Offshore wind energy - draft sectoral marine plan: habitat regulations appraisal

The habitats regulations appraisal is completed in accordance with the Habitats Regulations that implement the EC Habitats and Birds Directives in UK waters and has been completed for the sectoral marine plan for offshore wind.

11 Plan Impact Evaluation and Mitigation Requirements

11.1 Introduction

11.1.1 The appropriate assessment phase of the HRA (Stage 8) has reviewed the impacts arising from the Sectoral Offshore Wind Plan (Sections 5 to 9).  In advance of considering mitigation measures, it could not be concluded that there will be no AEOI on any European/Ramsar sites.  This is because of the inherent uncertainties that exist about future developments and the potential in-combination effects (Section 10).  These uncertainties relate to several aspects such as:

  • the detail of the Sectoral Offshore Wind Plan implementation process;
  • future generation capacities;
  • the location, scale and densities of development;
  • the proposed technologies to be used and future advances in these technologies;
  • the scale of the effects arising via some of the defined impact pathways; and
  • the efficacy of some project-level mitigation options.

11.1.2 Recognising these uncertainties, and the conclusions of Stage 8, there is clearly a need for appropriate and meaningful mitigation measures to accompany the Draft Plan. The following sections detail the plan-level mitigation required to conclude, with a high degree of certainty, that there will be no AEOI on any European/Ramsar site arising from the Sectoral Offshore Wind Plan, either alone or in-combination, with other known plans or projects. Thus, this section covers Stage 9 of the plan-level HRA process (see Figure 1).

11.2 Mitigation (Stage 9)

11.2.1 Given the inherent uncertainties associated with the Draft Plan (see above), plan-level mitigation measures are required to ensure there is no AEOI. Two mitigation measures were initially identified as integral to the Draft Plan:

  • The legal requirement for individual projects to undergo HRA.  All future developments that are undertaken as part of the individual Sectoral Offshore Wind Plan will be required to undergo an HRA and, wherever the possibility of a LSE on a European/Ramsar site cannot be excluded, a project-level AA will need to be completed.
  • The implementation of the Plan through an iterative management process.  In the future, the project-level assessments and the associated monitoring review work will be linked to (and will inform) regular reviews of the Plan as part of an (IPR) process.

11.2.2 It is important to confirm that this plan-level HRA will not be a substitute for project-level HRAs, where these are required for individual projects.  Such project-level HRA processes will still be required in accordance with the legislation. Accordingly, the requirement for a project-level AA, wherever there is possibility of a LSE, is an important mitigation measure for the plan-level HRA to ensure there is no adverse effect on integrity of designated sites once there is the required level of certainty about development location(s) and design.

11.2.3 For individual windfarm projects a range of mitigation measures are applied to help reduce or offset ecological effects where needed.  Lists of such measures have been developed during previous strategic assessments including the following: the preceding Scottish Marine Renewables SEA [348]; the HRAs for previous draft OWE and W&TE Plans [349] [350]; the HRA for the East of England Inshore and Offshore Marine Plans [351]; the Northern Ireland Offshore Renewable Energy Strategic Plan 2009-2020 [352]; and most recently the HRA for ORE in Scottish Waters[353].

11.2.4 From these sources, an overall list of project mitigation measures was collected which provides a central ‘project-level mitigation options’ data table (Table J1, Appendix J).  These measures were then compared against the impact matrix within Table J2 (Appendix J) to indicate which measures address which impacts.  As these mitigation measures were derived from past strategic assessment and plan-level HRA work, they are comprehensive and cover all of the 18 key impact pathways identified during the pre-screening process (see Table 2). Of these measures, an overarching consideration, and the one that is also most intuitive, is that during the early stages in the design of any development, ‘a primary consideration will be to try to avoid habitats within a European/Ramsar site and minimise exposure and risk’. There are no DPOs which overlap with European/Ramsar sites; however, cable routeing and landfall activities could overlap with designated sites.

11.2.5 While this list demonstrates the range of project-level mitigation measures that are available, they do not, by themselves, provide further certainty that any European/Ramsar site or features will not be affected.  This is because they are not a formal requirement of the Sectoral Offshore Wind Plan and they are too generic in nature to be assured that there will be no adverse effects as a result of their application.  However, they have been brought together for this HRA in order to provide a basis for understanding the measures that will or may be required for future projects.

