Publication - Report

Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters - Environmental Report Appendix D: Draft Plan Options Assessment

Published: 25 Jul 2013
Part of:
Marine and fisheries
ISBN:
9781782567455

Appendix D to the SEA Environmental Report of the Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters. This appendix contains a Draft Plan Options Assessment.

87 page PDF

1.4 MB

87 page PDF

1.4 MB

Contents
Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters - Environmental Report Appendix D: Draft Plan Options Assessment
1 Wind Draft Plan Options

87 page PDF

1.4 MB

1 Wind Draft Plan Options

OWSW1

SEA Topic

Summary of Key Baseline Evidence

Potential for Effects

Characteristics

Mitigation Available and Potential Residual Effects

Biodiversity, Flora and Fauna [1]

The Draft Plan Option is located near to Luce Bay and Sands SAC (primarily designated for habitats and sediments) and Loch of Inch and Torrs Warren SPA (for non-breeding harriers and geese). Close to the Draft Plan Option, in Luce Bay, is Back Bay to Carghidown SSSI (for coastal and sediment features), Mull of Galloway SSSI (recognised for breeding birds) and Scare Rocks SSSI (recognised for breeding birds including an important Gannet Colony), amongst others. Several IBAs have also been identified in the vicinity of the Draft Plan Option.

Further east is the Solway Firth SAC (with River Lamprey interests amongst others), Upper Solway Flats and Marshes SPA (with bird interests), and the River Bladnoch SAC (considered important for its Atlantic Salmon interests) amongst others. The implication is that the Solway Firth is an important area for a wide range of protected fish and bird species.

The seabird maps presented in the baseline indicates low seabird collision and displacement vulnerability for wind energy devices in winter, with slightly higher vulnerability during the breeding season. However, this vulnerability will differ for individual species.

The available distribution data indicates the potential presence of cetaceans within the Solway Firth area. Seal density surveys and the presence of Grey seal haul out sites within the area, particularly in Luce Bay and the Inner Solway Firth, indicates they use the area. Basking sharks are known to be located around the Isle of Man and have been sighted within the Firth, particularly to the south west of OWSW1. It is believed that Basking sharks travel up the west coast of Scotland, and there is the potential for other elasmobranch species in these waters.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout by many commercially caught species. The waters of the Solway Firth and the northern portion of the Irish Sea contain known nursery areas for several fish species, particularly the eastern portion of the Firth (including commercially important species such as Spurdog, Herring, Cod, Whiting and Sole amongst others). Spawning areas for Plaice and Sole have been identified within the eastern portion of the Solway Firth,

The Luce Bay coastline is a mix of intertidal rocks and sediments with the predominant habitat type in the vicinity of OWSW1 being shallow sub tidal sediments. Predominantly coarse sediments are found in areas further offshore. Parts of the Solway are generally turbid environments and the benthos present is conditioned to dynamic environments.

The vulnerability mapping included in the baseline identified a potential vulnerability for seabird collision and displacement, particularly in the breeding season. Given the presence of important seabird sites for a number of bird species (including Gannets and Greenland white-fronted goose in proximity to the Draft Plan Option and within the Solway and South West region), there remains a risk of collision and displacement within this area. However, the potential for such effects depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Basking sharks and other elasmobranchs, Cetaceans and fish within the Solway Firth, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

The presence of sub-tidal sediments indicates the potential for loss of habitat from placement of devices on the seabed, and from smothering of benthic habitats. However, the dynamic and turbid environment in the Solway would indicate that the benthos present will be conditioned to dynamic environments, and as a result, the magnitude of any impact may be reduced. However, there are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

Potential for significant effects on designated sites, particularly those in Luce Bay, if associated grid infrastructure was to be sited in this location.

Potential for bird strike with blades, collision for diving birds with underwater infrastructure, and the potential displacement for species. However, the significance of impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effects on populations cannot be ascertained at this strategic stage but should rather be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion). However, such effects may be limited as the existing environment is dynamic.

Project level investigation ( EIA) will need to include specific impact modelling and/or assessment to demonstrate that there will be no significant impact on the habitats ( e.g. Luce Bay SAC) from direct benthic impacts from siting of devices, and from changes to hydrology and sedimentation from the construction of devices.

Potential onshore effects from grid connections could be avoided if supporting onshore/offshore connections were located away from sensitive areas such as Luce Bay.

Further research into the potential collision, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The results of monitoring of existing and operational projects in this region have the potential to provide greater certainty on the scale of effects.

Population and Human Health [2]

Solway Firth and surrounding waters are used for a number of recreational activities including salmon and sea trout fisheries, recreational sea angling, sailing, bathing and recreational tourism.

