Tier 3

Construction phase
  1. In addition to the Tier 2 projects which will overlap with the Firth of Forth Banks Complex MPA, the construction and operation of the Tier 3 project Cambois connection, which is in the pre-application stages of development, will also overlap with the Firth of Forth Banks Complex MPA and temporally overlaps with the construction of the Proposed Development. There may be up to 35.58 km2 of cumulative temporary habitat disturbance associated with the Tier 3 projects (i.e. Tier 2 projects and the Cambois connection; see Table 1.54   Open ▸ ).
  2. The maximum length of cable associated with the Cambois connection which will overlap with the Firth of Forth Banks Complex MPA is 63 km, and there may be up to four cables. For the construction of this cable the zone of temporary disturbance is defined as a 25 m corridor within which the cables will be installed in a 2 m trench. This will result in up to 6.30 km2 of temporary habitat disturbance within the MPA which represents 0.30% of the total area of the MPA. The operation and maintenance phase of the Cambois connection will also overlap the construction phase of the Proposed Development. The values presented for the Cambois connection are based on information presented in the Scoping Report submitted in October 2022. There are currently no values available for temporary habitat disturbance associated with the operation and maintenance phase of the Cambois connection. It can however be assumed that the temporary habitat disturbance will be of the same magnitude as that for the Proposed Development, and therefore minimal.
  3. Up to 180 km of the Cambois connection cables may be installed within the Proposed Development array area which could result in up to 4.5 km2 of repeat disturbance of seabed within the Proposed Development array area, and the MPA, previously impacted during the construction of the Proposed Development. The disturbance associated with the Cambois connection cable installation will however be highly localised (25 m width of potential disturbance) and so the potential for repeat disturbance is considered low and unlikely to lead to cumulative impacts. The small extent of repeat disturbance is unlikely to affect, or delay, the recovery processes for the ecological communities affected and so the recovery timescales described for the Proposed Development alone will apply (see paragraphs 200 and 201).

 

Table 1.54:
Cumulative Temporary Habitat Disturbance Within the Firth of Forth Banks Complex MPA for the Proposed Development and Other Tier 3 Projects Included in the Cumulative Assessment

Table 1.54: Cumulative Temporary Habitat Disturbance Within the Firth of Forth Banks Complex MPA for the Proposed Development and Other Tier 3 Projects Included in the Cumulative Assessment

 

Offshore subtidal sands and gravels, and ocean quahog aggregations

  1. Due to the small area of additional temporary habitat disturbance associated with the Tier 3 Cambois connection, representing only 0.30% of the total area of the MPA (total of 1.67% for all Tier 2 and Tier 3 projects) the impact on the relevant features and their conservation objects is predicted to be minimal, therefore for a description of the impacts on offshore subtidal sands and gravels see paragraph 451 to 453, and for a description of the impacts on ocean quahogs see paragraph 454 to 456.
  2. Based on the information presented here, it can be concluded that increasing the cumulative habitat disturbance associated with the Tier 3 projects will not lead to a significant risk of hindering the achievement of the conservation objectives (i.e. “recover to favourable condition”) for the offshore subtidal sands and gravels feature or the ocean quahog aggregations feature of the Firth of Forth Banks Complex MPA for the same reasons presented in paragraph 452 et seq.

Increases in SSC and Associated Sediment Deposition

Tier 2

Construction phase
  1. The construction phase of the Proposed Development coincides with the construction and operation and maintenance phase of Seagreen 1A Project, the operation and maintenance phase of Seagreen 1 and the operation and maintenance phase of the Seagreen 1A Export Cable Corridor. As a result of the activities associated with these projects there is expected to be some intermittent cumulative increases in SSC and associated sediment deposition which may temporally overlap with activities resulting in from the Proposed Development.
  2. Seagreen 1 (including Seagreen 1A Project) is expected to displace 3,230,482 m3 of sediment during the construction phase due to installation of gravity based foundations and inter-array cables. During the operation and maintenance phase up to 227,165 m3 of sediment is predicted to be displaced due to the formation of scour holes around wind turbines and OSPs/Offshore convertor station platforms. Overall, this amounts to an increase in suspended sediments of 3,457,647 m3 across all phases of the Seagreen 1 and Seagreen 1A Project (Marine Scotland, 2014b). It is noted that the Seagreen 1A Project is due for completion at the end of 2025. Therefore, the installation of cables and foundations for these projects is unlikely to coincide with the Proposed Development construction phase.
  3. The Inch Cape Offshore Wind Farm will be in the final year of construction, with the installation of the offshore export cable being programmed for the period of overlap. The cable path is located to the east of the Proposed Development, beyond the Firth of Forth Banks Complex MPA and should trenching activities be undertaken simultaneously the sediment plumes would not interact with those from the Proposed Development.
  4. During the construction phase of the Proposed Development, the Neart na Gaoithe Offshore Wind Farm and the Seagreen 1A Export Cable Corridor will be in their operational phases and maintenance activities may result in increased suspended sediment concentrations, however these activities would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development.
  5. As discussed in paragraph 450, the MPA assessment undertaken for the Seagreen 1 and Seagreen 1A Project, together, concluded that the project was only capable of affecting, other than insignificantly, the ocean quahog aggregations and offshore subtidal sand and gravel protected features of the Firth of Forth Banks Complex MPA. The shelf banks and mounds and the Wee Bankie Key Geodiversity Area (Moraines) designated features have, therefore, not been considered in relation to the cumulative temporary habitat disturbance associated with the Seagreen 1 and Seagreen 1A Project.
  6. The ocean quahog aggregation habitat feature is not being considered for this feature because FeAST and MarESA both find ocean quahogs to be not sensitive to changes in to changes in SSC and the associated deposition due to their ability to burrow back to the surface following sediment deposition (Powilliet et al., 2006; 2009). Ocean quahogs are also not directly sensitive to changes in light availability although an increase in turbidity could lead to a release of higher-than-normal levels of nutrients resulting in increased levels of food availability (FeAST, 2013c).

