Migratory waterbird SPAs (and Ramsar sites)

  1. To identify European sites designated for migratory waterbirds which have potential connectivity with the Proposed Development, consideration has been given to the likely migratory pathways and distribution of coastal estuarine sites and inland waterbody roost sites for the associated species. The search area for initial screening is therefore focussed on the estuarine and inland waterbody SPAs and Ramsar sites within the Eastern Lowlands and Border Hills Natural Heritage Zones (NHZs) (Figure 4.4). The Slamannan Plateau SPA (in the West Central Belt NHZ) and the Ythan Estuary, Sands of Forvie and Meikle Loch SPA / Ythan Estuary and Meikle Loch Ramsar site (in the North East Coastal Plain NHZ) are also included because of the potential for the waterbird qualifying features from these sites to use migratory pathways within the vicinity of the Proposed Development. Additionally, the Northumbria Coast SPA (and Ramsar site), Lindisfarne SPA (and Ramsar site) and Holburn Lake and Moss SPA (and Ramsar site) are included following advice from Natural England (2021).
  2. Therefore, a total of 17 SPAs for migratory waterbirds are considered to have the potential for connectivity with the Proposed Development and are taken forward for determination of LSE ( Table 4.5   Open ▸ ). Within Table 4.5   Open ▸ , these SPAs are subdivided according to whether they are estuarine or inland sites.

Other SPAs (and Ramsar sites) within the ZOI

  1. The potential ZOI of impacts associated with the Proposed Development (e.g. habitat loss/disturbance, noise and risk of collision) is considered to be limited to the area within 2 km of the Proposed Development array area and offshore export cable corridor for most bird species, which is the area over which displacement effects are potentially considered to occur. This may extend to considerably greater distances for some species, notably red-throated diver which shows particular sensitivity to various sources of anthropogenic disturbance (e.g. Mendel et al., 2019, Dorsch et al., 2020). 
  2. Other than the Outer Firth of Forth and St Andrews Bay Complex SPA (considered above under marine SPAs), no SPAs or Ramsar sites occur within 2 km of the Proposed Development. However, the Firth of Forth SPA (and Ramsar site) is located within 5.9 km of the offshore export cable corridor and non-breeding red-throated diver is a qualifying feature of this SPA, suggesting that there may be the potential for disturbance effects on this SPA associated with the offshore export cable corridor. This SPA is already included for the determination of LSE in relation to effects on migratory waterbirds ( Table 4.5   Open ▸ ). In addition, consideration is also given to determining LSE as a result of the potential for such disturbance effects.

4.4.3.    Summary of Initial Screening of Sites for marine ornithological Features

  1. As detailed above, the initial screening process identifies 46 European sites with seabirds or migratory waterbirds as qualifying features to be taken forward for detailed determination of LSE in section 5.5 of this report. These sites are identified, together with their distance to the Proposed Development and the qualifying features of relevance, in Table 4.5   Open ▸ noting that the further details outlined in the above text mean that five of the 33 breeding seabird colony SPAs identified in Table 4.5   Open ▸ are excluded from further consideration). The locations of these different sites are shown in Figure 4.4. Table 4.5   Open ▸ identifies the full list of qualifying features for all but six of the 46 SPAs (and Ramsar sites) which are taken forward for determination of LSE. The Natura 2000 standard data forms for the six sites for which some qualifying features are not identified in Table 4.5   Open ▸ are provided in Appendix 1. These six sites are Hoy SPA, Ronas Hill – North Roe and Tingon SPA, Fetlar SPA, the Firth of Forth SPA and Ramsar site, Lindisfarne SPA and Ramsar site and the Ythan Estuary, Sands of Forvie and Meikle Loch SPA / Ythan Estuary and Meikle Loch Ramsar site.


Figure 44:
Location of European Sites Designated for Ornithological Features (Seabirds and Migratory Waterbirds) Taken Forward for Determination of LSE

Figure 44: Location of European Sites Designated for Ornithological Features (Seabirds and Migratory Waterbirds) Taken Forward for Determination of LSE

5. Determination of Likely Significant Effect

  1. The initial screening process documented in section 4, generated a list of designated sites and qualifying interest features ( Table 4.1   Open ▸ , Table 4.2   Open ▸ , Table 4.3   Open ▸ and Table 4.5   Open ▸ ) for further determination of LSE as a result of the Proposed Development. This section of the LSE screening process therefore documents the determination of LSE for those European sites which have been identified for further consideration through section 4.

