6.4.4. Disturbance due to Site-Investigation Surveys (Including Geophysical Surveys)

The LSE2 assessment during the HRA Stage One process identified that LSE2 could not be ruled out for disturbance due to site investigation surveys (including geophysical surveys) in the construction and operation and maintenance phases of the Array in-combination with other plans and projects. This relates to the following sites and relevant Annex II marine mammal features:

Berwickshire and North Northumberland Coast SAC;

– grey seal.

Southern North Sea SAC; and

– harbour porpoise.

Moray Firth SAC;

– bottlenose dolphin.

The risk of injury in terms of PTS to marine mammal receptors as a result of underwater noise due to site-investigation surveys would be expected to be localised to within the boundaries of the respective projects. The assessment for the Array alone found that the maximum impact range was 310 m for geophysical surveys and 45 m for geotechnical surveys (based on harbour porpoise) and this highly localised, with numbers of animals impacted will be extremely low (section 6.3.3). Furthermore, any risk of injury will be mitigated via the MMMP (volume 4, appendix 22 of the Array EIA Report) and there will no potential for in-combination injury. The in-combination assessment provided in this section therefore focuses on disturbance only.
The MDS considered for this in-combination assessment is shown in Table 6.73 Open ▸ . The designed in measures are presented in Table 6.33 Open ▸ for the assessment of the Array alone.

Table 6.73: MDS Considered for the Assessment of Potential Impacts to Annex II Marine Mammals due to Disturbance due to Site-Investigation Surveys in the Construction and Operation and Maintenance Phases of the Array In-Combination with other Plans and Projects

Project Phase	Tier	MDS
Construction and operation and maintenance phases	1	Construction Phase MDS as described for the construction phase in Table 6.32 Open ▸ , assessed cumulatively with construction of the following marine projects within the 50 km search buffer: Ossian Proposed offshore export cable corridor(s). Operation and Maintenance Phase MDS as described for the operation and maintenance phase in Table 6.32 Open ▸ , assessed cumulatively with operational phase of the following marine projects within the 50 km search buffer: Proposed offshore export cable corridor(s).
2	Construction Phase MDS as described for the construction phase in Table 6.32 Open ▸ ,assessed cumulatively with construction of the following marine projects within the 50 km search buffer: Morven Offshore Wind Farm; and Tier 1 Projects. Operation and Maintenance Phase There are currently no known projects which will result in a cumulative effect during the operation and maintenance phase of the Array.
3	Construction Phase The MDS is as described above for the Array alone in Table 6.32 Open ▸ , assessed in-combination with construction of the following projects within the 50 km search buffer: Bellrock Offshore Wind Farm; Bowdun Offshore Wind Farm; Campion Offshore Wind Farm; Morven Offshore Export Cable Corridor(s); and Tier 1 Projects and Tier 2 Projects. Operation and Maintenance Phase There are currently no known projects which will result in a cumulative effect during the operation and maintenance phase of the Array.

Project Phase

Tier

MDS

Construction and operation and maintenance phases

Construction Phase

MDS as described for the construction phase in Table 6.32 Open ▸ , assessed cumulatively with construction of the following marine projects within the 50 km search buffer:

Ossian Proposed offshore export cable corridor(s).

Operation and Maintenance Phase

MDS as described for the operation and maintenance phase in Table 6.32 Open ▸ , assessed cumulatively with operational phase of the following marine projects within the 50 km search buffer:

Proposed offshore export cable corridor(s).

Construction Phase

MDS as described for the construction phase in Table 6.32 Open ▸ ,assessed cumulatively with construction of the following marine projects within the 50 km search buffer:

Morven Offshore Wind Farm; and
Tier 1 Projects.

Operation and Maintenance Phase

There are currently no known projects which will result in a cumulative effect during the operation and maintenance phase of the Array.

Construction Phase

The MDS is as described above for the Array alone in Table 6.32 Open ▸ , assessed in-combination with construction of the following projects within the 50 km search buffer:

Bellrock Offshore Wind Farm;
Bowdun Offshore Wind Farm;
Campion Offshore Wind Farm;
Morven Offshore Export Cable Corridor(s); and
Tier 1 Projects and Tier 2 Projects.