Offshore subtidal sands and gravels

  1. The sensitivity of the biological attributes of this protected feature to increases in SSC and associated sediment deposition is as described in paragraph 270. Increases in SSC and sediment deposition will occur intermittently throughout the construction periods for both the Proposed Development and the Seagreen 1A Project. Given that the construction periods are only anticipated to overlap for one year, the scope for cumulative impacts to arise will be minimal.
  2. As a largely physical attribute, the small scale of these installation activities is unlikely to have an effect upon this large scale feature which extends across the full area of the Firth of Forth Banks Complex MPA (2,130 km2) (JNCC, 2018b). The increases in SSC and associated deposition will only result in temporary changes to the environment and those changes involve the transport and deposition of sediment within the MPA, the effects of which will be short lived with conditions returning to baseline within a few tidal cycles. Overall, the magnitude of these impacts suggests a minor short-term impact on the offshore subtidal sands and gravel protected features sediment composition and the fine scale topography.
  3. As discussed in paragraph 290, ocean quahog are the key influential species of this protected feature and, as a burrowing infaunal species, they exhibit tolerance to low level smothering which is a pressure expected as a result of this impact. This tolerance is also described in the scoping report for Seagreen 1A Export Cable Corridor which stated ocean quahog has shown high resistance and resilience to heavy smothering (MarLIN, 2020). Laboratory experiments have found ocean quahog may take many days to reach the surface of sediments, but no mortality was observed (Seagreen Energy Ltd., 2021). Additionally, in field conditions an increase in sediment smothering was found to have no effect on the population or growth (Powilliet et al., 2006; 2009). As a result, a conclusion of no impact can be drawn for this attribute. The characteristic communities of this feature are also expected to be minimally affected due to the small extent of this impact, and the sediment composition will be maintained, an attribute which these communities rely upon.
  4. As the physical and biological attributes of this protected feature will be preserved in this phase of the Proposed Development it is unlikely that the function will be compromised therefore any potential affect will the same as described in paragraph 298.
  5. Based on the information presented here, it can be concluded that cumulative increases in SSC and associated deposition during the Proposed Development construction phase will not lead to a significant risk of hindering the achievement of the conservation objectives for this feature of the Firth of Forth Banks Complex MPA (i.e. “recover to favourable condition”) for the following reasons:
  • The cumulative increases in SSC and associated deposition are predicted to affect a small proportion of the offshore subtidal sands and gravels feature during the construction phase, these habitats will recover such that the extent and distribution of the protected feature will remain stable following the construction phase; and
  • The structures and functions, quality, and the composition of characteristic communities will remain in (or recover to) a condition which is healthy and not deteriorating. Recovery of the seabed sediment will occur in the months following seabed preparation, wind turbine installation and cable installation, with complete recovery within the areas affected within a few years. The key and influential species are predicted to recolonise disturbed sediment, with full recovery of characteristic communities within months to years of construction. These communities will be supported by an undisturbed hydrodynamic regime which will continue to form the fine scale features of the MPA.

Tier 3

Construction phase
  1. During the construction phase of the Proposed Development there is the potential for cumulative impacts with one Tier 3 project. The Cambois connection is a 170 km cable route extending southwards from the Proposed Development array area at Berwick Bank and may also include cables within the Proposed Development array area. The Cambois connection may directly impact the Firth of Forth Banks Complex MPA and the construction phase is anticipated to overlap with the construction phase of the Proposed Development. The values for the Cambois connection are based on information presented in the Scoping Report submitted in October 2022 which indicates that the project will consist of four cables installed in 2 m wide trenches up to 3 m in depth. Installation techniques may include jet trenching, deep jet trencher, mechanical trencher, cable plough (displacement and non-displacement), mass flow excavator (MFE) or similar, as ground conditions dictate. Site preparation will be required, such as boulder and sand wave clearance as part of the approximately two year construction programme. These installation parameters are similar to those of the Proposed Development and therefore the magnitude of the impact on the MPA receptors is anticipated to be low.

Offshore subtidal sands and gravels

  1. The sensitivity of the biological attributes of this protected feature to increases in SSC and associated sediment deposition is as described in paragraph 270.
  2. The impact of the Cambois connection installation is likely to result in a low magnitude of impact, especially as the increase in SSC and associated deposition will be highly localised to the installation site which covers a very small proportion of the Berwick Bank section of the MPA. These similarities mean that much of the discussion in paragraph 469 and 470 is still relevant in this tier of the cumulative effects assessment and the increase in SSC and associated deposition is unlikely to greatly increase the overall cumulative effect of this impact.
  3. As the physical and biological attributes of this protected feature will be preserved in this phase of the Proposed Development it is unlikely that the function will be compromised therefore any potential effect will the same as described in paragraph 298.
  4. Based on the information presented here, it can be concluded that cumulative increases in SSC and associated deposition during the Proposed Development construction phase will not lead to a significant risk of hindering the achievement of the conservation objectives for this feature of the Firth of Forth Banks Complex MPA (i.e. “recover to favourable condition”) for the same reasons as described in paragraph 472.