11.3 Project-Level HRA

11.3.1 Acknowledgment of this measure is based on a recognition that, as a matter of law, any new project developed under the Draft Plan will be required to undergo a project-level HRA and to produce an AA wherever the possibility of LSE on a European/Ramsar site cannot be excluded. Each individual project will need to review the baseline conditions and undertake work in a manner that does not have an AEOI. As part of this plan-level HRA, information has been provided to aid future project level AAs.

11.3.2 All future project-level HRA work will need to be completed in the context of the latest scientific knowledge and evidence base (relating to the development of offshore wind farms) that is available at the time of the assessment.  It will also need to be done to the satisfaction of the consenting body (as competent authority at the project stage), taking account of advice from SNCBs and consultees where appropriate.  The pursuance of project-level HRAs (with reference to latest monitoring and scientific understanding) will be a legal requirement in all cases where LSE cannot be excluded as will the application of project-level mitigation (where these are necessary to avoid adverse effects at project level).  This work will provide assurances of no adverse effect from individual projects but will also improve understanding of the impacts from key pathways, with updated information fed back into the HRA process i.e. through the IPR process (see Section 11.4).  The information that will need to be supplied within the project-level HRAs includes:

  • Updates on the location and status of new European/Ramsar designations;
  • New information on interest feature sensitivities (in the context of the latest scientific understanding);
  • Assessment of effects during survey, construction and operational phases of the project (including the in-combination effects with other plans or projects); and
  • Proposed mitigation measures.

11.3.3 It should also be recognised that it may be necessary, as part of the project-level HRAs, to revisit the screening process that was undertaken for the Draft Plan.  Depending upon the outcome of the project-level AA, there might be a need for mitigation measures to be implemented to ensure that there is no AEOI.

11.3.4 Overall, it should be emphasised that uncertainties associated with the sensitivities of European/Ramsar site features to individual projects will be addressed through project-level HRA (with the benefit of project specific information), to demonstrate no adverse effect on integrity of these features.  The Habitats Regulations and the case-law that informs their implementation place great emphasis on developers demonstrating ‘no adverse effect’ using best available scientific knowledge and beyond reasonable scientific doubt.  The process of ongoing research and feeding the results of targeted monitoring back into the assessment process will address these uncertainties, but it should be noted that there is a process to be followed (see below) which is likely to influence the rate and scale of project-level developments.

11.4 Iterative Plan Review (IPR)

11.4.1 The proposal for an iterative management process, delivered through the IPR, is critical in providing assurance that the Draft Plan will have no AEOI.

11.4.2 The Plan will be implemented as a phased process allowing iterative reviews of the Draft Plan to occur at agreed intervals through consultation with the Advisory Group (which will be formed upon adoption of the final Plan). This will provide a mechanism whereby the project-level assessments and the associated monitoring work of windfarm projects inform regular reviews of the Plan and ongoing decision about project implementation. In particular, as monitoring data is collected (when projects are consented, such as that for Whooper Swan) it will then be used to validate the conclusions that are made as part of successive project level HRAs and, where required, AAs (including in-combination assessments).

11.4.3 To ensure that the process is iterative, the Scottish Government will revisit the Draft Plan every two years. This review process will involve particular consideration of the work undertaken within the DPOs that have been identified within the Draft Plan but will also encompass other individual projects that are prompted by other planning initiatives (such as the work being carried out to support TCE Round 4 offshore wind leasing). To ensure that the IPR is responsive, an annual forum will also be carried out to consider evidence which is potentially pertinent to the Plan. Where there is adequate justification, the Plan may then be revisited within the two-year review cycle.

11.4.4 There is no expectation that the review process will alter commitments for the DPOs, but they will guide the scale, extent and location of developments within the DPO boundaries.  Any developments within these DPOs will, though, still be subject to project-level HRA (Section 11.3) and will only go ahead if it can be shown that they have no AEOI (alone or in-combination with other plans or projects).

11.4.5 This process will be overseen by the Advisory Group.  They will be linked to, inform and be informed by, the work of other relevant groups and plans such as the Moray Firth Regional Advisory Group (MFRAG), the Forth and Tay Regional Advisory Group (FTRAG) and Marine Planning Partnerships (as appropriate).  The PSG will comprise members of the Scottish Government Marine Strategy Forum and include academics with expert knowledge of the key issues.  It will also apply and, where needed, take forward the principles of the Scottish Government survey, deploy and monitor licensing policy guidance [354].

