Sensitivity of the Receptor

Subtidal Habitat IEFs

  1. The subtidal coarse and mixed sediments, moderate energy subtidal rock, cobble/stony reef outside of an SAC, rocky reef outside an SAC, Sabellaria reef outside of an SAC IEFs are not sensitive to changes in local water flow from tidal current and local wave exposure changes based on the MarESA and FeAST ( Table 8.29   Open ▸ ).
  2. The FeAST assesses continental shelf sands and muds to have a low sensitivity to tidal current changes and wave exposure changes however this can be lowered to not sensitive based on the species present ( Table 8.29   Open ▸ ). Using the MarESA to examine the specific biotopes within the subtidal sand and muddy sand sediments IEF, all of them are judged to be not sensitive to both pressures. This is because these biotopes occur naturally in habitats where they are subject to strong water flow or wave exposure (Tillin, 2016). Alterations to this regime may have some impact on distribution and abundance but ultimately resistance and tolerance to this kind of change is likely to be high.
  3. The seapens and burrowing megafauna IEF are assessed by the MarESA to have a high sensitivity to changes in local water flow from tidal currents and are not sensitive to local wave exposure changes. This community is found in low energy environments with weak tidal currents (<0.5 m/s) (Connor et al., 2004). An increase in flow rate over 0.5 m/s can cause seapens to retract their tentacles and their stalks to retreat into the mud therefore reducing their ability to feed (Hiscock, 1983). The areas of tidal flow increase overlap with a very small proportion of the mapped seapens and burrowing megafauna IEF, additionally the predicted magnitude of change of tidal flow is 1 cm/s, which is much lower than the MarESA benchmark and therefore unlikely to result in alteration of behaviour or physical damage.
  4. Changes to tides, waves, littoral currents and sediment transport due to the presence of the infrastructure are not predicted to extend to coastal sites including the Barns Ness Coast SSSI, which extends over the Skateraw landfall site, or the Berwickshire and North Northumberland Coast SAC.
  5. The subtidal sand and muddy sand sediments IEF, and the subtidal coarse and mixed sediments IEF are deemed to be not sensitive, and of regional value. The sensitivity of all the IEFs is therefore, considered to be negligible.
  6. The moderate energy subtidal rock IEF, the cobble/stony reef outside of an SAC IEF, the rocky reef outside an SAC IEF, and the Sabellaria reef outside of an SAC IEF are deemed to be not sensitive, and of national value. The sensitivity of all the IEFs is therefore, considered to be negligible.
  7. The seapens and burrowing megafauna IEF is deemed to be of high vulnerability, low recoverability, and of national value. The sensitivity of all the IEF is therefore, considered to be high.
  8. Although there is an impact on PMF(s) this will not create significant impact on the national status of these features.

Table 8.29:
Sensitivity of the Benthic Subtidal IEFs to the Alteration of Seabed Habitat Arising from Effects of Physical Processes

Table 8.29: Sensitivity of the Benthic Subtidal IEFs to the Alteration of Seabed Habitat Arising from Effects of Physical Processes

 

 

Firth of Forth Banks Complex MPA

  1. The FeAST and the MarESA both assess the sensitivity of the subtidal sands and gravels IEF and shelf banks and mounds IEF to be not sensitive to tidal current and wave exposure changes ( Table 8.30   Open ▸ ).
  2. The FeAST assesses ocean quahog to have a low sensitivity to tidal current changes although an increase in flow can prevent larva or juveniles from settling and a decrease can reduce the availability of food that may be obtained by suspension feeding making them switch to deposit feeding. The MarESA identifies that a change in water flow of 1.0 m/s to 2.0 m/s is likely to be of limited effect given the species’ preferred high energy sediment type, therefore the predicted change within the Proposed Development site of 1 cm/s is very unlikely to result in a change in behaviour or physical damage to individuals. The FeAST also assesses ocean quahog to be of medium sensitivity to wave exposure change as an increase may cause the coarse sediments they settle on to become unstable and difficult to burrow in to as well as potentially causing physical damage. The MarESA states that a 3% to 5% change in significant wave height is unlikely to any significant effect on the population even in shallow waters, therefore the increase of less than 1% resulting from the Proposed Development is unlikely to adversely affect ocean quahog.
  3. The subtidal sands and gravels IEF and shelf banks and mounds IEFs found within the FFBC MPA are deemed to be not sensitive and of national value. The sensitivity of the IEFs is therefore, considered to be negligible.
  4. The ocean quahog IEF found within the FFBC MPA is deemed to be of low vulnerability and high recoverability to the scale of the predicted changes to physical processes, and of national value. The sensitivity of all the IEF is therefore, considered to be low.