5.1. Methodology

  1. The assessment of LSE in the following sections is presented as a series of matrices setting out whether no LSE can be concluded for the relevant features of the European sites identified in section 4.
  2. The matrix approach adopted is based upon an approach set out within the Planning Inspectorate’s Advice Note 10 on HRA (The Planning Inspectorate, 2017; Version 8) relating to Nationally Significant Infrastructure Projects (NSIPs). Although it is acknowledged that this guidance is not directly applicable to Scottish projects, the matrix approach used is considered to be a pragmatic approach and useful in defining the extent of impacts from the Proposed Development on identified designated sites’ qualifying interest features, in relation to the sites’ conservation objectives. It also provides a clear audit trail for agreement with the statutory consultees on the scope of the HRA and the features and impacts to be taken forward into the appropriate assessment for each site.
  3. The following matrix key is applicable to the matrices presented in the subsequent sections:
  • - Potential for a LSE/no LSE cannot be concluded
  • – No potential for an LSE
  • C = Construction
  • O&M = Operation and Maintenance
  • D = Decommissioning
    1. With respect to the consideration of mitigation at the LSE screening stage, in April 2018, the European Court of Justice issued a judgement in the People Over Wind and Sweetman case (Case C323/17) clarifying the stage in a HRA process when mitigation measures can be taken into account when assessing impacts on a European site. The ruling stated that “…in order to determine whether it is necessary to carry out, subsequently, an appropriate assessment of the implications, for a site concerned, of a plan or project, it is not appropriate, at the screening stage, to take account of the measures intended to avoid or reduce the harmful effects of the plan or project on that site.”
    2. NatureScot interprets the judgement to mean that it is those measures specifically intended to avoid or reduce harmful effects to a European site which cannot be considered at the screening stage[7]. In accordance with this ruling (and the interpretation by NatureScot), measures intended to avoid or reduce harmful effects on a European site have not been applied in the course of this Screening exercise to discount the potential for LSE. Measures intended specifically to protect European sites are however, considered distinct from those which may incidentally protect European sites to a degree, but which are intrinsic parts of the Proposed Development. For example, offshore wind farms typically require post-consent plans which cover the construction and operation phases and includes planning for accidental spills and biosecurity measures to limit the potential spread of Invasive Non-Native Species (INNS) (e.g. a Project Environmental Management and Monitoring Plan (PEMMP)), irrespective of the possible effects on European sites. On the advice of NatureScot and the Scottish Ministers, the applicant has determined not to exclude such ‘incidental’ measures from the Proposed Development when undertaking Screening for LSE.

5.2. Assessment of LSE for Annex I Habitats (Coastal and Subtidal)

  1. A single European site, the Berwickshire and North Northumberland Coast SAC, was identified in the initial screening process (section 4) to be taken forward for determination of LSE for Annex I habitats.

5.2.2.    Site Overview

Berwickshire and North Northumberland SAC

  1. The Berwickshire and North Northumberland Coast SAC is one of the most varied coastlines in the UK, stretching from Alnmouth to north of St Abbs head. The site contains a complex mix of marine habitats, associated species and communities which is unusually diverse for the North Sea, in both a UK and European context. The site contributes to an important range and variation of intertidal mudflats and sandflats and has one of the best examples of east coast clean sand and seagrass beds, and of moderately exposed reefs. Intertidal and submerged sea caves also contribute significantly to the site’s overall habitat diversity and international importance (Natural England and NatureScot, 2021). The Natura 2000 standard data form for the site is provided in Appendix 1.
  2. The qualifying interest features of this site are detailed in Table 5.3   Open ▸ .

5.2.3.    Pathways for LSE: Potential Impacts on Annex I Habitats

  1. There is considerable knowledge from previous offshore wind farm projects, including from Seagreen Alpha/Bravo, on the potential effects that the construction, operation and maintenance and decommissioning of an offshore wind farm may have on benthic receptors. In addition, the ‘advice on operations’ prepared jointly by Natural England and NS for the Berwickshire and North Northumberland Coast SAC site identifies the type of impacts that Annex I features are sensitive to for offshore wind farms and cables (Natural England and NatureScot, 2021). Using this information, together with the SNCBs responses to the Initial Berwick Bank Wind Farm Proposal LSE Screening Report (see below), a list of impacts that may result from the Proposed Development, and that need to be taken into account when determining the potential for LSE for the Berwickshire and North Northumberland Coast SAC, has been generated and are summarised in Table 5.1   Open ▸ . For consistency with the EIA, the terminology adopted for describing the potential impacts identified in Table 5.1   Open ▸ for Annex I habitats (coastal and subtidal) is the same as that used in the EIA Offshore Scoping Report for the Proposed Development (SSER, 2021). This, however, differs to the terminology used in the advice on operations package for the site and so for clarity the equivalent terms, as used in the Natural England Advice Package for the Berwickshire and North Northumberland Coast SAC, are also given in Table 5.1   Open ▸ .
Table 5.1:
Potential Impacts Identified for Annex I Habitats and Equivalent Terms from the Advice on Operations Document for the Berwickshire and North Northumberland Coast SAC

Table 5.1:  Potential Impacts Identified for Annex I Habitats and Equivalent Terms from the Advice on Operations Document for the Berwickshire and North Northumberland Coast SAC

 

  1. Consideration of the potential impacts identified for Annex I habitats is presented in the following sections to inform the determination of LSE in section 5.2.3.

