoping Report (Morven Offshore Wind Limited, 2023) considers up to 191 wind turbines and up to 11 OSPs. The following foundation types will be considered: monopile foundations, gravity base foundations, piled jacket foundations (three or four legs for wind turbines; three, four or six legs for OSPs), suction bucket jacket foundations (three or four legs for wind turbines; three, four or six legs for OSPs) (Morven Offshore Wind Limited, 2023). The construction phase of the Morven Array Project is estimated to occur from 2031 to 2038, meaning a potential for full overlap with the construction phase of the Array. Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  7. Muir Mhor Offshore Wind Farm is a floating offshore wind project located 51.38 km north-west from the site boundary, comprising up to 67 wind turbine foundations with a spacing of ≥ 1000 m. The turbines will be supported by a floating foundation with associated mooring and anchoring systems to keep the foundation ‘on station’. There are a number of floating foundation types under consideration, which include: semi-submersible, barge, tension leg platform, spar, multi-tower semi- submersible, buoy and semi-spar (Fred Olsen Seawind et al., 2023). The construction of the Muir Mhor Ooffshore wind Wind farm Farm is expected to occur between 2027 and 2030, and therefore whilst there is potential for no direct temporal overlap with the Array construction phase, piling at the Muir Mhor Offshore Wind Farm could lead to a longer duration of piling operations (i.e. sequential piling). Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  8. Salamander Offshore Wind Farm (Simply Blue Energy (Scotland) Limited, 2023) is located 79.49 km from the Array and is a proposed floating wind farm with an installed capacity of up to 100 MW. Up to seven offshore wind turbines with supporting floating substructures and mooring and anchoring systems, inter-array cables Underwater noise associated with piling activity is scoped in (from potential installation of piles associated with the mooring and anchoring system) in the Salamander Offshore Wind Farm Scoping Report (Simply Blue Energy (Scotland) Limited, 2023). A detailed construction programme with specific construction dates is not given in the scoping report, therefore a potential temporal overlap with construction at the Array cannot be discounted, but an indicative construction programme presents offshore construction from Q2 in year two and year three for six months per time, therefore potential temporal overlap is limited. Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  9. Stromar is located 170 km away from the site boundary, with the Stromar Array Area approximately 256 km2 in size. The EIA states up to 71 wind turbines with associate floating wind turbine substructures, with mooring and anchoring systems and inclusion of dynamic and static inter-array/interlink cable and up to three OSPs. Floating substructures may include spar, tension-leg platform, semi-submersible and barge (Stromar Offshore Wind Farm, 2024). The indicative programme presented in the EIA assumes Stromar become commercially operational between 2030 and 2033 and has an offshore construction programme of six years (7 years construction phase for onshore and offshore). Information on the numbers of animals is not available at this time to undertake a quantitative assessment.
  10. For Nordsren I, Nordsren II, Nordsren II vest, Nordsren III, N-10.1, Nordsren III vest, N-10.2, N-9.4 and Ten Noorden van de Waddeneilanden, whilst scoping reports cannot be obtained, it has been assumed piling is scoped in as a precautionary approach to assessment. However, these projects lie between ~330 km and ~437 km away from the site boundary and therefore any in-combination effect from piling is highly unlikely given the contours presented for piling for the Array alone (section 6.3.1).
