14 Conclusion of the Assessment

1772         A summary of the assessment presented in this Part Two of the RIAA, considering SACs, is provided below and in Table 14.1   Open ▸ . Table 14.1   Open ▸ presents the conclusions of Adverse Effects on Integrity in relation to the Proposed Development alone and in-combination with other plans and projects.

Berwickshire and North Northumberland Coast SAC

1773         Based on the information presented in sections 11 and 13, no Adverse Effect on Integrity on the Berwickshire and North Northumberland Coast SAC, with specific regard to the qualifying Annex I habitats and Annex II marine mammals for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

Tweed Estuary SAC

1774         Based on the information presented in section 12, no Adverse Effect on Integrity on the Tweed Estaury SAC, with specific regard to the qualifying Annex II diadromous fish for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

River Tweed SAC

1775         Based on the information presented in section 12, no Adverse Effect on Integrity on the River Tweed SAC, with specific regard to the qualifying Annex II diadromous fish for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

River South Esk SAC

1776         Based on the information presented in section 12, no Adverse Effect on Integrity on the River Tweed SAC, with specific regard to the qualifying Annex II diadromous fish, and dependant qualifying species (i.e. freshwater pearl mussel), for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

River Tay SAC

1777         Based on the information presented in section 12, no Adverse Effect on Integrity on the River Tay SAC, with specific regard to the qualifying Annex II diadromous fish for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

River Dee SAC

1778         Based on the information presented in section 12, no Adverse Effect on Integrity on the River Dee SAC, with specific regard to the qualifying Annex II diadromous fish, and dependant qualifying species (i.e. freshwater pearl mussel), for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

River Tay SAC

1779         Based on the information presented in section 12, no Adverse Effect on Integrity on the River Teith SAC, with specific regard to the qualifying Annex II diadromous fish for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

Isle of May SAC

1780         Based on the information presented in section 13, no Adverse Effect on Integrity on the Isle of May SAC, with specific regard to the qualifying Annex II marine mammals for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

Firth of Tay and Eden Estuary SAC

1781         Based on the information presented in section 13, no Adverse Effect on Integrity on the Firth of Tay and Eden Estuary SAC, with specific regard to the qualifying Annex II marine mammals for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

Southern North Sea SAC

1782         Based on the information presented in section 13, no Adverse Effect on Integrity on the Southern North Sea SAC, with specific regard to the qualifying Annex II marine mammals for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

Moray Firth SAC

1783         Based on the information presented in section 13, no Adverse Effect on Integrity on the Southern North Sea SAC, with specific regard to the qualifying Annex II marine mammals for which LSE could not be excluded, is predicted as a result of the Proposed Development, either alone or in-combination with other plans and projects.

Table 14.1: Summary of Conclusions of Adverse Effect on Integrity for SACs

15 Integrity Matrices

1784         This section presents the HRA integrity matrices for the Proposed Development and summarises the information presented in Part Two of the RIAA for SACs. Section 15.2 presents the integrity matrices for SACs designated for Annex I (coastal and subtidal) habitats, section 15.3 presents the integrity matrices for SACs designated for Annex II diadromous fish and section 15.4 presents the integrity matrices for SACs designated for Annex II marine mammals.

15.2 Integrity Matrices for Site Designated for Annex I Habitats

Table 15.1: Integrity Matrix for Annex I Habitats of the Berwickshire and North Northumberland Coast SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Increases in SSC and sediment deposition – the Berwickshire and North Northumberland Coast SAC is located 4.1 km from the Proposed Development export cable corridor at the closest point, therefore the effects resulting from changes to water quality and light smothering and siltation rate change, arising from pre-installation sand wave clearance and installation of the offshore export cables, are likely to be reduced due to dilution. Additionally, the qualifying Annex I habitats mudflats and sandflats not covered by seawater at low tide, and large shallow inlets and bays are concentrated in the English part of the SAC beyond the limit of the predicted maximum extent (10 km) for fine sediment. Sedimentation at the coastline is predicted to be low and typically <3 mm. Suspended sediment concentrations are predicted to reduce to background levels on slack tides. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II habitat qualifying interest features of the site during the construction and decommissioning phases.