Operation and Maintenance Phase

There are currently no known projects which will result in a cumulative effect during the operation and maintenance phase of the Array.

In-combination assessment

There is the potential for in-combination impacts from site-investigation surveys in the construction and operation and maintenance phases of the Array and other plans and projects. For the purposes of this assessment, this potential impact has been assessed using the tiered approach outlined in section 4.6. The plans and projects screened into the in-combination assessment for this potential impact and their respective tiers are outlined in Table 6.73 Open ▸ .

Tier 1

One Tier 1 project was identified with potential for in-combination effects associated with this potential impact within the 50 km buffer, during the construction and operation and maintenance phases:

Proposed offshore export cable corridor(s) (construction and operation and maintenance phases) ( Table 6.73 Open ▸ ).

As discussed in section 4.6, there is uncertainty of the final design and location details of the Proposed offshore export cable corridor(s) and therefore it is not possible to provide a quantitative assessment of the in-combination impact from site-investigation surveys. It can be reasonably assumed the extent of the impacts for the Proposed offshore export cable corridor(s) are expected to be similar to those of the Array alone (see section 6.3.3), as, whilst the geographical location of the geophysical survey areas of other projects will differ, the extent of the disturbance per survey equipment at any one point will likely be very similar. The construction phase (and associated pre-construction surveys) of the Proposed offshore export cable corridor(s) (2030 to 2037) overlaps with that of the Array and therefore there is the potential for temporal overlap in site-investigation surveys. However, it should be noted that site-investigation survey equipment will not be operating continuously, it will be used when required for investigations of particular areas of the seabed where additional information is required to inform the construction. Site-investigation surveys for Proposed offshore export cable corridor(s) are likely to be carried out at the start of the construction phase (2030) and therefore direct overlap with the site-investigation surveys for the Array is unlikely (particularly given the need for limited resource to undertake site-investigation surveys).
For the Array alone, the maximum disturbance range across all geophysical surveys was estimated as 1,340 m (SBP) activity and the maximum range across geotechnical activities was 9,101 m (vibrocoring) for all species (see section 6.3.3). Given that the distance between the Array and the Proposed offshore export cable corridor(s) is less than the estimated disturbance ranges from geophysical surveys, there is potential for spatial overlap. However, the likelihood of temporal overlap of site investigation surveys at these projects is very low, and it is therefore unlikely, due to the temporal separation, that site-investigation surveys at the Array and Proposed offshore export cable corridor(s) will spatially overlap at any one time.
Site-investigation surveys are anticipated to be short term in nature (weeks to a few months) and occur intermittently over the construction phase. For example, the site-investigation surveys for the Array will be carried out over 5 months within a 3 year period.
This potential impact has also been considered for the operation and maintenance phase. For the Array, routine geophysical surveys will take place once every 24 months for wind turbines and OSP foundations as well as wind turbines interior and exterior. For inter-array cables and interconnector cables routine geophysical surveys will be undertaken annually for the first three years, then every 24 months. The duration of routine geophysical survey campaign is up to three months. It is possible that routine geophysical surveys for the Proposed offshore export cable corridor(s) will be similar to those of the inter-array cables and interconnector cables for the Array and therefore, there is potential for geophysical surveys during the operation and maintenance phase to temporally overlap with the Proposed offshore export cable corridor(s). As for the construction phase, surveys are anticipated to be short term in nature (weeks to a few months) and occur intermittently over the operation and maintenance phase.
For construction and operation and maintenance activities, it is likely that the Proposed offshore export cable corridor(s) will also include an MMMP as a designed in measure, similar to that adopted for the Array alone ( Table 6.33 Open ▸ ). While this primarily mitigates against injury (which has not been assessed in-combination, see paragraph 895) it will also aid in reducing disturbance to marine mammals. In addition, this potential impact is of high reversibility, with animals returning to baseline levels shortly after surveys have ceased. As such, and in consideration of the potential designed in measure of an MMMP, population-level effects associated with this potential impact are unlikely for the marine mammal features of the SACs.