11.4.6 The mechanism of IPR implementation is itself expected to have some adaptability but the main processes over the initial two-year cycle are summarised below.

11.5 Outline of Proposed IPR Programme (Two-Year Cycle)

11.5.1 The IPR process will begin following the completion of the HRA report (including the AA Information report) and the final HRA record and Appropriate Assessment (to be carried out by the Scottish Government) for the Sectoral Offshore Wind Plan.  Once completed there will be a period of consultation on these documents.  Then, following this phase and subsequent Plan adoption, the IPR process will operate on a biennial rolling cycle. Work undertaken in the initial phase of Plan implementation (first two-year cycle) will include the following elements:

  • Creating and updating Project Impacts and Mitigation Evaluation Framework. This step will be facilitated through the Scottish Marine Energy Research (ScotMER) programme.  The programme is focussed on carrying out high priority research projects to fill knowledge gaps and further the evidence base. The outputs from this programme will be used to update project level impacts and mitigation measures (see Table 2, Tables J1 and J2 (Appendix J)) as appropriate. The framework will help to identify all extant projects and allow for the compilation of key documents into a single, accessible and regularly reviewed database listing the public-domain assessments, strategic monitoring work, mitigation guidance documents or individual project-level mitigation measures that developers can use to achieve impact reductions.  This will assist with the implementation of projects by alerting all interested parties to the issues and opportunities that exist and also can be developed and improved over time as the efficacy of mitigation measures is better understood through monitoring.  This will include an updated review of the status of European/Ramsar sites (including the identification of sites that are designated subsequent to the completion of this HRA).  On a regular basis this established online framework will be updated based on the following review tasks.
  • Project Assessment and Review (process). In the early stages there will be a progression, by developers and competent authorities, of EIAs and AAs for initial projects undertaken in response to the Sectoral Offshore Wind Plan.  These documents will be collated and reviewed on an ongoing basis. However, acknowledgement will continue to be given to the assessments already carried out for those windfarm projects that are either proposed or consented (see Table 21).
  • Project Monitoring and Review (process). As offshore renewable energy projects are put in place there will be the completion, collation and dissemination of project-level monitoring.  This will include monitoring work on the initial projects undertaken in response to the Sectoral Offshore Wind Plan but also other relevant projects (in UK and Europe).  It is envisaged that there will be collaboration between developers and regulators and that, as often as possible, there would be integrated work undertaken across sectors and between projects.  Mechanisms and initiatives for such collaborations already exist such as the Offshore Renewables Joint Industry Programmes (ORJIP); the Knowledge Transfer Network (KTN) for offshore renewables (e.g. Offshore Wind Innovation Hub (including Offshore Wind Innovation Exchange (OWiX)); the Partnership for Research in Marine Renewable Energy (PRIMaRE); the Habitats Directive Implementation Review (England); Marine Scotland’s ongoing strategic research.
  • Project Mitigation and Review (process). Directly accompanying the monitoring review there would be an evaluation of the efficacy of established mitigation measures.  Research is currently being undertaken by Marine Scotland, The Crown Estate, MFRAG and FTRAG into the effectiveness of various mitigation measures and such reviews will provide a valuable contribution to this part of the IPR process.
  • Progression of strategic-level monitoring and research (process).  Alongside the project-level survey work, strategic work will continue to fill identified gaps in understanding.  Especially to aspects such as seabird and cetacean distributions, collision mortality of seabirds, migratory pathways, seabird behaviour at sea and seabird body-mass survival rates.  These topics are being progressed through Marine Scotland research programmes, such as ScotMER.
  • Review Gaps Understanding (workshop/review and Advisory Group meeting). Building on the above reviews of project-level and strategic monitoring and mitigation, there will be an evaluation of gaps in understanding and of the progress made to address these gaps (e.g. the results of seabird body mass survival rates and how these inform the seabORD tool for estimating the fate of birds displaced by offshore renewable developments).
  • Review status of future projects in the context of research and planning developments (workshop/review and Advisory Group meeting).  Regular reviews will be taken about the future projects to be implemented and the need for Plan revisions.  These will be based again on the above information but will also take into consideration emerging marine spatial planning requirements (e.g. Marine Planning Partnerships), ongoing industry led research (e.g. ORJIP and OWSMRF), as well as future marine protected areas.

11.5.2 Linked to these elements will be an annual forum to discuss new evidence, information and research outcomes relevant to the Plan. Where there is adequate justification, this will enable the forum to trigger an earlier review of the Plan (i.e. within the two-year review cycle) in response to new information and as required. Accordingly, this biennial programme of review work may be subject to amendment.