Construction Phase

Temporary Habitat Loss / Disturbance
  1. There is the potential for temporary, direct habitat loss and disturbance as a result of seabed preparation activities in advance of foundation installation, cable installation activities (including pre-cabling seabed clearance and anchor placements), and placement of jack-up barge legs on the seabed during the construction phase of the Proposed Development. This impact will be spatially restricted to within the footprint of the Proposed Development and, therefore, there is no potential for spatial overlap with any Annex I habitat features of the Berwickshire and North Northumberland Coast SAC.
  2. There is considered to be no potential for LSE on any Annex I habitat features of the Berwickshire and North Northumberland Coast SAC as a result of temporary habitat loss/disturbance.
Increases in SSC and Sediment Deposition
  1. Sediment disturbance arising from construction activities (e.g. foundation and cable installation, and seabed preparation works) may result in indirect impacts on benthic communities as a result of temporary increases in suspended sediment concentrations (SSCs) and associated sediment deposition (i.e. smothering effects). The extent of this impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area (which will be refined through physical processes modelling to be undertaken for the EIA). Therefore, for the purposes of this LSE screening, there is considered to be potential for LSE on Annex I features of the Berwickshire and North Northumberland Coast SAC which are within the ZOI from increased SSC (defined as 20 km; see section 4.1).
  2. On this basis, effects associated with the Proposed Development array area are screened out as the Proposed Development array area is located 36 km from the boundary of the Berwickshire and North Northumberland Coast SAC (see Table 4.1   Open ▸ ) and therefore outside the ZOI. There is only considered to be LSE from the activities along the proposed ECC as this lies within 3 km of the Berwickshire and North Northumberland Coast SAC (see Table 4.1   Open ▸ ) and therefore within the ZOI.
Release of Sediment Bound Contaminants
  1. Seabed disturbance associated with construction (e.g. seabed preparation in advance of foundation and cable installation) could lead to the remobilisation of sediment-bound contaminants that may result in harmful and adverse effects on benthic communities. Site-specific benthic baseline characterisations surveys undertaken in support of the Proposed Development have, however, identified very low levels of contamination within the sediments likely to be disturbed during construction activities. Levels of metals (see Table 5.2   Open ▸ ) were all at low levels and below the Marine Scotland chemical guideline Action Level 1 (AL1) and Action Level 2 (AL2). The majority of the metal contaminants also did not exceed the Canadian Threshold Effect Level (TEL), with the exception of arsenic at five sample stations within the Proposed Development Array Area; levels were however well below the Canadian Probable Effect Level (PEL) for arsenic ( Table 5.2   Open ▸ ). Levels of organotins were very low (<0.005 mg/kg for dibutyltin and <0.002 mg/kg for tributyltin) and below the ALs. Levels of polyaromatic hydrocarbons (PAHs) were consistently very low (mostly below the limit of detection) and levels for all samples were found to be below AL1. Similarly, levels of polychlorinated biphenyl (PCB) congeners were below the limit of detection for each PCB at each sample station, and below the respective Marine Scotland ALs.

 

Table 5.2:
Concentrations of Metals Recorded in Sediments within the Proposed Development Benthic Subtidal and Intertidal Ecology Study Area

Table 5.2:  Concentrations of Metals Recorded in Sediments within the Proposed Development Benthic Subtidal and Intertidal Ecology Study Area

* Indicates an exceedance of the Canadian TEL.

 

  1. The low level of contaminants is likely due to the limited historic oil and gas activities in the vicinity of the Proposed Development, the nature of the sediments present (i.e. low levels of fines) and the large distance from shore which suggests a limited input from onshore sources. The levels of sediment bound contaminants present are not considered to be at concentrations likely to be harmful to benthic receptors or to present a risk to benthic receptors.
  2. On this basis, there is considered to be no potential for LSE on any Annex I habitat features of Berwickshire and North Northumberland Coast SAC from this impact.
Accidental Pollution
  1. There is a risk of pollution being accidentally released during the construction phase of the Proposed Development from sources including vessels/vehicles and equipment/machinery. It is anticipated that the risk of such events occurring will be managed by the implementation of measures set out in standard post consent plans (e.g. a PEMMP including a Marine Pollution Contingency Plan) which will be implemented as part of the Proposed Development irrespective of the HRA process. These plans include planning for accidental spills, address all potential contaminant releases and include key emergency contact details. It will also set out industry good practice and OSPAR (Oslo-Paris), International Maritime Organization (IMO) and MARPOL (International Convention for the Prevention of Pollution from Ships) guidelines for preventing pollution at sea. Therefore the potential for LSE on Annex I habitat features of the Berwickshire and North Northumberland Coast SAC from accidental pollution can be discounted at this stage.