b: Increases in SSC and sediment deposition – the impact of increased SSC and associated sediment deposition resulting from offshore export cable maintenance activities will be the same or less than those predicted for construction and decommissioning. Additionally, the qualifying Annex I habitats mudflats and sandflats not covered by seawater at low tide, and large shallow inlets and bays are concentrated in the English part of the SAC beyond the limit of the predicted maximum extent (10 km) for fines. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II habitat qualifying interest features of the site during the operation and maintenance phase.

c: Changes in Physical Processes – modelling has demonstrated that effects on tidal flows will not reach the Berwickshire and North Northumberland Coast SAC. Any impacts on tidal flow and wave climate are predicted to be localised around the array structures. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II habitat qualifying interest features of the site during the operation and maintenance phase.

d: In-combination – the in-combination assessment considered the potential for increases in SSC and associated sediment deposition, and alteration of seabed habitats arising from effects of physical processes, arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. Any increases in SSC from these projects are unlikely to interact or be of negligible magnitude and changes in physical processes 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. It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II habitat qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.

15.3 Integrity Matrices for Site Designated for Annex II Diadromous Fish

Table 15.2: Integrity Matrix for Annex II Diadromous Fish Species of the Tweed Estuary SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Injury and/or disturbance from underwater noise – For peak pressure noise levels when piling energy is at its maximum (i.e.4,000 kJ), mortal injury and recoverable injury ranges for sea lamprey and river lamprey may occur within approximately 138 m of the piling. For cumulative SEL, injury ranges calculated for piling activities indicate that, with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for peak sound pressure levels. Thresholds for mortality and recoverable injury for sea lamprey and river lamprey for both the maximum energy scenario and realistic hammer energy scenario were not exceeded. During UXO clearance, mortality/mortal injury for all fish would occur within a range of 30-45 m from the source following low order detonation. In the event of a high-order detonation event mortality would occur within 410-680 m of the noise source. The use of soft start piling procedures, allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on sea lamprey and river lamprey. Behavioural impacts, whilst expected over a larger range, are unlikely to cause a barrier to the migration routes of sea lamprey along the east coast of Scotland. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning phases as a result of underwater noise.

b: SSC and associated sediment deposition – modelling has indicated that increases in SSC are predicted to be temporary, short-lived and at levels well below those naturally experienced in estuarine environments. Additionally, sea lamprey are expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development. As such, no barriers to the migratory patterns of sea lamprey are expected. River lamprey have a preference for estuarine waters, so it is unlikely that this species lamprey will interact with SSC and sediment deposition arising from the construction and decommissioning of the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning phases as a result of SSC and associated sediment deposition.

c: EMF – emission of localised EMFs from the operation of cables could potentially interfere with the navigation of diadromous fish species. However, the limited available evidence suggests that disturbance to sea lamprey from EMF occurs at intensities considerably higher than those expected from AC subsea cables. Due to sea lamprey's parasitic nature at sea, attaching to the body of larger, highly mobile species, well above the seafloor also means that they can be expected to rarely be exposed to the EMF at the lowest levels from AC undersea power cables buried in the seafloor. Therefore, any impacts would be localised and transient. Given river lamprey's preference for estuarine waters, it is unlikely that river lamprey will interact with cables associated with the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the operation and maintenance phases as a result of EMF.

d: Colonisation of foundations, scour protection and cable protection – colonisation of foundations, scour protection and cable protection, has the potential to result in increased predation on diadromous fish species by marine mammal species. Sea lamprey are parasitic in their marine phase, feeding off larger fish and marine mammals, so it is not expected that they will be particularly attracted to structures associated with offshore wind developments. Sea lamprey that are likely to interact with the Proposed Development are only likely to do so whilst passing through the area during migrations to and from rivers located on the east coast of Scotland. As such significant predation on sea lamprey is not expected. Given river lamprey's preference for estuarine waters, it is unlikely that river lamprey will interact with structures associated with the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the operation and maintenance phases as a result of colonisation of structures.

e: In-combination – the in-combination assessment considered the potential for underwater noise, increases in SSC and associated sediment deposition, EMF and colonisation of structures arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. In-combination effects as a result of injury and/or disturbance from underwater noise and vibration during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the limited range over which injury effects may occur due to piling activities (i.e. tens to hundreds of metres), mitigation to minimise the potential for injury and the minor overlap in construction phases of the Proposed Development and other projects. In-combination effects as a result of increased SSC and sediment deposition during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the fact that activities associated with other projects would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development. In-combination effects as a result of colonisation of hard structures during the operation of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone as diadromous fish spend little time in coastal waters, they are unlikely to utilise the increase in hard substrate for feeding or shelter opportunities, and are therefore at low risk from increased predation, It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.