Long Term Subtidal Habitat Loss

Tier 2

Construction, and operation and maintenance phase
  1. The long term habitat loss arising during the construction, and operation and maintenance phases of the Proposed Development is predicted to temporally overlap with the construction and operation and maintenance phases of the Seagreen 1A Project, the operation and maintenance phase of Seagreen 1, and the operation and maintenance of Seagreen 1A Export Cable Corridor. Table 1.55   Open ▸ presents the cumulative long term habitat loss / habitat alteration within the MPA. The values of long term habitat loss associated with the Seagreen 1 and Seagreen 1A Project are taken from the MPA Assessment undertaken by Marine Scotland for the projects (Marine Scotland, 2014b). As stated previously (paragraph 446) the long term habitat loss values from the MPA assessment for Seagreen 1 and Seagreen 1A Project cannot be separated so will be presented together.
  2. The Offshore EIA Report and MPA Assessment undertaken for Seagreen 1A Export Cable Corridor (Seagreen Wind Energy Ltd., 2021), does not quantify the long term habitat loss specifically attributable to the presence of cable protection. The MPA Assessment undertaken for Seagreen 1A Export Cable Corridor assumes that cable protection will be 6 m wide and may cover up to 20% of the 110 km offshore export cables. The EIA Report for the Seagreen 1A Export Cable Corridor states that not all cable protection, however, will be installed in the MPA and there is the possibility that no cable protection would be required in the MPA for the Seagreen 1A Export Cable Corridor (see Figure 3-4 in Seagreen Wind Energy Ltd., 2021). The impact of long term habitat loss is highly localised/occur in discrete locations therefore the area of impact from long term habitat loss as a result of the Seagreen 1A Export Cable Corridor will be small. NatureScot, therefore, acknowledged that although the works would be capable of affecting these features of the MPA, any effects would be insignificant and that no further assessment of the MPA was required.
  3. On the basis of these assumptions, there may be up to 3.00 km2 of cumulative long term habitat alteration within the MPA, equating to 0.14% of the total area of the MPA.
  4. The long term habitat loss values for Seagreen 1 and Seagreen 1A Project are the total value for disturbance and is composed of loss within both Scalp and Wee Bankie and Montrose Bank. The Proposed Development does not coincide with Montrose Bank therefore there will be no cumulative impact in that component of the MPA, cumulative effects will only occur in Scalp and Wee Bankie. Individual disturbance values for each MPA section are not provided in the MPA assessment for Seagreen 1 and Seagreen 1A Project, therefore it has not been possible to apportion the numbers to get a specific value for the disturbance in Scalp and Wee Bankie, therefore the actual value for loss within the Scalp and Wee Bankie will be less than the value presented.

 

Table 1.55:
Cumulative Long Term Habitat Loss Within the Firth of Forth Banks Complex MPA for the Proposed Development and Other Tier 2 Projects Included in the Cumulative Assessment

Table 1.55: Cumulative Long Term Habitat Loss Within the Firth of Forth Banks Complex MPA for the Proposed Development and Other Tier 2 Projects Included in the Cumulative Assessment

 

  1. As discussed in paragraph 450, the MPA assessment undertaken for the Seagreen 1 and Seagreen 1A Project concluded that the project was only capable of affecting, other than insignificantly, the ocean quahog aggregations and offshore subtidal sand and gravel protected features of the Firth of Forth Banks Complex MPA. The shelf banks and mounds and the Wee Bankie Key Geodiversity Area (Moraines) designated features have, therefore, not been considered in relation to the cumulative temporary habitat disturbance associated with the Seagreen 1 and Seagreen 1A Project.