Operation and Maintenance Phase

Long-term Subtidal Habitat Loss
  1. There is the potential for long-term habitat loss to occur directly under all foundation structures and associated scour protection, and under any cable protection required along the inter-array and export cables for the duration of the operation and maintenance phase. This impact will be spatially restricted to within the footprint of the Proposed Development and as there is no physical overlap between the site and the Proposed Development, there is no potential for LSE on any Annex I features of the Berwickshire and North Northumberland Coast SAC.
Temporary Habitat Loss / Disturbance
  1. Temporary habitat loss/disturbance may occur during the operational and maintenance phase as a result of maintenance operations (e.g. cable repair/reburial, use of jack-up vessels to facilitate wind turbine component repairs etc.). This impact will be spatially restricted to within the footprint of the Proposed Development and as there is no physical overlap between the site and the Proposed Development, there is no potential for LSE on any Annex I habitat features of Berwickshire and North Northumberland Coast SAC as a result of temporary habitat loss/disturbance.
Increases in SSC and Sediment Deposition
  1. Temporary increases in SSC and associated sediment deposition may arise during maintenance activities (e.g. cable reburial or replacement works) and may affect benthic communities. The magnitude of this impact will be substantially less than that during construction as no seabed preparation will be required. The extent of the impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area (which will be refined through physical processes modelling to be undertaken for the EIA). Therefore, for the purposes of this LSE screening, there is considered to be potential for LSE on any Annex I features of the Berwickshire and North Northumberland Coast SAC which are within the ZOI from increased SSC (defined as 20 km; see section 4.1).
  2. On this basis, effects associated with the Proposed Development array area are screened out as the Proposed Development array area is located 36 km from the boundary of the Berwickshire and North Northumberland Coast SAC (see Table 4.1   Open ▸ ) and therefore outside the ZOI. There is only considered to be LSE from the activities along the proposed ECC as this lies within 3 km of the Berwickshire and North Northumberland Coast SAC (see Table 4.1   Open ▸ ) and therefore within the ZOI.
Changes in Physical Processes
  1. The presence of foundation structures, associated scour protection and cable protection may introduce localised changes to the tidal flow and wave climate, resulting in potential changes to the sediment transport pathways and associated effects on benthic ecology. The extent of the impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area (which will be refined through physical processes modelling to be undertaken for the EIA). Therefore, for the purposes of this LSE screening, there is considered to be potential for LSE on Annex I features of the Berwickshire and North Northumberland Coast SAC which are within the ZOI (defined as 20 km; see section 4.1).
  2. On this basis, effects associated with the Proposed Development array area are screened out as the Proposed Development array area is located 36 km from the boundary of the Berwickshire and North Northumberland Coast SAC (see Table 4.1   Open ▸ ) and therefore outside the ZOI. There is only considered to be LSE from the presence of physical structures (e.g. cable protection) along the proposed offshore ECC as this lies within 3 km of the Berwickshire and North Northumberland Coast SAC (see Table 4.1   Open ▸ ) and therefore within the ZOI.
Colonisation of Hard Structures
  1. Artificial structures placed on the seabed (i.e. foundations and scour/cable protection) in the offshore environment are expected to be colonised by a range of marine organisms leading to localised increases in biodiversity and changes in community composition. These structures may also facilitate the spread of marine INNS. Protection against bio-invasion risk is provided by assumed compliance with international legislation, guidelines, and methodologies.[8] Further the initial risk of introduction of marine INNS resulting from the Proposed Development will be limited by good practice measures to reduce the potential for release and spread of INNS and to provide a process to deal with any should they occur. These measures would be implemented irrespective of the HRA process are not in place to protect European sites.
  2. The environmental risk associated with invasive species is considered to be relative to the capacity for a new species to enter a new environment and spread. The greatest risk exists where new opportunities are provided for novel invasive species. Although there would be new infrastructure as a result of the Proposed Development, there is not considered to be a new route to impact due to the presence of other local offshore wind farms and major shipping lanes off the east coast of Scotland. It is considered that the addition of hard substratum in the array and EEC and infrastructure associated with the Proposed Development would not create any new connectivity routes or "stepping-stones" that were previously absent. As there is already a potential for marine INNS to occur due to the presence of other local offshore wind farms and major shipping lanes off the east coast of Scotland, it is considered that there is no additional risk posed by the Proposed Development. Further, there is also no physical overlap between the Proposed Development and the European site and adherence to international law and good practice would further reduce the low risk of bio-invasions associated with the Proposed Development. As such, there is considered to be no potential for LSE on any Annex I habitat features of Berwickshire and North Northumberland Coast SAC from this impact.
EMF from Subsea Cabling
  1. Electromagnetic fields (EMF) generated through the subsea electrical cabling may affect benthic subtidal and intertidal ecology by inhibiting/interfering with behaviours of the relevant benthic receptors. Research has demonstrated that even when buried, emission of EMF can impact the behaviour of invertebrates (Hutchison et al., 2020). Any impacts associated with EMF will be spatially restricted to within the footprint of the Proposed Development and as there is no physical overlap between the site and the Proposed Development, there is considered to be no potential for LSE on any Annex I habitat features of the Berwickshire and North Northumberland Coast SAC as a result of EMF effects.
Accidental Pollution
  1. The potential for LSE on any Annex I habitat features of the Berwickshire and North Northumberland Coast SAC as a result of accidental pollution can be discounted at this stage. The justification is as presented in section 5.2.3 – Construction Phase: Accidental Pollution.

Decommissioning Phase

  1. The impacts during the decommissioning phase are considered to be similar and potentially less than those outlined in the construction phase (see section 5.2.3 – Construction Phase). The only additional impact, unique to the decommissioning phase, is the removal of hard substrates which is considered below.
Removal of Hard Structures
  1. The removal of foundations and any scour/cable protection during decommissioning has the potential to lead to loss of species/habitats colonising these structures. Such effects will be highly localised and small scale and, as there is no physical overlap between the Proposed Development and the site, there is considered to be no potential for LSE on any Annex I habitat features of the Berwickshire and North Northumberland Coast SAC as a result the removal of hard substrates.