                        Tier 3
  1. There were 11 Tier 3 projects identified within the regional marine mammal study area with potential for in-combination effects associated with this impact:
  • Arven Offshore Wind Farm;
  • Ayre Offshore Wind Farm;
  • Bellrock Offshore Wind Farm;
  • Bowdun Offshore Wind Farm;
  • Campion Offshore Wind Farm;
  • Flora Floating Wind Farm;
  • Aspen Offshore Wind Farm;
  • INTOG Site 8: Harbour Energy;
  • Beech Offshore Wind Farm;
  • Cedar Offshore Wind Farm;
  • INTOG Site 13: Harbour Energy;
  • Yell Sound Array;
  • BP Exploration Operating Company Limited; and
  • Morven Offshore Export Cable Corridor ( Table 6.58   Open ▸ ).
  1. Tier 3 projects are in the pre-application phase and no EIA Scoping Report, EIA Report, or HRA documentation is available to inform a quantitative assessment. Therefore, a qualitative assessment is provided below.
  2. The construction of the Array, together with construction phase of Tier 1, Tier 2 and Tier 3 projects may lead to in-combination injury and disturbance to marine mammals from underwater noise generated during piling.
  3. The data in relation to Tier 3 projects available at the time of writing is limited and it is not possible to carry out a quantitative assessment. This is particularly the case for INTOG projects, where little is known about the scale of the potential environmental impacts associated with these projects, though it is likely that many will be floating projects. Tier 3 projects were screened in on a precautionary basis due to their location (they lie within the regional marine mammal study area), though there is limited/no information on the construction/operation dates or project design with regards to piling. It should be acknowledged that there is a potential for piling activities to be taking place and therefore projects cannot be discounted, however it is not possible to undertake quantified assessment for potential in-combination impacts as a result of elevated underwater noise due to uncertainty in piling schedules for Tier 3 projects. Therefore, a qualitative assessment has been undertaken to determine in-combination impacts with tier 3 projects.
  4. There is no publicly available piling parameters or published assessments for Tier 3 projects (which are at pre-scoping stage), however given the phase of development, temporal overlap with the Array may be limited. Furthermore, given the maximum injury ranges for the Annex II marine mammal species associated with piling from the Array (maximum PTS range of 1,600 m modelled for harbour porpoise), there is low likelihood of any spatial overlap of ranges between the Array and the Tier 3 projects. For example, the closest Tier 3 projects are the Morven Offshore Export Cable Corridor (5.5 km away) and Bellrock Offshore Wind Farm (8.67 km away), which both far exceed the maximum PTS range for all species. Further, the potential for PTS is reduced through the application of designed-in measures, and animals are expected to be able to flee the injury zone due to ADD activation prior to commencement of soft starts ( Table 6.11   Open ▸ ). Therefore there is limited potential for an in-combination impact associated with the Tier 3 projects, and each project will likely implement their own mitigation to limit injury and disturbance as per the JNCC (2010c) guidelines, thus further reducing the potential for in-combination effects associated with piling.