Tier 2

In addition to Tier 1 projects, one Tier 2 project was identified with potential for in-combination effects associated with this impact, which lies within the 50 km buffer used for site-investigation surveys:

Morven Offshore Wind Farm ( Table 6.73 Open ▸ ).

Disturbance to marine mammals from pre-construction site-investigation surveys is scoped in for Morven Offshore Wind Farm (Morven Offshore Wind Limited, 2023). The Scoping Report details comparative sound modelling for geophysical activities will be undertaken to inform an assessment of possible effects from elevated levels of underwater noise. At this point in time, there is not quantitative information upon which to take a more detailed assessment of site-investigation surveys. The site boundary lies, at the closest point, 5.5 km from the Morven Array and based on the maximum disturbance range predicted for the Array (9,101 m for vibrocoring for all species) there is potential for spatial overlap between these two projects for vibrocoring surveys. However, the likelihood of temporal overlap of site investigation surveys at the Array and Morven Offshore Wind Farm is very low (e.g. there are limitations on the number of survey vessels that could carry out such surveys at one time) and it is therefore unlikely, due to the temporal separation, that site-investigation surveys at Morven Offshore Wind Farm would overlap with the area disturbed during site-investigation surveys at the Tier 1 project, Proposed offshore export cable corridor(s) (see paragraph 631 for detail). Within the Morven Offshore Wind farm Scoping Report (Morven Offshore Wind Limited, 2023), this potential impact was not scoped in for the operation and maintenance phase, and has thus not been discussed further in this Tier 2 assessment.
For construction activities, it is likely that Morven Offshore Wind Farm will also include an MMMP as a designed in measure, similar to that adopted for the Array alone ( Table 6.33 Open ▸ ). While this primarily mitigates against injury (which has not been assessed in-combination, see paragraph 895) it will also aid in reducing disturbance to marine mammals. In addition, behavioural disturbance is of high reversibility, with animals returning to baseline levels shortly after surveys have ceased. As such, and in consideration of the potential designed in measure of an MMMP, population-level effects associated with this potential impact are considered unlikely for the marine mammal features of the SACs.

Tier 3

Four Tier 3 projects were identified with potential for in-combination effects associated with this impact, which lie within the 50 km buffer used for site-investigation surveys:

Bellrock Offshore Wind Farm;
Bowdun Offshore Wind Farm;
Campion Offshore Wind Farm;
Morven Offshore Export Cable Corridor(s) ( Table 6.73 Open ▸ ).

Tier 3 projects are in a pre-application phase and no EIA Scoping Report, EIA Report, or HRA documentation are available to inform a quantitative assessment. Therefore, a qualitative assessment is provided below.
Whilst there is no information on the timeline for construction at Bellrock Offshore Wind Farm and therefore it cannot be excluded from the in-combination assessment, the likelihood of direct temporal overlap with site-investigation surveys at Bellrock Offshore Wind Farm and the Array is unlikely given the different stages of status of development. Furthermore, surveys are likely to be short term and intermittent and disturbance ranges associated with these projects would be highly localised. Bellrock Offshore Wind Farm is located 8.57 km north-west from the Array and therefore site-investigation surveys will have no spatial overlap given the small disturbance ranges presented for the Array assessment (see section 6.3.3).
Whilst there is no information on the timeline for construction at Bowdun Offshore Wind Farm and therefore it cannot be excluded from the in-combination assessment, the likelihood of direct temporal overlap with site-investigation surveys at Bowdun Offshore Wind Farm and the Array is unlikely given the different stages of status of development. Furthermore, surveys are likely to be short term and intermittent and disturbance ranges associated with these projects would be highly localised. Bowdun Offshore Wind Farm is located 25.35 km north-west from the Array and therefore site-investigation surveys will have no spatial overlap given the small disturbance ranges presented for the Array assessment (see section 6.3.3).
The likelihood of direct temporal overlap with site-investigation surveys at Campion Offshore Wind and the Array is unlikely given the different stages of status of development. Furthermore, surveys are likely to be short term and intermittent and disturbance ranges associated with these projects would be highly localised. Campion Offshore Wind Farm is located 44.15 km north-east from the Array and therefore site-investigation surveys will have no spatial overlap given the small disturbance ranges presented for the Array assessment (see section 6.3.3).
Further, site-investigation surveys associated with the Morven Offshore Export Cable Corridor(s) are likely to occur during its construction phase, however it is unknown whether they will persist over the operation and maintenance phase, as is assumed for the Tier 3 offshore wind farm projects. It is likely that these surveys will be completed prior to those associated with the construction of the Array, however, overlap has been assumed as a precaution.
For site-investigation surveys, it is likely that Tier 3 projects will also include an MMMP as a designed in measure, similar to that adopted for the Array alone ( Table 6.33 Open ▸ ). While this primarily mitigates against injury (which has not been carried forward for assessment in-combination, see paragraph 895) it will also aid in reducing disturbance to marine mammals. In addition, behavioural disturbance is of high reversibility, with animals returning to baseline levels shortly after surveys have ceased. As such, and in consideration of the potential designed in measure of an MMMP, population-level effects associated with this potential impact are unlikely for the marine mammal features of the SACs.

