1. MPA Assessment

1.1.        Introduction

1.1. Introduction

1. Berwick Bank Wind Farm Limited (BBWFL) is a wholly owned subsidiary of SSE Renewables Limited and will hereafter be referred to as ‘the Applicant’.
2. The Applicant is developing the Berwick Bank Wind Farm (hereafter referred to as ‘the Project’). The Project is an offshore wind farm project located in the outer Firth of Forth and Firth of Tay, approximately 37.8 km east of the Scottish Borders coastline (St. Abb’s Head) and 47.6 km to the East Lothian coastline, in the southern region of the North Sea (Figure 1.1).
3. The Project is comprised of both the offshore and onshore infrastructure required to generate and transmit electricity from the offshore components of the Project (hereafter referred to as the ‘Proposed Development’) array area to a Scottish Power Transmission (SPT) 400 kV Grid Substation located at Branxton, south-east of Torness Power station. The Proposed Development export cable corridor will make landfall on the East Lothian coast, specifically at Skateraw. The offshore components (the Proposed Development) include the offshore wind farm (the wind turbines, their foundations and associated inter-array cabling), together with associated infrastructure of the Offshore Transmission Asset (OTA), Offshore Substation Platforms (OSPs)/Offshore convertor station platforms, their foundations and the offshore export cables and cable protection.
4. The Applicant is also developing an additional export cable grid connection to Blyth, Northumberland (the Cambois connection). Applications for necessary consents (including marine licences) will be applied for separately. The Cumulative Effects Assessment (CEA) of the Cambois connection is based on information presented in the Cambois connection Scoping Report (SSER, 2022e), submitted in October 2022.
5. RPS Energy Limited (RPS) was commissioned to undertake a Marine Protected Area (MPA) assessment for the Proposed Development and this document provides the final MPA Assessment to accompany the Proposed Development Offshore EIA Report. It is intended that this document, alongside the Offshore EIA Report, will be used to inform an MPA assessment undertaken by Scottish Ministers.

1.2.        Purpose of this Report

1.2. Purpose of this Report

6. Specific consideration of MPAs[1] is required for consent applications in UK waters. Under section 126 of the Marine and Coastal Access Act 2009, and section 83 of the Marine (Scotland) Act 2010, public authorities (in this case Marine Scotland - Licensing Operations Team (MS-LOT) on behalf of the Scottish Ministers) have specific duties for MPAs in relation to certain decisions. The public authority is required to consider whether the activity which is the subject of the application (i.e. marine licensable activities subject to a marine licence application) are capable of affecting (other than insignificantly) a protected feature in a Nature Conservation (nc) MPA or any ecological or geomorphological process on which the conservation of any protected feature in a ncMPA (hereafter referred to as an MPA) is dependant. MS-LOT must not grant authorisation of the activity unless the person applying for the authorisation satisfies MS-LOT that there is no significant risk of the activity hindering the achievement of the conservation objectives for the MPA. If the person seeking the authorisation is not able to satisfy MS-LOT that there is no significant risk of the activity hindering the achievement of the conservation objectives, then the authorisation must only be granted if:

1. MS-LOT is satisfied that there are no other means of proceeding with the activity which would create a substantially lower risk of hindering the achievement of those objectives (to include proceeding in another manner or at another location);
2. MS-LOT is satisfied that the benefit to the public of proceeding with the activity clearly outweighs the risk of damage to the environment that will be created by proceeding with it; and
3. MS-LOT is satisfied that the person seeking the authorisation will undertake, or make arrangements for the undertaking of, measures of equivalent environmental benefit to the damage which the activity will or is likely to have in or on the MPA concerned.
   7. This report has been produced to provide evidence on whether the potential impacts of the Proposed Development give rise to a significant risk of hindering the conservation objectives of any MPA which may be screened in.
   8. This document is informed by guidance published by Marine Scotland (2014a) on how these assessments should be undertaken and by advice from the Statutory Nature Conservation Bodies (SNCBs) during consultation in the pre-application phase (as outlined in section 1.2.2). This MPA Assessment has been undertaken based on the Proposed Development information detailed within volume 1, chapter 3 of the Offshore EIA Report and section 1.4 of this report.
   9. This MPA Assessment should be read alongside the following chapters of the Offshore EIA Report, all of which have been drawn upon and referred to throughout this document:

• volume 2, chapter 7: Physical Processes;
• volume 2, chapter 8: Benthic Subtidal and Intertidal Ecology;
• volume 3, appendix 8.1: Benthic Subtidal and Intertidal Ecology Technical Report;
• volume 2, chapter 9: Fish and Shellfish;
• volume 3, appendix 6.1: Scoping Report; and
• volume 3, appendix 6.2: Scoping Opinion.
  10. This report is structured as follows:
• section 1.1: Introduction;
• section 1.3: Methodology, including description of the staged approach to the MPA Assessment following the relevant published guidelines, and how information presented in the Offshore EIA Report has been used to support the assessments presented herein;
• section 1.4: Project description, provides an outline description of the Proposed Development and describes the activities likely to be associated with the construction, operation, and maintenance, and decommissioning of the Proposed Development;
• section 1.4.3: Initial screening of MPAs which have conservation objectives with the potential to be affected by the Proposed Development;
• section 1.6: Background information on MPAs considered in the main assessment;
• section 1.7: Main assessment;
• section 1.8: Conclusion; and
• section 1.9: Summary.

1.2.2.    Consultation

11. This MPA Assessment has been informed by consultation with key stakeholders, including Marine Scotland Science (MSS), MS-LOT and NatureScot, through the scoping process and through the Benthic Ecology, Fish and Shellfish Ecology, and Physical Processes Road Map process. A summary of the key issues raised during pre-application consultation is outlined in Table 1.1   Open ▸ , together with how these issues have been considered in the production of this report.

Table 1.1: Summary of Key Consultation Issues Raised During Pre-Application Consultation Activities Undertaken of Relevance to the MPA Assessment

1.3.        Methodology

1.3. Methodology

12. The Marine (Scotland) Act 2010 and the Marine and Coastal Access Act 2009 introduced provisions to support the management of MPAs. Under section 126 of the Marine and Coastal Access Act 2009 and section 83 of the Marine (Scotland) Act 2010, the public authority (MS-LOT) is required, when determining consenting application, to consider whether the activity applied for is capable of affecting (other than insignificantly) a protected feature in an MPA or any ecological or geomorphological process on which the conservation of any protected feature in an MPA is dependant.
13. It was highlighted by MS-LOT and NatureScot in the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022) that the Offshore EIA Report must make a full and clear assessment of the potential impacts of the Proposed Development on all the designated features of any scoped in MPA. The Applicant confirmed during a Benthic Ecology, Fish and Shellfish Ecology and Physical Processes Road Map meeting (Meeting 1) on 3 September 2021 that this would be presented as a separate standalone document alongside the Offshore EIA Report.
14. Marine Scotland’s Nature Conservation Marine Protected Areas: Draft Management Handbook (Marine Scotland, 2014a) recommends a staged approach to the assessment, starting with an initial screening process which should focus on what can reasonably be predicted as a consequence of the proposal and whether it is ‘capable of affecting (other than insignificantly)’ a protected feature of an MPA. This should then be followed by a main assessment which focuses on determining whether the exercise of a function would or might significantly hinder, or there is or may be a significant risk of the act hindering, the achievement of the conservation objectives. Full details of each of these stages of the approach have been provided in sections 1.3.2 and 1.3.3, respectively.
15. If certain activities, sites or impacts are screened into the MPA Assessment process, these are then considered within the main assessment if significant risks to the achievement of the MPA conservation objectives have been identified by the initial screening.

1.3.2.    Initial Screening

16. Marine Scotland’s Nature Conservation Marine Protected Areas: Draft Management Handbook (Marine Scotland, 2014a) states that the initial screening stage should focus on what can reasonably be predicted as a consequence of the proposal and whether it is ‘capable of affecting (other than insignificantly)’ a protected feature of an MPA. The screening should use information that is currently available on the activities applied for and consider aspects such as the scale, timing and duration of proposed activities/developments. These considerations should include proposals for developments or activities out-with the boundary of an MPA.
17. Firstly, consideration of ‘capable of affecting’ should result in removing from further consideration all proposals/functions which are not in any way connected to the protected feature(s). A capability that is both remote (in terms of likelihood of occurrence) and hypothetical should not be the basis of a conclusion that further assessment is required. This can be determined by considering whether the activity will exert pressures which the protected feature(s) are sensitive to (Marine Scotland, 2014a). Generic guidance and evidence on activities which exert pressures on the protected features is available through the online Feature Activity Sensitivity Tool (FeAST) sensitivity tool.
18. Secondly, if the conclusion is that there is ‘capability of affecting’, the focus should then be on considering whether the activity will affect the protected features of an MPA, other than insignificantly. Consideration of the degree of pressure that could be exerted by the activity on a spatial basis should help to establish what level of effect might occur. Where it is concluded that the act or function is capable of affecting (other than insignificantly) the protected features of an MPA then a main assessment must be carried out considering the conservation objectives.
19. In order to determine the ‘nearness’ of the activities associated with the Proposed Development for the purposes of this MPA Assessment, the same screening criteria as used for the Berwick Bank Habitats Regulations Appraisal (HRA) Offshore Screening Report (SSER, 2021b) were applied. These initial assumptions have subsequently been validated and refined through consultation with the SNCBs throughout the pre-application process (i.e. via the Benthic Ecology, Fish and Shellfish and Physical Processes Road Map process; see Table 1.1   Open ▸ ). These are as follows for the different protected features of MPAs:

