4. Information to Inform the Appropriate Assessment

4.1. Introduction

  1. As described in section 2 of Part 1 of the RIAA, a European site is progressed to the Appropriate Assessment stage (Stage Two of the HRA process) where it is not possible to exclude a LSE2 on one or more of its qualifying interest features in view of the site’s conservation objectives. European sites, features and potential impacts requiring an Appropriate Assessment for the Array are therefore those for which LSE2 could not be ruled out during the Screening exercise and following consultation.
  2. Information to help inform the Appropriate Assessment for SPAs (and Ramsar sites) is provided in sections 4.2 to 4.6. The information provided includes a description of the SPAs (and Ramsar sites) under consideration, their qualifying interest features, and an assessment of the implications of the Array for the site in view of the conservation objectives of each site and considering any adverse effect on site integrity. A cross-referencing approach has been adopted to aide readability and reduce repetition where relevant, but this has been carefully carried out to ensure that all information required for a robust HRA of each site is presented.
  3. In addition, two appendices have been produced to aid with Stage Two of the HRA process, these reports are:
  • Appendix 3A - Offshore Ornithology Apportioning Technical Report.
  • Appendix 3B - Offshore Ornithology PVA Technical Report.

4.2. Maximum Design Scenarios

  1. All SPAs (and Ramsar sites) assessment presented in this part of the RIAA have been based on a realistic Maximum Design Scenario (MDS), which was derived from the Project Description (as described in Part 1). The final design will be no greater than the parameters set out in the MDS, and in some instances may be less. An overview of the MDS considered for the assessment of potential impacts on ornithological features is presented per potential impact (see sections 5.4 and 5.5). This MDS is consistent with that used for the ornithology assessment in the Array EIA Report (Ossian OWFL, 2024).

4.3. Designed in Measures

  1. As part of the project design process, a number of designed in measures have been included in the Array and are committed to be delivered by the Applicant as part of the Array. These designed in measures are integrated into the project description for the Array and are not considered as mitigation measures intended to specifically avoid or reduce effects on European sites.
  2. Measures intended specifically to avoid or reduce effects on European sites were not considered during the Array HRA Stage One LSE2 Screening but are included within the HRA Stage Two Appropriate Assessment for determination of Adverse Effects on Integrity. Where relevant, this Part of the RIAA indicates whether adverse impacts on European sites are likely and if so, whether those effects can be avoided through the introduction of mitigation measures that avoid or reduce the impact. These measures are referred to as secondary mitigation and may be taken from the relevant chapters of the Array EIA Report (Ossian OWFL, 2024) or, where necessary, may have been developed specifically to comply with HRA requirements. Where the latter is the case, this has been made clear throughout.

 

4.4. Baseline Information

  1. Baseline information on the European sites (i.e. SPAs for this Part of the RIAA) identified for further assessment within HRA Stage Two Appropriate Assessment has been collated through site-specific surveys, in addition to a desktop study of existing studies and datasets. Baseline information is presented in detail in volume 2, chapter 11 of the Array EIA Report (Ossian OWFL, 2024) and associated technical reports which are derived from analyses of the baseline survey data. These technical reports include:
  • volume 3, appendix 11.1: Offshore Ornithology Baseline Characterisation Technical Report.
  • volume 3, appendix 11.2: Offshore Ornithology Collision Risk Modelling (CRM) Technical Report.
  • volume 3, appendix 11.2, annex B: Offshore Ornithology Migratory CRM Technical Report.
  • volume 3, appendix 11.3: Offshore Ornithology Displacement Technical Report.
  • volume 3, appendix 11.4: Offshore Ornithology MRSea Technical Report.
  1. Any additional sources of information used in the HRA Stage Two Appropriate Assessment are summarised within the main body of this Part of the RIAA.