                        Construction phase

                        Berwickshire and North Northumberland Coast SAC
Grey seal

                        Tier 1

  1. As presented in paragraphs 769 et seq., there were three Tier 1 projects identified with potential for in-combination effects, and two projects (Berwick Bank and Hornsea Project Three) assessed as part of the Tier 1 assessment.
  2. The assessment for Berwick Bank Wind Farm (SSE Renewables, 2022c) predicted up to 1,358 animals have the potential to be disturbed from concurrent piling at a maximum hammer energy of 4,000 kJ (3.19% of the East Scotland plus Northeast England SMU populations), based upon Carter et al. (2020) maps ( Table 6.61   Open ▸ ). Grey seal could also be potentially disturbed within the zone of possible disturbance during single piling at a wind turbine or an OSPs/Offshore convertor station platform at a maximum hammer energy of 4,000 kJ with up to 705 animals disturbed (1.66% of the East Scotland plus Northeast England SMU populations). In the Berwick Bank EIA, population modelling for grey seal against the SMU populations showed that the median of the ratio of the impacted population to the unimpacted population was 1 (100%) at 25 years and it was considered that there is no potential for a long-term effect on this species. The magnitude for Berwick Bank Wind Farm, for behavioural impacts from piling on grey seal, was considered to be low (SSE Renewables, 2022c).
  3. Within the RIAA for Berwick Bank Wind Farm, there was predicted to be a small overlap with northern part of the Berwickshire and North Northumberland Coast SAC with the unweighted SELss 145 dB re 1 μPa2s behavioural disturbance contour for grey seal (SSE Renewables, 2022e). This threshold of 145 dB re 1 μPa2s was used as it was the level at which behavioural responses have been observed in seals (Whyte et al., 2020). However, the RIAA concluded that although there is a potential for overlap of disturbance contours with northern section of the SAC, it is the southern half of the SAC which is an important breeding site for grey seals (SCOS, 2020). The RIAA concluded that grey seals present in the southern part of the SAC, in the vicinity of the habitats which they utilise throughout their life cycle (submerged/partially submerged sea caves, intertidal mud/rock/sediment), are therefore unlikely to experience disturbance as these areas lie outside of the noise disturbance contours. As such, piling at Berwick Bank Wind Farm was concluded to be highly unlikely to disrupt normal behaviours of grey seals or adversely affect maintenance of the supporting habitats (SSE Renewables, 2022e).
  4. The assessment for Hornsea Project Three predicted 53 grey seal to be exposed to behavioural disturbance during concurrent piling events (monopiles), based upon noise contours overlain on grey seal at-sea density surfaces from Russell et al. (2017) ( Table 6.61   Open ▸ ). Given that Hornsea Project Three completes construction prior to the commencement of construction activities at the Array, animals are likely to recover from the disturbance between piling events and therefore the numbers of animals potentially disturbed at respective projects are not added together. Hornsea Project Three is 319.38 km away from the site boundary and is located in the southern North Sea between England and the Netherlands ( Figure 6.13   Open ▸ ). It is located 266 km away from the Berwickshire and North Northumberland Coast SAC, and this SAC was assessed in the RIAA for Hornsea Project Three (Ørsted, 2018b). The Hornsea Project Three RIAA presented no spatial overlap between the unweighted SELss noise disturbance contours and this SAC (Ørsted, 2018b).

 

Table 6.61:
Grey Seal In-Combination Assessment – Numbers Predicted to be Disturbed as a Result of Underwater Noise During Piling for Tier 1 Projects

Table 6.61: Grey Seal In-Combination Assessment – Numbers Predicted to be Disturbed as a Result of Underwater Noise During Piling for Tier 1 Projects

 

  1. Population modelling (see volume 3, appendix 10.3 of the Array EIA Report) considered Berwick Bank Wind Farm and Hornsea Project Three alongside the Array (a quantitative assessment for Proposed offshore export cable corridor(s) is not available at this stage), with respective numbers of animals potentially impacted against the combined SMUs reference population. Results of the in-combination iPCoD modelling for grey seal showed that the median of the ratio of impacted population to unimpacted population was 1 at all modelled time points, and there was no difference in the mean size of the impacted and unimpacted populations at all time points. Therefore, it was considered that there is no potential for a long-term effect on this species as a result of in-combination piling at the Array and respective Tier 1 projects.
  2. Based on the information presented in paragraphs 797 et seq., it is concluded that piling in-combination at the Array and the Tier 1 projects will not have an adverse effect on the integrity of grey seal feature of this SAC.

                        Tier 2

  1. The Tier 2 assessment, presented in paragraphs 781 et seq., concluded that in-combination effects as a result of piling in the construction phase are unlikely to occur. This is largely due to the distance between many Tier 2 projects and the site boundary (i.e. often over hundreds of kilometres). Further, piling at the Tier 2 projects will be intermittent, and the effects of behavioural disturbance are reversible. Based on this, it is concluded that piling in-combination at the Array and the Tier 2 projects will not have an adverse effect on the integrity of grey seal feature of this SAC.