Offshore subtidal sands and gravels

  1. As the offshore subtidal sands and gravels protected features is assumed to cover the entirety of the Firth of Forth Banks Complex MPA it has been assumed all of the cumulative long term habitat loss could occur within this feature. The sensitivity of this feature and its biological components is described in paragraph 296.
  2. The following can be concluded with respect to the physical and biological attributes of this protected features of the Firth of Forth Banks Complex MPA:
  • The extent and distribution of the offshore subtidal sands and gravels protected feature will be maintained with the long term loss of only a small proportion (0.14%) the total area of this feature. The habitat loss will occur in discrete locations, mostly within Scalp and Wee Bankie but also in sections of the Berwick Bank part of the MPA (associated with the Proposed Development only) and Montrose Bank (associated with Seagreen 1 and Seagreen 1A Project only). Large areas of unaffected habitat will remain which will enable the feature to persist and not be lost in large quantities from any one section. The majority will be associated with cable protection which represents a shift in substrate type rather than a total loss of habitat. It can be assumed that epifaunal hard substrate communities will in time colonise these areas, potentially providing some recovery of communities in areas where cable protection is placed and reducing the extent of long term habitat loss in the MPA. This is consistent with the ‘conserve’ objective of the extent and distribution attribute for this feature.
  • The hydrodynamic regime will be minimally impacted by long term habitat loss as a result of the installation of infrastructure with protrudes into the water column (see paragraph 411). The infrastructure associated with habitat loss from the Seagreen 1A Export Cable Corridor is cable protection, which does not extend far enough into the water column to cause any change in the hydrodynamic regime. Seagreen 1 and Seagreen 1A Project includes infrastructure spanning the water column (i.e. wind turbine/OSP-Offshore convertor station platform foundations), although its effect is not discussed in its MPA assessment (Marine Scotland, 2014b), it is likely to have a similar effect as that of the Proposed Development. Overall, the impact of the long term habitat loss on the hydrodynamic regime is likely to be negligible, as concluded in paragraph 411. This is consistent with the ‘conserve’ objective of the supporting processes attribute for this feature.
  • As the hydrodynamic regime is not affected by this impact the fine scale topography, which relies upon it for the formation of banks and mounds, will also remain unaffected. This is consistent with the ‘recover’ objective of the structure and function attribute for this feature.
  • The sediment composition of the feature will not be affected by long term habitat loss as 0.14% of the total area will be lost to hard structures, some of which will be returned to their original sedimentary substrate following decommissioning. This is consistent with the ‘recover’ objective of the structure and function attribute for this feature.
  • Ocean quahogs, the key influential species of this feature, are highly sensitive to a change in substrate such as from sedimentary to hard substrate as a burrowing filter/deposit feeder. Due to the small scale of the impact and the low likelihood of long term detrimental effects as the majority of their habitat across the feature is maintained and the stability/lack of interference with the seabed in the operation and maintenance will help support the population recovery. Cumulative long term habitat loss especially at this scale, is unlikely to result in long term changes to the key influential species of this feature. This is consistent with the ‘recover’ objective of the structure and function attribute for this feature.
  • The characteristic communities that define this feature rely upon the sedimentary habitat that it provides. The cumulative impact is likely to result in the same effect described in paragraph 307, with communities recovering following installation and continuing to occupy the areas around the lost habitat. This is consistent with the ‘recover’ objective of the structure and function attribute for this feature.
  • The limited extent of this impact on the physical and biological attributes of this protected feature as a result of this cumulative impact this suggest that the effects on the function of the feature will be the same as in paragraph 307. This is consistent with the ‘recover’ objective of the structure and function attribute for this feature.
    1. Based on the information presented here, it can be concluded that cumulative long term habitat loss during the Proposed Development operation and maintenance phase will not lead to a significant risk of hindering the achievement of the overall conservation objective (i.e. “recover to favourable condition”) for this feature of the Firth of Forth Banks Complex MPA for the following reasons:
  • Cumulative long term habitat loss and habitat alteration is predicted to affect a small proportion of the offshore subtidal sands and gravels feature (0.14%, although this is likely to be an overestimation) during the operation and maintenance phase. These habitats are likely to recover in some areas following decommissioning and the removal of infrastructure, such that the extent and distribution of the protected feature will be maintained; and
  • The structures and functions, quality, and the composition of characteristic communities will remain in a condition which is healthy and not deteriorating. The key and influential species are predicted to continue to colonise the areas around the areas of long term loss. These communities will be supported by an undisturbed hydrodynamic regime which will continue to form the fine scale features of the MPA.

Ocean quahog aggregations

  1. As the ocean quahog aggregations protected feature is assumed to cover the entirety of the Firth of Forth Banks Complex MPA (JNCC, 2018b), for the purposes of this assessment it is assumed all of the cumulative long term habitat loss could occur within this feature (see Table 1.55   Open ▸ ). The sensitivity of this feature to long term habitat loss is as described in paragraphs 308 and 309.
  2. The following can be concluded with respect to the physical and biological attributes of this protected feature of the Firth of Forth Banks Complex MPA:
  • The extent of cumulative habitat loss is small in the context of the total area that this feature covers (i.e. up to 0.14% of the supporting habitat for this feature could be affected) which is considered unlikely to result in changes to the overall extent of this feature throughout the Firth of Forth Banks Complex MPA. The cumulative habitat loss will be localised to discrete areas of the MPA with extensive undisturbed habitat suitable for ocean quahog remaining between wind turbines and cable protection in the different projects. This is consistent with the ‘conserve’ objective of the extent and distribution attribute for this feature.
  • The structure of the ocean quahog aggregations is dependent on the continued ability of ocean quahog to reproduce at the site. The small proportion of habitat loss will not result in any long term impacts upon ocean quahog or affect their ability to reproduce in the area as >99% of suitable habitat will be maintained. Furthermore, as noted in paragraph 309, a likely reduction in fishing pressure in the immediate vicinity of the wind turbines will likely aid the recovery of the ocean quahog population within the MPA. This is consistent with the ‘conserve’ objective of the structure and function attribute for this feature.
  • The cumulative long term loss of habitat will not change the prevailing hydrodynamic conditions of the site however it may cause a localised change in sediment transport and a very small change to wave and tidal conditions (paragraphs 484), the limited scale of these changes is unlikely to compromise the conditions, upon which, ocean quahog rely. This is consistent with the ‘conserve’ objective of the supporting processes attribute for this feature. The continuation of the prevailing hydrodynamic regime throughout the Firth of Forth Banks Complex MPA, will maintain the availability of suitable habitat which relies upon the regime for the transport of the right sediment in to the MPA as well as the high energy currents make this a high productivity habitat that ocean quahog aggregations favour. This is consistent with the ‘conserve’ objective of the structure and function attribute for this feature.
  • There is not yet any direct evidence regarding the function of ocean quahogs (JNCC, 2018b), however the preservation of the extent, distribution, structure and supporting habitat of this feature under the cumulative long term habitat loss impact would suggest that the impact on the potential functions of the site would be same as described in paragraph 310 of the Proposed Development individual assessment This is consistent with the ‘conserve’ objective of the structure and function attribute for this feature.
    1. Based on the information presented here, it can be concluded that cumulative long term habitat loss/habitat alteration during the construction and operation and maintenance phases will not lead to a significant risk of hindering the achievement of the overall conservation objective for this feature of the Firth of Forth Banks Complex MPA (i.e. “recover to favourable condition”) for the following reasons:
  • Cumulative long term habitat alteration is predicted to affect a small proportion (0.14%, although this is likely to be an over estimation) of supporting habitat for ocean quahog during the operation and maintenance phase but the quality and quantity of ocean quahog habitat will be maintained. Whilst some ocean quahog individuals may be directly affected by the loss of habitat, this is predicted to be to an extent that will not affect the composition of its population in terms of number, age and sex ratio or its ability to thrive in the future and a likely reduction in fishing pressure in the immediate vicinity of the wind turbines will potentially aid the recovery of the ocean quahog population within the MPA.