 

Table 8.30:
Sensitivity of the Benthic Subtidal IEFs found within the FFBC MPA to Alteration of Seabed Habitat Arising from Effects of Physical Processes

Table 8.30: Sensitivity of the Benthic Subtidal IEFs found within the FFBC MPA to Alteration of Seabed Habitat Arising from Effects of Physical Processes

Berwickshire and North Northumberland Coast SAC

  1. The FeAST assesses the sensitivity of mudflats and sandflats not covered by seawater at low tide to changes in tidal currents and wave exposure to be low ( Table 8.31   Open ▸ ). Increases in both can lead to physical damage and reduction in suspension feeding, as well as potential shifts in sediment and community characteristics over extended periods. Whereas a reduction in flow from tides can result in the clogging of suspension and deposit feeders feeding apparatus. The MarESA finds that for both pressures’ biotopes with organisms such as Zostera noltii and Mytilus edulis are the most sensitive as changes to currents and wave exposure can impact feeding as well as their distribution due to species differing levels of tolerance.
  2. The sensitivity of the reefs (subtidal and intertidal rocky reef) IEF ranges from not sensitive to medium sensitivity to tidal current change and not sensitive to medium sensitivity to wave exposure change ( Table 8.31   Open ▸ ). The reasons for this classification are similar to those noted in the previous paragraph largely focussing on alteration to feeding pattern of suspension feeds, potential physical damage and changes to sediment and community characteristics.
  3. The submerged or partially submerged sea caves IEF is not sensitive to tidal current change and to wave exposure change ( Table 8.31   Open ▸ ). This is because of the largely sheltered nature of sea caves reducing the impact of tidal and wave exposure changes.
  4. The large shallow inlets and bays IEF does not have any specific biotopes associated with it, although the feature consists of the following sub-features: intertidal sand and muddy sand; subtidal coarse sediment; subtidal sand; subtidal mud, subtidal mixed sediment and saltmarsh habitat. The sensitivity of the component habitats is therefore likely to be as described previously for equivalent IEFs.
  5. As outlined in paragraph 422, tidal flows will not be affected in the nearshore as a result of the Proposed Development. Whilst there may be some small changes to wave climates at the coast during storm events, these are predicted to be imperceptible from natural variation. The combination of the two (littoral currents) and thus the impact on sediment transport is also not predicted to give rise to any discernible change in physical processes at the coast and, therefore, within the Berwickshire and North Northumberland Coast SAC.
  6. The submerged or partially submerged sea caves IEF is deemed to be not sensitive and of international value. The sensitivity of the IEF is therefore, considered to be negligible.
  7. The mudflats and sandflats not covered by seawater at low tide IEF and reefs (subtidal and intertidal rocky reef) IEF are deemed to be of medium vulnerability and medium recoverability and international value. The sensitivity of the IEFs is therefore, considered to be medium.
  8. Large shallow inlets and bays (based on similar IEFS) are deemed to be not sensitive and of international value. The sensitivity of the IEF is therefore, considered to be negligible.

 

Table 8.31:
Sensitivity of the Benthic Subtidal IEFs found within the Berwickshire and North Northumberland Coast SAC Alteration of Seabed Habitat Arising from Effects of Physical Processes

Table 8.31: Sensitivity of the Benthic Subtidal IEFs found within the Berwickshire and North Northumberland Coast SAC Alteration of Seabed Habitat Arising from Effects of Physical Processes

Significance of the Effect

Subtidal Habitat IEFs

  1. For the seapens and burrowing megafauna IEF the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms, because of the small scale of the change as a result of the Proposed Development which is within the range if this IEF to adapt.
  2. Overall, for all other subtidal IEFs (subtidal sand and muddy sand sediments IEF, subtidal coarse and mixed sediments IEF, moderate energy subtidal rock IEF, seapens and burrowing megafauna IEF, cobble/stony reef outside of an SAC IEF, rocky reef outside an SAC IEF and the Sabellaria reef outside of an SAC IEF) the magnitude of the impact is deemed to be low and the sensitivity of the receptors is considered to be negligible. The effect will, therefore, be of negligible adverse significance, which is not significant in EIA terms, because of the small scale of the change as a result of the Proposed Development and their resilience.

Firth of Forth Banks Complex MPA

  1. For the subtidal sands and gravels and shelf banks and mounds IEFs the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be negligible. The effect will, therefore, be of negligible adverse significance, which is not significant in EIA terms, because of the small scale of the change as a result of the Proposed Development and the dynamic nature of these IEFs.
  2. For the ocean quahog IEF the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible adverse significance, which is not significant in EIA terms, because of the small scale of the change as a result of the Proposed Development and the ability of ocean quahogs to deal with a range of tidal flows.