                        Tier 3

  1. The Tier 3 assessment, presented in paragraphs 792 et seq., highlighted that it was not possible to undertake quantitative in-combination assessment for the 11 Tier 3 projects identified for this impact. This was due to the lack of publicly available information surrounding piling parameters and lack of information in general about INTOG projects. The CEA presented in the Array EIA Report (volume 2, chapter 10 of the Array EIA Report) concluded a minor significance of effect for this potential impact associated with the Tier 3 projects.
  2. There is no publicly available piling parameters or published assessments for Tier 3 projects (which are at pre-scoping stage), however given the phase of development, temporal overlap with the Array may be limited. Furthermore, given the maximum injury ranges for grey seal associated with piling from the Array (maximum PTS range of 379 m modelled for the Array alone), there is low likelihood of any spatial overlap of ranges between the Array and the Tier 3 projects. For example, the closest Tier 3 projects are the Morven Offshore Export Cable Corridor (5.5 km away) and Bellrock Offshore Wind Farm (8.67 km away), which both far exceed the maximum PTS range for grey seal. Further, the potential for PTS is reduced through the application of designed-in measures, and animals are expected to be able to flee the injury zone due to ADD activation prior to commencement of soft starts ( Table 6.11   Open ▸ ). Therefore there is limited potential for an in-combination impact associated with the Tier 3 projects, and each project will likely implement their own mitigation to limit injury and disturbance as per the JNCC (2010c) guidelines, thus further reducing the potential for in-combination effects associated with piling.
  3. Based on this, it is concluded that piling in-combination at the Array and the Tier 3 projects will not have an adverse effect on the integrity of grey seal feature of this SAC.

                        Conclusion

  1. Adverse effects on the qualifying Annex II marine mammal features of the Berwickshire and North Northumberland Coast SAC which undermine the conservation objectives of the SAC will not occur as a result of in-combination underwater noise generated during piling in the construction phase. Potential effects from this activity on the relevant conservation objectives (as presented in section 6.2.1) are discussed in turn below in Table 6.62   Open ▸ .

 

Table 6.62:
Conclusions Against the Conservation Objectives of the Berwickshire and North Northumberland Coast SAC from Underwater Noise Generated During Piling in the Construction Phase of the Array In-Combination with other Plans and Projects

Table 6.62: Conclusions Against the Conservation Objectives of the Berwickshire and North Northumberland Coast SAC from Underwater Noise Generated During Piling in the Construction Phase of the Array In-Combination with other Plans and Projects

 

  1. It can be concluded, beyond reasonable scientific doubt, that there is no risk of an adverse effect on the integrity of the Berwickshire and North Northumberland Coast SAC as a result of underwater noise generated during piling with respect to the construction phases of the Array in-combination with other plans and projects.
                        Southern North Sea SAC
Harbour porpoise