Construction and operation and maintenance phases

Berwickshire and North Northumberland Coast SAC

Grey seal

All Tiers

There was no species or SAC specific information available for any of projects identified for in-combination effects for this impact, therefore all Tiers have been addressed here.
As detailed in paragraphs 898 et seq., site-investigation surveys for the Tiers 1, 2, and 3 projects are expected to be short term in nature and occur intermittently. In addition, behavioural disturbance is of high reversibility, with animals returning to baseline levels shortly after surveys have ceased. As per the values modelled for the Array alone (section 6.3.3), disturbance ranges are likely to be within the metres to low kilometres depending on the survey technique. For the Array alone, the maximum disturbance range across all geophysical surveys was estimated as 1,340 m for SBP activity and the maximum range across geotechnical activities was 9,101 m for vibrocoring) for all species (see Table 6.37 Open ▸ ). Therefore, the potential for in-combination effects is reduced, particularly for projects that are tens of kilometres away from the site boundary (such as Bowdun and Campion Offshore Wind Farms in Tier 3). In-combination behavioural disturbance ranges are therefore highly unlikely to overlap with the Berwickshire and North Northumberland Coast SAC, which is a minimum of 113.95 km south-west from the site boundary.
For construction and operation and maintenance activities, it is likely that the Tier 1, 2, and 3 projects will also include an MMMP as a designed in measure, similar to that adopted for the Array alone ( Table 6.33 Open ▸ ). As such, and in consideration of the potential designed in measure of an MMMP, population-level effects associated with this potential impact are unlikely for the grey seal feature of this SAC.

Conclusion

Adverse effects on the qualifying Annex II marine mammal features of the Berwickshire and North Northumberland Coast SAC which undermine the conservation objectives of the SAC will not occur as a result of in-combination disturbance due to site-investigation surveys during the construction and operation and maintenance phases. Potential effects from this activity on the relevant conservation objectives (as presented in section 6.2.1) are discussed in turn below in Table 6.74 Open ▸ .

Table 6.74: Conclusions Against the Conservation Objectives of the Berwickshire and North Northumberland Coast SAC from Disturbance due to Site-Investigation Surveys (Including Geophysical Surveys) during the Construction and Operation and Maintenance Phases of the Array In-Combination with other Plans and Projects