Table 15.3:  Integrity Matrix for Annex II Diadromous Fish Species of the River Tweed SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Injury and/or disturbance from underwater noise – For peak pressure noise levels when piling energy is at its maximum (i.e.4,000 kJ), mortal injury and recoverable injury ranges for sea lamprey and river lamprey may occur within approximately 138 m of the piling and within 228 m for Atlantic salmon. For cumulative SEL, injury ranges calculated for piling activities indicate that, with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for peak sound pressure levels. Thresholds for mortality and recoverable injury for sea lamprey and river lamprey for both the maximum energy scenario and realistic hammer energy scenario were not exceeded and were predicted to extent to 19 m for Atlantic salmon with a recoverable injury range of 67 m under the maximum energy scenario. TTS, from which animals will recover, was predicted to occur out to a maximum range of 4,161 m for Atlantic salmon, sea lamprey and river lamprey. For concurrent piling, TTS ranges for Atlantic salmon, sea lamprey and river lamprey may be increased to up to 7.1 km from the piling location for the maximum energy scenario. During UXO clearance, mortality/mortal injury for all fish would occur within a range of 30-45 m from the source following low order detonation. In the event of a high-order detonation event mortality would occur within 410-680 m of the noise source. The use of soft start piling procedures, allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on Atlantic salmon, sea lamprey and river lamprey. Behavioural impacts, whilst expected over a larger range, are unlikely to cause a barrier to the migration routes of Atlantic salmon or sea lamprey along the east coast of Scotland. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning phases as a result of underwater noise.

b: SSC and associated sediment deposition – modelling has indicated that increases in SSC are predicted to be temporary, short-lived and at levels well below those naturally experienced in estuarine environments. Additionally, Atlantic salmon and sea lamprey are expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development. As such, no barriers to the migratory patterns of Atlantic salmon or sea lamprey are expected. River lamprey have a preference for estuarine waters, so it is unlikely that this species lamprey will interact with SSC and sediment deposition arising from the construction and decommissioning of the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning phases as a result of SSC and associated sediment deposition.

c: EMF – emission of localised EMFs from the operation of cables could potentially interfere with the navigation of diadromous fish species. However, the limited available evidence suggests that disturbance to sea lamprey from EMF occurs at intensities considerably higher than those expected from AC subsea cables. Due to sea lamprey's parasitic nature at sea, attaching to the body of larger, highly mobile species, well above the seafloor also means that they can be expected to rarely be exposed to the EMF at the lowest levels from AC undersea power cables buried in the seafloor. Therefore, any impacts would be localised and transient. Given that Atlantic salmon is a pelagic species, it is unlikely to swim at depths sufficient to detect levels of EMF that would cause behavioural changes during migration. Any changes in salmonid behaviour, will be temporary and will not interfere with migration success or population health. Given river lamprey's preference for estuarine waters, it is unlikely that river lamprey will interact with cables associated with the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the operation and maintenance phases as a result of EMF.

d: Colonisation of foundations, scour protection and cable protection – colonisation of foundations, scour protection and cable protection, has the potential to result in increased predation on diadromous fish species by marine mammal species. Sea lamprey are parasitic in their marine phase, feeding off larger fish and marine mammals, so it is not expected that they will be particularly attracted to structures associated with offshore wind developments. Sea lamprey that are likely to interact with the Proposed Development are only likely to do so whilst passing through the area during migrations to and from rivers located on the east coast of Scotland. As such significant predation on sea lamprey is not expected. Atlantic salmon smolts spend little time in the coastal waters and make their way to feeding grounds in the north quickly. Evidence also suggests that Atlantic salmon tend not to forage in the coastal waters of Scotland so it is unlikely that they will spend time foraging around wind turbine foundations and therefore are at low risk of impact from increased predation from seals and other predators. Given river lamprey's preference for estuarine waters, it is unlikely that river lamprey will interact with structures associated with the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the operation and maintenance phases as a result of colonisation of structures.