5.2.4.    Determination of LSE for Annex I Habitats

  1. Table 5.3   Open ▸ presents the results of the LSE determination assessment as a result of the Proposed Development on relevant qualifying interest features of the Berwickshire and North Northumberland Coast  SAC in the absence of mitigation measures. The footnotes to this table provide a brief assessment to support the screening in or out of each of these likely significant effects on the identified SAC features. Where effects are not applicable to a particular feature they are greyed out.
Likely Significant Effects in combination
  1. The LSE test requires consideration of the Proposed Development alone and/ or in-combination with other plans and projects. Therefore, it is not necessary at the LSE stage to consider sites/features for which an LSE ‘alone’ has already been identified, as in-combination effects will be considered at the Appropriate Assessment. The focus at this stage should be to identify sites/features for which no LSE alone was concluded, but there is potential for a LSE in-combination with other plans and projects (e.g. where contributions are made by a number of external projects as well as the Proposed Development). 
  2. Given the highly precautionary method for site selection applied during this Screening assessment, it is considered that the consolidation of information regarding external plans and projects would not likely result in additional LSEs being identified for the Screening assessment. 
  3. For Annex I habitats, the potential for LSE alone is identified for all sites within the widest ranging effect, therefore effects in-combination will be considered at Appropriate Assessment. For effects discounted for LSE alone, there is either no pathway to effect, or the Proposed Development would result in only negligible or inconsequential effects that would not contribute (even collectively) in a material way to in-combination effects and therefore, no additional in-combination issues are identified.

 

Table 5.3:
LSE Matrix for Annex I Habitats of the Berwickshire and North Northumberland Coast SAC

Table 5.3:  LSE Matrix for Annex I Habitats of the Berwickshire and North Northumberland Coast SAC

a: Temporary habitat loss/disturbance – there will be no direct physical overlap between any of the activities associated with the Proposed Development and the Annex I habitat features of the SAC. It can, therefore, be concluded that there is no potential for LSE on any Annex I habitat features of the site across all phases of the Proposed Development from temporary habitat loss/disturbance.

b: Increases in SSC and sediment deposition - the extent of this impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area (which will be refined through physical processes modelling to be undertaken for the EIA). Effects on benthic habitats from activities within the Proposed Development array area across all phases are screened out on the basis of the distance of the Proposed Development array area from the site (36 km). Effects are only likely to arise from works along the proposed ECC and, until the Proposed Development ECC is refined, it is considered that there is potential for LSE on all Annex I habitat features of the site during ECC works only.

c: Release of sediment bound contaminants – the site-specific survey data has demonstrated that the levels of sediment bound contaminants present in the sediments likely to be disturbed are very low and at concentrations which are unlikely to be harmful to, or represent a risk to, benthic receptors. On this basis, it is not considered that there is potential for LSE on any Annex I habitat features of the site from the release of sediment bound contaminants.

d: Long-term subtidal habitat loss – there will be no direct physical overlap between the footprint of the Proposed Development and the Annex I habitat features of the SAC. It can therefore be concluded that there is no potential for LSE on any Annex I habitat features of the site from long-term habitat loss.

e: Colonisation of hard structures – Protection against bio-invasion risk is provided by assumed compliance with international legislation, guidelines, and methodologies. The initial risk of introduction of marine INNS will further be limited by good practice measures to reduce the potential for release and spread of INNS and to provide a process to deal with any should they occur. Although there would be new infrastructure as a result of the Proposed Development, there is not considered to be a new route to impact, due to the presence of other local offshore wind farms and major shipping lanes off the east coast of Scotland.  As the movement of commercial vessels is common throughout the region and hard substrates are already prevalent throughout the region, the Proposed Development would not create any new ‘connectivity routes’ or "stepping-stones" that were previously absent. Given these factors and that there is no physical overlap between the Proposed Development and the site, it can therefore be concluded that there is no potential for LSE on any Annex I habitat features of the site as a result of the colonisation of hard substrates.              

f: Changes in physical processes – effects associated with the Proposed Development array area are screened out on the basis of distance. There is considered to be potential for LSE on all Annex I habitat features of the site during the operation and maintenance phase from the proposed ECC only.

g: EMF - there will be no direct physical overlap between the cabling associated with the Proposed Development and the Annex I habitat features of the SAC. It can, therefore, be concluded that there is no potential for LSE on any Annex I habitat features of the site from EMF effects during the operation and maintenance phase.

h: Removal of hard structures - there is no physical overlap between the Proposed Development and the site. It can, therefore, be concluded that there is no potential for LSE on any Annex I habitat features of the site from the removal of hard substrate during the decommissioning phase.

i: Accidental pollution – a good practice approach will be implemented as part of the Proposed Development via post-consent plans (e.g. a PEMMP) to reduce potential impacts associated with accidental pollution events across all phases of the Proposed Development irrespective of the possible effects on European sites. Following advice from NS (2021) and MSS (2021), accidental pollution associated with construction activities is not considered as an effect pathway because this will be subject to other regulatory control through both legislation and the requirements for contingency plans. This rationale is taken to apply to all phases of the Proposed Development. On this basis and given the distance of the Proposed Development array area from the site (36 km), the potential for LSE is therefore discounted.

j: In-combination effects - Activities associated with planned projects or other activities in the vicinity of the Proposed Development have the potential to result in LSE to Annex I habitat features of the SAC as a result of in-combination effects across all phases. Where potential for LSE has been concluded alone, the potential for LSE has been concluded in-combination. For effects discounted for LSE alone, there is either no pathway to effect, or the Proposed Development would result in only negligible or inconsequential effects that would not contribute (even collectively) a materially to in-combination effects and therefore, no additional in-combination issues are identified.