Feature	Conservation Objectives (Natural England, 2020)	Conclusion
Grey seal	The extent and distribution of qualifying natural habitat and habitats of the qualifying species are maintained	There is no pathway for potential impact between site-investigation surveys and the extent, distribution, structure, and function of the habitats and supporting processes of grey seal (i.e. no overlap with the area of significant disturbance with the SAC). Therefore, the extent, distribution, structure, and function of the habitats and supporting processes of grey seal will not be adversely affected by site-investigation surveys from the Array in-combination with the Tier 1, 2, and 3 projects.
	The structure and function of the habitats of the qualifying species are maintained
	The supporting processes on which qualifying natural habitats and the habitats of qualifying species rely are maintained
	The populations of each of the qualifying species are maintained	Overall, site-investigation surveys in the construction and operation and maintenance phases of the Array in-combination with other plans and projects are unlikely to lead to strong behavioural responses to grey seal. There were no disturbance ranges available for any of the Tier 1, 2, or 3 projects, however the maximum disturbance range modelled for the Array alone was 9,101 m for vibrocoring ( Table 6.37 Open ▸ ). Given the scale and nature of the Tier 1, 2, and 3 projects (other offshore wind farms and a subsea transmission cable), disturbance ranges are likely to be similar to those modelled for the Array alone. Therefore, it is unlikely that disturbance ranges will extend to the SAC (113.95 km away) and therefore animals are unlikely to experience significant disturbance within the site. Site-investigation surveys will therefore not affect areas important for breeding and pupping within the SAC, and therefore grey seal will remain a viable component of the site. Overall, including the implementation of designed in mitigation measures, site-investigation surveys associated with the Array in-combination with other plans and projects are not predicted to prevent the population or distribution of grey seal within the site from being maintained.
	The distribution of qualifying species within the site are maintained

It can be concluded, beyond reasonable scientific doubt, that there is no risk of an adverse effect on the integrity of the Berwickshire and North Northumberland Coast SAC as a result of disturbance due to site-investigation surveys during the construction and operation and maintenance phases of the Array in-combination with other plans and projects.

Southern North Sea SAC

Harbour porpoise

All Tiers

There was no species or SAC specific information available for any of projects identified for in-combination affects for this impact, therefore all Tiers have been addressed here.
As detailed in paragraphs 898 et seq., site-investigation surveys for the Tiers 1, 2, and 3 projects are expected to be short term in nature and occur intermittently. In addition, this potential impact is of high reversibility, with animals returning to baseline levels shortly after surveys have ceased. As per the values modelled for the Array alone (section 6.3.3), disturbance ranges are likely to be within the metres to low kilometres depending on the survey technique. For the Array alone, the maximum disturbance range across all geophysical surveys was estimated as 1,340 m for SBP activity and the maximum range across geotechnical activities was 9,101 m for vibrocoring) for all species (see Table 6.37 Open ▸ ). Therefore, the potential for in-combination effects is reduced, particularly for projects that are tens of kilometres away from the site boundary (such as Bowdun and Campion Offshore Wind Farms in Tier 3). In-combination behavioural disturbance ranges are therefore highly unlikely to overlap with the Southern North Sea SAC, which is a minimum of 129.86 km south-east from the site boundary.
For construction and operation and maintenance activities, it is likely that the Tier 1, 2, and 3 projects will also include an MMMP as a designed in measure, similar to that adopted for the Array alone ( Table 6.33 Open ▸ ). As such, and in consideration of the potential designed in measure of an MMMP, population-level effects associated with this potential impact are unlikely for the harbour porpoise feature of this SAC.

Conclusion

Adverse effects on the qualifying Annex II marine mammal features of the Southern North Sea SAC which undermine the conservation objectives of the SAC will not occur as a result of in-combination disturbance due to site-investigation surveys during the construction and operation and maintenance phases. Potential effects from this activity on the relevant conservation objectives (as presented in section 6.2.2) are discussed in turn below in Table 6.75 Open ▸ .

Table 6.75: Conclusions Against the Conservation Objectives of the Southern North Sea SAC from Disturbance due to Site-Investigation Surveys (Including Geophysical Surveys) during the Construction and Operation and Maintenance Phases of the Array In-Combination with other Plans and Projects