Stakeholder consultation has also identified that the Draft Plan Option straddles cruising routes for vessels navigating the Mull of Galloway from the isle of man, and harbours within the Scottish and English sides of the Solway.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value.

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS-LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment [3]

The coastal waters within the draft plan area and Luce Bay to the north, were classified at being of good status under the WFD in 2011.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning, is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors [4]

Potential coastal flooding issues associated with surge threats at heads of estuaries ( e.g. Solway Firth).

Coastal erosion and accretion have been identified in the soft coastal landforms in the Solway Firth, including in Luce Bay.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly in vulnerable sections of coastline such as the Luce Bay Sands.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development. Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes [5]

The seabed in the vicinity of the Draft Plan Option is shallow (between 20 - 60m depth) and varied, ranging from mixed coarse sediments ( i.e. sandy gravels, gravelly sands and some gravelly muddy sands) to the south west of the Rhins Peninsula and to the south of Wigtown Bay, to coarser sediments in waters south of Luce Bay, and muddy sands and gravels within Luce Bay itself.

The region has moderate wave and tidal energy across much of the Draft Plan Option, with higher resource in the north west and north east portions near to the Rhins Peninsula and Burrowhead respectively.

Some sediment disturbance and loss of seabed habitat is likely with the site preparation and placement of device foundations, although the significance of the effect will depend on the type and size of the device.

Sediment disturbance caused during the installation process could also lead to secondary impacts such as increased turbidity during installation in areas with fine sediments and release of existing contaminants present in fine sediments.

Water quality impacts from installation works are considered to be less likely in areas of high wave or tidal energies, and where coarse seabed sediments are predominant.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site. This could lead to general effects such as scour and abrasion at the site, and deposition of sediments in nearby areas. This may be of particular concern for sites near to relatively sheltered areas such as Luce Bay. However, these systems are likely to be complex and, as such, the potential for impacts is likely to be site specific and dependent on a range of factors, including the type and size of the devices and their foundations.

Direct effects such as disturbance of the seabed during installation are likely to be temporary and localised ( e.g. increased turbidity in sediments with muddy components).

Loss of seabed area beneath device foundations may be permanent, although some natural regeneration may occur upon decommissioning of devices and removal of infrastructure.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. changes to local sediment dynamics, deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly in relation to Luce Bay.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment [6]

Solway Firth and surrounding coastlines are rich in historic features, particularly the south coast of Dumfries and Galloway which contains a number of scheduled monuments ( e.g. coastal fortifications, chambered cairns and early church sites including at Whitthorn Peninsula).

Numerous historic wrecks have been identified in or near to Draft Plan Option area, and within the Solway Firth.

The proximity of the Draft Plan Option to the south coast of Dumfries and Galloway suggests that there is potential for impacts on the site and setting of historic environment assets located both within the marine environment and along the nearby coastline. Effects could be direct, caused by changes to coastal conditions ( e.g. coastal processes, scour, sedimentation, etc.) or from the siting of devices and associated infrastructure, or indirect effects on the setting of features.

There may also be the potential for impacts on historic wreck sites if devices were to be installed near to these sites.

Direct effects on historic environment assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Landscape / Seascape [7]

Three NSAs are located along the Solway Coast: Fleet Valley, East Stewartry Coast and Nith Estuary. However, direct views to the plan option from these areas may be limited.

Local landscape designations extend over much of the Solway coastline, and there are several local designated landscapes in proximity to the option area. These include the southern tip of the Rhins Peninsula (Rhins Coast RSA), Burrowhead (Machars Coast RSA) and within Luce Bay (Mochrum Lochs RSA).

Wind energy developments in the Draft Plan Option are likely to be visible from the coastline, from areas of local landscape designations, and potentially, from the northern coastline of the Isle of Man.

It is considered unlikely that the Draft Plan Option would be highly visible from the identified NSAs located along the Solway coast.

There are a number of potential offshore receptors, including recreational boats that may sail close to the Draft Plan Option.

It is likely that construction and maintenance works, and navigational aids ( e.g. marker buoys, lighting) will have visual effects.

The wind devices will likely be visible from the mainland and Isle of Man, and will include areas designated for their landscape importance at a local level.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Development within the Draft Plan Option would likely alter the current seascape.

Visual impacts would likely be greater for offshore receptors, such as recreational sea users, as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of any effects. However, the potential for visual impacts to onshore receptors could be limited by undertaking construction further from the mainland.

Impacts to the landscape and seascape character of Luce Bay would also need to form part of project level assessments.

Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

OWSW2

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Draft Plan Option is located near to the Solway Firth SAC (with River Lamprey interests), Upper Solway Flats and Marshes SPA (with bird interests) and the Borgue Coast SSSI (with an assemblage of breeding Gulls). To the North West of the site, the River Bladnoch SAC is recognised for its Atlantic Salmon interests, Several IBAs have also been identified in the vicinity of the Draft Plan Option

To the west of the Draft Plan Option, the Luce Bay and Sands SAC (primarily designated for habitats and sediments), Loch of Inch and Torrs Warren SPA (for non-breeding harriers and geese) and Scare Rocks SSSI on the edge of Luce Bay (recognised for breeding birds including an important Gannet Colony), indicating that the Solway Firth is an important area for breeding birds and protected fish species.

The seabird maps presented in the baseline indicate lower collision and displacement vulnerability for wind energy devices in winter, with slightly higher vulnerability during the breeding season. However, this vulnerability may differ for individual species.

The available distribution data shows that cetaceans are present within the Solway Firth area. Seal density surveys and the presence of Grey seal haul out sites within the area, particularly in the Inner Solway Firth to the north east of OWSW2, indicates the presence of Seals in the vicinity of the Draft Plan Option. Basking sharks sightings are common around the Isle of Man and within the western portion of the Firth, although no recorded sightings have been made in the vicinity of OWSW2. It is believed that Basking sharks travel up the west coast of Scotland, and there is the potential for other elasmobranch species in these waters.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. The waters of the Solway Firth and the northern portion of the Irish Sea contain known nursery areas for several fish species, particularly the eastern portion of the Firth (including commercially important species such as Spurdog, Herring, Cod, Whiting and Sole amongst others). Spawning areas for Plaice and Sole have been identified within the eastern portion of the Solway Firth,

The Solway Firth coastline is a mix of intertidal rocks and sediments with the predominant habitat type being the shallow sub tidal sediments and finer sediments (muddy sands and sands) located in the eastern part of the Firth. The Solway is a turbid environment and the benthos present will be conditioned to dynamic environments.

The vulnerability mapping included in the baseline identified a potential vulnerability for seabird collision and displacement, particularly during the breeding season. Given the presence of important sites for a number of birds (including Geese, Plover and Shelduck amongst others), in proximity to the Draft Plan Option and within the Solway and South West region, there remains a likely a risk of collision and displacement in this area. However, the potential for such effects depends on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Basking sharks and other elasmobranchs, Cetaceans and fish within the Solway Firth, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

The presence of sub-tidal sediments indicates the potential for loss or smothering of benthic habitats. However, the dynamic and turbid environment in the Solway would indicate that the benthos present will be conditioned to dynamic environments, and as a result, the magnitude of such impacts may be reduced. However, there are currently gaps in research knowledge which means it is difficult to establish certainty of impact.

Potential for bird strike with blades, collision for diving birds with underwater infrastructure, and disturbance of these species. However, the significance of impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish include barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effects on populations cannot be ascertained at this strategic stage but should rather be a consideration at the project level ( e.g. monitoring).

Effects associated with construction activities (such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain..

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion). However, such effects may be limited as the existing environment is already dynamic.

Potentially significant effects on designated sites, such as the Solway Firth SAC, if associated grid infrastructure was to be sited in this location.

Project level investigation ( EIA) will need to include specific impact modelling and/or assessment to demonstrate that there will be no significant impact on important habitats ( e.g. Solway Firth SAC) from direct benthic impacts from siting devices and from changes to hydrology and sedimentation from the construction of devices. The results of monitoring from operational projects and those currently in the application process have the potential to help provide greater certainty on the scale of these effects.

Potential onshore effects could be avoided if supporting onshore/offshore grid connections were located away from sensitive areas, such as Luce Bay and the Inner Solway Firth SAC.

Further research into potential collision and displacement effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The results of monitoring of existing and operational sites have the potential to help provide greater certainty on the scale of effects.

Population and Human Health

Solway Firth and surrounding waters are used for a number of recreational activities including salmon and sea trout fisheries, recreational sea angling, sailing, bathing and recreational tourism.

Stakeholder consultation has also identified that the Draft Plan Option straddles cruising routes for vessels navigating the Mull of Galloway from the isle of man, and harbours within the Scottish and English sides of the Solway.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters within and to the east of the Draft Plan Option, were classified at being of high status under the WFD in 2011.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment.

Climatic Factors

Potential coastal flooding issues associated with surge threats at heads of estuaries ( e.g. Solway Firth).