Berwickshire and North Northumberland Coast SAC

  1. Overall, the magnitude of the impact is deemed to be negligible and the sensitivity of all the receptors (mudflats and sandflats not covered by seawater at low tide, large shallow inlets and bays, reefs (subtidal and intertidal rocky reef), and submerged or partially submerged sea caves) is considered to be negligible to low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms, because of the small scale of the change as a result of the Proposed Development.
Secondary Mitigation and Residual Effect
  1. No benthic subtidal and intertidal ecology mitigation is considered necessary as a result of the alteration of seabed habitats may arise from the effects of changes to physical processes because the likely effects in the absence of further mitigation (beyond the designed in measures outlined in section 8.10), is not significant in EIA terms.

Removal of Hard Substrates Resulting in Loss of Colonising Communities

  1. The removal of hard substrates due to the decommissioning of jacket foundations, scour protection and cable protection infrastructure will have a direct effect on benthic subtidal IEFs, with the seabed returning to sandy and mixed sediments following removal of structures.
  2. The relevant MarESA pressures and their benchmarks which have been used to inform this assessment of effect are described below.
  • Physical change (to another substratum type): change in sediment type by one Folk class (Long, 2006) (based on UK SeaMap simplified classification) and change from sedimentary or soft rock substrata to hard rock or artificial substrata or vice-versa.
    1. The relevant FeAST pressures and their benchmarks which have used to inform this assessment of effect are described below.
  • Physical change (to another seabed type): permanent change of one marine habitat type to another marine habitat type, through the change in substratum. For instance, a change from sediment to solid substrate including artificial (e.g. concrete mattresses, rock deposition, and moorings), or from one type of sediment to another. This pressure concerns disposal or the deposit of material, whilst the removal of material is covered under abrasion pressures.
    1. These pressures relate to the removal of seabed infrastructure such as wind turbine and OSP/Offshore convertor station platform foundations.
    2. As discussed in paragraph 40, this assessment has been undertaken on the broad IEFs and separately on the IEFs that comprise features of the FFBC MPA.

Decommissioning Phase

Magnitude of Impact

Subtidal Habitat IEFs

  1. The decommissioning of Proposed Development infrastructure may result in the removal of 10,198,971 m2 of hard substrate, resulting in the loss of colonising communities. This includes the removal of jacket foundations for up to 307 jacket foundations for wind turbines and ten jacket foundations for OSPs/Offshore convertor station platforms as well as associated scour protection. Additionally, the maximum design scenario assumes that cable protection for 1,225 km of inter-array cables, 94 km of OSP/Offshore convertor station platform interconnector cables and 872 km of offshore export cables will be removed, as well as all cable crossings ( Table 8.10   Open ▸ ). This represents 100% of the area created by hard structures and colonised in the operation and maintenance phase.
  2. The impact is predicted to be of local spatial extent, long term duration, continuous and low reversibility. It is predicted that the impact will affect the receptors directly. The magnitude is therefore considered to be low.

Firth of Forth Banks Complex MPA

  1. The FFBC MPA overlaps with the site boundary for the Proposed Development and therefore the decommissioning of infrastructure within the site will result in the loss of colonising communities within the FFBC MPA. The overall figures for the spatial overlap are outlined in paragraph 85 together with the assumptions for the overlap of infrastructure/activities with the FFBC MPA. Based on this percentage of overlap and the maximum design scenario for the decommissioning phase, up to 2,789,582 m2 of hard substrate will be removed within the FFBC MPA, which equates to 0.13% of the FFBC MPA. For the purposes of this assessment, it is assumed that this may comprise up to 1,930,085 m2 within the area of Berwick Bank (0.36% of the area) and up to 859,497 m2 within the area of Scalp and Wee Bankie (0.10% of the area).
  2. The impact is predicted to be of local spatial extent, long term duration, continuous and low reversibility. It is predicted that the impact will affect the receptors directly. The magnitude is therefore considered to be low.