• Benthic habitats/species and geodiversity features: there is the potential for indirect effects to sites designated for benthic features, as well as geodiversity features, as a result of impacts associated with increased suspended sediment concentrations (SSC) arising from construction activities or from changes to the hydrodynamic regime as a result of the presence of offshore infrastructure associated with the Proposed Development. The extent of these impacts is considered likely to extend beyond the boundaries of the Proposed Development. The zone of influence (ZOI) for such indirect effects is typically defined from the outputs of physical processes modelling to determine, for example, the fate of sediments resuspended during the construction process. Physical processes modelling had not been carried out at the Scoping stage. Therefore, a buffer of one mean tidal excursion was used initially to inform this area, with a reasonable level of precaution applied. One mean tidal excursion in the vicinity of the Proposed Development equates to approximately 6.5 km, as derived from the Atlas of UK Marine Renewable Energy Resources (ABPmer, 2008). For the purposes of MPA screening, a precautionary was adopted and this buffer was increased to 20 km. This buffer is considered to be sufficiently precautionary to capture all sites likely to be in the ZOI from direct and indirect effects associated with construction activities. This buffer has also been applied for geodiversity features of MPAs;
• Fish species: the HRA screening does not propose a screening distance for fish, as all European sites with diadromous fish species with the potential to be affected have been considered. For the purposes of this MPA Assessment (which does not consider diadromous fish, only marine fish) a nominal buffer of 100 km has been adopted to screen in MPA sites with fish features (e.g. sandeel species), on the basis that this is sufficiently precautionary to capture the ZOI from the project from key impacts such as underwater noise;
• Marine mammals: the HRA screening considers sites with cetaceans as qualifying interest features within a buffer that equates to the regional marine mammal study areas. For seals, all sites within the East Scotland Management Unit (MU) have been considered. These buffers are considered to be sufficiently precautionary to capture all sites likely to be in the ZOI from indirect effects associated with construction activities; and
• Ornithology: the HRA screening considers sites with breeding seabirds as qualifying interest features within a buffer that equates to the offshore ornithological regional study area. Published mean-maximum foraging ranges (plus one standard deviation (+1 S.D.)) in Woodward et al. (2019) were used to define the offshore ornithology regional study area. Northern gannet Morus bassanus has the largest foraging range (315.2 km ± 194.2 km) of the key species considered in the ornithology assessment. The offshore ornithology regional study area therefore extends 509.4 km from the Proposed Development. For seabirds in the non-breeding season, the ZOI is based on Furness (2015) which presents Biologically Defined Minimum Population Scales (BDMPS). These buffers are considered to be sufficiently precautionary to capture all sites likely to be in the ZOI from indirect effects associated with construction and operational activities. Following the establishment of the screening criteria and in view of the outputs of the collision risk, displacement and Population Viability Analysis assessments (volume 3, appendix 11.3 and appendix 11.6 of the Offshore EIA Report) the buffers have been refined and it was determined that no sites are likely to be in the ZOI in relation to ornithology.
  20. Additionally since Scoping, the assumptions applied for the MPA screening have been revisited in view of the outputs of the physical processes modelling undertaken for the Proposed Development (as reported in full in volume 2, chapter 7 of the Offshore EIA Report and volume 3, appendix 7.1 of the Offshore EIA Report). This modelling found that there would be no changes in tidal currents or sediment transport that would extend to the border of the 20 km study area and would further not disrupt beach and offshore bank morphological processes or destabilise coastal features. It is therefore concluded that the buffer applied is sufficiently precautionary to ensure all of the potentially affected benthic ecology receptors have been taken account of.
  21. The screening criteria applied however will depend in the nature of the MPA for example should none of the MPAs within the ZOI for the Proposed Development have seabirds as a qualifying feature then the ornithology screening criteria becomes redundant and will be screened out.
  22. Following identification of the MPAs considered in this initial screening, information presented within the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022) and the Offshore EIA Report has been reviewed to further refine this list of sites where the Proposed Development is capable of significantly affecting the protected/proposed features of those sites, or any ecological or geomorphological processes on which the conservation objectives of those features may depend. This included advice provided by the SNCBs and regulators on which sites should be included in the MPA Assessment as well as a review of outputs from volume 2, chapter 7 of the Offshore EIA Report to identify potential far field effects (e.g. increases in SSC, and changes to the tidal and wave regime due to the operational Proposed Development). Where robust evidence is available to screen out MPAs, this evidence has been referenced and justification presented within section 1.4.3.
  23. Individual impacts on designated protected features of the MPAs are also considered in the screening. Some impacts identified and assessed in volume 2, chapter 8 of the Offshore EIA Report were considered to be of sufficiently low risk of resulting in a likely significant effect on protected/proposed MPA features and have therefore been screened out (i.e. are considered insignificant). This may have been due, for example, to the extremely limited extent and/or duration of the impact, a lack of sensitivity of the receptors to the impact (as determined through the FeAST sensitivity tool or from the Advice on Operations Guidance documents), or due to control measures to be implemented by the Proposed Development to minimise the risk of any likely significant effect occurring. This is consistent with the guidance provided in Marine Scotland’s Nature Conservation Marine Protected Areas: Draft Management Handbook (Marine Scotland, 2014a).

1.3.3.    Main Assessment

24. The main assessment stage focuses on determining whether the exercise of a function would or might significantly hinder, or there is or may be a significant risk of the act hindering, the achievement of the conservation objectives of the MPA.
25. In doing so, the Marine Scotland (2014a) guidelines suggest the decision-maker would use the information supplied by the applicant along with the licence application, advice from the SNCBs and any other relevant information to determine whether there is no significant risk of hindering the achievement of the stated conservation objectives for the Nature Conservation MPA. Aspects such as scale, timing and duration of the proposed activities or developments will all need to be considered. However, whilst the initial screening focuses on the protected features, the main assessment focuses on the potential impact on the achievement of the conservation objectives of the protected features. Therefore, this stage must also include consideration of the scale of the potential impact. Consideration of cumulative effects with other activities and functions should also be undertaken.
26. In determining 'significant risk of hindering', the Marine Scotland (2014a) guidance states “The assessment should build on the initial screening assessment that considers the pressures associated with the activity and the sensitivity of the protected features, and information on the likely spatial overlap. To determine whether there is a 'significant risk of hindering' the achievement of the conservation objectives of the protected features of a nature conservation MPA aspects such as the intensity, frequency, and duration of any activities associated with the function or act should be considered.” This approach is presented in the Proposed Development interpretation of the Marine Scotland (2014a) guidance as outlined in the following section.
27. If MS-LOT determines that there is or may be a significant risk of the proposal hindering the achievement of the conservation objectives, then they must notify the appropriate statutory conservation bodies (NatureScot for MPAs within 12 nautical miles (nm) or the Joint Nature Conservation Committee (JNCC) for MPAs out with 12 nm) of that fact.
28. In those circumstances, in order to grant consent MS-LOT must determine that:

• there is no other means of proceeding with the project which would create a substantially lower risk of hindering the achievement of those objectives;
• the benefit to the public of proceeding with the project clearly outweighs the risk of damage to the environment that will be created by proceeding with it; and
• the person seeking the authorisation will undertake, or make arrangements for the undertaking of, measures of equivalent environmental benefit to the damage which the project will or is likely to have in or on the MPA concerned.
  29. When considering whether an activity may hinder the conservation objectives of a site, consideration should be given to the direct impact of an activity upon a protected feature as well as any applicable indirect impacts. Such an indirect impact could include changing the effectiveness of a management measure put in place to further the conservation objectives.

Assessment of risk to conservation objectives

30. Volume 2, chapter 7 and chapter 8 of the Offshore EIA Report have presented assessments of the impacts of the Proposed Development on the physical and biological marine environment respectively, with definitions of impact, effect, and significance of effects on the identified receptors (including protected features of MPA) drawn from guidelines published in the Design Manual for Roads and Bridges (DMRB) (Highways Agency, 2020). These definitions have also been used within this MPA Assessment, with the term 'effect' to express the consequence of an impact. This is expressed as the 'significance of effect' and is determined by considering the magnitude of the impact alongside the importance, or sensitivity, of the receptor or resource, in accordance with defined significance criteria.
31. Volume 2, chapter 8 of the Offshore EIA Report presents significance levels according to EIA/Ecological Impact Assessment (EcIA) methodologies. While this MPA Assessment will draw on the information presented in volume 2, chapter 8 of the Offshore EIA Report to support the conclusions made about effects of the Proposed Development on the achievement of conservation objectives for the relevant MPA, the EIA/EcIA approach has not been used to inform the conclusions made.
32. As discussed in section 1.3.3, the main assessment has considered whether there is a risk that the Proposed Development could hinder the achievement of the conservation status of protected features and conservation objectives for the MPA. This includes assessing the risks in the context of the conservation status of each of the individual MPA protected features.
33. The conservation objectives are detailed in section 1.6 for the sites and the protected features which have been considered in the main assessment. For the Firth of Forth Banks Complex MPA, further information on the conservation objectives for each of the protected features was available in the Supplementary Advice on Conservation Objectives for the site (JNCC, 2018a). The Supplementary Advice presents attributes, and sub-attributes, which describe the ecological characteristics of the protected features. The attributes each have an objective(s) which is either quantitative or qualitative, depending on the available evidence. The objective identifies the desired state to be achieved for the attribute and an objective of recover or conserve is set for each feature attribute.
34. The main assessment considers each of the attributes for all protected features of the relevant MPA, where there is a clear impact-receptor pathway, to help determine whether there is a significant risk to the conservation objectives of the MPA. This draws on information presented within the relevant chapters of the Offshore EIA Report (see paragraph 9). When considering ecological attributes, the sensitivities of the species and communities (often represented by biotopes; see section 1.6.2) associated with the MPA features have been defined by the following, according to the Marine Evidence based Sensitivity Assessment (MarESA) (OSPAR, 2008; Laffoley et al., 2000):

• Intolerance or resistance, which is the likelihood of damage due to a pressure; and
• Recoverability or resilience, which is the rate of (or time taken for) recovery once the pressure has abated or been removed. Recoverability is the ability of a habitat to return to the state before the activity or event which caused change. It is dependent on its ability to recover or recruit subject to the extent of disturbance/damage incurred. Full recovery does not necessarily mean that every component species has returned to its prior condition, abundance or extent but that the relevant functional components are present, and the habitat is structurally and functionally recognisable as the initial habitat of interest.
  35. The FeAST tool allows users to investigate the sensitivity of marine features in Scotland's seas to pressures arising from human activities. This tool also bases its definition of sensitivity upon the features tolerance/intolerance as well as its recoverability (Marine Scotland, 2013). As these features are all located in Scottish waters both MarESA and FeAST were used to determine the sensitivity of protected features.
  36. Therefore, where sensitivity levels have been presented within the main assessment of this document, these are the definitions according to the MarESA and FeAST (Tillin et al., 2010) and not according to the definitions used to inform the EIA in volume 2, chapter 8 of the Offshore EIA Report, the latter also considering the importance (e.g. conservation, commercial or ecological) of the receptors. Use of the MarESA and FeAST definitions also ensures consistency with the JNCCs conservation advice for the Firth of Forth Banks Complex MPA and other MPAs. Information on these aspects of sensitivity of the species, communities, and biotopes to given impacts has been informed by the best available evidence following environmental impact or experimental manipulation in the field and evidence from the offshore wind industry and analogous activities such as those associated with cable installation and operations, aggregate extraction and oil and gas industries. Where applicable, MarESA and FeAST have also been drawn upon to support the assessments of sensitivity, including evidence of sensitivity to particular activities and benchmarks for the relevant pressures considered for each attribute.
  37. Following consideration of the relevant impacts of the Proposed Development on attributes and targets of the individual MPA features, conclusions are presented as to the potential risks of the activities associated with the Proposed Development hindering achievement of conservation objectives for the sites and consequently whether the conditions in section 126 of the Marine and Coastal Access Act 2009 and section 83 of the Marine (Scotland) Act 2010 can be met (see paragraphs 24 and 26) (i.e. there is no significant risk of the activity hindering the achievement of the conservation objectives stated for the MPA).
  38. If it cannot be concluded that there is no significant risk of the activity hindering the achievement of the conservation objectives of an MPA, and that mitigation or consideration of alternative means of proceeding, would not create a substantially lower risk of hindering achievement of the conservation objectives (see paragraph 28), the Applicant must undertake, or make arrangements for the undertaking of, measures of equivalent environmental benefit to the damage which the project will or is likely to have in or on the MPA concerned. The assessment outcomes presented within this MPA Assessment demonstrate that there is no significant risk of the Proposed Development hindering the achievement of the conservation objectives of an MPA (see section 1.7), and so these latter stages are not relevant.