Feature	Conservation Objectives (JNCC and Natural England, 2019)	Conclusion
Harbour porpoise	1. Harbour porpoise is a viable component of the site	Overall, site-investigation surveys in the construction and operation and maintenance phases of the Array in-combination with other plans and projects are unlikely to lead to strong behavioural responses to harbour porpoise. There were no disturbance ranges available for any of the Tier 1, 2, or 3 projects, however the maximum disturbance range modelled for the Array alone was 9,101 m for vibrocoring ( Table 6.37 Open ▸ ). Given the scale and nature of the Tier 1, 2, and 3 projects (other offshore wind farms and a subsea transmission cable), disturbance ranges are likely to be similar to those modelled for the Array alone. Therefore, it is unlikely that disturbance ranges will extend to the SAC (129.86 km away) and therefore animals are unlikely to experience significant disturbance within the site. Site-investigation surveys will therefore not affect areas important for breeding and calving within the SAC, and therefore harbour porpoise will remain a viable component of the site. Overall, including the implementation of designed in mitigation measures, site-investigation surveys associated with the Array in-combination with other plans and projects are not predicted to impact the population from being able to maintain itself as a viable component of the site over the long term.
	2. There is no significant disturbance of the species	As noted in the row above, given that in-combination disturbance ranges are unlikely to extend to the site (129.86 km away), it is anticipated that there will be no significant disturbance to the harbour porpoise feature of the site.
	3. The condition of supporting habitats and processes, and the availability of prey is maintained	There is no pathway for potential impact between site-investigation surveys and the habitats and supporting processes of harbour porpoise. With respect to the availability of prey, long term effects were not predicted (see volume 2, chapter 9 of the Array EIA Report and the assessment of ‘Changes in prey availability’ in section 6.4.5), therefore prey species populations are expected to be maintained in the long term. Therefore, the condition of habitats and species required to support harbour porpoise will not be adversely affected by this potential impact from the Array in-combination with the Tier 1, 2, and 3 projects.

It can be concluded, beyond reasonable scientific doubt, that there is no risk of an adverse effect on the integrity of the Southern North Sea SAC as a result of disturbance due to site-investigation surveys during the construction and operation and maintenance phases of the Array in-combination with other plans and projects.

Moray Firth SAC

Bottlenose dolphin

All Tiers

There was no species or SAC specific information available for any of projects identified for in-combination affects for this impact, therefore all Tiers have been addressed here.
As detailed in paragraphs 898 et seq., site-investigation surveys for the Tiers 1, 2, and 3 projects are expected to be short term in nature and occur intermittently. In addition, this potential impact is of high reversibility, with animals returning to baseline levels shortly after surveys have ceased. As per the values modelled for the Array alone (section 6.3.3), disturbance ranges are likely to be within the metres to low kilometres depending on the survey technique. For the Array alone, the maximum disturbance range across all geophysical surveys was estimated as 1,340 m for SBP activity and the maximum range across geotechnical activities was 9,101 m for vibrocoring) for all species (see Table 6.37 Open ▸ ). Therefore, the potential for in-combination effects is reduced, particularly for projects that are tens of kilometres away from the site boundary (such as Bowdun and Campion Offshore Wind Farms in Tier 3). In-combination behavioural disturbance ranges are therefore highly unlikely to overlap with the Moray Firth SAC, which is a minimum of 175.86 km north-west from the site boundary.
For construction and operation and maintenance activities, it is likely that the Tier 1, 2, and 3 projects will also include an MMMP as a designed in measure, similar to that adopted for the Array alone ( Table 6.33 Open ▸ ). As such, and in consideration of the potential designed in measure of an MMMP, population-level effects associated with this potential impact are unlikely for the bottlenose dolphin feature of this SAC.

Conclusion

Adverse effects on the qualifying Annex II marine mammal features of the Moray Firth SAC which undermine the conservation objectives of the SAC will not occur as a result of in-combination disturbance due to site-investigation surveys during the construction and operation and maintenance phases. Potential effects from this activity on the relevant conservation objectives (as presented in section 6.2.3) are discussed in turn below in Table 6.76 Open ▸ .