                        Tier 1

  1. As presented in paragraphs 769 et seq., there were three Tier 1 projects identified with potential for in-combination effects, and two projects (Berwick Bank and Hornsea Project Three) able to be assessed as part of the Tier 1 assessment.
  2. The assessment for Berwick Bank Wind Farm predicted up to 2,822 harbour porpoise (based on seasonal peak density) are predicted to experience potential disturbance from concurrent piling at a maximum hammer energy of 4,000 kJ (SSE Renewables, 2022c), which equates to 0.81% of the North Sea MU population and 7.3% of SCANS III Block R estimated abundance ( Table 6.63   Open ▸ ). This was based upon a 1% conversion factor and peak seasonal density of 0.826 animals per km2, assuming all animals are uniformly distributed within all noise contours to provide a precautionary assessment. The EIA stated the duration of piling could potentially affect harbour porpoise over a maximum of five breeding cycles, with the magnitude of the potential impact having the potential to result in a small but measurable alteration to the distribution of marine mammals during piling only (372 days over 52 months) and may affect the fecundity of small proportion of the population (up to 0.81% of the North Sea MU at any one time) over the medium term ( Table 6.63   Open ▸ ). Results of the iPCoD modelling for Berwick Bank Wind Farm for harbour porpoise against the MU population showed that the median of the ratio of the impacted population to the unimpacted population was 0.99 at 25 years regardless of the conversion factor scenario assessed (SSE Renewables, 2022c) and therefore, it was considered that there is no potential for a long-term effect. The magnitude for Berwick Bank Wind Farm, for behavioural impacts from piling, was considered to be low.
  3. Within the RIAA for Berwick Bank Wind Farm, behavioural disturbance to harbour porpoise was based on the unweighted SELss contours using conversion factors (SSE Renewables, 2022e), so is not the same as the approach taken for the assessment for the Array alone. There was no potential for overlap between the modelled unweighted SELss disturbance contours modelled from 180 out to 120 dB re 1 µPa2s and the Southern North Sea SAC predicted for Berwick Bank Wind Farm (SSE Renewables, 2022e), however it should be noted that this is not an area-based approach and numbers of animals potentially affected cannot be attributed solely to the SAC population.
  4. The assessment for Hornsea Project Three predicted up to 7,330 harbour porpoises to be exposed to behavioural disturbance during concurrent piling events (monopiles), by combining the site-specific density surface estimates and the SCANS III density data (where potential impact areas extended beyond the mapped survey area). The North Sea MU harbour porpoise reference population was used for this assessment (227,298 individuals (Ørsted, 2018a)). The effect of disturbance of harbour porpoise from piling was predicted to be of minor adverse significance. Cumulative iPCoD modelling for Hornsea Project Three on the North Sea MU harbour porpoise population as a result of a number of scenarios of offshore wind farm construction was carried out for the CEA within the Hornsea Project Three EIA (Ørsted, 2018a)). The assessment found that even with 15% of the population potentially disturbed due to multiple Tier 2 projects (Dogger Bank Creyke Beck A, Dogger Bank Creyke Beck B, Dogger Bank Teesside A, Dogger Bank Teesside B (Sofia) and East Anglia Three), there was only a small (6%) increase in the risk of an annual population decline of 1% per year and that overall, impacted population trajectories were not significantly different from baseline population trajectories (Ørsted, 2018a).
  5. Given that Hornsea Project Three completes the construction prior to the commencement of construction activities at the Array, animals are likely to recover from the disturbance between piling events and therefore the numbers of animals potentially disturbed at respective projects are not added together. However, there is the potential overlap of one year of piling with Berwick Bank Wind Farm which may lead to in-combination effects. Up to 11,131 animals may be disturbed if concurrent piling of wind turbines at Berwick Bank Wind Farm and concurrent piling at the Array occur simultaneously ( Table 6.63   Open ▸ ). However, Berwick Bank Wind Farm is located 56.84 km from the Array, and the likelihood of in-combination effects with projects located at large distances is considered to be reduced.
  6. Hornsea Project Three is 319.38 km away from the site boundary and is located in the southern North Sea between England and the Netherlands ( Figure 6.13   Open ▸ ). It is located 2 km away from the Southern North Sea SAC, and was assessed in the RIAA for Hornsea Project Three (Ørsted, 2018b). The 140 dB and 160 dB (rms) contours for mild and strong disturbance were not included in the RIAA, neither was the 143 dB (SELss) disturbance contour (Ørsted, 2018b). However, 26 km buffers were used to assess disturbance associated with piling, equivalent to the 26 km EDR recommended in the JNCC (2020) guidance which was published after the Hornsea Project Three RIAA. The RIAA concluded that only the piling for the HVAC booster stations could overlap with the winter component of the SAC (the northern portion) based on the 26 km disturbance buffers (Ørsted, 2018b). This equated to a maximum of four piling days over the winter season (182 days). Considering a return time of 72 hours an additional two days was added onto every piling day, resulting in 14.4 days. Therefore, the percentage overlap over the winter component, was 0.046%. The RIAA approach was stated to be over precautionary as it assumed no overlap between one set of piling events plus return time and the next piling event plus return time. It additionally considers the HVAC piling occurring during both the winter and summer seasons (Ørsted, 2018b).
  7. Many projects refer to the North Sea MU as a reference population, which, as presented in the original Seagreen EIA (Seagreen Wind Energy Limited, 2012) stretches across an area of 750,000 km2. The number of harbour porpoise potentially disturbed has been considered for projects located in the marine mammal study area, which means some, including Hornsea Three, lie over 300 km from the Array. Delineating the spatial extent of in-combination effects is commonly acknowledged as a challenge. Although harbour porpoise is generally rare in waters >200 m depth, the fact that this species utilises such a vast area further complicates a choice of appropriate spatial scale (Clarke Murray et al., 2014). Given the vast extent of available habitat, the fact that harbour porpoise is a wide-ranging species and the low percentage of the North Sea MU population disturbed as a result of piling at respective projects, the likelihood of in-combination effects with projects located at large distances (e.g. >100 km) from the site boundary (i.e. Hornsea Three) is considered to be low.