 

5.3. Assessment of LSE for Annex II Diadromous Fish

  1. A total of six European sites were identified in the initial screening process (section 4) to be taken forward for determination of LSE for Annex II diadromous fish species. These sites are:
  • Tweed Estuary SAC;
  • River Tweed SAC;
  • River South Esk SAC;
  • River Tay SAC;
  • River Dee SAC; and
  • River Teith SAC.

5.3.2.    Site Overviews

  1. The following sections provide a brief overview of each of the sites brought forward for consideration of LSE and a summary of their designated features. The Natura 2000 standard data forms are provided in Appendix 1 for all sites.

Tweed Estuary SAC

  1. The Tweed Estuary SAC is a complex estuary located on the north east coast of England flowing into the North Sea (see Figure 4.2). The site is designated for migratory river lamprey and sea lamprey. Sea and river lamprey are present in the spring when adults pass through the estuary to spawn in silt and sand beds in the river upstream (JNCC, 2020a). Adjoining upstream of the Tweed Estuary SAC is the River Tweed SAC (see River Tweed SAC below).

River Tweed SAC

  1. The River Tweed SAC (see Figure 4.2) is designated for Atlantic salmon, sea lamprey and river lamprey. The site supports a very large, high-quality salmon population in a river which drains a large catchment on the east coast of the UK, with sub-catchments in both Scotland and England. The high proportion of the River Tweed accessible to salmon, and the variety of habitat conditions in the river, have resulted in the Scottish section of the river supporting the full range of salmon life-history types, with sub-populations of spring, summer salmon and grilse all being present (JNCC, 2020b). The run-timing of adult salmon returning to the River Tweed SAC has changed very considerably in just the last few years. Previously, September and October were the main months of return, this is now July to August (RTC, 2021). Sea and river lamprey are also widespread within the site (JNCC, 2020b).

River South Esk SAC

  1. The River South Esk SAC (see Figure 4.2) is designated for Atlantic salmon and the freshwater pearl mussel. Atlantic salmon are found throughout the site. The high proportion of the South Esk which is accessible to salmon, and the range of ecological conditions in the river allows it to support the full range of life-history types of Atlantic salmon found in Scotland, with sub-populations of spring, summer salmon and grilse all being present (SNH, 2011).
  2. Freshwater pearl mussels are abundant in the River South Esk, representing the south-eastern range of the species in Scotland. The freshwater pearl mussel population is most abundant in the middle reaches of the river where they attain densities of more than 20 individuals per m-2. The conservation importance of the site is further increased by the abundance of juvenile freshwater pearl mussels which comprise approximately 20% of the population (JNCC, 2020c).

River Tay SAC

  1. The River Tay SAC (see Figure 4.2) is designated for Atlantic salmon, river lamprey and sea lamprey. The River Tay supports a high-quality Atlantic salmon population, with rod catch returns showing that the Tay is consistently one of the top three salmon rivers in Scotland (JNCC, 2020d). The Tay supports the full range of Atlantic salmon life-history types found in Scotland, with adult salmon entering the River Tay throughout the year to spawn in different parts of the catchment. Sea and river lamprey are also widespread within the site and the site is likely to support one of the most important sea lamprey populations in Scotland (JNCC, 2020d).

River Dee SAC

  1. The River Dee (see Figure 4.2) is a major east coast Scottish river which has been designated for freshwater pearl mussel and Atlantic salmon. Freshwater pearl mussel are present from approximately 30 km from the river source to approximately 6-7 km upstream from its mouth. Juvenile freshwater pearl mussel make up approximately 30% of the recorded population, which is among the highest proportions recorded in Scotland. This indicates that the population is recruiting strongly and is one of the most important in the UK.
  2. The site supports the full range of life-history types of Atlantic salmon found in Scotland, with sub-populations of spring, summer salmon and grilse all being present. The headwaters which drain the southern Cairngorm and northern Grampian mountains are particularly important for multi sea-winter spring salmon, but there has been a significant decline in their abundance in recent years. The extensive areas accessible to salmon means the River Dee supports a significant proportion of the Scottish salmon resource (JNCC, 2020e). The Dee has been categorised as a Grade 1 river, meaning that the stocks have most likely been above the critical threshold - the Conservation Limit - over the last five years (DDSFB, 2021). Further assessment of the juvenile salmon stocks in the Dee through the National Electrofishing Programme for Scotland (NEPS) programme has assessed the juvenile stocks in the Dee as being Grade 2, suggesting that there are significant issues with recruitment and survival within the catchment (Malcolm et al., 2020).

River Teith SAC

  1. The River Teith SAC (see Figure 4.2) is designated for Atlantic salmon, river lamprey and sea lamprey. The River Teith represents part of the east coast range of the sea lamprey in the UK and young sea lampreys have been recorded throughout the lower reaches of the main river. The site also supports a strong population of river lamprey and as the river lacks any significant artificial barriers to migration, has good water quality and the necessary habitat types (extensive gravel beds and marginal silt beds), it supports the river lamprey’s full life-cycle (JNCC, 2020f). The River Teith SAC also supports a significant population of Atlantic salmon and although this species is a qualifying feature of the site, it is not a primary reason for its designation.