1.4.        Project description

1.4. Project description

39. This section provides an outline description of the Proposed Development and describes the activities likely to be associated with the construction, operation, and maintenance, and decommissioning of the Proposed Development. It summarises the design and components of the Proposed Development infrastructure, based on design concept and current understanding of the environment associated with the Proposed Development from site specific survey work.
40. The Project Design Envelope (PDE) approach has been adopted for the assessment of the Proposed Development, which allows for a project to be assessed on the basis of maximum project design parameters. This provides flexibility, while ensuring all potential likely significant effects (positive or negative) are assessed. Those parameters presented include a range of potential values up to and including the maximum project design parameters.
41. The Proposed Development will be located in the central North Sea, 43 km offshore of the East Lothian coastline and 33.5 km from the Scottish Borders coastline at St, Abbs. The Proposed Development is already the subject of Agreements for Lease (AfL). The Proposed Development operational lifetime is 35 years.
42. The Proposed Development encompasses the:

• Proposed Development array area: This is where the offshore wind farm will be located, which will include the wind turbines, wind turbine foundations, inter-array cables, and a range of offshore substations and offshore interconnector cables; and
• Proposed Development export cable corridor up to mean high water springs (MHWS): This is where the offshore electrical infrastructure such as offshore export cables will be located.

1.4.2.    Offshore Infrastructure

Overview

43. The key offshore components of the Proposed Development (seaward of MHWS), as shown in Figure 1.2   Open ▸ , will include:

• up to 307 wind turbines (each comprising a tower section, nacelle and three rotor blades) and associated support structures and foundations;
• up to ten Offshore Substation Platforms (OSPs)/Offshore convertor station platforms and associated support structures and foundations to accommodate for a combined High Voltage Alternating Current (HVAC)/High Voltage Direct Current (HVDC) transmission system solution or a HVDC solution;
• estimated scour protection of up to 10,984 m2 per wind turbine and 11,146 m2 per OSP/Offshore convertor station platforms;
• a network of inter-array cabling linking the individual wind turbines to each other and to the OSPs/Offshore convertor station platforms plus inter-connections between OSPs/Offshore convertor station platforms (approximately 1,225 km of inter-array cabling and 94 km of interconnector cabling); and
• up to eight offshore export cables connecting the OSPs/Offshore convertor station platforms to landfall at Skateraw. Offshore export cables design includes both HVAC and HVDC solutions.
  44. The Applicant is also developing an additional export cable and grid connection to Blyth, Northumberland (hereafter the “Cambois connection”). Applications for the necessary consents (including marine licences) will be applied for separately once further development work has been undertaken on this offshore export corridor. The Cambois connection has been included as a cumulative project for the purposes of the offshore EIA and assessed based on the information presented in the Cambois connection Scoping Report submitted in October 2022 (SSER, 2022e). An EIA and HRA will be prepared to support any relevant consent applications that are required to deliver the Cambois connection which will also consider cumulative effects with the Proposed Development.

Figure 1.2: Project Overview[3]

Wind turbines

45. The Proposed Development will comprise up to 307 wind turbines, with the final number of wind turbines dependent on the capacity of individual wind turbines used, and also environmental and engineering survey results. The PDE considers a range of wind turbines with parameters reflective of potential generating capacities, allowing for a degree of flexibility to account for any anticipated developments in wind turbine technology while still allowing each of the impacts assessed within the technical assessments (volume 2, chapters 7 to 21), to define the maximum design scenario for the assessment of effects. Consent is therefore sought for the physical parameters of the wind turbines which form the basis of the maximum design scenario such as maximum tip height or rotor diameter, as presented in the PDE rather than actual installed capacity of the wind turbines.
46. A range of wind turbine options have been considered. The parameters in Table 1.2   Open ▸ provide for both the maximum number of wind turbines, as well as the largest wind turbine within the PDE. As set out in paragraph 1.2.8, the coupling of these maximum dimensions will not provide a realistic design scenario; as a reduced number of wind turbines will likely be required if an increased rated output of wind turbine model is chosen.
47. The wind turbines will comprise a horizontal axis rotor with three blades connected to the nacelle of the wind turbine. Figure 1.3   Open ▸ illustrates a schematic of a typical offshore wind turbine.

Figure 1.3: Indicative Schematic of an Offshore Wind Turbine on a Jacket Foundation

48. The maximum rotor blade diameter will be no greater than 310 m, with a maximum blade tip height of 355 m above LAT and a minimum lower blade tip height of 37 m above LAT. A scheme for wind turbine lighting and navigation marking will be approved by Scottish Ministers following consultation with appropriate consultees post consent. Outlines plans have been provided with the Application in volume 4 of this Offshore EIA Report.
49. The layout of the wind turbines will be developed to best utilise both the available wind resource, suitability of seabed conditions and wake effects, while seeking to minimise environmental effects and impacts on other marine users (such as fisheries and shipping routes).
50. Figure 1.4   Open ▸ presents an indicative wind farm layout based on the maximum design scenario of 307 wind turbines, while Figure 1.5   Open ▸ displays an indicative wind farm layout should 179 wind turbines were to be installed. The final layout of the wind turbines will be confirmed at the final design stage post consent with details being submitted to Marine Scotland Licensing Team (MS-LOT) for approval.

Table 1.2: Design Envelope: Wind Turbines

Figure 1.4: Berwick Bank Wind Farm Preliminary Indicative Layout for 307 Wind Turbines Each Square Being 5 km x 5 km)

Figure 1.5: Berwick Bank Wind Farm Preliminary Indicative Layout for 179 Wind Turbines Each Square Being 5 km x 5 km)

51. To improve operation, productivity and prevent wear on parts, a number of consumables may be required for the wind turbines. These may include:-

• grease;
• synthetic oil;
• hydraulic oil;
• gear oil;
• lubricants;
• nitrogen;
• water/glycerol;
• transformer silicon/ester oil;
• diesel fuel;
• sulphur hexafluoride SF6; and
• glycol/coolants
  52. The quantities required are dependent on the make and model of the wind turbines yet to be selected. Indicative values are provided in the relevant chapters (e.g. volume 2, chapter 19) that enable a precautionary assessment to be undertaken.

Wind turbine foundations and support structures

53. To allow for flexibility in foundation choice, two types of wind turbine support structures and foundations are being considered for the Proposed Development:

• piled jacket; and
• suction caisson jacket.
  54. Foundations will be fabricated offsite, stored at a suitable port facility (if required) and transported to site by sea. Specialist vessels will transport and install foundations. Scour protection (typically rock) may be required on the seabed and will be installed before and/or after foundation installation. The following section provides an overview of the foundation types which are being considered for wind turbines - foundation structures for OSPs/Offshore convertor station platforms are discussed in paragraph 58 and seq.

Piled jacket foundation

55. The piled jacket foundations will be transported to site by sea. Once at site, the jacket foundation will be lifted by the installation vessel using a crane and lowered towards the seabed in a controlled manner. Piled jacket foundations are formed of a steel lattice construction (comprising tubular steel members and welded joints) secured to the seabed by driven and/or drilled pin piles attached to the jacket feet (as illustrated in Figure 1.6   Open ▸ ). The hollow steel pin piles are typically driven or drilled into the seabed, relying on the frictional and end bearing properties of the seabed for support. The PDE for jacket foundations with pin piles is provided in Table 1.3   Open ▸ .

Table 1.3: Design Envelope: Wind Turbine Jacket Foundation with Pin Piles

Figure 1.6: Indicative Schematic of a Jacket Foundation with Pin Piles

Suction caisson jacket foundations

56. Suction caisson jacket foundations are formed with a steel lattice construction (comprising tubular steel members and welded joints) fixed to the seabed by suction caissons installed below each leg of the jacket (as per Figure 1.7   Open ▸ ). The suction caissons are typically hollow steel cylinders, capped at the upper end, which are fitted underneath the legs of the jacket structure. They do not require a hammer or drill for installation.
57. The suction caisson jacket foundations will be transported to site by sea. Once at site, the jacket foundation will be lifted by the installation vessel using a crane and lowered towards the seabed in a controlled manner. When the steel caisson reaches the seabed, a pipe running up through the stem above each caisson will begin to suck water out of each bucket. The buckets are pressed down into the seabed by the resulting suction force. When the bucket has penetrated the seabed to the desired depth, the pump is turned off. A thin layer of grout is then injected under the bucket to fill the air gap and ensure contact between the soil within the bucket, and the top of the bucket itself. The PDE for jacket foundations with suction caissons is provided in Table 1.4   Open ▸ .

Table 1.4: Design Envelope: Wind Turbine Jacket Foundation with Suction Caisson

Figure 1.7: Indicative Schematic of a Jacket Foundation with Suction Caissons

Offshore substation platforms and offshore convertor station platforms

58. The Applicant has three signed grid connection agreements with the network operator. Two agreements are for connection at the Branxton substation, with a third additional connection at Blyth, Northumberland (the Cambois connection). The Cambois connection agreement, was confirmed in June 2022 following National Grid’s Electricity System Operator (NGESO) Holistic Network Review, and will enable the Project to reach full generating capacity (4.1 GW) by early 2030’s.
59. The installation of offshore export cables including landfall methodologies for the Cambois connection is being consented separately to the Proposed Development but has been considered cumulatively as part of this Application.
60. The Project is currently considering HVAC and HVDC solutions for the Offshore Transmission Infrastructure. These solutions include:

• Combined Option A or Combined Option B: a combined HVAC/HVDC solution comprising the following:

–           up to eight HVAC OSPs to facilitate connections to Branxton and two HVDC Offshore convertor station platforms that will be required for the Cambois connection (see Table 1.5   Open ▸ ); or

–           up to five larger HVAC OSPs to facilitate connections to Branxton and two HVDC Offshore convertor station platforms that will be required for the Cambois connection (see Table 1.6   Open ▸ ).

• HVDC Option: Up to five HVDC Offshore convertor station platforms, two for the Branxton connection and two for the additional Cambois connection (see Table 1.7   Open ▸ ) This also includes an offshore interconnector platform.
  61. These offshore platforms will be utilised as OSPs/Offshore convertor stations platforms which transform electricity generated by the wind turbines to a higher voltage and thereby allowing the power to be efficiently transmitted to shore. The platforms’ topsides size will depend on the final electrical design for the wind farm but maximums could be up to 100 m (length) by 80 m (width) and up to 80 m in height (above LAT), excluding the helideck, antenna structure or lightning protection. The maximum design parameters for OSPs/Offshore convertor station platforms are presented in Table 1.5   Open ▸ and Table 1.6   Open ▸ (Combined Options) and Table 1.7   Open ▸ (HVDC Option). It is proposed that the OSP/Offshore convertor station platform foundations will be painted yellow from the water line up to the topside structure and the topside will be painted light grey.

Table 1.5: Design Envelope: OSP/Offshore Convertor Station Platform (Combined Option A)

Table 1.6 Design Envelope: OSP/Offshore Convertor Station Platform (Combined Option B)

Table 1.7: Design Envelope: Offshore Convertor Station Platforms (HVDC Option)

62. Table 1.8   Open ▸ presents the consumables which will be required for the OSPs/Offshore convertor station platforms at the Proposed Development. In addition, Uninterruptible Power Supply (UPS) batteries, fire suppression systems, HVAC coolant and SF6 will also be required.