Tier 3

Construction, and operation and maintenance phases
  1. In addition to the Tier 2 projects which will overlap with the Firth of Forth Banks Complex MPA, the Tier 3 project Cambois connection, which is in the pre-application stages of development, will also overlap with the Firth of Forth Banks Complex MPA potentially resulting in cumulative long term habitat loss.
  2. The maximum length of cable which will overlap with the Firth of Forth Banks Complex MPA is 63 km and there will be up to four cables (i.e. up to 252 km of cable in total within the MPA). The values for the Cambois connection are based on information presented in the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a) submitted in October 2022. Cable protection may be required for up to 15% of the total length of the cable. For the purpose of this assessment, it has been assumed that 15% of the cables within the MPA may require cable protection however there is the potential that none of the cable protection will be required within the MPA.As a result, for the purposes of the cumulative assessment it is assumed that up to 0.11 km2 of cable protection may be required within the MPA for the Cambois connection ( Table 1.56   Open ▸ ), equating to 0.005% of the total area of the MPA. All habitat loss associated with the Cambois connection within the Firth of Forth Banks Complex MPA will occur within the Berwick Bank section of the MPA, which equates to 0.02% of the total area of the Berwick Bank section of the MPA.
  3. On the basis of these assumptions, there may be up to 3.11 km2 of cumulative long term habitat loss/alteration within the MPA associated with the Tier 3 projects (i.e. Tier 2 projects and Cambois connection; see Table 1.56   Open ▸ ).

 

Table 1.56:
Cumulative Long Term Habitat Loss Within the Firth of Forth Banks Complex MPA for the Proposed Development and Other Tier 3 Projects Included in the Cumulative Assessment

Table 1.56: Cumulative Long Term Habitat Loss Within the Firth of Forth Banks Complex MPA for the Proposed Development and Other Tier 3 Projects Included in the Cumulative Assessment

 

Offshore subtidal sands and gravels, and ocean quahog aggregations

  1. Due to the small additional area of habitat loss/alteration associated with the Cambois connection, representing only 0.007% of the total area of the MPA, the impact on the relevant features and their conservation objects is predicted to be minimal, therefore for a description of the impacts on offshore subtidal sands and gravels see paragraphs 0 to 485, and for a description of the impacts on ocean quahogs see paragraphs 486 to 488.
  2. Based on the information presented here, it can be concluded that increasing the cumulative habitat loss associated with the Tier 3 projects will not lead to a significant risk of hindering the achievement of the conservation objectives (i.e. “recover to favourable condition”) for the offshore subtidal sands and gravels feature or the ocean quahog aggregations feature of the Firth of Forth Banks Complex MPA for the same reasons presented in paragraph 484 et seq.

Colonisation of Hard Structures

Tier 2

Operation and maintenance phase
  1. The operation and maintenance phase of the Proposed Development is predicted to temporally overlap with the operation and maintenance phase of Seagreen 1, the Seagreen 1A Project, and the Seagreen 1A Export Cable Corridor. Whilst estimates of the potential areas of new hard substrate available for colonisation within the MPA are not provided in the relevant documentation for Seagreen 1 and Seagreen 1A Project, or the Seagreen 1A Export Cable Corridor however colonisation is likely to occur on the wind turbine/OSP-Offshore convertor station platform foundations as well as on cable protection and scour protection as predicted for the Proposed Development. As a result the amount of hard substrate available for colonisation is likely to be similar to the estimate of long term habitat loss (1.03 km2). In combination with the area of hard substrate from the Proposed Development this would equate to 3.75 km2 of hard substrate potentially occurring in the Firth of Forth Banks Complex MPA. Paragraphs 338 to 342 describe the potential effects of the introduction of hard structures into sedimentary environments. These studies suggest that the communities which will colonise these structures will be ecologically distinct from those typically found across the largely sedimentary environment of the Firth of Forth Banks Complex MPA, comprising mostly of epifauna. Studies also found the introduction of these new communities has no significant impact upon the wider soft sediment habitats, this is supported by the studies such as those conducted by Hutchinson et al (2020a) and recent monitoring of the Beatrice Offshore Wind Farm (APEM, 2021).