5.3.3.    Pathways for LSE: Potential Impacts on Annex II Diadromous Fish

  1. A list of potential impacts and effects on diadromous fish that may result from the Proposed Development has been provided below. These are the impacts which must be taken into account when determining the potential for LSE on the designated sites and qualifying fish features identified in section 4.2. The list of potential impacts has been compiled using the experience and knowledge gained from previous offshore wind farm projects and Natural England’s ‘advice on operations’ (Natural England, 2020a and Natural England, 2020b), and the pressures data available on Scotland’s environment web (https://www.environment.gov.scot/) for individual features of sites. The list of potential impacts has also been informed by the SNCBs responses to the Initial Berwick Bank Wind Farm Proposal LSE Screening Report (see Table 1.1   Open ▸ and below). Consideration of the potential impacts identified for Annex II diadromous fish species is presented in the following sections to inform the determination of LSE in section 5.3.3.

Construction Phase

Temporary Habitat Loss / Disturbance
  1. There is potential for temporary, direct habitat loss and disturbance as a result of seabed preparation activities in advance of foundation installation, cable installation activities (including pre-cabling seabed clearance and anchor placements), and placement of spud-can legs during jack-up operations during the construction phase of the Proposed Development. This impact will be spatially restricted to within the footprint of the Proposed Development. No European sites with Annex II diadromous fish species physically overlap with the Proposed Development (see Figure 4.2) and so there is no potential for direct impacts to supporting habitats for Annex II diadromous fish species within any site. There is the potential for migratory fish to be present in the waters in and around the Proposed Development, and to be affected by temporary habitat loss/disturbance (e.g. effects on feeding grounds). Similar habitats are however widespread within this part of the North Sea and it is considered that there would be no barrier effects to migratory fish reaching the designated sites as a result of this impact. Furthermore, any impacts to supporting habitats such as foraging grounds outside the designated sites would be temporary and would not be expected to result in any long-term effects on the availability of food in the area. On this basis there is considered to be no potential for LSE on any Annex II fish species of any of the European sites screened in as a result of temporary habitat loss/disturbance. This impact is screened out for all sites.
Increases in SSC and Sediment Deposition
  1. Sediment disturbance arising from construction activities (e.g. foundation and cable installation, and seabed preparation works) may result in temporary, indirect impacts on diadromous fish as a result of temporary increases in SSCs. The extent of this impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area. This distance will be refined through physical processes modelling to be undertaken for the EIA but for the purposes of this LSE screening is defined as a precautionary distance of 20 km from the boundary of the Proposed Development (see section 4.1). There are no sites within this ZOI and so there is no potential for direct impacts to supporting habitats for Annex II diadromous fish species within any European site. There is the potential for migratory fish to be present in the waters in and around the Proposed Development and to be affected by increased SSC and deposition (e.g. effects on feeding and feeding grounds). Similar habitats are however widespread within this part of the North Sea and given the highly mobile nature of migratory fish it is anticipated that they will be able to avoid areas of temporary increases in SSC and seek alternative foraging grounds in the vicinity. Any effects, should they occur would be temporary and intermittent and would not be expected to result in any long-term effects on the availability of food in the area. On this basis, there is considered to be no potential for LSE on any Annex II features of European sites as a result of increased SSC during construction activities. This impact is screened out for all sites.
Underwater Noise
  1. There is potential for mortality, injury and/or disturbance to migratory fish as a result of construction activities including pile-driving to install foundations and clearance of UXOs, as well as construction/installation vessel noise. The greatest potential for noise to be generated will occur within the Proposed Development array area as a result of piling activities and UXO clearance. SSER also acknowledges advice received from the SNCBs that there will be stages when fish do not move much at all, for example salmon are likely to aggregate in the open sea near river mouths, prior to the upriver migration (e.g., Matz, 2014). The nearest European site with Annex II diadromous fish qualifying interest features is located 44.5 km from the Proposed Development array area (see Figure 4.2), but there is potential for migratory species to be present within or transiting through the Proposed Development array area and potential area of impact. The zone of impact will be determined for the EIA through noise modelling and therefore, at this stage of the development process, the potential for LSE on any Annex II features of European sites as a result of underwater noise arising from construction activities cannot be excluded. Underwater noise is therefore screened in for further consideration for diadromous fish.
Accidental Pollution
  1. There is a risk of pollution being accidentally released during the construction phase of the Proposed Development from sources including vessels/vehicles and equipment/machinery. The risk of such events occurring will be managed by the implementation of measures set out in standard post consent plans (e.g. a PEMMP including a Marine Pollution Contingency Plan) which will be implemented as part of the Proposed Development, notwithstanding potential pathways to European sites. These plans include planning for accidental spills, address all potential contaminant releases and include key emergency contact details. They will also set out industry good practice and OSPAR, IMO and MARPOL guidelines for preventing pollution at sea. Following advice from NS (2021) and MSS (2021), accidental pollution associated with construction activities is not considered as an effect pathway because of the wider regulatory controls as above (not associated with HRA) that govern the requirement for these contingency plans.