11.5.3 With each of iteration of the Plan, understanding about the relevant issues and risks will be progressively enhanced as ongoing research provides information about species sensitivities and the effectiveness of mitigation measures.

11.5.4 Detail on project implementation, including connection to the national grid and coastal infrastructure will also be better understood at each successive stage.

11.5.5 In addition to this temporal component, this process will require continual consideration of the spatial/regional context (e.g. the effects of those on the east or west coast) for project-level AAs to ensure that there is no AEOI on any European/Ramsar site from projects either individually or in-combination with other plans or projects.  It will also need to include regular consultation with other EU Member States to address issues relating to transnational sites.

11.5.6 The IPR process will thus provide the mechanism for updates to the Plan as new information becomes available. This information may be the result of technological advances, scientific evidence, project monitoring and the results of project level assessments.

11.6 DPOs subject to higher levels of ornithological constraint

11.6.1 Review of the in-combination assessment has highlighted the significant concerns raised by SNCBs over further windfarm development in the East (Forth and Tay) and North-East (Moray) regions (see Sections 10.8 and 10.9).  Based on modelling (e.g. collision risk) and the best available scientific evidence there are concerns that additional windfarm development would have adverse in-combination effects on seabird populations, in particular from collision risk to Kittiwake.

11.6.2 The SNCB consultation advice provided in 2018 and 2019, in relation to commercial offshore windfarm proposals in these regions, objected to all the proposals on the basis that they would all have or were likely to have an AEOI when considered in-combination with consented windfarm developments (see Table 23). Despite the advice being based on worst case scenarios, with a number of precautionary assumptions, at this time it is reasonable to conclude, based on current evidence, that further development in these regions, as defined within the Sectoral Offshore Wind Plan, could result in an AEOI on Kittiwakes as a qualifying feature of a designated site, if development occurred in any of the following DPOs:

  • E3
  • NE2
  • NE3
  • NE4
  • NE5

11.6.3 Considering that Kittiwake colonies around Moray will already be affected by the consented windfarm developments, there is an increased risk of an in-combination AEOI on Kittiwake as a qualifying feature of the Troup, Pennan and Lion’s Heads SPA if development occurs at NE6. However, this is assuming that development occurred at NE4 and NE5.

11.6.4 Furthermore, consideration has been given, based on discussion with SNCBs, as to the potential effect of construction within E1 and E2. These sites are generally beyond the mean max foraging ranges for Kittiwake and Razorbill, and therefore a LSE has not been identified. However, if the more precautionary measure of mean max foraging range in addition to one standard deviation is considered this would include more significant areas of the two sites. Based on this, although the extent to which developments in sites E1 and E2 would increase currently assessed cumulative impacts for east coast SPAs is unclear, the sites may overlap with the foraging distribution for some seabird species from east coast SPAs, especially the western parts of E1 and E2 that are more inshore.  Therefore, whilst not classed in the same risk category as DPOs E3 and NE2-NE6, there will be a requirement for the collection and assessment of regional-level ornithology survey data (e.g. from digital aerial surveys) in this region. This would improve confidence in assessing the likely level of effects from collision, displacement, and barrier effects from any developments. The potential for LSE on east coast SPAs could be further understood by tracking studies of seabirds from these SPAs. Such information would improve confidence in assessing what proportion of any effects at the two sites should be apportioned to these SPAs and hence support project level HRA.

11.6.5 Currently, as a further mitigation measure, in order to conclude no AEOI, DPOs  E3 and NE2-6 have been classed as being subject to high levels of ornithological constraint. It is proposed, therefore, that development will only be able to progress at DPOs E3 and NE2-6 where sufficient scientific evidence can be provided to reduce the risk to an acceptable level (unless it can be determined that there are imperative reasons of overriding public interest that require development to proceed).