e: In-combination – the in-combination assessment considered the potential for underwater noise, increases in SSC and associated sediment deposition, EMF and colonisation of structures arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. In-combination effects as a result of injury and/or disturbance from underwater noise and vibration during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the limited range over which injury effects may occur due to piling activities (i.e. tens to hundreds of metres), mitigation to minimise the potential for injury and the minor overlap in construction phases of the Proposed Development and other projects. In-combination effects as a result of increased SSC and sediment deposition during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the fact that activities associated with other projects would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development. In-combination effects as a result of colonisation of hard structures during the operation of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone as diadromous fish spend little time in coastal waters, they are unlikely to utilise the increase in hard substrate for feeding or shelter opportunities, and are therefore at low risk from increased predation, It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.

Table 15.4:  Integrity Matrix for Annex II Diadromous Fish (and dependent) Species of the River South Esk SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Injury and/or disturbance from underwater noise – For peak pressure noise levels when piling energy is at its maximum (i.e.4,000 kJ), mortal injury and recoverable injury ranges for sea lamprey and river lamprey may occur within approximately 228 m of the piling for Atlantic salmon. For cumulative SEL, injury ranges calculated for piling activities indicate that, with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for peak sound pressure levels. For cumulative SEL, the modelling indicated a mortality range of 19 m and a recoverable injury range of 67 m under the maximum energy scenario for Atlantic salmon). TTS, from which animals will recover, was predicted to occur out to a maximum range of 4,161 m for Atlantic salmon from piling operations. For concurrent piling, whilst mortality and recoverable injury ranges were unchanged (i.e. 228 m) TTS ranges for may be increased to up to 7.1 km from the piling location for the maximum energy scenario. During UXO clearance, mortality/mortal injury for all fish would occur within a range of 30-45 m from the source following low order detonation. In the event of a high-order detonation event mortality would occur within 410-680 m of the noise source. The use of soft start piling procedures, allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on Atlantic salmon. Behavioural impacts, whilst expected over a larger range, are unlikely to cause a barrier to the migration routes of Atlantic salmon along the east coast of Scotland. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the construction and decommissioning phases as a result of underwater noise

b: SSC and associated sediment deposition – modelling has indicated that increases in SSC are predicted to be temporary, short-lived and at levels well below those naturally experienced in estuarine environments. Additionally, Atlantic salmon are expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development. As such, no barriers to the migratory patterns of Atlantic salmon are expected. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the construction and decommissioning phases as a result of SSC and associated sediment deposition.

c: EMF – emission of localised EMFs from the operation of cables could potentially interfere with the navigation of diadromous fish species. However, the limited available evidence suggests that disturbance to sea lamprey from EMF occurs at intensities considerably higher than those expected from AC subsea cables. Given that Atlantic salmon is a pelagic species, it is unlikely to swim at depths sufficient to detect levels of EMF that would cause behavioural changes during migration. Any changes in salmonid behaviour, will be temporary and will not interfere with migration success or population health. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the operation and maintenance phases as a result of EMF.

d: Colonisation of foundations, scour protection and cable protection – colonisation of foundations, scour protection and cable protection, has the potential to result in increased predation on diadromous fish species by marine mammal species. Atlantic salmon smolts spend little time in the coastal waters, and make their way to feeding grounds in the north quickly. Evidence also suggests that Atlantic salmon tend not to forage in the coastal waters of Scotland so it is unlikely that they will spend time foraging around wind turbine foundations and therefore are at low risk of impact from increased predation from seals and other predators. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the operation and maintenance phases as a result of colonisation of structures.

e: In-combination – the in-combination assessment considered the potential for underwater noise, increases in SSC and associated sediment deposition, EMF and colonisation of structures arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. In-combination effects as a result of injury and/or disturbance from underwater noise and vibration during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the limited range over which injury effects may occur due to piling activities (i.e. tens to hundreds of metres), mitigation to minimise the potential for injury and the minor overlap in construction phases of the Proposed Development and other projects. In-combination effects as a result of increased SSC and sediment deposition during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the fact that activities associated with other projects would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development. In-combination effects as a result of colonisation of hard structures during the operation of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone as diadromous fish spend little time in coastal waters, they are unlikely to utilise the increase in hard substrate for feeding or shelter opportunities, and are therefore at low risk from increased predation, It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.