Table 6.76: Conclusions Against the Conservation Objectives of the Moray Firth SAC from Disturbance due to Site-Investigation Surveys (Including Geophysical Surveys) during the Construction and Operation and Maintenance Phases of the Array In-Combination with other Plans and Projects

Feature	Conservation Objectives (NatureScot, 2021)	Conclusion
Bottlenose dolphin	2a. The population of bottlenose dolphin is a viable component of the site	Overall, site-investigation surveys in the construction and operation and maintenance phases of the Array in-combination with other plans and projects are unlikely to lead to strong behavioural responses to bottlenose dolphin. There were no disturbance ranges available for any of the Tier 1, 2, or 3 projects, however the maximum disturbance range modelled for the Array alone was 9,101 m for vibrocoring ( Table 6.37 Open ▸ ). Given the scale and nature of the Tier 1, 2, and 3 projects (other offshore wind farms and a subsea transmission cable), disturbance ranges are likely to be similar to those modelled for the Array alone. Therefore, it is unlikely that disturbance ranges will extend to the SAC (175.86 km away) and therefore animals are unlikely to experience significant disturbance within the site. Site-investigation surveys will therefore not affect areas important for breeding and calving within the SAC, and therefore bottlenose dolphin will remain a viable component of the site. Overall, including the implementation of designed in mitigation measures, site-investigation surveys associated with the Array in-combination with other plans and projects are not predicted to impact the population from being able to maintain itself as a viable component of the site.
2b. The distribution of bottlenose dolphin throughout the site is maintained by avoiding significant disturbance	As noted in the row above, given that in-combination disturbance ranges are unlikely to extend to the site (175.86 km away), it is anticipated that there will be no significant disturbance to the bottlenose dolphin feature of the site.
2c. The supporting habitats and processes relevant to bottlenose dolphin and the availability of prey for bottlenose dolphin are maintained	There is no pathway for potential impact between this potential impact and the habitats and supporting processes of bottlenose dolphin. With respect to the availability of prey, long term effects were not predicted (see volume 2, chapter 9 of the Array EIA Report and the assessment of ‘Changes in prey availability’ in section 6.4.5), therefore prey species populations are expected to be maintained in the long term. Therefore, the condition of habitats and species required to support bottlenose dolphin will not be adversely affected by this impact.

Feature

Conservation Objectives (NatureScot, 2021)

Conclusion

Bottlenose dolphin

2a. The population of bottlenose dolphin is a viable component of the site

Overall, site-investigation surveys in the construction and operation and maintenance phases of the Array in-combination with other plans and projects are unlikely to lead to strong behavioural responses to bottlenose dolphin. There were no disturbance ranges available for any of the Tier 1, 2, or 3 projects, however the maximum disturbance range modelled for the Array alone was 9,101 m for vibrocoring ( Table 6.37 Open ▸ ). Given the scale and nature of the Tier 1, 2, and 3 projects (other offshore wind farms and a subsea transmission cable), disturbance ranges are likely to be similar to those modelled for the Array alone. Therefore, it is unlikely that disturbance ranges will extend to the SAC (175.86 km away) and therefore animals are unlikely to experience significant disturbance within the site. Site-investigation surveys will therefore not affect areas important for breeding and calving within the SAC, and therefore bottlenose dolphin will remain a viable component of the site. Overall, including the implementation of designed in mitigation measures, site-investigation surveys associated with the Array in-combination with other plans and projects are not predicted to impact the population from being able to maintain itself as a viable component of the site.

2b. The distribution of bottlenose dolphin throughout the site is maintained by avoiding significant disturbance

As noted in the row above, given that in-combination disturbance ranges are unlikely to extend to the site (175.86 km away), it is anticipated that there will be no significant disturbance to the bottlenose dolphin feature of the site.

2c. The supporting habitats and processes relevant to bottlenose dolphin and the availability of prey for bottlenose dolphin are maintained

There is no pathway for potential impact between this potential impact and the habitats and supporting processes of bottlenose dolphin. With respect to the availability of prey, long term effects were not predicted (see volume 2, chapter 9 of the Array EIA Report and the assessment of ‘Changes in prey availability’ in section 6.4.5), therefore prey species populations are expected to be maintained in the long term. Therefore, the condition of habitats and species required to support bottlenose dolphin will not be adversely affected by this impact.

It can be concluded, beyond reasonable scientific doubt, that there is no risk of an adverse effect on the integrity of the Moray Firth SAC as a result of disturbance due to site-investigation surveys during the construction and operation and maintenance phases of the Array in-combination with other plans and projects.