Table 1.8: Design Envelope: Consumables for the Offshore Substation Platforms (per OSP/Offshore Convertor Station Platform)

63. Project design layout has not yet been finalised, however the OSPs/Offshore convertor station platforms will be located within the Proposed Development array area. The offshore platforms will be installed with piled jacket foundations or suction caissons. The PDE for offshore platforms piled jacket foundations is shown in Table 1.9   Open ▸ (Combined Option A), Table 1.10   Open ▸ (Combined Option B) and Table 1.11   Open ▸ (HVDC Option). The PDE for offshore platforms suction caissons foundations is shown in Table 1.12   Open ▸ (Combined Option A), Table 1.13   Open ▸ (Combined Option B) and Table 1.14   Open ▸ Table 1.14   Open ▸ (HVDC Option).

Table 1.9: Maximum Design Envelope: Jacket Foundation with Pin Piles for OSPs/Offshore Convertor Station Platforms (Combined Option A)

Table 1.10 Maximum Design Envelope: Jacket Foundation with Pin Piles for OSPs/Offshore Convertor Station Platforms (Combined Option B)

Table 1.11: Maximum Design Envelope: Jacket Foundation with Pin Piles for OSPs/Offshore Convertor Station Platforms (HVDC Option)

Table 1.12: Maximum Design Envelope: Suction Caisson Foundation for OSPs/Offshore Convertor Station Platforms (Combined Option A)

Table 1.13: Maximum Design Envelope: Suction Caisson Foundation for OSPs/Offshore Convertor Station Platforms (Combined Option B)

Table 1.14: Maximum Design Envelope: Suction Caisson Foundation for OSPs/Offshore Convertor Station Platforms (HVDC Option)

Scour protection for foundations

64. Foundation structures for wind turbines and substations are at risk of seabed erosion and ‘scour hole’ formation due to natural hydrodynamic and sedimentary processes. The development of scour holes is influenced by the shape of the foundation structure, seabed sedimentology and site-specific metocean conditions such as waves, currents and storms. Scour protection may be employed to mitigate scour around foundations. There are several commonly used scour protection types, including:

• concrete mattresses: several metres wide and long, cast of articulated concrete blocks which are linked by a polypropylene rope lattice which are placed on and/or around structures to stabilise the seabed and inhibit erosion;
• rock placement: either layers of graded stones placed on and/or around structures to inhibit erosion or rock filled mesh fibre bags which adopt the shape of the seabed/structure as they are lowered on to it; or
• artificial fronds: mats typically several metres wide and long, composed of continuous lines of overlapping buoyant polypropylene fronds that create a drag barrier which prevents sediment in their vicinity being transported away. The frond lines are secured to a polyester webbing mesh base that is itself secured to the seabed by a weighted perimeter or anchors pre-attached to the mesh base.
  65. The most frequently used scour protection method is ‘rock placement’, which entails the placement of crushed rock around the base of the foundation structure.
  66. The amount of scour protection required will vary for the two foundation types being considered for the Proposed Development. The final choice of scour protection will be made after design of the foundation structure, taking into account a range of aspects including geotechnical data, meteorological and oceanographical data, water depth, foundation type, maintenance strategy and cost. Scour protection PDE parameters for foundations with piled jackets and suction caissons are presented in Table 1.15   Open ▸ .

Table 1.15: Scour Protection Parameters – Wind Turbine Foundations and OSP/Offshore Convertor Station Platform

Subsea cables

67. The type of cable laying vessel that will be used to lay subsea cables on the seabed has not been selected at this time. Therefore, the maximum design envelope accounts for both the use of a Dynamic Positioning (DP) vessel and vessels which require the use of anchor during cable laying activities (see Table 1.16   Open ▸ to Table 1.19   Open ▸ ).

Inter-array cables

68. Inter-array cables carry the electrical current produced by the wind turbines to an offshore substation platform or an offshore convertor station platform. A small number of wind turbines will typically be grouped together on the same cable ‘string’ connecting those wind turbines to the substation/convertor platform, and multiple cable ‘strings’ will connect back to each offshore substation/convertor platform.
69. The inter-array cables will be buried where possible and protected with a hard protective layer (such as rock or concrete mattresses) where adequate burial is not achievable, for example where crossing pre-existing cables, pipelines or exposed bedrock. The requirement for additional protection will be dependent on achieving target burial depths which will be influenced by several factors such as seabed conditions, seabed sedimentology, naturally occurring physical processes and possible interactions with other activities including bottom trawled fishing gear and vessel anchors. There is the potential for seabed preparation to be required prior to cable installation with methods such dredge and deposit of sediments material, use jet trenchers, mechanic trenchers or grapnels currently being considered. The cable installation methodology and potential cable protection measures will be finalised at the final design stage (post-consent). The PDE for inter-array cables is presented in Table 1.16   Open ▸ .

Table 1.16: Design Envelope: Inter-Array Cables

Interconnector cables

70. Interconnector cables will be required to connect the OSPs/Offshore convertor station platforms to each other in order to provide redundancy in the case of failures within the electrical transmission system. The cables are likely to consist of a cross-linked polyethylene (XLPE) insulated aluminium or copper conductor cores.
71. These cables will be either HVDC or a combination of HVDC and HVAC. Table 1.17   Open ▸ provides the maximum design scenario for interconnector cables.
72. The interconnector cables will have a minimum target burial depth of 0.5 m. If burial is not possible due to ground conditions or target burial depths not being achievable, then cable protection techniques will be employed (paragraph 78). The total length of interconnector cables will not exceed 94 km. There is the potential for seabed preparation to be required prior to cable installation with methods such dredge and deposit of sediments material, use jet trenchers, mechanic trenchers or grapnels currently being considered.

Table 1.17: Design Envelope: Interconnector Cables

Offshore export cables

73. Offshore export cables are used for the transfer of power from the OSPs/Offshore convertor station platforms to the transition join bay at landfall where they become onshore export cables. Up to eight offshore export cables will be required (applicable to both Combined and HVDC Options).
74. The offshore export cables will have a maximum total length of 872 km, comprised of up to eight cables connecting the OSPs/Offshore convertor station platforms to landfall at Skateraw. Each of these offshore export cables will be installed in a trench up to 2 m wide with a target burial depth of between 0.5 m and 3 m per cable.
75. Although the Proposed Development export cable corridor has been identified, the exact route of the offshore export cables is yet to be determined and will be based upon geophysical and geotechnical survey information. This information will also support the decision on requirements for any additional cable protection. Flexibility is required in the location, depth of burial and protection measures for the offshore export cables to ensure physical and technical constraints, changes in available technology and Project economics can be accommodated within the final design.
76. The proposed method for the installation of the offshore export cables through the intertidal zone at landfall at Skateraw is by using a trenchless technique burial method ( Figure 1.9   Open ▸ ). Following punch out of offshore export cables, onwards installation to the wind farm will be completed by using jetting, trenching and ploughing as summarised in Table 1.18   Open ▸ , noting pre-sweeping/dredging may be required in some areas.

Table 1.18: Design Envelope: Offshore Export Cable Method of Installation

77. The maximum design scenario for the offshore export cables is described in Table 1.19   Open ▸ .

Table 1.19: Design Envelope: Offshore Export Cables

Cable protection

78. Cable protection will be used to prevent movement or exposure of the cables over the lifetime of the Proposed Development when target cable burial depth is not achieved due to seabed conditions. This will protect cables from other activities such as fishing or anchor placement, dropped objects, and limit the effects of heat and/or induced magnetic fields. Cable protection may comprise sleeving, cast iron shells, concrete mattressing or rock placement. The preferred solution for protection will depend on seabed conditions along the route and the need to protect cables from other activities which may occur in that area.
79. The maximum design scenario for inter-array, interconnector and offshore export cables, are presented in Table 1.20   Open ▸ .

Table 1.20: Design Envelope: Cable Protection Parameters

Concrete mattressing

80. Concrete mattresses are constructed using high strength concrete blocks and U.V. stabilised polypropylene rope. They are supplied in standard 6 m x 3 m x 0.3 m units of standard density, however modifications to size, density, and shape (tapered edges for high current environments, or denser concrete) can be engineered bespoke to the locality.
81. The mattresses can be installed above the cables with a standard multicat type DP vessel and free-swimming installation frame. The mattresses are lowered to the seabed and once the correct position is confirmed, a frame release mechanism is triggered and the mattress is deployed on the seabed. This single mattress installation is repeated for the length of cable that requires protection. The mattresses may be gradually layered in a stepped formation on top of each other dependant on expected scour. Concrete mattressing can be used for cable protection and at cable crossings.

Rock placement

82. Rock placement on top of cables to provide additional protection is carried out either by creating a berm or by the use of rock bags (see Figure 1.8   Open ▸ ).

Figure 1.8: Rock Cable Protection Methods (Left: Rock Placement; Right: Rock Bags)

83. Rock placement is achieved using a vessel with equipment such as a ‘fall pipe’ which allows installation of rock close to the seabed. The rock protection design for the Proposed Development will be within a maximum height of 3 m and 20 m width (see Table 1.20   Open ▸ ), with an approximate slope of 1:3 both sides of the cable. This shape is designed to provide protection from anchor strike and anchor dragging, and to allow over trawl by fishing vessels. The cross-section of the berm may vary dependent on expected scour. The length of the berm is dependent on the length of the cable which requires protection.
84. Alternatively, pre-filled rock bags can be placed above the cables with specialist installation beams. Rock bags consist of various sized rocks contained within a rope or wire net. Similar to the installation of the concrete mattresses, they are lowered to the seabed and when in the correct position, are deployed on to the seabed. Typically, each rock bag is 0.7 m in height and has a diameter of 3 m. Rock placement can be used for cable protection and at cable crossings. The number of rock bags required is dependent on the length of cable which requires protection.

Cable crossing

85. Up to 16 cable crossings may be required for the offshore export cables. The offshore export cables will cross each of the Neart na Gaoithe cables and will avoid crossing each other. This will be facilitated by the installation of standard cable crossing designs, likely to be comprised of ducting, concrete mattresses or rock as described above. Offshore export cables will avoid crossing interconnector cables. The maximum design scenario for cable crossing is presented in Table 1.20   Open ▸ .
86. It is also possible that up to 78 inter-array cable crossings will be required. Additional cable protection will be required at these crossings, and these crossings and the required protection are accounted for in Table 1.20   Open ▸ . The design will look to minimise cable crossings with up to 78 inter-array crossings predicted in total.

Table 1.21: Design Envelope: Cable Crossing Parameters (Inter-Array Cables and Offshore Export Cables)

1.4.3.    Site Preparation Activities

87. A number of site preparation activities will be required in the Proposed Development array area and Proposed Development export cable corridor. Site preparatory works are assumed to begin prior to the first activities within the Proposed Development array area and continue as required throughout the construction programme. As such, site preparation activities may happen at any point during the construction phase.
88. An overview of these activities is provided below.