Table 15.5:  Integrity Matrix for Annex II Diadromous Fish Species of the River Tay SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Injury and/or disturbance from underwater noise – For peak pressure noise levels when piling energy is at its maximum (i.e.4,000 kJ), mortal injury and recoverable injury ranges for sea lamprey and river lamprey may occur within approximately 138 m of the piling and within 228 m for Atlantic salmon. For cumulative SEL, injury ranges calculated for piling activities indicate that, with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for peak sound pressure levels. Thresholds for mortality and recoverable injury for sea lamprey and river lamprey for both the maximum energy scenario and realistic hammer energy scenario were not exceeded and were predicted to extent to 19 m for Atlantic salmon with a recoverable injury range of 67 m under the maximum energy scenario. TTS, from which animals will recover, was predicted to occur out to a maximum range of 4,161 m for Atlantic salmon, sea lamprey and river lamprey. For concurrent piling, TTS ranges for Atlantic salmon, sea lamprey and river lamprey may be increased to up to 7.1 km from the piling location for the maximum energy scenario. During UXO clearance, mortality/mortal injury for all fish would occur within a range of 30-45 m from the source following low order detonation. In the event of a high-order detonation event mortality would occur within 410-680 m of the noise source. The use of soft start piling procedures, allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on Atlantic salmon, sea lamprey and river lamprey. Behavioural impacts, whilst expected over a larger range, are unlikely to cause a barrier to the migration routes of Atlantic salmon or sea lamprey along the east coast of Scotland. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning phases as a result of underwater noise.

b: SSC and associated sediment deposition – modelling has indicated that increases in SSC are predicted to be temporary, short-lived and at levels well below those naturally experienced in estuarine environments. Additionally, Atlantic salmon and sea lamprey are expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development. As such, no barriers to the migratory patterns of Atlantic salmon or sea lamprey are expected. River lamprey have a preference for estuarine waters, so it is unlikely that this species lamprey will interact with SSC and sediment deposition arising from the construction and decommissioning of the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning phases as a result of SSC and associated sediment deposition.

c: EMF – emission of localised EMFs from the operation of cables could potentially interfere with the navigation of diadromous fish species. However, the limited available evidence suggests that disturbance to sea lamprey from EMF occurs at intensities considerably higher than those expected from AC subsea cables. Due to sea lamprey's parasitic nature at sea, attaching to the body of larger, highly mobile species, well above the seafloor also means that they can be expected to rarely be exposed to the EMF at the lowest levels from AC undersea power cables buried in the seafloor. Therefore, any impacts would be localised and transient. Given that Atlantic salmon is a pelagic species, it is unlikely to swim at depths sufficient to detect levels of EMF that would cause behavioural changes during migration. Any changes in salmonid behaviour, will be temporary and will not interfere with migration success or population health. Given river lamprey's preference for estuarine waters, it is unlikely that river lamprey will interact with cables associated with the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the operation and maintenance phases as a result of EMF.

d: Colonisation of foundations, scour protection and cable protection – colonisation of foundations, scour protection and cable protection, has the potential to result in increased predation on diadromous fish species by marine mammal species. Sea lamprey are parasitic in their marine phase, feeding off larger fish and marine mammals, so it is not expected that they will be particularly attracted to structures associated with offshore wind developments. Sea lamprey that are likely to interact with the Proposed Development are only likely to do so whilst passing through the area during migrations to and from rivers located on the east coast of Scotland. As such significant predation on sea lamprey is not expected. Atlantic salmon smolts spend little time in the coastal waters and make their way to feeding grounds in the north quickly. Evidence also suggests that Atlantic salmon tend not to forage in the coastal waters of Scotland so it is unlikely that they will spend time foraging around wind turbine foundations and therefore are at low risk of impact from increased predation from seals and other predators. Given river lamprey's preference for estuarine waters, it is unlikely that river lamprey will interact with structures associated with the Proposed Development. As such, it is concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the operation and maintenance phases as a result of colonisation of structures.

e: In-combination – the in-combination assessment considered the potential for underwater noise, increases in SSC and associated sediment deposition, EMF and colonisation of structures arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. In-combination effects as a result of injury and/or disturbance from underwater noise and vibration during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the limited range over which injury effects may occur due to piling activities (i.e. tens to hundreds of metres), mitigation to minimise the potential for injury and the minor overlap in construction phases of the Proposed Development and other projects. In-combination effects as a result of increased SSC and sediment deposition during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the fact that activities associated with other projects would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development. In-combination effects as a result of colonisation of hard structures during the operation of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone as diadromous fish spend little time in coastal waters, they are unlikely to utilise the increase in hard substrate for feeding or shelter opportunities, and are therefore at low risk from increased predation, It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.