6.4.5. Changes in Prey Availability

The LSE2 assessment during the HRA Stage One process identified that LSE2 could not be ruled out for changes in prey availability due to underwater noise from piling and UXO clearance in the construction phase of the Array in-combination with other plans and projects. This relates to the following sites and relevant Annex II marine mammal features:

Berwickshire and North Northumberland Coast SAC;

– grey seal.

Southern North Sea SAC; and

– harbour porpoise.

Moray Firth SAC;

– bottlenose dolphin.

The MDS considered for this in-combination assessment is shown in Table 6.77 Open ▸ . The designed in measures are presented in Table 6.43 Open ▸ for the assessment of the Array alone.

Table 6.77: MDS Considered for the Assessment of Potential Impacts to Annex II Marine Mammals due to Changes in Prey Availability in the Construction Phase of the Array In-Combination with other Plans and Projects

Project Phase	Tier	MDS
Construction	1	The MDS is as described above for the Array alone ( Table 6.42 Open ▸ ) has been assessed in-combination with the following plans and projects: Construction Phase Proposed offshore export cable corridor(s); and Berwick Bank Offshore Wind Farm.
2	The MDS is as described above for the Array alone ( Table 6.42 Open ▸ ) and has been assessed in-combination with the following plans and projects: Construction Phase Morven Offshore Wind Farm; Cenos Offshore Wind Farm; Salamander Offshore Wind Farm; and Tier 1 projects.
3	The MDS is as described above for the Array alone ( Table 6.42 Open ▸ ) and has been assessed in-combination with the following plans and projects: Construction Phase Morven Offshore Export Cable Corridor(s); Bellrock Offshore Wind Farm; Bowdun Offshore Wind Farm; Campion Offshore Wind Farm; Cedar Offshore Wind Farm; Flora Floating Wind Farm; Aspen Offshore Wind Farm; and Tier 1 and Tier 2 projects.

Project Phase

Tier

MDS

Construction

The MDS is as described above for the Array alone ( Table 6.42 Open ▸ ) has been assessed in-combination with the following plans and projects:

Construction Phase

Proposed offshore export cable corridor(s); and
Berwick Bank Offshore Wind Farm.

The MDS is as described above for the Array alone ( Table 6.42 Open ▸ ) and has been assessed in-combination with the following plans and projects:

Construction Phase

Morven Offshore Wind Farm;
Cenos Offshore Wind Farm;
Salamander Offshore Wind Farm; and
Tier 1 projects.

The MDS is as described above for the Array alone ( Table 6.42 Open ▸ ) and has been assessed in-combination with the following plans and projects:

Construction Phase

Morven Offshore Export Cable Corridor(s);
Bellrock Offshore Wind Farm;
Bowdun Offshore Wind Farm;
Campion Offshore Wind Farm;
Cedar Offshore Wind Farm;
Flora Floating Wind Farm;
Aspen Offshore Wind Farm; and
Tier 1 and Tier 2 projects.

In-combination assessment

There is the potential for in-combination impacts due to changes in prey availability in the construction phase of the Array and other plans and projects. For the purposes of this assessment, this potential impact has been assessed using the tiered approach outlined in section 4.6. The plans and projects screened into the in-combination assessment for this potential impact and their respective tiers are outlined in Table 6.77 Open ▸ .
As concluded in the Array HRA Stage One LSE2 Screening Report (Array RIAA Part 1, appendix 1A) Annex II grey seal, harbour porpoise, and bottlenose dolphin are likely to be present within the Array marine mammal study area and may forage within the area. Effects on prey fish populations across all phases of the Array alone, and in-combination with other plans and projects, are likely to be temporary, of a short duration, localised and not significant (as per the conclusions presented for the assessment on Annex II diadromous fish; section 5.3). The widest ranging effect was concluded to be of increased underwater noise during the construction phase (mainly due to piling) and is unlikely to be significant in other phases (Array RIAA Part 1, appendix 1A). However, as impacts to prey species have been assessed as part of the underwater noise modelling assessment that has been undertaken for the EIA, this potential impact was included for the construction phase in the in-combination assessment as a precaution for the Annex II marine mammal features of their respective SACs.

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