Offshore subtidal sands and gravels

  1. The effects of the colonisation of hard substrates are very similar to the project alone assessment due to the same type of habitat being provided by Seagreen 1, Seagreen 1A Project, and Seagreen 1A Export Cable Corridor. The assessment and the sensitivity of the offshore subtidal sands and gravels feature to this impact is therefore as presented in paragraphs 346 to 347.
  2. It can be concluded that the cumulative colonisation of hard structures during the Proposed Development operation and maintenance phase will not lead to a significant risk of hindering the achievement of the conservation objectives (i.e. “recover to favourable condition”) for the offshore subtidal sands and gravels feature of the Firth of Forth Banks Complex MPA for the following reasons:
  • The cumulative colonisation of hard structures is predicted to have a near negligible effect on the offshore subtidal sands and gravels feature, based on studies and monitoring data, therefore the extent and distribution of the protected feature will remain stable throughout the operation and maintenance phase; and
  • The structures and functions, quality, and the composition of characteristic communities will remain in (or recover to) a condition which is healthy and not deteriorating. The key and influential species and characteristic communities are unlikely to be affected by the colonising communities as they are adapted for ecologically distinct habitats. These communities will be supported by an undisturbed hydrodynamic regime which will continue to form the fine scale features of the MPA.

Ocean quahog aggregations

  1. The effects of the colonisation of hard substrates are very similar to the project alone assessment due to the same type of habitat being introduced by Seagreen 1 and Seagreen 1A Project, and Seagreen 1A Export Cable Corridor. The assessment and the sensitivity of the ocean quahog aggregations feature to this impact therefore is presented in paragraph 353.
  2. It can be concluded that the cumulative colonisation of hard structures to the MPA will not lead to a significant risk of hindering the achievement of the conservation objectives for the ocean quahog aggregations feature of the Firth of Forth Banks Complex MPA (i.e. “recover to favourable condition”) for the following reasons:
  • Cumulative colonisation of hard structures is predicted to have a near negligible effect on the suitable habitat for ocean quahog during the operation and maintenance phase, therefore the quality and quantity of ocean quahog habitat is maintained. The colonisation of hard structures in any of the assessed projects will not affect the composition of its population in terms of number, age and sex ratio or its ability to thrive in the future.

Tier 3

Operation and maintenance phase
  1. The operation and maintenance phase of the Proposed Development is predicted to temporally overlap with the construction and operation and maintenance phase of Cambois connection, as well as the Tier 2 projects. Estimates of the potential areas of colonisation within the MPA are not currently available for the Cambois connection however colonisation is likely to occur on any cable protection installed within the MPA, of which there is predicted to be up to 0.04 km2 (see Table 1.56   Open ▸ ). In combination with the Tier 2 projects this could result in up to 3.86 km2 of hard substrate potentially occurring within the Firth of Forth Banks Complex MPA. Paragraphs 338 to 342 describe the potential effects of the introduction of hard structures into sedimentary environments. These studies suggest that the communities which will colonise these structures will be ecologically distinct from those typically found across the largely sedimentary environment of the Firth of Forth Banks Complex MPA, comprising mostly of epifauna. Studies also found the introduction of these new communities has no significant impact upon the wider soft sediment habitats, this is supported by the studies such as those conducted by Hutchinson et al. (2020a) and recent monitoring of the Beatrice Offshore Wind Farm (APEM, 2021).

Offshore subtidal sands and gravels, and ocean quahogs

  1. The effects of the colonisation of hard substrates are very similar to the project alone assessment and the cumulative assessment for the Tier 2 projects due to small additional area of the hard substrate being added and the same type of habitat being provided by the Cambois connection. The assessment and the sensitivity of the offshore subtidal sands and gravels feature to this impact is therefore as presented in paragraphs 346 to 347 and the conclusions of the cumulative assessment can be found in paragraphs 0 and 496. The assessment and the sensitivity of the ocean quahog aggregations feature to this impact therefore is presented in paragraph 353 and the conclusions for the cumulative assessment can be found in paragraphs 497 and 498.
  2. It is concluded that increasing the cumulative habitat creation associated with the Tier 3 projects will not lead to a significant risk of hindering the achievement of the conservation objectives (i.e. “recover to favourable condition”) for the offshore subtidal sands and gravels feature or the ocean quahog aggregations feature of the Firth of Forth Banks Complex MPA for the same reasons presented in paragraph 496 and paragraph 498.