Table 15.6: Integrity Matrix for Annex II Diadromous Fish (and dependent) Species of the River Dee SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Injury and/or disturbance from underwater noise – For peak pressure noise levels when piling energy is at its maximum (i.e.4,000 kJ), mortal injury and recoverable injury ranges for sea lamprey and river lamprey may occur within approximately 228 m of the piling for Atlantic salmon. For cumulative SEL, injury ranges calculated for piling activities indicate that, with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for peak sound pressure levels. For cumulative SEL, the modelling indicated a mortality range of 19 m and a recoverable injury range of 67 m under the maximum energy scenario for Atlantic salmon). TTS, from which animals will recover, was predicted to occur out to a maximum range of 4,161 m for Atlantic salmon from piling operations. For concurrent piling, whilst mortality and recoverable injury ranges were unchanged (i.e. 228 m) TTS ranges for may be increased to up to 7.1 km from the piling location for the maximum energy scenario. During UXO clearance, mortality/mortal injury for all fish would occur within a range of 30-45 m from the source following low order detonation. In the event of a high-order detonation event mortality would occur within 410-680 m of the noise source. The use of soft start piling procedures, allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on Atlantic salmon. Behavioural impacts, whilst expected over a larger range, are unlikely to cause a barrier to the migration routes of Atlantic salmon along the east coast of Scotland. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the construction and decommissioning phases as a result of underwater noise.

b: SSC and associated sediment deposition – modelling has indicated that increases in SSC are predicted to be temporary, short-lived and at levels well below those naturally experienced in estuarine environments. Additionally, Atlantic salmon are expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development. As such, no barriers to the migratory patterns of Atlantic salmon are expected. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the construction and decommissioning phases as a result of SSC and associated sediment deposition.

c: EMF – emission of localised EMFs from the operation of cables could potentially interfere with the navigation of diadromous fish species. However, the limited available evidence suggests that disturbance to sea lamprey from EMF occurs at intensities considerably higher than those expected from AC subsea cables. Given that Atlantic salmon is a pelagic species, it is unlikely to swim at depths sufficient to detect levels of EMF that would cause behavioural changes during migration. Any changes in salmonid behaviour, will be temporary and will not interfere with migration success or population health. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the operation and maintenance phases as a result of EMF.

d: Colonisation of foundations, scour protection and cable protection – colonisation of foundations, scour protection and cable protection, has the potential to result in increased predation on diadromous fish species by marine mammal species. Atlantic salmon smolts spend little time in the coastal waters and make their way to feeding grounds in the north quickly. Evidence also suggests that Atlantic salmon tend not to forage in the coastal waters of Scotland so it is unlikely that they will spend time foraging around wind turbine foundations and therefore are at low risk of impact from increased predation from seals and other predators. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the operation and maintenance phases as a result of colonisation of structures.

e: In-combination – the in-combination assessment considered the potential for underwater noise, increases in SSC and associated sediment deposition, EMF and colonisation of structures arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. In-combination effects as a result of injury and/or disturbance from underwater noise and vibration during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the limited range over which injury effects may occur due to piling activities (i.e. tens to hundreds of metres), mitigation to minimise the potential for injury and the minor overlap in construction phases of the Proposed Development and other projects. In-combination effects as a result of increased SSC and sediment deposition during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the fact that activities associated with other projects would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development. In-combination effects as a result of colonisation of hard structures during the operation of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone as diadromous fish spend little time in coastal waters, they are unlikely to utilise the increase in hard substrate for feeding or shelter opportunities, and are therefore at low risk from increased predation, It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.