 

Table 6.63:
Harbour Porpoise In-Combination Assessment – Numbers Predicted to be Disturbed as a Result of Underwater Noise During Piling for Tier 1 Projects

Table 6.63 Harbour Porpoise In-Combination Assessment – Numbers Predicted to be Disturbed as a Result of Underwater Noise During Piling for Tier 1 Projects

 

  1. As undertaken for the assessment of the Array alone (paragraph 541), an EDR approach has also been used for the assessment of disturbance associated with piling during the construction phase for harbour porpoise features in-combination with other plans and projects. The maximum EDR of 26 km was used for the Array alone, with the southern piling location representing the closest distance to the SAC ( Figure 6.8   Open ▸ ). Only two in-combination projects were relevant for inclusion: Berwick Bank Wind Farm (Tier 1) and Morven Offshore Wind Farm (Tier 2). This is based on their proximity to the site boundary and public availability of their potential piling parameters. Although there are some Tier 3 projects in close proximity to the site boundary (such as Bellrock and Bowdun Offshore Wind Farms), there are no publicly available piling parameters, and the construction schedules are still unknown, so they can only be assessed as Tier 3 projects. Based on publicly available piling parameters in respective EIAs and scoping reports (Morven Offshore Wind Limited, 2023, SSE Renewables, 2022c), including monopiles, 26 km EDRs have been plotted for Berwick Bank Wind Farm and Morven Offshore Wind Farm ( Figure 6.14   Open ▸ ) to assess the potential for in-combination disturbance to the Southern North Sea SAC. It should be noted that as individual modelled piling locations are not currently publicly available for these projects (unlike the Array) and so a 26 km EDR buffer region has been drawn around the entire project boundaries, as opposed to precise maximum piling locations. Therefore, these 26 km EDRs plotted for Berwick Bank and Morven Wind Farms are overly precautionary. Given that there is no overlap between these EDRs and the Southern North Sea SAC, the conclusion that there will not be an in-combination impact to this SAC is further supported.


Figure 6.14:
Maximum Spatial Overlap of Underwater Noise Impacts upon the Southern North Sea SAC from In-Combination Piling with the Array and Relevant Plans and Projects Based on the Maximum 26 km EDR Approach

Figure 6.14: Maximum Spatial Overlap of Underwater Noise Impacts upon the Southern North Sea SAC from In-Combination Piling with the Array and Relevant Plans and Projects Based on the Maximum 26 km EDR Approach


  1. Population modelling (see volume 3, appendix 10.3 of the Array EIA Report) considered Berwick Bank Wind Farm and Hornsea Project Three alongside the Array, with respective numbers of animals potentially impacted against the MU population. The construction phase of Hornsea Project Three ends in 2030, prior to the commencement of the Array construction phase. Furthermore, there is a three-month period at the start of each year in which no piling will take place for the Array, thus allowing a further cessation of the potential impact between the two projects. Results of the in-combination iPCoD modelling for harbour porpoise showed that the median of the ratio of impacted population to unimpacted population approaches a ratio of 1 at all modelled time points. Although there was a difference in the number of animals between the disturbed and undisturbed populations, it was not considered that there is a potential for a long-term effect on this species as a result of in-combination piling at the Array and respective Tier 1 projects.
  2. Based on the information presented in paragraphs 809 et seq., it is concluded that piling in-combination at the Array and the Tier 1 projects will not have an adverse effect on the integrity of harbour porpoise feature of this SAC.