Pre-construction surveys

89. A number of pre-construction surveys will be undertaken to identify in detail:

• seabed conditions and morphology;
• presence/absence of any potential obstructions or hazards; and
• to inform detailed project design work.
  90. These geophysical and geotechnical surveys will be conducted across the Proposed Development array area and Proposed Development export cable corridor and are expected to have a duration of three months. Geophysical surveys will comprise techniques such as Side Scan Sonar (SSS), Sub-bottom Profiling (SBP), Multibeam Echo-Sounder (MBES), Single Beam Echo-Sounder (SBES), high-density magnetometer surveys and Ultra High Resolution Seismic (UHRS). Geotechnical surveys will comprise techniques such as boreholes, Cone Penetration Tests (CPTs) and vibrocores.
  91. Geotechnical surveys will be conducted at specific locations within the footprint of the Proposed Development export cable corridor and the Proposed Development array area.
  92. Geophysical survey works will be carried out to provide details of Unexploded Ordnance (UXO), bedform and boulder mapping, detailed bathymetry, a topographical overview of the seabed and an indication of sub-surface layers. These will be carried out within the whole Proposed Development array area and Proposed Development export cable corridor, utilising mutilsensor towed arrays and sonar.

Clearance of unexploded ordnance

93. It is possible that UXO originating from World War I or World War II may be encountered during the construction or installation of offshore infrastructure. This poses a health and safety risk where it coincides with the planned location of infrastructure and associated vessel activity, and therefore it is necessary to survey for and carefully manage UXO.
94. The following methodologies are considered for UXO avoidance/clearance:

• avoid and leave in situ;
• micrositing to avoid UXO;
• relocation of UXO to avoid detonation;
• low order (e.g. deflagration); and
• high order detonation (with associated mitigation measures).
  95. Where it is not possible to avoid or relocate a UXO, the preferred method for UXO clearance is for a low order technique (subsonic combustion) with a single donor charge of up to 80 g Net Explosive Quantity (NEQ) for each clearance event. Due to the intensity of the surveys required to accurately identify UXO, this work cannot be conducted before detailed design work has confirmed the planned location of infrastructure. Based on existing knowledge of the area (Seagreen 1), it has been assumed that there may be up to 14 UXO which require clearance by a low order technique (such as deflagration). However, due to risk of unintended high order detonation, it has been assumed that 10% of all clearance events may result in high order detonation (see volume 2, chapter 10).
  96. The maximum design scenario for UXO clearance is provided in Table 1.22   Open ▸ .

Table 1.22: Design Envelope: Unexploded Ordnance Parameters

Sand wave clearance

97. In some areas within the Proposed Development array area and along the Proposed Development export cable corridor, existing sand waves and similar bedforms may need to be removed prior to the installation of cables. This is carried out mainly for two reasons, although others may arise:

• many of the cable installation tools require a relatively flat seabed surface in order to work effectively. Installing cables on up or down a slope over a certain angle, or where the installation tool is working on a camber may reduce the ability to meet target burial depths; and
• the cable must be installed to a depth where it may be expected to stay buried for the duration of the Proposed Development operational lifetime (35 years). Sand waves are generally mobile in nature therefore the cable must be buried beneath the level where natural sand wave movement could uncover it. Sometimes this can only be achieved by removing the mobile sediments before installation takes place.
  98. Sand wave clearance may take place throughout the construction phase. If required, sand wave clearance will be completed in areas within the Proposed Development array area along the inter-array cables, OSP/Offshore convertor station platform interconnector cables and the Proposed Development export cable corridor. Seabed features clearance will involve removal of the peaks of the seabed features by techniques such as dredging, with material replaced in the troughs, thereby levelling the seabed. A specialist dredging vessel may be required to complete the seabed features clearance.
  99. Sand wave clearance may also be undertaken using other methodologies including pre-installation ploughing tools to flatten sand waves, pushing sediment from wave crests into adjacent troughs and levelling the seabed.
  100. The maximum design scenario for sand wave clearance in the Proposed Development array area and Proposed Development export cable corridor is summarised in Table 1.23   Open ▸ . Final values for sand wave clearance will be refined following completion of a geophysical survey campaign prior to construction.
  101. In addition to sand wave clearance, boulder clearance and pre-lay grapnel run may be required to prepare the site for cable installation.

Table 1.23: Design Envelope: Sand Wave Clearance Parameters

Boulder clearance

102. Boulder clearance is commonly required during offshore wind farm site preparation. A boulder is typically defined as being over 200 mm in diameter/length. It is expected that the boulder clearance campaign will be carried out with the use of a DP vessel.
103. Boulder clearance may be required along the inter-array cables, OSP/Offshore convertor station platform interconnector cables and the Proposed Development export cable corridor. Boulder clearance is required to reduce the risk of shallow cable burial resulting in the need for further cables burial works and/or cable protection, as well minimising risk of damage to cables during installation. It may also be required in the vicinity of the foundation locations (including within the jack-up vessel zone around the foundation locations), in order to avoid disruption to installation activities and to ensure stability for the jack-up vessel. Table 1.24   Open ▸ provides the maximum design scenario for boulder clearance in the Proposed Development array area and Proposed Development export cable corridor.
104. Cable routes may be pre-ploughed to remove boulders or, alternatively clearance may be undertaken using a boulder grab. The method to be deployed will be informed by geophysical and pre construction surveys and will be dependent on the size, density and location of boulders, and more than one method of boulder removal may be deployed across the Proposed Development.

Table 1.24: Design Envelope: Boulder Clearance Parameters

Vessels for site preparation activities

105. Table 1.25   Open ▸ includes all vessels to be used during site preparation activities.

Table 1.25: Design Envelope: Vessels for Site Preparation Activities

1.4.4.    Construction Phase

Methodology

106. The Proposed Development is likely to be constructed according to the general sequence below, although the final sequence may vary from this:

• step 1 – offshore export cables – landfall installation;
• step 2 – foundation installation and scour protection installation;
• step 3 – OSP/Offshore convertor station platform topside installation/commissioning;
• step 4 – inter-array and interconnector cable installation and cable protection installation;
• step 5 – offshore export cables – offshore installation and cable protection installation; and
• step 6 – wind turbine installation/commissioning.

Figure 1.9: Typical Long Section of Trenchless Technique Method

107. Each stage is outlined in further detail in the following sections.

Step 1 – Offshore export cables – landfall installation

108. Figure 1.10   Open ▸ shows the Proposed Development export cable corridor as it reaches landfall at Skateraw.
109. Offshore export cables landfall installation parameters are presented in Table 1.26   Open ▸ . Works landward of MHWS are described and assessed in the Berwick Bank Wind Farm Onshore EIA Report (SSER. 2022a), although those works are assessed cumulatively with the Proposed Development in this Offshore EIA Report.
110. It is proposed that the cables are installed through the intertidal zone using trenchless technology ( Figure 1.9   Open ▸ ), such as HDD. HDD involves drilling a hole (or holes) along an underground pathway from one point to another, through which the offshore export cables are installed, without the need to excavate an open trench. To achieve this a drill rig is located onshore, landward of MHWS. A working area will be established containing the drill rig, electrical generator, water tank, mud recycling unit and temporary site office. The drilling installation will commence from above the MHWS, with the HDD exit point (punch out location) located seaward of MLWS between 488 m and 1,500 m below MWHS. As such, no works are planned to take place in the intertidal zone.
111. A drilling fluid, such as Bentonite, is pumped into the drilling head during the drilling process to stabilise the hole and retrieve the drilled material. Once the drilling is complete, cable ducts may be installed from land and pushed out, or towed into position by a vessel offshore and pulled in. The offshore export cables are then pulled through the pre-installed ducts by land-based winches.
112. The HDD punch out may also require the excavation of HDD exit punches out.
113. The HDD works comprise the following main stages:

1. A pilot hole will be drilled from onshore to offshore.
2. Once the pilot hole has been completed, the reaming process will commence, increasing the diameter of the pilot hole to accommodate the safe installation of HDD duct. The reaming process will continue back and forth for a number of passes to achieve a minimum bore diameter. During the drilling procedure, drilling fluid is continuously pumped to the drill head to act as a lubricant. Solids are removed from the returning fluid, and the spoil is transported off site or into the mud pit (landward of the MHWS) to settle.
3. A jack-up vessel or dredger will be used at the at the HDD exit point to create a HDD exit punch out.
4. The last forward HDD reamer exits the seabed at the HDD exit punch out.
5. The HDD reamer is then disconnected from the drill pipe and recovered.
6. The High-Density Polyethylene (HDPE) liner pipe will be pre-assembled and then floated in, connected to the drill pipe, and pulled onshore from the offshore end through the pre-drilled bore into position.
7. Steps a to f are then repeated for all the 220 kV (or 275 kV) offshore export cable circuits.
8. Trenches are then excavated from the HDD entry points above the MHWS to the transition joint bay and ducts installed and backfilled; (covered as part of the onshore submission).
9. HDD construction equipment and plant is then demobilised from site.
10. The ducts are then proved ready for cable pull in and messenger wires are installed.
11. Cables will then be installed in the ducts by pulling onshore through the ducts from the offshore delivery vessel to the transition joint bays.
    114. Once commenced, the HDD drilling activities may be required to operate continuously over a 24-hour period until each bore is complete. Subject to further construction planning and availability of drilling rigs, drilling may be carried out concurrently to accelerate the construction works programme.
    115. There are typically two pulls in techniques considered for the HDD landfall installation. The first being direct pull in, where the cable vessel will sit a short stand-off distance from the HDD exit point, where the cable is pulled directly and unreeled from the vessel. The second being floated pull in, where the vessel will stand-off at a suitable water depth for its safe operation and float the cable toward the duct, with a second vessel assisting located above the HDD exit point to guide the cable through the duct.
    116. Bentonite comprises 95% water and 5% bentonite clay which is a non-toxic, natural substance. Bentonite drilling fluid is non-toxic and can be commonly used in farming practices. Every endeavour will be made to avoid a breakout (loss of drilling fluid to the surface). A typical procedure for managing a breakout under water would include:

• stop drilling immediately;
• pump lost circulation material (mica), which will swell and plug any fissures;
• check and monitor mud volumes and pressures as the works recommence; and
• repeat process as necessary until the breakout has been sealed.
  117. As part of the detailed design work required to inform the final landfall methodology, the potential risks relating to cable exposure due to coastal recession and beach lowering will be considered in greater detail including the effects to climate change over the operational and maintenance phase of the Proposed Development. Indicative trenchless burial depths are provided in Table 3.25 but this is subject to further refinement post consent.