Table 15.7: Integrity Matrix for Annex II Diadromous Fish Species of the River Teith SAC

× - no Adverse Effect on Integrity

 - Adverse Effect on Integrity

a: Injury and/or disturbance from underwater noise – For peak pressure noise levels when piling energy is at its maximum (i.e.4,000 kJ), mortal injury and recoverable injury ranges for sea lamprey and river lamprey may occur within approximately 228 m of the piling for Atlantic salmon. For cumulative SEL, injury ranges calculated for piling activities indicate that, with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for peak sound pressure levels. For cumulative SEL, the modelling indicated a mortality range of 19 m and a recoverable injury range of 67 m under the maximum energy scenario for Atlantic salmon). TTS, from which animals will recover, was predicted to occur out to a maximum range of 4,161 m for Atlantic salmon from piling operations. For concurrent piling, whilst mortality and recoverable injury ranges were unchanged (i.e. 228 m) TTS ranges for may be increased to up to 7.1 km from the piling location for the maximum energy scenario. During UXO clearance, mortality/mortal injury for all fish would occur within a range of 30-45 m from the source following low order detonation. In the event of a high-order detonation event mortality would occur within 410-680 m of the noise source. The use of soft start piling procedures, allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on Atlantic salmon. Behavioural impacts, whilst expected over a larger range, are unlikely to cause a barrier to the migration routes of Atlantic salmon along the east coast of Scotland. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the construction and decommissioning phases as a result of underwater noise

b: SSC and associated sediment deposition – modelling has indicated that increases in SSC are predicted to be temporary, short-lived and at levels well below those naturally experienced in estuarine environments. Additionally, Atlantic salmon are expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development. As such, no barriers to the migratory patterns of Atlantic salmon are expected. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the construction and decommissioning phases as a result of SSC and associated sediment deposition.

c: EMF – emission of localised EMFs from the operation of cables could potentially interfere with the navigation of diadromous fish species. However, the limited available evidence suggests that disturbance to sea lamprey from EMF occurs at intensities considerably higher than those expected from AC subsea cables. Given that Atlantic salmon is a pelagic species, it is unlikely to swim at depths sufficient to detect levels of EMF that would cause behavioural changes during migration. Any changes in salmonid behaviour, will be temporary and will not interfere with migration success or population health. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the operation and maintenance phases as a result of EMF.

d: Colonisation of foundations, scour protection and cable protection – colonisation of foundations, scour protection and cable protection, has the potential to result in increased predation on diadromous fish species by marine mammal species. Atlantic salmon smolts spend little time in the coastal waters and make their way to feeding grounds in the north quickly. Evidence also suggests that Atlantic salmon tend not to forage in the coastal waters of Scotland so it is unlikely that they will spend time foraging around wind turbine foundations and therefore are at low risk of impact from increased predation from seals and other predators. Adult freshwater pearl mussel are confined to freshwater habitats, so there is no pathway for direct effects to this species during construction and decommissioning as a result of underwater noise impacts. Indirect adverse effects on the larval stage of freshwater pearl mussel are not predicted on the basis of the absence of adverse effects on individual salmon host species. As such, it is concluded that there is no potential for Adverse Effects on Integrity on the Annex II diadromous fish qualifying interest feature of the site, or the freshwater pearl mussel qualifying interest feature, during the operation and maintenance phases as a result of colonisation of structures.

e: In-combination – the in-combination assessment considered the potential for underwater noise, increases in SSC and associated sediment deposition, EMF and colonisation of structures arising from the Proposed Development alone to interact with similar effects arising from other projects included in the Tier 2 and Tier 3 assessments. In-combination effects as a result of injury and/or disturbance from underwater noise and vibration during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the limited range over which injury effects may occur due to piling activities (i.e. tens to hundreds of metres), mitigation to minimise the potential for injury and the minor overlap in construction phases of the Proposed Development and other projects. In-combination effects as a result of increased SSC and sediment deposition during the construction phase of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone due to the fact that activities associated with other projects would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development. In-combination effects as a result of colonisation of hard structures during the operation of the Proposed Development in-combination with other projects are not predicted to result in effects of greater significance than as assessed for the Proposed Development alone as diadromous fish spend little time in coastal waters, they are unlikely to utilise the increase in hard substrate for feeding or shelter opportunities, and are therefore at low risk from increased predation, It is therefore concluded that there is no potential for Adverse Effects on Integrity on Annex II diadromous fish qualifying interest features of the site during the construction and decommissioning or operation and maintenance phases in-combination with other projects.