Berwickshire and North Northumberland Coast SAC

  1. The Berwickshire and North Northumberland Coast SAC is located 4.12 km from the Proposed Development export cable corridor. On the basis that there is no spatial overlap there is no pathway for impact from the removal of hard substrate and associated communities and therefore no further assessment is required for this impact.
Sensitivity of the Receptor

Subtidal Habitat IEFs

  1. The removal of hard substrate would result in localised declines in biodiversity. However, areas of seabed where Proposed Development infrastructure was not present prior to decommissioning would be expected to recover, with benthic communities in these areas recolonising habitats previously lost beneath offshore structures. In time, these communities are predicted to revert to their pre-construction state. Recovery of the IEFs affected is likely to be high as a result of a combination of recruitment from surrounding unaffected areas, adult migration and larval dispersal (paragraphs 92 to 95). This is highlighted in the assessment of subtidal IEFs undertaken in the assessment of long term subtidal habitat loss ( Table 8.25   Open ▸ ).
  2. All of the benthic subtidal IEFs are deemed to be of high vulnerability, high recoverability, and regional to national value. The sensitivity of the IEFs is therefore, considered to be low.
  3. Although there is an impact on PMF(s) this will not create significant impact on the national status of these features.

Firth of Forth Banks Complex MPA

  1. The sensitivity of IEFs found within the FFBC MPA is likely to be similar to the subtidal IEFs described in paragraph 469.
  2. All of the IEFs found within the FFBC MPA are deemed to be of high vulnerability, high recoverability, and national value. The sensitivity of the IEFs is therefore, considered to be medium.
Significance of the Effect

Subtidal Habitat IEFs

  1. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor (subtidal sand and muddy sand sediments, subtidal coarse and mixed sediments, and Sabellaria reef outside of an SAC) is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms. This is concluded because of the ability of the species associated with these IEFs to re-colonise the areas of soft sediment which may, over time, constitute a return to baseline conditions in some areas.

Firth of Forth Banks Complex MPA

  1. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor (subtidal sands and gravels, shelf banks and mounds, and ocean quahog) is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms, because of the ability of these IEFs to re-colonise the areas of soft sediment.
Secondary Mitigation and Residual Effect
  1. No benthic subtidal and intertidal ecology mitigation is considered necessary for the impact of removal of hard substrate resulting in loss of colonising communities because the likely effects in the absence of further mitigation (beyond the designed in measures outlined in section 8.10), are not significant in EIA terms.

8.11.1.              Proposed Monitoring

  1. No generic benthic subtidal and intertidal ecology monitoring is considered necessary. This has been concluded because of sufficient confidence in the assessment, with effects identified that are not significant in the long-term. The Applicant is however committed to engaging with the SNCBs to identify suitable strategic benthic monitoring or research studies that the Project could contribute to, to improve the knowledge base for long term impacts associated with offshore wind farms. Proposed monitoring measures are outlined in Table 8.32   Open ▸ .

 

Table 8.32:
Monitoring Commitments for Benthic Subtidal and Intertidal Ecology

Table 8.32: Monitoring Commitments for Benthic Subtidal and Intertidal Ecology

 

8.12. Cumulative Effects Assessment

8.12.1.              Methodology

  1. The CEA assesses the impact associated with the Proposed Development together with other relevant plans, projects and activities. Cumulative effects are therefore the combined effect of the Proposed Development in combination with the effects from a number of different projects, on the same receptor or resource. Please see volume 1, chapter 6 for detail on CEA methodology.
  2. The projects and plans selected as relevant to the CEA presented within this chapter are based upon the results of a screening exercise (see volume 3, appendix 6.4 of the Offshore EIA Report). Volume 3, appendix 6.4 further provides information regarding how information pertaining to other plans and projects is gained and applied to the assessment. Each project or plan has been considered on a case-by-case basis for screening in or out of this chapter's assessment based upon data confidence, effect receptor pathways and the spatial/temporal scales involved.
  3. In undertaking the CEA for the Proposed Development, it is important to bear in mind that other projects and plans under consideration will have differing potential for proceeding to an operational stage and hence a differing potential to ultimately contribute to a cumulative impact alongside the Proposed Development. Therefore, a tiered approach has be adopted. This provides a framework for placing relative weight upon the potential for each project/plan to be included in the CEA to ultimately be realised, based upon the project/plan’s current stage of maturity and certainty in the projects’ parameters. The tiered approach which will be utilised within the Proposed Development CEA employs the following tiers:
Table 8.33:
List of Other Developments Considered Within the CEA for Benthic Subtidal and Intertidal Ecology

Table 8.33: List of Other Developments Considered Within the CEA for Benthic Subtidal and Intertidal Ecology

Figure 8.7:
Other Projects/Plans Screened into the Cumulative Effects Assessment for Benthic Subtidal and Intertidal Ecology

8.12.2.              Maximum Design Scenario

  1. The maximum design scenarios identified in Table 8.34   Open ▸ have been selected as those having the potential to result in the greatest effect on an identified receptor or receptor group. The cumulative effects presented and assessed in this section have been selected from the details provided in volume 1, chapter 3 of the Offshore EIA Report as well as the information available on other projects and plans (see volume 3, appendix 6.4), to inform a ‘maximum design scenario’. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the PDE (e.g. different wind turbine layout), to that assessed here, be taken forward in the final design scheme.