Operation and Maintenance Phase

Temporary Habitat Loss / Disturbance
  1. Temporary habitat loss/disturbance may occur during the operational and maintenance phase of the Proposed Development as a result of maintenance operations (e.g. cable repair/reburial, use of jack-up vessels to facilitate wind turbine component repairs etc.). This impact will be spatially restricted to within the footprint of the Proposed Development and there is no physical overlap with the Proposed Development and any European sites (see Figure 4.2) and so there is no potential for direct impacts to supporting habitats for Annex II diadromous fish species within any site. There is the potential for migratory fish to be present in the waters in and around the Proposed Development, and to be affected by temporary habitat loss/disturbance (e.g. effects on feeding grounds). Similar habitats are however widespread within this part of the North Sea and it is considered that there would be no barrier effects to migratory fish reaching the designated sites as a result of this impact. Furthermore, any impacts to supporting habitats such as foraging grounds outside the designated sites would be temporary and would not be expected to result in any long-term effects on the availability of food in the area. On this basis, there is considered to be no potential for LSE on any Annex II diadromous fish qualifying interest features of European sites as a result of temporary habitat loss/disturbance and so this impact is screened out from further consideration.
Increases in SSC and Sediment Deposition
  1. Temporary increases in SSC and associated sediment deposition may arise during maintenance activities (e.g. cable reburial or replacement works). The magnitude of this impact will be substantially less than that during construction as no seabed preparation will be required for these activities. The extent of the impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area (which will be refined through physical processes modelling to be undertaken for the EIA). This distance will be refined through physical processes modelling to be undertaken for the EIA but for the purposes of this LSE screening is defined as a precautionary distance of 20 km from the boundary of the Proposed Development (see section 4.1). There are no European sites within this ZOI and so there is no potential for direct impacts to supporting habitats for Annex II diadromous fish species within any European site. There is the potential for migratory fish to be present in the waters in and around the Proposed Development and to be affected by increased SSC and deposition (e.g. effects on feeding and feeding grounds). Similar habitats are however widespread within this part of the North Sea and given the highly mobile nature of migratory fish it is anticipated that they will be able to avoid areas of temporary increases in SSC, and seek alternative foraging grounds in the vicinity. Any effects, should they occur would be temporary and intermittent and would not be expected to result in any long-term effects on the availability of food in the area. On this basis, there is considered to be no potential for LSE on any Annex II features of European sites as a result in increased SSC during maintenance activities and so this impact is screened out of further consideration.
Underwater Noise
  1. During the operation and maintenance phase there is the potential for noise generated by the operational wind turbines, and from vessels undertaking operation and maintenance activities to result in disturbance to migratory fish as they pass through the Proposed Development. The operational noise from wind turbines is however of a very low frequency and low sound pressure level (Andersson et al., 2011). Studies have found that sound levels are only high enough to have the potential to cause a behavioural reaction within metres from a wind turbine (Sigray and Andersson 2011; Andersson et al., 2011) and therefore such levels are not considered likely to result in significant effects on diadromous fish species. Similarly, underwater noise generated from operation and maintenance vessels is likely to be at a low level and effects would only occur if fish remain within the immediate vicinity of the vessel (i.e. within metres) for a number of hours which is unlikely given the likely movements that the majority of vessels (e.g. crew transfer vessels etc.) will be making within the Proposed Development. It is therefore considered that there is no potential for LSE on any Annex II diadromous fish qualifying interest features of European sites as a result of underwater noise during the operation and maintenance phase and this impact is screened out of further consideration for all sites.
Long-term Habitat Loss
  1. There is the potential for long-term habitat loss to occur directly under all foundation structures and associated scour protection, and under any cable protection required along the inter-array and offshore export cable for the duration of the operation and maintenance phase. This impact will be spatially restricted to within the footprint of the Proposed Development and there is no physical overlap between the Proposed Development and any European sites (see Figure 4.2). As such, there is no potential for direct impacts to supporting habitats for Annex II diadromous fish species within any site. There is the potential for migratory fish to be present in the waters in and around the Proposed Development, and to be affected by long-term habitat loss (e.g. loss of feeding grounds). Similar habitats are however widespread within this part of the North Sea and the areas of seabed impacted by long term loss will be discreet and small in the content of the habitats present in the wider area. Furthermore, it is considered that there would be no barrier effects to migratory fish reaching the designated sites as a result of this impact. Any impacts to supporting habitats such as foraging grounds outside the designated sites would be localised and would not be expected to result in any long-term effects on the availability of food in the area. On this basis, there is no potential for LSE on any Annex II diadromous fish qualifying interest features of European sites as a result of long-term habitat loss, and this impact is screened out from further consideration.
Electromagnetic Fields (EMF)
  1. The presence of subsea electrical cabling has the potential to emit a localised EMF which may interfere with the navigation of migratory fish, particularly in shallow nearshore waters (Gill and Bartlett, 2010). At this stage, the potential for LSE on Annex II features of European sites as a result of EMF from subsea cabling cannot be excluded.
Colonisation of Hard Structures
  1. Artificial structures placed on the seabed (i.e. foundations and scour/cable protection) in the offshore environment are expected to be colonised by a range of marine organisms leading to localised increases in biodiversity and potential changes in prey-predator interactions. These structures may also facilitate the spread of marine invasive and non-native species (INNS). Further, the introduction of hard substrate into the marine environment could increase the time fish would spend in the vicinity of the structures (known as the fish aggregation (or reef) effect. While it is anticipated that the risk of bio-invasion and the spread of marine INNS is low (as set out in the discussion of the risk to Annex I habitats), due to the specific dynamics that relate to fish (and predator prey relationships) the potential for LSE on Annex II diadromous fish features of European sites from effects associated with the colonisation of hard structures, including changes to predator-prey interactions, cannot be discounted at this stage.