                        Tier 2

  1. The Tier 2 assessment, presented in paragraphs 781 et seq., concluded that in-combination effects as a result of piling in the construction phase are unlikely to occur. This is largely due to the distance between many Tier 2 projects and the site boundary (i.e. often over hundreds of kilometres). Further, piling at the Tier 2 projects will be intermittent, and the effects of behavioural disturbance are reversible. As presented in Figure 6.14   Open ▸ , the 26 km EDR for the Tier 2 Morven Offshore Wind Farm will not overlap with the Southern North Sea SAC and therefore does not contribute to the in-combination impact of the Array. Based on this, it is concluded that piling in-combination at the Array and the Tier 2 projects will not have an adverse effect on the integrity of harbour porpoise feature of this SAC.

                        Tier 3

  1. The Tier 3 assessment, presented in paragraphs 792 et seq., highlighted that it was not possible to undertake a quantitative in-combination assessment for the 11 Tier 3 projects identified for this impact. This was due to the lack of publicly available information surrounding piling parameters and lack of information in general about INTOG projects. The CEA presented in the Array EIA Report (volume 2, chapter 10 of the Array EIA Report) concluded a minor significance of effect for this potential impact associated with the Tier 3 projects.
  2. There is no publicly available piling parameters or published assessments for Tier 3 projects (which are at pre-scoping stage), however given the phase of development, temporal overlap with the Array may be limited. Furthermore, given the maximum injury ranges for harbour porpoise associated with piling from the Array (maximum PTS range of 1,600 m modelled for the Array alone), there is low likelihood of any spatial overlap of ranges between the Array and the Tier 3 projects. For example, the closest Tier 3 projects are the Morven Offshore Export Cable Corridor (5.5 km away) and Bellrock Offshore Wind Farm (8.67 km away), which both far exceed the maximum PTS range for harbour porpoise. Further, the potential for PTS is reduced through the application of designed-in measures, and animals are expected to be able to flee the injury zone due to ADD activation prior to commencement of soft starts ( Table 6.11   Open ▸ ). Therefore there is limited potential for an in-combination impact associated with the Tier 3 projects, and each project will likely implement their own mitigation to limit injury and disturbance as per the JNCC (2010c) guidelines, thus further reducing the potential for in-combination effects associated with piling.
  3. Based on this, it is concluded that piling in-combination at the Array and the Tier 3 projects will not have an adverse effect on the integrity of harbour porpoise feature of this SAC.

                        Conclusion

  1. Adverse effects on the qualifying Annex II marine mammal features of the Southern North Sea SAC which undermine the conservation objectives of the SAC will not occur as a result of in-combination underwater noise generated during piling in the construction phase. Potential effects from this activity on the relevant conservation objectives (as presented in section 6.2.2) are discussed in turn below in Table 6.64   Open ▸ .

 

Table 6.64:
Conclusions Against the Conservation Objectives of the Southern North Sea SAC from Underwater Noise Generated During Piling in the Construction Phase of the Array In-Combination with other Plans and Projects

Table 6.64: Conclusions Against the Conservation Objectives of the Southern North Sea SAC from Underwater Noise Generated During Piling in the Construction Phase of the Array In-Combination with other Plans and Projects

 

  1. It can be concluded, beyond reasonable scientific doubt, that there is no risk of an adverse effect on the integrity of the Southern North Sea SAC as a result of underwater noise generated during piling with respect to the construction phases of the Array in-combination with other plans and projects.