Increased Risk of Introduction and Spread of INNS

Construction and operation and maintenance phases
  1. The construction and operation and maintenance phases of the Proposed Development are predicted to temporally overlap with the construction and operation and maintenance phases of Seagreen 1A Project, the operation and maintenance of Seagreen 1 and the operation and maintenance phase only of the Seagreen 1A Export Cable Corridor.
  2. The EIA Report for the Seagreen 1A Export Cable Corridor states that an INNS management plan, as part of an EMP, will be developed for vessels as part of the EMP, in line with best practice guidance where relevant (Cook et al., 2014) and the IMO Ballast Water Convention (IMO, 2004). The implementation of these measures will ensure that the risk of introducing INNS is reduced as far as possible, and as a result, the assessment concludes that this impact is not considered capable of affecting the environment (Seagreen Wind Energy Ltd., 2021).
  3. The risk of introduction of INNS was not specifically addressed in the MPA assessment for Seagreen 1 and Seagreen 1A Project (Marine Scotland, 2014b) or in the Offshore EIA Report (Seagreen Wind Energy Ltd., 2020). The project will however develop an EMP, a Vessel Management Plan as well as a risk assessment process for invasive and/or non-native species. They must also follow best practice guidance and the IMO Ballast Water Convention (IMO, 2004). The level of impact will be similar to the Proposed Development, but smaller due to the scale of the project, including activities such as boat trips for maintenance and the introduction of new infrastructure which can be colonised (1.03 km2 of Seagreen 1 and Seagreen 1A Project) (see paragraph 368). In combination with the area of hard substrate from the Proposed Development this would equate to up to 3.75 km2 of hard substrate potentially occurring in the Firth of Forth Banks Complex MPA.
  4. Due to the measures which will be implemented for the cumulative projects and the Proposed Development, the effects resulting from an increased risk of introduction and spread of INNS will be the same as those described in the Proposed Development alone assessment.

Offshore subtidal sands and gravels

  1. The assessment and the sensitivity of the offshore subtidal sands and gravels feature to this impact is as presented in paragraphs 373 and 376.
  2. It can be concluded that the cumulative increased the risk of introduction and spread of INNS during the Proposed Development operation and maintenance phase will not lead to a significant risk of hindering the achievement of the conservation objectives (i.e. “recover to favourable condition”) for this feature of the Firth of Forth Banks Complex MPA for the following reasons:
  • The cumulative risk of introduction and spread of INNS will not impact upon the extent and distribution of the protected feature and this will therefore remain stable during the construction and operation and maintenance phase; and
  • The structures and functions, quality, and the composition of characteristic communities will remain in (or recover to) a condition which is healthy and not deteriorating. The measures put in place to minimise the transfer of ecological material as well as the limited record of INNS in this region the likelihood of damaging effects is minimal.

Ocean quahog aggregations

  1. The assessment and the sensitivity of the ocean quahog aggregations feature to this impact is as discussed in paragraphs 380 and 382.
  2. Based on the information presented here, it can be concluded that cumulatively increasing the risk of introduction and spread of INNS during the Proposed Development operation and maintenance phases will not lead to a significant risk of hindering the achievement of the conservation objectives for this feature of the Firth of Forth Banks Complex MPA (i.e. “to recover to favourable condition”) for the following reasons:
  • While there is an increased risk of introduction and spread of INNS during the construction and operation and maintenance phases to the ocean quahog aggregations protected feature, the designed in measures will reduce the risk and ensure the quality and quantity of the protected feature remain stable and its population structure will be maintained throughout the Proposed Developments phases.

Tier 3

Construction, and operation and maintenance phases
  1. The construction and operation and maintenance phase of the Proposed Development is predicted to temporally overlap with the construction phase and operation and maintenance phase of Cambois connection, as well as the Tier 2 projects. Specific values for increased risk of INNS introduction and spread within the MPA are not currently specified for the Cambois connection however INNS is likely to be introduced on any cable protection installed within the MPA which is predicted to be up to 0.11 km2 (see Table 1.56   Open ▸ ). In combination with the Tier 2 projects this would result in up to 3.86 km2 of hard substrate potentially occurring within the Firth of Forth Banks Complex MPA.

Offshore subtidal sands and gravels, and ocean quahogs

  1. The effects of the increased risk of the introduction and spread of INNS are very similar to the project alone assessment and the cumulative assessment for the Tier 2 projects due to small additional area of the hard substrate being added and the same type of habitat being provided by the Cambois connection. The assessment and the sensitivity of the offshore subtidal sands and gravels feature to this impact is therefore as presented in paragraph 376. The assessment and the sensitivity of the ocean quahog aggregations feature to this impact therefore is presented in paragraph 381.
  2. It is concluded that increasing the cumulative habitat creation associated with the Tier 3 projects will not lead to a significant risk of hindering the achievement of the conservation objectives (i.e. “recover to favourable condition”) for the offshore subtidal sands and gravels feature or the ocean quahog aggregations feature of the Firth of Forth Banks Complex MPA for the same reasons presented in paragraphs 507 and 509.