Figure 1.10: Location of the Proposed Development Export Cable Corridor

Table 1.26: Design Envelope: Offshore Export Cables (Seaward of MHWS)

Step 2 – Foundation installation and scour protection installation

Jacket foundations

118. Wind turbines and OSP/Offshore convertor station platform foundations will be transported to the Proposed Development array area by vessel from the fabrication site or port facility.
119. Jacket foundations could use either piles or suction caissons. Information on the methodology to be followed during suction caissons installation is provided in paragraphs 56 and 57. The piled jacket foundation will be installed into the seabed by either piling or drilling techniques, or a combination of both (drive-drill-drive), depending on seabed conditions. Typically, piles will be piled into the seabed using a vibro/hydraulic hammer until any hard ground is encountered, with drilling techniques deployed to install the remaining length of pile, if required.
120. Piling characteristics are presented in Table 1.27   Open ▸ . In order to complete the piling, the pile is usually lowered to the seabed with the help of a crane while kept in position using a pile gripper. A pile installation frame will be temporarily placed on the seabed to facilitate pile placement and spacing. The frame will be removed and moved to the next location once the piles are installed. The impact of the temporary placement of the frame on the seabed is bound by the maximum design scenario of disturbance caused by placement of scour protection. The hydraulic hammer is then positioned onto the pile and driven to target depth. Although a hammer energy of 4,000 kJ is considered as the maximum design scenario for the purposes of assessment, the realistic maximum average energy used when piling will be lower for the majority of the time (3,000 kJ). It is worth noting that the piles are likely to be pre-piled in advance with the jackets then installed on top at a later date.
121. Piling will commence with a lower hammer energy of 600 kJ, with a slow ramp up of energy up to a realistic 3,000 kJ over a period of 20 minutes. If necessary, this will be followed by a gradual increase to the maximum required installation energy (if higher than 3,000 kJ, but not to exceed the maximum energy of 4,000 kJ) during the piling of the final metres of pile, which is typically significantly less than the maximum hammer energy. The PDE includes for up two piling events occurring simultaneously at wind turbines (or wind turbine and OSPs/Offshore convertor station platform locations), with no concurrent piling of OSPs/Offshore convertor station platforms proposed. Table 1.27   Open ▸ provides the maximum deign scenario for the jacket piling.

Table 1.27: Design Envelope: Jacket Piling Characteristics

122. Drilling characteristics are presented in Table 1.28   Open ▸ . If drilling is required (i.e. in the event that pile driving may not be suitable due to hard ground), a sacrificial caisson may need to be installed to support surficial soils during the drilling activities. The caisson would be driven and left in place. The pile would then be lowered into the drilled bore and grouted in place, with the voids (annuli) between the pile and the rock, and between the pile and the caisson, filled with inert grout. The grout would fill the voids by being pumped from a vessel into the bottom of the drilled hole. The process would be carefully controlled and monitored to ensure minimal spillage to the marine environment.
123. Drilling will result in the release of seabed material, which will be deposited adjacent to each drilled foundation location.

Table 1.28: Design Envelope: Jacket Drilling Characteristics

Step 3 – OSP/Offshore convertor station platform topside installation/commissioning

124. The OSP/Offshore convertor station platform topsides will be transported to the Proposed Development by vessel either from the fabrication yard or the pre-assembly harbour, after the foundations are installed. The OSP/Offshore convertor station platform will be transported by the installation vessel or on a barge towed by a tug. Once on site, the OSP/Offshore convertor station platform will be rigged up, seafastening cut, lifted and installed onto the foundation. The OSP/Offshore convertor station platform will then be welded or bolted to the foundation. The installation vessel will mobilise with all the required equipment including rigging, welding and bolting equipment.
125. All necessary cable connecting and commissioning works are expected to be carried out with the assistance of a jack-up or DP vessel, with assisting support and supply vessels as required. Crew Transfer Vessels (CTVs) likely will be used to transfer personnel to and from the installation vessel.

Step 4 – Inter-array and interconnector cable installation and cable protection installation

126. A range of possible cable installation options may be required in order bury cables to the required target burial depths. While the nature of the seabed sediments within the Proposed Development array area may tend to installation of inter-array and interconnector cables being largely carried out using jetting tools any, or a combination of the options highlighted in Table 1.18   Open ▸ may be required.
127. The same installation and cable protection methodologies apply as described for the offshore export cables. Cable crossing required for the inter-array and interconnector cables are discussed in paragraph 132.

Step 5 – Offshore export cables – offshore installation and cable protection installation

Offshore export cables installation

128. A range of possible cable installation options may be required in order bury cables to the required target burial depths. There are various types of installation tools that may be used to install the offshore export cables, including:

• jet trenching, which injects water at high pressure in the area surrounding the cable using a jetting tool. allowing the cable to sink to the required burial depth;
• deep jet trenching;
• mechanical trenching, which excavates a trench in the seabed in which the cable is layed; and
• cable ploughs, which opens a narrow trench in the seabed using a towed plough, inserting the cable simultaneously.
  129. Pre-sweeping and/or dredging may be required in some areas. This will allow for the selected cable installation method to be used. Trenchless techniques will also be used at landfall as explained in Table 1.26   Open ▸ .

Cable protection installation

130. Cable protection will be used where minimum target burial depths are not achieved during installation and at cable crossings. Cable protection systems are also to be used as cables approach and enter the wind turbines and OSPs/Offshore convertor station platforms.
131. It is proposed that cable protection will consist of the following cable protection systems:

• rock placement;
• rock bags;
• concrete mattresses
• cast iron shells; and;
• sleeving.

Cable crossing installation

132. Up to 16 cable crossings may be required for the offshore export cables. The crossings would be protected using one of the protection technologies described in Table 1.20   Open ▸ . A crossing angle close to 90 degrees relative to the existing cable is the preferred option, however this might differ depending on the final design and protection technology used.

Step 6 – Wind turbine installation/commissioning

133. The wind turbines will be transported to the Proposed Development array area by vessel from the pre-assembly port where sub-assemblies (nacelle, rotor blades and towers), assembly parts, tools and equipment will be loaded onto an installation or support vessel.
134. At the installation location, the wind turbine towers will be lifted onto the pre-installed foundation and transition piece by the crane on the installation vessel. The nacelle and rotor blades will then be lifted into position. The exact methodology for the assembly will be dependent on the installation contractor and wind turbine type.
135. Following installation of the wind turbine, commissioning activities will take place including mechanical completion, electrical completion, HV commissioning and HV energisation.
136. Following energisation, the HV commissioning activities will be completed and the wind turbines will undergo performance and reliability testing.

Installation vessels and helicopters

137. A range of installation vessels will be used for the construction of the Proposed Development. This includes main installation vessels (e.g. jack-up or DP vessels with heavy lifting equipment), support vessels (including Service Operation Vessels (SOVs), tugs and anchor handlers, cable installation vessels, guard vessels, survey vessels, crew transfer vessels and scour/cable protection installation vessels. In addition, it is possible that helicopters will be used for crew transfers.
138. Installation vessel and helicopter parameters are presented in Table 1.29   Open ▸ for activities associated with the construction of the Proposed Development. The table provides an overview of the number of vessels/helicopters (and return trips) for construction of the Proposed Development including within the array area and along the Proposed Development export cable corridor (including landfall) at any one time during the entire construction phase. The number of vessels required seabed preparation activities are also provided separately in Table 3.24. It should be noted that the numbers presented are an estimated maximum adverse scenario for assessment purposes and in reality, vessel and helicopter numbers are anticipated to be less than this. The maximum number of vessels is 155 on site at any one time with up to 11,484 return trips.

Table 1.29: Design Envelope: Infrastructure Installation (Proposed Development Array Area and Export Cable (Including Landfall)) - Vessels and Helicopters

139. Jack-up vessels/barges make contact with the seabed when their jack-up spud cans (base structure of each leg) are lowered into place. For the purposes of the Offshore EIA Report, jack-up vessel parameters are presented in Table 1.30   Open ▸ .

Table 1.30: Design Envelope: Jack-up Vessels

Construction ports

140. It is likely that the Proposed Development components will be fabricated at a number of manufacturing sites across Scotland, the UK and Europe, while the substructures could be fabricated in the Middle East or Far East. Components may be transported directly to the Proposed Development from where they are manufactured or may be delivered to a port where they are stored in line with the day to day practice of that port before onward transport to the Proposed Development. This will be determined as part of competitive tendering processes whilst aiming to maximise UK and Scottish content, in line with Supply Chain Plan commitments.
141. All components are anticipated to be transported via sea transport to the Proposed Development for installation via vessels and associated equipment. Therefore, there is not anticipated to be a requirement for large components (e.g. wind turbine blades) to be transported via road.
142. The construction port for the storage, fabrication, pre-assembly and delivery of Proposed Development infrastructure has not yet been confirmed at the time of writing this Offshore EIA Report., however the majority of large infrastructure will go to site via vessel. Suitable ports will be selected based on the presence of appropriate facilities to handle and process offshore wind farm components. It is anticipated that all activities carried out within port will fall under established port licences and operational controls. For the purposes of this Offshore EIA Report and in order to assess a maximum design scenario, the assessments consider a maximum number of vessels and vessel movements to/from site, where relevant.
143. Construction personnel will transit to the location of the Proposed Development on the installation vessels or other vessels listed in Table 1.29   Open ▸ . Crew transfers may also take place between the construction port and the site of the Proposed Development via Crew Transfer Vessels (CTVs), Service Operation Vessels (SOVs), or by helicopter operating from a licenced airfield. Crew transfers during construction, operation and decommissioning will launch from existing port sites.

Construction programme

144. An outline of the programme for construction of the Proposed Development is provided below. The indicative commencement and completion dates, together with estimated durations of key construction activities, have been used to inform the assessment of construction impacts. Further detail on specific timeframes, durations and sequencing of activities is provided in the maximum design scenario tables that are included in each of the technical chapters.
145. Due to its scale, the Proposed Development will be built out over a period of up to eight years including site preparation works and snagging activities following installation of the wind turbines prior to final commissioning. The majority of activities will occur over various campaigns targeted at the relevant assets. Most activities will have a maximum duration of five years or less. Although construction activities will typically occur sequentially there are expected to be periods where certain construction activities occur concurrently. For example, substructure installation and inter-array cables installation, or commencement of wind turbine installation while foundation installation is being completed.
146. Indicative outline construction programme includes the following:

• commencement of offshore construction (site preparation and landfall activities) expected Q1 2025;
• completion of construction (including snagging) expected Q1 2033;
• key construction activity and estimated durations:

–           site preparation works – will occur for the duration of the construction phase but will not be continuous;

–           landfall installation – up to approximately 15 months;

–           wind turbine substructure installation – up to four years and six months across two installation campaigns;

–           OSPs/Offshore convertor station platforms installation – up to three years across two installation campaigns;

–           Inter-array cables installation - up to five years across two installation campaigns;

–           offshore export cables installation – up to two years and one month;

–           wind turbine installation – up to three years across two installation campaigns; and

–           completion and snagging – up to five years across two campaigns periods.

Recommended safe passing distances and aids to navigation

Safety zones, recommended safe passing distances and Notice to Mariners

147. It is standard practice during the construction and operation of an offshore development to communicate with other mariners of safe clearance distances around construction, installation, maintenance and decommissioning activities.

Statutory safety zones

148. The legal mechanism for establishing statutory safety zones is discussed in volume 1, chapter 2. The following safety zones will be recommended for the Proposed Development:

• temporary (or rolling) 500 m safety zones surrounding the location of all fixed (surface piercing) structures where work is being undertaken by a construction vessel;
• 50 m safety zones around all surface structures until commissioning where construction work is not active; and
• 500 m around any structure where major maintenance is ongoing (major maintenance- works are defined within the Electricity (Offshore Generating Stations)(Safety Zones) (Application Procedures and Controls of Access) Regulations 2007.
  149. Statutory decommissioning safety zones will be applied for during the decommissioning phase as appropriate and are not expected to exceed the standard 500 m.