 

Table 8.34:
Maximum Design Scenario Considered for Each Impact as part of the Assessment of Likely Significant Cumulative Effects on Benthic Subtidal and Intertidal Ecology

Table 8.34: Maximum Design Scenario Considered for Each Impact as part of the Assessment of Likely Significant Cumulative Effects on Benthic Subtidal and Intertidal Ecology


8.12.3.              Cumulative Effects Assessment

  1. An assessment of the likely significance of the cumulative effects of the Proposed Development upon benthic subtidal and intertidal ecology receptors arising from each identified impact is given in the following sections.

Temporary Habitat Loss/Disturbance

Tier 2

Construction phase

Magnitude of impact

Subtidal Habitat IEFs

  1. The construction and operation and maintenance of the projects/plans/activities shown in Table 8.34   Open ▸ may lead to cumulative temporary subtidal habitat loss/disturbance within the benthic subtidal and intertidal ecology CEA study area. A total cumulative area of habitat loss/disturbance has not been calculated as it is not appropriate to add all areas together. This would create an unrealistic total area as the majority of the disturbance would not occur at the same time, rather small proportions of habitat loss would occur across the CEA study area over the construction phase for the Proposed Development. Table 8.34   Open ▸ and Figure 8.7   Open ▸ show all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1, Eastern Link 2 and Eyemouth disposal site. There is small temporal overlap between construction phase for the Proposed Development and that of the Inch Cape Offshore Wind Farm and Seagreen 1A Project as well as the operation and maintenance phase once construction has been completed. The remaining projects will be in their operation and maintenance phase during the Proposed Developments construction phase.
  2. Table 8.35   Open ▸ shows the cumulative temporary habitat disturbance within the benthic subtidal and intertidal ecology cumulative study area, noting that the Seagreen 1A Project and Seagreen 1A Export Cable Corridor assessment does not provide estimates for temporary habitat disturbance associated with operation and maintenance. The maximum design scenario values for temporary habitat disturbance/loss during the construction phase of the Seagreen 1A Project (i.e. for the 36 wind turbines associated with this project) are presented in Table 8.35   Open ▸ and have been calculated, for the purposes of this CEA, using publicly available datasets (i.e. Seagreen Wind Energy, 2012b[21]; Seagreen Wind Energy, 2022[22]; and Seagreen Wind Energy 2020[23]). The maximum design scenario for temporary habitat loss/disturbance associated with the Seagreen 1A Project (i.e. 689,394 m2) has been subtracted from those provided in the Seagreen 1 assessment (Seagreen Wind Energy, 2012a) to calculate the realistic maximum design scenario for Seagreen 1 (i.e. to represent the scenario associated with 114 of the 150 wind turbines). This has approach has been adopted to prevent double counting and to ensure these projects are assessed realistically and proportionately. The Seagreen 1 assessment, as presented in the EIA for the project (Seagreen Wind Energy, 2012b), was undertaken on the basis that 114 of the 150 wind turbines for Seagreen 1 will have already been installed before construction of the Proposed Development is due to commence. Therefore, the Seagreen 1A Project will involve the construction of only the remaining 36 out of the 150 wind turbines.
  3. There is also expected to be temporary habitat disturbance from the construction and operation and maintenance of Eastern Link 1 and 2. The environmental appraisal for Eastern Link 1 does not give a specific value for temporary habitat loss in the project however it is expected to include a pre-installation footprint of 50 m and a 30 m footprint for cable installation. Additionally only 24% of the 176 km Eastern Link 1 cable will be within the Proposed Development benthic subtidal and intertidal study area therefore only a proportion of the overall impact will be cumulative. Table 8.35   Open ▸ shows that in the construction phase Eastern Link 2 will result in 15,200,000 m2 of temporary habitat disturbance however only 18% of the 436 km cables will occur with the Proposed Development benthic subtidal and intertidal ecology study area.
  4. There is potential for cumulative impacts to arise with disposal activities at the Eyemouth disposal site. The total area of the site is 664,761 m2 (see Table 8.35   Open ▸ ), however only a small portion of this would be affected at any one time by an individual disposal event.
  5. The maximum design scenario for habitat loss from the cumulative offshore wind farms, and the Eyemouth disposal site has been considered in this cumulative assessment. However, this is considered to be precautionary as activities associated with the operation and maintenance phase of wind farms occur intermittently throughout the phase and therefore are unlikely to completely overlap with the construction period of the Proposed Development.
  6. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. Given the minor temporal overlap in construction activities and that the operation and maintenance activities associated with the relevant projects will not add substantially to the total footprint associated with the Proposed Development and with only a proportion of the operation and maintenance operations occurring during the construction phase of the Proposed Development, the magnitude of the impact will not be greater than that assumed for the project alone. The magnitude is therefore, considered to be medium.