11.6.6 In order to address the uncertainties described above, a number of key knowledge gaps (OR[355]) relating to the potential effects of offshore wind farm developments on seabirds have been identified by the ScotMER process. These are:

  • Collision mortality and avoidance behaviour of Black-legged Kittiwake, Northern Gannet and Great Black-backed Gull (OR. 17). All three species concerned are of direct relevance to future offshore wind farm development in the Moray Firth region, whilst in the Forth and Tay region Kittiwake and Gannet are the key species of concern in relation to potential collision mortality.
  • The consequences of displacement and barrier effects on survival and productivity (OR. 23), and subsequently populations of Atlantic Puffin, Razorbill and Common Guillemot are key constraints in the Forth and Tay region, and to a lesser extent in the Moray Firth region.
  • The drivers of any observed changes in distribution and abundance of Black-legged Kittiwake, Northern Gannet, Atlantic Puffin, Razorbill, and Common Guillemot in and around offshore wind farms (OR. 06, OR<. 19, OR. 20, OR. 21).
  • The movements of adult birds during the non-breeding season and immature birds during the entire year, and their level of exposure to cumulative effects (OR. 02, OR. 03, OR. 09).

11.6.7 These key knowledge gaps are best addressed via targeted strategic monitoring activities:

  • Deployment of collision detection and tracking technologies at operational wind farms to establish interactions and behavioural responses of key species to wind farms, wind turbine generators, and blades, and the estimation of collision mortality. Appropriate technologies may include radar, cameras, thermal imaging, acoustic collision detection systems, GPS tagging of individual birds that pass through operational wind farms etc. Ideally data would be collected from multiple wind farms, multiple years and multiple locations within each wind farm to ensure representativeness. Data collection at wind farm/s in the Forth and Tay and in the Moray Firth regions would be appropriate.
  • Tracking of tagged individuals of key species during the breeding season to quantify use of the marine environment, interactions with offshore wind farm/s and linking these data with body condition, survival, and productivity of known individuals would be required. This type of study would be logistically challenging and there are limited colonies where such a study could be undertaken. However, the Forth and Tay region would be a suitable study region, due to the accessibility of the isle of May and the long term research undertaken there providing invaluable baseline data sets.
  • Gathering oceanographic and ecological data  (ocean mixing, primary productivity, prey species) to better explain the distribution and abundance of the key seabird species, determining which if any wind farm effects are driving observed changes in seabird abundance, distribution, or associated population consequences. Ideally data would be collected from multiple wind farms, multiple years, and multiple locations within each wind farm to ensure representativeness. Data collection at wind farm/s in the Forth and Tay and in the Moray Firth regions would be appropriate.
  • Tagging and tracking of key species to provide information on movements, habitat use and energetics during the non breeding season. Tagging would need to be carried out at multiple colonies to fully understand movements and mixing of birds from different source populations. There are a number of existing tracking projects that could be expanded or built upon.

11.6.8 In addition, various monitoring surveys (pre-construction and post-construction) are planned for 2019 and 2020 (e.g. pre-construction for Neart na Gaoithe, Inch Cape, Seagreen and Moray West; post-construction for Beatrice (including aerial surveys)). Among other things, the seabird monitoring surveys will help to understand small scale displacement due to construction disturbance, connectivity (inferred) and flight heights for comparison inside and outside the wind farm and potential displacement during operation. The results of these surveys, and ongoing research, will provide valuable evidence to support the assessments and assist with understanding the implication of in-combination effects while reducing the level of uncertainty. The findings of the monitoring surveys will feed into the IPR process during the regular reviews of the Draft Plan.

11.7 Additional Considerations

11.7.1 To further reduce consenting risk, consideration could also be given to the extent and boundaries of several DPOs. A number of DPO boundaries are currently located immediately adjacent to designated sites (Table 24). However, it is considered that this risk can best be managed at project level through spatial planning within DPOs to avoid or minimise risks to sensitive features where necessary.

Table 24: DPOs located immediately adjacent to a designated site. 

DPO Adjacent Designated Site  Qualifying Features
SW1 Luce Bay and Sands SAC North Channel SAC Includes reefs, subtidal sandbanks and intertidal mudflats; Harbour porpoise
W1 Inner Hebrides and the Minches SAC; Gruinart Flats, Islay SPA Harbour porpoise; Includes Chough, Greenland barnacle goose, Canadian light bellied brent goose
N2 Solan Bank SAC Reefs
NE1 Pobie Bank SAC Reefs

11.7.2 Coincident windfarm construction activities at DPOs within the same broad geographical area may increase the risk of an in-combination AEOI on marine mammal and fish qualifying features. For example, in the event that concurrent piling noise in a particular geographical region may increase risk of AEOI, then implementing sequential development of windfarms could help minimise in-combination effects from the construction phase, although such an approach could extend the duration of such effects. It is considered that such risks are most appropriately and effectively managed at project level.



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