Recommended safe passing distances

150. Recommended safe passing distances may also be used during the construction, operation and maintenance and decommissioning phases to ensure the safety of third party vessels. These will be communicated via Notice to Mariners (NtMs) during all phases of the Proposed Development.

Aids to navigation

151. The lighting and marking of wind turbines and OSPs/Offshore convertor station platforms to aid navigation will be defined post consent in consultation with the Northern Lighthouse Board (NLB), Marine and Coastguard Agency (MCA), the Civil Aviation Authority (CAA) and the Ministry of Defence (MoD).
152. Throughout the lifetime of the Proposed Development, marine aids to navigation will be provided in accordance with the requirements of the NLB, MCA and adherence to Civil Aviation Publication (CAP) 393 Article 223 (CAA, 2016), unless otherwise agreed. All navigational aids associated with the Proposed Development will be suitably monitored and maintained to ensure the relevant CAA availability targets are met.

1.4.5.    Operation and Maintenance Phase

Methodology

153. The overall operation and maintenance strategy will be finalised once the operation and maintenance base location and technical specification of the Proposed Development are known, including wind turbine type, electrical export option and final project layout.
154. This section, therefore, provides a description of the reasonably foreseeable planned and unplanned maintenance activities at the Proposed Development.
155. Table 1.31   Open ▸ provides a list of all operation and maintenance activities planned for the Proposed Development.
156. The offshore operation and maintenance will be both preventative and corrective. The operation and maintenance strategy will include an onshore (harbour based) operation and maintenance base, supported by a SOV and/or Crew Transfer Vessel (CTV) logistics strategy. This will be developed at a later stage once further detail is confirmed for the Proposed Development.

Table 1.31: Design Envelope: Operation and Maintenance Activities

Operation and maintenance vessels

157. The maximum design scenario for operation and maintenance vessel requirements for the Proposed Development are presented in Table 1.32   Open ▸ .

Table 1.32: Design Envelope: Vessels Required During the Operation and Maintenance Activities

1.5.        Screening

1.5. Screening

1.5.1.    MPA Screening

158. According to the Marine Scotland (2014a) guidelines, section 126 of the MCAA and section 82 of the Marine (Scotland) Act would apply if it is determined through the course of screening that “the proposal is capable of affecting (other than insignificantly) the protected features of the MPA.”
159. The Applicant presented a Preliminary MPA Screening for the Proposed Development in the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a). On the basis of the screening criteria outlined in section 1.3.2, three MPAs were identified for initial inclusion on the basis that the Proposed Development was deemed to be potentially capable of affecting (other than insignificantly) a protected feature of the site:

• Firth of Forth Banks Complex MPA (partially overlaps the Proposed Development);
• Turbot Bank MPA (approximately 96 km to the north-east of the Proposed Development array area); and
• Southern Trench MPA (for minke whale only; approximately 99 km to the north of the Proposed Development array area).
  160. The wide reach of the ornithology regional study area, as described in the screening criteria, includes some MPAs and English MCZs which have seabird/waterfowl features. However, the Proposed Development was not deemed to be potentially capable of affecting (other than insignificantly) a protected ornithological feature of these sites. Similarly, the SNCBs did not raise any issues regarding MPAs/MCZs designated for birds in the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022) and did not suggest that any such sites were considered in the MPA Assessment.
  161. The Preliminary Screening was, however, revisited following receipt of the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022) and revised on the advice provided by the SNCBs and regulators with regards to fish and marine mammals. As outlined in Table 1.1   Open ▸ , NatureScot and MS-LOT advised that both the Turbot Bank MPA and the Southern Trench MPA could be screened out of the MPA Assessment due to the distance of these sites from the Proposed Development.
  162. The Firth of Forth Banks Complex MPA site overlaps with the Proposed Development (Figure 1.11). This site, and the impacts upon it, have therefore been considered within this MPA Assessment.

1.5.2.    Screening of Protected Features

163. As outlined in paragraph 158 and in the Marine Scotland (2014a) guidelines, following identification of MPAs to be considered, section 126 of the Marine and Coastal Access Act 2009 and section 83 of the Marine (Scotland) Act 2010 would apply if it is determined through the course of screening that “the activity is capable of affecting (other than insignificantly) either (i) any protected feature of a Nature Conservation MPA; or (ii) any ecological or geomorphological process on which the conservation of any protected feature in a Nature Conservation MPA is (wholly or in part) dependent.”
164. All of the designated features of the Firth of Forth Banks Complex MPA were identified as having the potential to be affected by the Proposed Development in the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a) and based on the criteria outlined in paragraph 19 have been included due to the MPA’s overlap with the Proposed Development.
165. Following the Marine Scotland (2014a) guidelines, any impacts that are concluded in the Offshore EIA Report to have an effect of negligible significance on benthic ecology receptors (including protected features of the MPA) can be screened out and not taken through to the main assessment. Impacts which were concluded to have an effect of negligible significance on protected features of the MPA, within volume 2, chapter 8 of the Offshore EIA Report, are considered to present a sufficiently low risk to these features or the ecological or geomorphological processes on which the conservation of these features are (wholly or in part) dependent, so as to allow these to be screened out at this stage. The following impacts have therefore been screened out and are not considered in the main assessment:

• Temporary habitat disturbance during the operation and maintenance phase for all features except ocean quahog - volume 2, chapter 8 of the Offshore EIA Report predicted an effect of negligible significance on all features of the MPA, with the exception of ocean quahog, due to the short term, temporary nature of the impact, due to the high recovery potential of the habitats and associated communities affected and the highly limited area of seabed predicted to be affected during the operation and maintenance phase;
• Increases in Suspended Sediment Concentration (SSC) and associated sediment deposition during the operation and maintenance phase - volume 2, chapter 8 of the Offshore EIA Report predicted an effect of negligible significance due to the short term, temporary nature of the impact, the high recovery potential of the habitats and associated communities affected and the highly limited area of seabed predicted to be affected during the operation and maintenance phase; and
• Removal of hard substrates resulting in loss of colonising communities during the decommissioning phase - volume 2, chapter 8 of the Offshore EIA Report predicted an effect of minor significance. This impact however would not affect protected features of the MPA because none of the protected features of the MPA would be adversely impacted by the removal of the communities colonising the hard substrates as they all are composed of or rely upon sedimentary habitats. As a result, the effect of this impact is likely to be negligible and therefore it has not been considered further in this MPA Assessment.
  166. It should be noted that impacts to benthic invertebrates from Electromagnetic Fields (EMFs) were predicted to result in effects of negligible significance in volume 2, chapter 8 of the Offshore EIA Report due to the highly localised nature of the impact and the low sensitivity of the benthic receptors. However, on the basis of advice received from the SNCBs (see Table 1.1   Open ▸ ) this impact pathway has been screened into this MPA Assessment.
  167. The Marine Scotland (2014a) guidelines also note that many functions and activities can be screened out of the process using generic guidance and evidence on activities which exert pressures on the protected features, which is available through online sensitivity tools. NatureScot’s FeAST online tool has therefore been used to further refine the list of impacts to be included within this MPA Assessment for each of the designated features. On the basis of the FeAST assessments, the following impacts have been screened out where the FeAST tool concludes that the features are not sensitive or not exposed:
• For ocean quahog aggregations, increases in SSC and associated sediment deposition across all phases of the Proposed Development have been screened out on the basis that the FeAST tool concludes that this feature is not sensitive to smothering (siltation changes (low)) and is not exposed to increased SSC (i.e. water clarity changes);
• For the moraines representative of the Wee Bankie key geodiversity area, increases in SSC and associated sediment deposition across all phases of the Proposed Development has been screened out on the basis that the FeAST tool concludes that this feature is not sensitive to increased SSC (i.e. water clarity changes) and smothering (siltation changes (low)) is not relevant to geodiversity features;
• For the moraines representative of the Wee Bankie key geodiversity area, increased risk of introduction and spread of invasive and non-native species (INNS) across all phases of the Proposed Development has been screened out on the basis that the FeAST tool concludes that this pressure is not relevant to geodiversity features;
• For the moraines representative of the Wee Bankie key geodiversity area, colonisation of hard structures has been screened out on the basis that the FeAST tool concludes that this feature is not sensitive to a physical change (to another seabed type);
• For the shelf banks and mounds feature, increased risk of introduction and spread of INNS across all phases of the Proposed Development has been screened out on the basis that the FeAST tool concludes that this pressure is not relevant to geodiversity features; and
• For the shelf banks and mounds feature, colonisation of hard structures has been screened out on the basis that the FeAST tool concludes that this pressure is not relevant to geodiversity features.

1.5.3.    Screening Conclusion

168. For the Firth of Forth Banks Complex MPA, the following impacts are screened into the main assessment:

• Construction phase:

–           temporary habitat disturbance (for all features of the MPA);

–           long term subtidal habitat loss (for all features of the MPA); and

–           increases in SSC and associated sediment deposition (for the following features of the MPA: offshore subtidal sands and gravels, and shelf banks and mounds).

• Operation and maintenance phase:

–           temporary habitat disturbance (for the following features of the MPA: ocean quahog aggregations);

–           long term subtidal habitat loss (for all features of the MPA);

–           colonisation of hard structures (for the following features of the MPA: offshore subtidal sands and gravels, ocean quahog aggregations, and shelf banks and mounds);

–           increased risk of introduction and spread of INNS (for the following features of the MPA: offshore subtidal sands and gravels and ocean quahog aggregations);

–           alteration of seabed habitat arising from effects of physical processes (for all features of the MPA); and

–           EMF (for the following features of the MPA: offshore subtidal sands and gravels and ocean quahog aggregations).

• Decommissioning phase:

–           temporary habitat disturbance (for all features of the MPA);

–           increases in SSC and associated sediment deposition (for the following features of the MPA: offshore subtidal sands and gravels, and shelf banks and mounds);

–           permanent subtidal habitat alteration (for all features of the MPA);

–           permanent creation of habitat (for the following features of the MPA: offshore subtidal sands and gravels, ocean quahog aggregations, and shelf banks and mounds); and

–           increased risk of introduction and spread of INNS (for the following features of the MPA: offshore subtidal sands and gravels and ocean quahog aggregations).

1.6.        Background Information on The Firth of Forth Banks Complex MPA

1.6. Background Information on The Firth of Forth Banks Complex MPA

169. This section provides a summary of the baseline information for the Firth of Forth Banks Complex MPA considered within the main assessment.