 

Table 8.35:
Total Area and Component Parts of Temporary Habitat Disturbance of the Relevant Tier 2 Cumulative Impact Projects in the Construction Phase of the Proposed Development

Table 8.35: Total Area and Component Parts of Temporary Habitat Disturbance of the Relevant Tier 2 Cumulative Impact Projects in the Construction Phase of the Proposed Development

 

Firth of Forth Banks Complex MPA

  1. Neither Inch Cape Offshore Wind Farm nor Neart na Gaoithe Offshore Wind Farm have a spatial overlap with the FFBC MPA, however Seagreen 1 and Seagreen 1A Project do overlap with the FFBC MPA. For the purposes of this assessment, the values for Seagreen 1 and Seagreen 1A Project have been reported together as a single value, as per the assessment that was presented in the MPA Assessment for Seagreen 1 (MS-LOT, 2014), which included the relevant elements of the Seagreen 1A Project
  2. The Seagreen 1 and Seagreen 1A Project, together, overlap with 7.17% of the FFBC MPA (MS-LOT, 2014), which represents 31.59% of the total combined area of Seagreen 1 and the Seagreen 1A Project. The Seagreen 1A Export Cable Corridor also overlaps with the FFBC MPA, the area of overlap represents 3.8% of the total area of the MPA (Seagreen Wind Energy Ltd., 2021). During the construction phase of Seagreen 1 and Seagreen 1A Project, up to 4,582,171 m2 of temporary habitat disturbance/loss is predicted to occur within the FFBC MPA, which accounts for 0.22% of the total area of the FFBC MPA. Neither Seagreen 1, Seagreen 1A Project or Seagreen 1A Export Cable Corridor provide specific figures for temporary habitat loss/disturbance in the operation and maintenance phase so it has not been possible to quantify the extent of temporary habitat loss that may occur within the boundary of the FFBC MPA, however it can be assumed that it will add a small amount on to the temporary habitat loss/disturbance from the Proposed Development based on the total extent of the overlap.
  3. The cumulative impact is predicted to be of regional spatial extent, medium term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be medium.

Sensitivity of receptor

Subtidal Habitat IEFs

  1. The sensitivity of the IEFs are as detailed in paragraph 91 to 101 as well as Table 8.18   Open ▸ .
  2. The subtidal sand and muddy sand sediments IEF, and subtidal coarse and mixed sediments IEF are deemed to be of medium vulnerability, medium to low recoverability and regional value. The sensitivity of the IEFs is therefore, considered to be medium.
  3. The Sabellaria reef outside of an SAC IEF is deemed to be of medium vulnerability, medium recoverability, and national value. The sensitivity of the IEF is therefore, considered to be high.
  4. The seapens and burrowing megafauna IEF is deemed to be of high vulnerability, low recoverability and national value. The sensitivity of the IEF is therefore, considered to be high.
  5. The moderate energy subtidal rock, cobble/stony reef outside of an SAC and rocky reef outside an SAC IEFs are deemed to be of medium vulnerability and medium recoverability to temporary habitat disturbance (i.e. abrasion effects) and of national value. The sensitivity of the IEFs is therefore, considered to be medium.
  6. Although there is an impact on PMF(s), this will not create a significant impact on the national status of these features as only a small proportion of these PMFs will be affected compared to their overall national distribution and the temporary nature of the disturbance will limit the time over which disturbance will occur. Additionally, many will recover fully within a few years of the completion of construction, resulting in no change to their overall national status.

Firth of Forth Banks Complex MPA

  1. The sensitivity of the IEFs are as detailed in paragraphs 103 to 107, as well as Table 8.19   Open ▸ .
  2. The subtidal sands and gravels IEF, and the shelf banks and mounds IEF are deemed to be of medium vulnerability, medium recoverability and national value. The sensitivity of the IEFs is therefore, considered to be medium.
  3. The ocean quahog IEF is deemed to be of high vulnerability, low recoverability and national value. The sensitivity of the IEF is therefore, considered to be high.