4.5. Conservation Objectives and Conservation Advice

  1. Conservation objectives set the framework for establishing appropriate conservation measures for each feature of a site and provide a framework against which the impacts associated with plans or projects can be assessed. Within this part of the RIAA, the most up-to-date conservation objectives and conservation advice has been referenced. The statutory nature conservation bodies (SNCBs) have produced conservation advice for European sites under their statutory remit. This conservation advice provides supplementary information on sites and features, and although the content provided is similar, the format of the advice provided varies between the different SNCBs.
  2. For European sites under the statutory remit of NatureScot, Conservation and Management Advice documents (CMAs) have been produced for all marine SPAs. These documents contain revised and updated conservation objectives for the features of each site, site-specific clarifications and advice in order for the conservation objectives to be achieved, and advice on management required to achieve the conservation objectives. Each objective includes site-specific supplementary advice.
  3. For European sites under the statutory remit of Natural England, Supplementary Advice to the conservation objectives has been produced for some SPAs, which provide site-specific attributes and targets specific to the features of the site.
  4. Where Ramsar interests coincide with qualifying features within an SPA, the advice for overlapping designations is considered to be sufficient to support the management of the Ramsar interests. Therefore, the conservation objectives are referenced for both designations.
  5. Information on the designated sites mentioned within this RIAA are provided in section 5.3.

4.6. Approach to the In-Combination Assessment

  1. The Habitats Regulations require the consideration of the potential effects of a project on European sites both alone and in-combination with other plans or projects.
  2. When undertaking an in-combination assessment projects, plans or activities with which the Array alone may interact to produce an in-combination effect must be identified. These interactions may arise within the construction, operations and maintenance or decommissioning phases. The approach taken for the assessment of in-combination impacts in this Part of the RIAA has been informed by the cumulative effects assessment (CEA) carried out in volume 2, chapter 11 of the Array EIA Report.
  3. The process of identifying those projects, plans or activities for which there is the potential for an interaction to occur is referred to as ‘screening’. A specialised process has been developed to methodically and transparently screen the large number of projects, plans and activities that may be considered cumulatively alongside the Array alone. This involves a staged process that considers the level of detail available for projects, plans and activities, as well as the potential for interactions on a conceptual, physical and temporal basis. Screening for the Array alone is summarised in section 3, with screening for the project in-combination being provided here. For in-combination screening, there is a presumption that where potential for LSE2 has been identified for the Array alone, then potential LSE2 in-combination applies.
  4. For the Array in-combination assessment a tiered approach has been adopted. This approach provides a framework for placing relative weight on the potential for each project/plan to be included in the in-combination assessment to ultimately be realised, based upon the project/plan’s current stage of maturity and certainty in the project’s parameters. The allocation of each project, plan and activity into tiers is not affected by the screening process but is merely a categorisation applied to all projects, plans and activities that have been screened in for assessment.
  5. The tiered approach which has been utilised within the in-combination assessment employs the following tiers:
  • Tier 1 assessment – Array with Proposed offshore export cable corridor(s) and Proposed onshore transmission infrastructure and all plans/projects which became operational since baseline characterisation, those under construction, and those with consent and submitted but not yet determined;
  • Tier 2 assessment – All plans/projects assessed under Tier 1, plus projects with a Scoping Report; and
  • Tier 3 assessment – All plans/projects assessed under Tier 2, which are reasonably foreseeable, plus those projects likely to come forward when an Agreement for Lease (AfL) has been granted.
  1. An overview of the projects or activities considered for each receptor group are tabulated separately in each of the receptor chapters according to the effect-pathway under consideration. A summary of all projects considered are presented in Table 4.1   Open ▸ . Note that due to uncertainty around Tier 3 and a lack of quantitative information regarding most Tier 2 projects, these projects are not considered quantitatively within the in-combination assessment, although they are considered qualitatively. Final compilation of in-combination impacts was carried out in March 2024, and any subsequently published information has not been considered.
  2. Impacts from plans and projects that are not offshore wind farms were initially considered, as detailed in volume 3, appendix 6.4 of the Array EIA Report (Ossian OWFL, 2024). However, no plans or projects other than offshore windfarms have been taken forward for quantitative in-combination assessment.