Alteration of Seabed Habitat Arising from Effects of Physical Processes

Tier 2

Operation and maintenance
  1. During the operation and maintenance phase of the Proposed Development Inch Cape Offshore Wind Farm and Seagreen 1A Project will be in their construction and operation and maintenance phases. Additionally Neart na Gaoithe, Seagreen 1 and Seagreen 1A Export Cable Corridor only be in their operation and maintenance phases. All projects may be decommissioned during the Proposed Development operation and maintenance phase.
  2. The Neart na Gaoithe Offshore Wind Farm Environmental Statement (Mainstream Renewable Power Ltd, 2012) included a comprehensive numerical modelling study which incorporated modelling of the cumulative impacts of the offshore wind farms within the CEA study area for the Proposed Development (Intertek METOC, 2011). The modelling and assessment for Neart na Gaoithe included Neart na Gaoithe, Inch Cape, Seagreen 1 and Seagreen 1A Project in addition to the Proposed Development which is referred to in the documentation as Seagreen Phase 2 and Phase 3. Within the modelling the Proposed Development was modelled with 725 wind turbines each with an 8 m tower diameter relating to 6 MW devices. The Proposed Development however actually incorporates a maximum of 179 larger wind turbines which is significantly less than the scenario modelled and therefore the impacts would, in reality, be less than those reported. The impact of multiple developments on tidal currents was predicted by the study to be low and localised to the near field of each development.
  3. The Neart na Gaoithe study also showed that with all offshore wind farms in situ, the cumulative effect on the wave climate is low (< 3% average significant wave height) but the effect on wave climate has a larger extent than a single offshore wind farm. The cumulative effect from the combined wind farm developments on sediment transport processes is low, resulting in a 1% to 3% exceedance in the typical critical bed shear stress. Changes are within the immediate vicinity of each of the developments and it is not expected that there would be changes to the far-field sediment regimes.
  4.  Based on the above, the effects of this cumulative impact on the Firth of Forth Banks Complex MPA are likely to be similar to those assessed in the project alone assessment, which overall were found no impact on the conservation objectives of the protected features of the Firth of Forth Banks Complex MPA.

Offshore subtidal sands and gravels

  1. The cumulative effect of alteration of seabed habitats arising from changes in physical processes is unlikely to change based on the inclusion of Seagreen 1A Project, Neart na Gaoithe and Inch Cape offshore wind farms and Seagreen 1A Export Cable Corridor. Therefore paragraphs 397, 0 and 400 provide the details of the assessment and the sensitivity of the offshore subtidal sands and gravels to this impact.
  2. Based on the information presented here, it can be concluded that the cumulative alteration of seabed habitat arising from effects of physical processes during the Proposed Development operation and maintenance phase will not lead to a significant risk of hindering the achievement of the conservation objectives for the shelf banks and mounds feature of the Firth of Forth Banks Complex MPA (i.e. “maintain in favourable condition”) for the following reasons:
  • The cumulative alteration of seabed habitat arising from changes to physical processes is predicted to affect a small proportion of the offshore subtidal sands and gravels feature during the operation and maintenance phase, such that the extent and distribution of the protected feature will remain stable; and
  • The structures and functions, quality, and the composition of characteristic communities will remain in (or recover to) a condition which is healthy and not deteriorating. The impact on the seabed will be limited in spatial scale, only within 200 m of wind turbines (where change to littoral currents was limited to 5%) and will revert to baseline conditions following decommissioning. The key and influential species are predicted to shift their distribution due to these changes in conditions. These communities will be supported by an undisturbed hydrodynamic regime which will continue to form the fine scale features of the MPA.

Shelf banks and mounds

  1. The cumulative effect of alteration of seabed habitats arising from changes in physical processes is unlikely to change based on the inclusion of Seagreen 1, the Seagreen 1A Project, Neart na Gaoithe and Inch Cape offshore wind farms and Seagreen 1A Export Cable Corridor. The assessment and the sensitivity of shelf banks and mounds to this impact is therefore as presented in paragraphs 400 and 401.
  2. Based on the information presented here, it can be concluded that the cumulative alteration of seabed habitat arising from effects of physical processes during the Proposed Development operation and maintenance phase will not lead to a significant risk of hindering the achievement of the conservation objectives for this feature of the Firth of Forth Banks Complex MPA (i.e. “maintain in favourable condition”) for the following reasons:
  • While the cumulative alteration of seabed habitat arising from effects of physical processes is predicted to affect a high limited area of the habitat feature during the operation and maintenance phase the extent and distribution of the protected feature remaining stable;
  • The function will remain in a condition which is healthy and not deteriorating. The limited extent of the change and the maintenance of the physical nature of the feature will ensure that it continues to support its characteristic biological communities and their use of the site for feeding, courtship, spawning, or use as nursery ground; and
  • The supporting processes which enable the formation of these large features and create the necessary environmental conditions to enable its structure and function will be maintained.

Ocean quahog aggregations

  1. As discussed above the cumulative effect of the increased risk of alteration of seabed habitats arising from changes in physical processes is unlikely to change based on the inclusion of Seagreen 1, Seagreen 1A Project, Neart na Gaoithe, and Inch Cape offshore wind farms and Seagreen 1A Export Cable Corridor, therefore refer to paragraphs 407 to 409 for details of the assessment and the sensitivity of ocean quahog aggregations to this impact.
  2. Based on the information presented here, it can be concluded that the cumulative alteration of seabed habitat arising from effects of physical processes during the Proposed Development operation and maintenance phase will not lead to a significant risk of hindering the achievement of the conservation objectives for the ocean quahog aggregations feature of the Firth of Forth Banks Complex MPA (i.e. “recover to favourable condition”) for the following reasons:
  • Cumulative alteration of seabed habitat arising from changes to physical processes is predicted to affect only a small proportion of supporting habitat for ocean quahog during the operation and maintenance phase, thus ensuring that the quality and quantity of ocean quahog habitat is maintained. Whilst some ocean quahog individuals may be directly affected by localised and minor changes to physical processes as a result of the presence of offshore wind farm infrastructure, this is predicted to be to an extent that will not affect the composition of its population in terms of number, age and sex ratio or its ability to thrive in the future.

Impacts to Benthic Invertebrates from EMF