1.6.2.    Firth of Forth Banks Complex MPA

170. The Firth of Forth Banks Complex MPA, which was designated in July 2014, is located in offshore waters off the east coast of Scotland and covers a total area of 2,130 km2. The MPA is composed of three distinct sections (not connected but in the same area; see Figure 1.11): Berwick Bank (541. 2 km2); Scalp and Wee Bankie (827.1 km2); and Montrose Bank (761.8 km2). Strongly influenced by ocean currents, the mosaic of different types of sands and gravels create a unique mixture of habitats that overlie the underwater banks and mounds within the MPA and support ocean quahog aggregations. The Wee Bankie includes moraines, formed from underwater glacial ridges deposited during the last Ice Age. The moraines are scientifically important for their role in improving the understanding of the history of glaciation around Scotland (JNCC,2018a).
171. Volume 3, appendix 8.1 of the Offshore EIA Report provides a detailed description of benthic ecology baseline characterisation within the Proposed Development, including the area overlapping with the Firth of Forth Banks Complex MPA. The baseline was informed by desktop data sources and site-specific surveys (fully detailed in volume 3, appendix 8.1 of the Offshore EIA Report) which were used to characterise the areas of the MPA sections overlapping with the Proposed Development.
172. Table 1.33   Open ▸ presents the protected features of the Firth of Forth Banks Complex MPA, with their spatial extents within the MPA (JNCC, 2018b), the condition of the protected feature (JNCC, 2020) and the overarching conservation objectives (JNCC, 2018b). These features, as mapped by the JNCC, are shown relative to the Proposed Development array area and Proposed Development export cable corridor in Figure 1.12. The MPA is characterised by four protected features: ocean quahog aggregations; offshore subtidal sands and gravels; shelf banks and mounds; and moraines (which are representative of the Wee Bankie Key Geodiversity Area).
173. Whilst Figure 1.12 represents the offshore subtidal sands and gravels feature as point data only, the JNCC Supplementary Advice on Conservation Objectives for Firth of Forth Banks Complex Nature Conservation MPA (JNCC, 2018b) states that this habitat has been mapped using full coverage bathymetry and backscatter data, as well as benthic video and image sample data, which demonstrated that >99% of the MPA is modelled as offshore subtidal sands and gravels. Offshore subtidal sands and gravels and supporting habitat for ocean quahog aggregations are therefore assumed to extend across the whole of the MPA. The shelf banks and mounds protected feature characterises sizable areas within each of the sections of the MPA and overall covers ~264 km2 within the MPA. The moraines representative of the Wee Bankie key geodiversity area feature occur most extensively in the Scalp and Wee Bankie section of the MPA but are also mapped within Berwick Bank and a small area within Montrose Bank (Figure 1.12); overall this feature covers ~750 km2 of the MPA. Beyond the protected features, the MPA is dominated by Atlantic and Mediterranean moderate energy infralittoral rock and deep circalittoral coarse sediment, with smaller areas of deep circalittoral mixed sediment and deep circalittoral mud.

Table 1.33: Protected Features of the Firth of Forth Banks Complex MPA, Recorded Extents (see Figure 1.12), Condition and Conservation Objectives

174. For the Firth of Forth Banks Complex MPA, the conservation objectives for the site are that the protected features:

• so far as already in favourable condition, remain in such condition; and
• so far as not already in favourable condition, be brought into such condition, and remain in such condition.
  175. For the offshore subtidal sands and gravel protected feature within the Firth of Forth Banks Complex MPA, "favourable condition" is when:
• extent is stable or increasing;
• structures and functions, quality, and the composition of characteristic biological communities (which includes a reference to the diversity and abundance of species forming part of or living within the habitat) are such as to ensure that they remain in a condition which is healthy and not deteriorating.
  176. For the shelf banks and mounds protected feature within the Firth of Forth Banks Complex MPA, "favourable condition" is when:
• the extent, distribution and structure is maintained;
• the function is maintained to ensure that it continues to support its characteristic biological community (which includes a reference to the diversity of any species associated with the large- scale feature), and their use of the site for, but not restricted to, feeding, courtship, spawning, or use as nursery grounds; and
• the processes necessary to support the feature are maintained.
  177. For the ocean quahog aggregations protected feature, "favourable condition" is when:
• the quality and quantity of its habitat and the composition of its population in terms of number, age and sex ratio are such as to ensure that the population is maintained in numbers which enable it to thrive.
  178. For the moraines representative of the Wee Bankie key geodiversity area within the Firth of Forth Banks Complex MPA, "favourable condition" is when:
• its extent, component elements and integrity are maintained;
• its structure and function are unimpaired; and
• its surface remains sufficiently unobscured for the purposes of determining whether the above criteria are satisfied.
  179. As set out in Table 1.33   Open ▸ , the offshore subtidal sands and gravels and ocean quahog aggregations features need to be recovered to favourable condition (JNCC, 2020). The Supplementary Advice on Conservation Objectives document (JNCC, 2018b) advise that, for the offshore subtidal sands and gravels, this relates to the structure and function attribute and, specifically, the characteristic communities and consequently function. While the feature is naturally exposed to moderate energy levels (due to the tidal currents present in the site), the level of fishing activity present in the site suggests the structure and function of the feature has been impacted as a result of this activity. JNCC consider that the activities which are capable of significantly affecting the protected features of the site and should be managed to prevent further deterioration to offshore subtidal sands and gravels and ocean quahog aggregations are demersal trawling and renewable energy (JNCC, 2020).
  180. Volume 3, appendix 8.1 of the Offshore EIA Report provides a detailed description of the baseline environment within the Firth of Forth Banks Complex MPA which was informed by desktop data sources and site-specific surveys undertaken for the Proposed Development. It should be noted that the spatial extent of the site-specific benthic subtidal surveys included some areas which, due to refinements to the boundary of the Proposed Development, extend beyond the boundary of Proposed Development benthic subtidal and intertidal ecology study area shown in Figure 1.13. This resulted in some sampling of areas to the north-west, south-west and south-east of the Proposed Development array area, and also inshore areas to the south of the Proposed Development export cable corridor. The data collected from these areas were analysed and included in the baseline characterisation as they provide further context to the data collected within the Proposed Development benthic subtidal and intertidal ecology study area. Samples were collected within the area of the Firth of Forth Banks Complex MPA which overlaps with the benthic subtidal and intertidal ecology study area (Figure 1.11). Within the Berwick Bank section of the MPA, 13 stations were sampled via a combination of grab and drop-down video (DDV), three sites used only DDV sampling and two epibenthic trawls were conducted. Within the Scalp and Wee Bankie section of the MPA, 13 stations were sampled via grab and DDV, one sites used only DDV sampling and two epibenthic trawls were conducted. A geophysical survey campaign was also undergone to characterise the Proposed Development benthic subtidal and intertidal ecology study area including the areas which overlap with the Firth of Forth Banks Complex MPA.
  181. Figure 1.13 shows the results of the geophysical surveys which indicated that both the Berwick Bank and Scalp and Wee Bankie sections of the MPA, which overlap with the Proposed Development, are characterised by featureless areas as well as sections of ripples and mega ripples, sand waves, ribbons, and bars. The geophysical data also showed areas of trawl marks within both sections of the MPA as well as areas of deposition and erosion. Figure 1.13 also shows the results of the particle size analysis (PSA) which indicated that the sediments within the Berwick Bank part of the MPA which overlaps with the Proposed Development are characterised based on the Folk classification system (Folk, 1954; Long, 2006) described in volume 3, appendix 8.1 of the Offshore EIA Report) as slightly gravelly sand and gravelly sand. The sediments within the Scalp and Wee Bankie part of the MPA which overlap with the Proposed Development are characterised by slightly gravelly sands and sandy gravels with two samples of gravelly sand, one in the north and one in the south. The site-specific data is therefore consistent with the modelled distribution of the offshore subtidal sands and gravels feature within the MPA (i.e. extending across the whole MPA) as presented in the Supplementary Advice on Conservation Objectives document (JNCC, 2018b). This would also, therefore, indicate that the sediments present within the Proposed Development array area represent suitable supporting habitat for ocean quahog. The parts of the Firth of Forth Banks Complex MPA which are outside the Proposed Development array area and Proposed Development export cable corridor were not surveyed as part of the site-specific surveys undertaken for the Proposed Development.
  182. Figure 1.14 shows the subtidal biotopes mapped within and around the Firth of Forth Banks Complex MPA from the Proposed Development site-specific survey data detailed in paragraph 171. The process by which these biotopes were assigned is fully described in volume 3, appendix 8.1 of the Offshore EIA Report. The part of the Proposed Development which coincides with the Berwick Bank section of the MPA was primarily characterised by the Amphiura filiformis, Mysella bidentata and Abra nitida in circalittoral sandy mud biotope (SS.SMu.CSaMu.AfilMysAnit) with smaller areas of offshore circalittoral sand (SS.SSa.OSa), offshore circalittoral sand with Echinocyamus pusillus (SS.SSa.OSa [Echinocyamus pusillus]), and the Echinocyamus pusillus, Ophelia borealis and Abra prismatica in circalittoral fine sand biotope (SS.SSa.CFiSa.EpusOborApri). The section of the Proposed Development which coincides with the Scalp and Wee Bankie section of the MPA was primarily characterised by the polychaete-rich deep Venus community in offshore mixed sediments biotope (SS.SMx.OMx.PoVen) and the SS.SMu.CSaMu.AfilMysAnit biotope. Smaller areas of the SS.SSa.CFiSa.ApriBatPo biotope, the seapens and burrowing megafauna in circalittoral fine mud biotope (SS.SMu.CFiMu.SpnMeg), the SS.SSa.CFiSa.EpusOborApri biotope, and SS.SSa.OSa were also present. The site-specific data is therefore consistent with the evidence from the MPA designation documents (JNCC, 2014) and the Supplementary Advice on Conservation Objectives document (JNCC, 2018b) which states that the offshore subtidal sands and gravels feature equates to the EUNIS habitats A5.1: Subtidal coarse sediments, A5.2: Subtidal sand, and A5.4: Subtidal mixed sediments.
  183. Additionally, as previously mentioned within Scalp and Wee Bankie, the site-specific grabs, trawls and DDV sampling recorded two ocean quahogs in the area which overlaps with the Proposed Development array area. The ocean quahog recorded within the MPA during the grab sampling was in the western central section of the Proposed Development array area and was 0.2 cm in size and estimated to be less than a year old. The ocean quahog recorded during the epibenthic trawls was in the north-east of the Proposed Development array area, was 11 cm in size and estimated to be 193 years old (volume 3, appendix 8.1 of the Offshore EIA Report). Again, this is consistent with the sediments within the Proposed Development array area representing suitable supporting habitat for ocean quahog.
  184. Annex I reef assessments, for both biogenic (e.g. Sabellaria spinulosa) and geogenic reefs, were also conducted within the Proposed Development benthic subtidal and intertidal ecology study area using DDV and in accordance with the latest guidance, however no sites within the Firth of Forth Banks Complex MPA were found to contain Annex I reefs. The nearest potential reef site lay over a kilometre away, north of Berwick Bank at sample site 38 which was found to be a low reefiness (Jenkins et al., 2015; Gubbay, 2007) rocky reef.
  185. Additionally M. modiolus were recorded in several of the benthic trawls and therefore the full extent of the benthic trawls are presented in Figure 1.14 as the exact location of the M. modiolus is unknown. M. modiolus was recorded within a single trawl in the Berwick Bank section of the Firth of Forth Banks Complex MPA (Figure 1.14).