  3. For tidal farms, the effects of displacement are still relatively unknown (Isaksson et al., 2020) due to the limited number and small spatial footprint of operational devices currently deployed in a few tidal lease sites (Fox et al., 2018). However, as the majority of infrastructure associated with tidal farms is underwater, there is likely to be a negligible impact from disturbance and displacement. Long (2017) stated that some displacement was detected during construction, but that numbers returned to previous levels once the tidal turbines were installed and operational.
  4. Additionally, assessing collision using collision risk models for tidal stream energy developments have limitations (Horne, 2021; Horne et al., 2023). Traditional models, such as the Encounter Rate and Band Models, do not fully account for animals’ ability to change direction, detect and avoid underwater structures, or evade structures at close range (Horne et al., 2023). These models may also struggle to estimate risk for novel device designs. A review by Isaksson et al. (2020) highlighted that while studies investigating the interaction between seabirds and tidal stream environments exist, there is little synthesis of what the results mean for collision risk and displacement due to tidal energy devices. Horne et al. (2023) stated that improved understanding and application of collision risk models are needed to ensure accurate risk evaluations for the sustainable development of the tidal energy industry. Consequently, collision impacts from tidal farms are considered to have significant uncertainty. However, given tidal stream turbine technology is still at an early stage of deployment with only a small number of turbines at a small number of lease sites, it can be concluded the risk of collision from tidal turbines is negligible and makes no material contribution to any in-combination effect.
  5. Regarding impacts from oil and gas activities, aggregate extraction, disposal sites, coastal protection, infrastructure, subsea cables and transmission assets, there will be limited spatial and temporal overlap, and limited overlap in terms of impact pathways. Any impacts which could overlap with impacts from the Array would be negligible. For example, disturbance and displacement related to maintenance of existing subsea cables will be restricted to routine monitoring or damage repair, both of which would be highly spatially and temporally restricted and so have a negligible impact on seabirds. Therefore, all projects within these activity sectors were screened out as having no potential to contribute to an in-combination effect. These details are within volume 3, appendix 6.4 of the Array EIA Report. For other elements of Ossian, including the Proposed offshore export cable corridor(s) and Proposed onshore transmission infrastructure, information is currently limited and therefore could not be included in this assessment. Those other elements will be subject to a separate application in which in-combination assessment of impacts will be carried out.
  6. It should be noted that the Culzean Floating Offshore Wind Turbine Pilot Project, Greater Gabbard, Gunfleet Sands 1 and 2, Inner Dowsing, Lynn, Methil Demo and Scroby Sands are currently operational. However, the operational consents for these projects expires before the Array becomes operational. These projects are therefore discounted from the in-combination assessment as there is no temporal overlap between the operational phases of these projects and the Array.
  7. Table 4.1   Open ▸ sets out the Tier 1 and Tier 2 projects that are included in the in-combination assessment. Data from the recent Berwick Bank Offshore Wind Farm has been used to provide the most up-to-date mortality figures for a number of the Tier 1 offshore wind farms. These offshore wind farms have been grouped by Berwick Bank and are referred to collectively in this RIAA as “UK North Sea Projects”.

 

Table 4.1:
Summary of Tier 1 and 2 Projects Considered Within the In-Combination Assessment

Table 4.1: Summary of Tier 1 and 2 Projects Considered Within the In-Combination Assessment

 

  1. Potential impacts from the Array alone assessment are taken forward to the in-combination assessment where they have the potential to overlap with the same impact from other plans and projects. Where the impact is associated with a specific project phase of development (e.g. construction, operations and maintenance or decommissioning), phases which do not have the potential for in-combination effects have been omitted from further consideration in the in-combination assessment. Additionally, some of the potential impacts considered within the alone assessment are not considered in the in-combination assessment due to:
  1. Further details on the criteria used to determine which sites and features were taken forward to the in-combination assessment are provided in section 5.5.
  2. In addition, the in-combination projects considered for each relevant SPA was based upon species’ by sea foraging range from the SPAs, where there is the potential for individuals to have connectivity to the Array and the other plans/projects. Foraging ranges presented in volume 3, appendix 11.1 of the Array EIA Report were used (Woodward et al. 2019). Projects considered for each species during each season are presented within the in-combination assessments within section 5.5.