Significance of the effect

Subtidal Habitat IEFs

  1. Overall, for the subtidal sand and muddy sand sediments IEF, the subtidal coarse and mixed sediments IEF, the moderate energy subtidal rock IEF, cobble/stony reef outside of an SAC IEF and rocky reef outside an SAC IEF, the magnitude of the cumulative impact is deemed to be medium and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of moderate adverse significance in the short term (i.e. within two years of completion of construction activities), with this decreasing to minor adverse significance in the medium to long term as the sediments and communities are predicted to recover. Therefore, minor effects are predicted in the long-term which are not significant in EIA terms. This is on the basis that current research suggests that hard and soft substrates can recover from this impact following the cessation of associated activities over time.
  2. Overall, for the seapens and burrowing megafauna IEF, and Sabellaria reef outside of an SAC IEFs the magnitude of the cumulative impact is deemed to be medium and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of moderate adverse significance in the short term (i.e. within two years of completion of construction activities), with this decreasing to minor adverse significance in the medium to long term as the sediments and communities are predicted to recover. Therefore, minor effects are predicted in the long-term which are not significant in EIA terms. This is based on the limited scale of the impact on these habitats and their ability to recover after disturbance, over extended time periods.

Firth of Forth Banks Complex MPA

  1. Overall, for the subtidal sands and gravels IEF and the shelf banks and mounds IEF, the magnitude of the cumulative impact is deemed to be medium and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of moderate adverse significance in the short term (i.e. within two years of completion of construction activities), with this decreasing to minor adverse significance in the medium to long term as the sediments and communities are predicted to recover. Therefore, minor effects are predicted in the long-term which are not significant in EIA terms.
  2. Overall, for ocean quahog IEF the magnitude of the cumulative impact is deemed to be medium and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of moderate adverse significance in the medium term, because of the slower rate of recovery for this species in comparison with surrounding habitats (i.e. within ten years of completion of construction activities), with this decreasing to minor adverse significance in the long term as the sediments and ocean quahog populations are predicted to recover. Therefore, minor effects are predicted in the long-term which are not significant in EIA terms.

Further mitigation and residual effect

  1. No benthic subtidal and intertidal ecology mitigation is considered necessary for the impact of temporary habitat loss/disturbance during the operation and maintenance phase because the likely effects, in the absence of further mitigation (beyond the designed in measures outlined in section 8.10), are not significant in EIA terms.
Operation and maintenance phase

Magnitude of impact

Subtidal Habitat IEFs

  1. Table 8.34   Open ▸ and Figure 8.7   Open ▸ show all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1, Eastern Link 2 and Eyemouth disposal site.
  2. During the operation and maintenance phase of the Proposed Development the other Tier 2 wind farms will reach their decommissioning age before the Proposed Development reaches its anticipated decommissioning in 2068. The operational lifetime of Inch Cape is expected to be up to 35 years, with construction ending in 2025 and decommissioning is expected in 2060 (Inch Cape Offshore Limited, 2018). The operational lifetime of Neart na Gaoithe is expected to be 25 years, with construction ending in 2023 and decommissioning is expected in 2049 (Mainstream Renewable Power, 2019). Seagreen 1 and Seagreen 1A Project have an operation and maintenance phase of 25 to 30 years which will lead to its decommissioning in 2048 – 2053 (Seagreen Wind Energy, 2012).
  3. The maximum design scenario for temporary habitat disturbance from each phase of the relevant cumulative offshore wind farms has been considered in this cumulative assessment. However, this is considered to be precautionary as activities associated with the operation and maintenance of the Proposed Development will occur intermittently throughout the lifetime of the Proposed Development and therefore are unlikely to temporally overlap with the decommissioning periods of the other offshore wind farms. Furthermore, Inch Cape Offshore Wind Farm and Neart na Gaoithe Offshore Wind Farm assume in their environmental statements that the decommissioning process will produce similar levels of temporary habitat disturbance to their construction phase however this is likely to be an over estimation because not all of the infrastructure is likely to be removed from the seabed in the final plans (Inch Cape Offshore Limited, 2018; Mainstream Renewable Power, 2019), The EIA for Seagreen 1 (including the elements of the Seagreen 1A Project) however does not include any assumption for habitat disturbance associated with maintenance activities although it is assumed that, during decommissioning, all structures will be removed and so the magnitude of the effect is that same as the construction phase impact (Seagreen Wind Energy, 2012). Values for the maximum design scenario for Seagreen 1 and the Seagreen 1A Project have been determined using the publicly available information detailed in paragraph 490.
  4. The environmental assessment for Seagreen 1A Export Cable Corridor provides no values for the operation and maintenance of the cable; however, it is expected to be small in comparison with the Proposed Development and the other offshore wind farms considered. The impacts during decommissioning are expected to be similar, and less significant, than those predicted during installation (Seagreen Wind Energy Ltd., 2021).
  5. The environmental appraisals for Eastern Link 1 (National Grid Electricity Transmission and Scottish Power Transmission, 2022) and Eastern Link 2 (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022) do not provide detail regarding the temporary habitat disturbance of their maintenance activities. They do however expect it to be highly reduced from the construction phase and repair works are likely to be highly localised to the area of concern and therefore the spatial extent of any impacts would be small in extent.
  6. Currently it is unknown when the Eyemouth disposal site may close therefore to ensure the worst-case scenario it has been assumed it will still be open and the area of temporary habitat loss can be seen in Table 8.36   Open ▸ (MS-LOT, 2018).
  7. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

 

Table 8.36:
Total Area and Component Parts of Temporary Habitat Disturbance of the Relevant Tier 2 Cumulative Projects in the Operation and Maintenance Phase of the Proposed Development

Table 8.36: Total Area and Component Parts of Temporary Habitat Disturbance of the Relevant Tier 2 Cumulative Projects in the Operation and Maintenance Phase of the Proposed Development

 

Firth of Forth Banks Complex MPA

  1. Neither Inch Cape Offshore Wind Farm, nor Neart na Gaoithe Offshore Wind Farm have a spatial overlap with the FFBC MPA, however Seagreen 1 and Seagreen 1A Project do overlap with the FFBC MPA. In total Seagreen 1 and Seagreen 1A Project overlap with 7.17% of the FFBC MPA, which represents 31.59% of the total area of Seagreen 1 and Seagreen 1A Project. Seagreen 1A Export Cable Corridor also overlaps with the FFBC MPA, the area of overlap represents 3.8% of the total area of the MPA (Seagreen Wind Energy Ltd., 2021).
  2. The MPA assessment for Seagreen 1 (which included the Seagreen 1A Project elements) (MS-LOT, 2014) provides figures for the decommissioning of the project (assuming the worst-case scenario is the removal of all infrastructure, therefore it is the same as construction) but not operation and maintenance. Based on this information 287,961 m2 of temporary habitat disturbance will occur as a result of these projects within the FFBC MPA (0.12% of the total area of the MPA).
  3. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

Subtidal Habitat IEFs

  1. The sensitivity of the IEFs are as detailed in paragraphs 91 to 101 as well as Table 8.19   Open ▸ of the project alone assessment and paragraph 499 to 503 in the CEA assessment.

Firth of Forth Banks Complex MPA

  1. The sensitivity of the IEFs are as detailed in paragraphs 103 to 107, as well as Table 8.20   Open ▸ in the project alone assessment and in paragraphs 505 and 506 in the CEA assessment.

Significance of the effect

Subtidal Habitat IEFs

  1. Overall, for the subtidal sand and muddy sand sediments IEF, the subtidal coarse and mixed sediments IEF, the moderate energy subtidal rock IEF, cobble/stony reef outside of an SAC IEF and rocky reef outside an SAC IEF the magnitude of the cumulative impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms, because of the small scale of the impact and the high rate of recovery for these habitats.
  2. Overall, for the seapens and burrowing megafauna, and Sabellaria reef outside of an SAC IEFs, the magnitude of the cumulative impact is deemed to be low, and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms, because of the small scale of the impact and the high rate of recovery for these habitats.

Firth of Forth Banks Complex MPA

  1. Overall, for the subtidal sands and gravels IEF and the shelf banks and mounds IEF, the magnitude of the cumulative impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms, because of the small scale of the impact and the high rate of recovery for these habitats.
  2. Overall, for ocean quahog IEF the magnitude of the cumulative impact is deemed to be low, and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms. This has been concluded on the basis that only a very small proportion of the habitat for this species in the south western North Sea is predicted to be affected and, furthermore, as described in section 8.7, with further detail in the Benthic Subtidal and Intertidal Ecology Technical Report (volume 3, appendix 8.1), this species was recorded is very low abundances within the site-specific surveys and predominately as juveniles.

Further mitigation and residual effect

  1. No benthic subtidal and intertidal ecology mitigation is considered necessary for the impact of temporary habitat loss/disturbance during the operation and maintenance phase because the likely effects, in the absence of further mitigation (beyond the designed in measures outlined in section 8.10), are not significant in EIA terms.