Coastal erosion and accretion have been identified along soft coastal landforms in the Solway Firth, particularly in the eastern part of the Firth at the Upper Solway Flats and Marshes SPA, at heads of estuaries located along the coastline and along the Cumbrian Coast.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly in the vicinities of estuaries and the Upper Solway Flats and Marshes SPA.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes [8]

The seabed in the vicinity of the Draft Plan Option is varied, ranging from mixed coarse sediments with finer sediments such as extensive sands and muddy sands located further into the Firth to the east of the River Dee, particularly at the mouths of rivers within the Inner Firth.

The region has moderate wave and tidal resources across much of the Draft Plan Option, with higher resource in the north west and north east near to the Rhins Peninsula and Burrowhead respectively..

Some sediment disturbance and loss of seabed habitat is likely with the site preparation and placement of device foundations, although the significance of the effect will depend on the type and size of the device.

Sediment disturbance caused during the installation process could also lead to secondary impacts such as increased turbidity during installation in areas with fine sediments and release of existing contaminants present in fine sediments. However, water quality impacts from installation works are considered to be less likely in areas of high wave or tidal energies, and where coarse seabed sediments are predominant.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site. This could lead to general effects such as scour and abrasion at the site, and deposition of sediments in nearby areas. This may be of particular concern for sites near to relatively sheltered areas and areas of high accretion located along the Solway Firth coastline. However, these systems are likely to be complex and, as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct effects such as disturbance of the seabed during installation are likely to be temporary and localised ( e.g. increased turbidity in sediments with muddy components).

While loss of seabed may be permanent ( e.g. beneath foundations), some natural regeneration may occur upon decommissioning of devices.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited during the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas such as those in the Inner Firth ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly given the proximity of the Draft Plan Option to the Inner Solway Firth.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation may include measures such as the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

The Dumfries and Galloway coastline to the Solway Firth is rich in historic features, particularly the south coast of Dumfries and Galloway nearest to the Draft Plan Option which contains various scheduled monuments, gardens and designed landscapes included on the Inventory ( e.g. Barnhourie Milland Arbigland) and category A-listed buildings ( e.g. Castle Muir and Southerness Lighthouse).

Numerous historic wrecks have been identified in or near to OWSW2, and surrounding areas within the Solway Firth.

The proximity of the Draft Plan Option to the south coast of Dumfries and Galloway suggests that there is potential for impacts on the site and setting of historic environment assets located both within the marine environment and along the nearby coastline. Effects could be direct, caused by changes to coastal conditions ( e.g. coastal processes, scour, sedimentation, etc.) or from the siting of devices and associated infrastructure, or indirect effects on the setting of features.

There may also be the potential for impacts on historic wreck sites if devices were to be installed near to these sites.

Direct effects on historic environment assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Landscape / Seascape

Three NSAs are located along the Solway Coast (Fleet Valley, East Stewartry Coast and Nith Estuary) and one Area of Outstanding Natural beauty (Solway Coast AONB) in proximity to the Draft Plan Option. Local landscape designations extend over much of the Solway coastline, and there are several local designated landscapes in proximity to the Draft Plan Option. These include Burrowhead (Machars Coast RSA), Wigtown Bay (Galloway hills RSA) and along the Solway Coast (Solway Coast RSA).

The Heritage Coast of St Bee's Head is located on the southern coast of the Solway Firth.

Wind energy developments in the Draft Plan Option are likely to be visible from the north and south coastlines of the Solway Firth. The majority of these coastlines are covered by national and local level landscape designations.

There are a number of potential offshore receptors, including recreational boats that sail close to the Draft Plan Option.

It is likely that construction and maintenance works, and navigational aids ( e.g. marker buoys, lighting) will have some visual effects.

The wind devices will likely be visible from the mainland and Isle of Man, and will include areas designated for their landscape importance at a local level.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Development within the Draft Plan Option would likely alter the current seascape.

Visual impacts would likely be greater for offshore receptors, such as recreational sea users, as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of any effects. However, the potential for visual impacts to onshore receptors could be limited by undertaking construction further from the mainland.

Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

OWW1

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The plan option is located in proximity to the Rinns of Islay SPA and SSSI (designated for a number of bird species including Chough, Greenland white-fronted goose and Whooper swan) and to the north east is the Oronsay and South Colonsay SPA and SSSI (with Corncrake and Chough qualifying features). The North Colonsay and Western Cliffs SPA is designated for breeding seabird assemblage (with Chough, Kittiwake and Guillemot present). The local area also contains a number of IBAs on Colonsay and Islay.

The Draft Plan Option is also located south of the Skye to Mull MPA search area, considered to be important for its geodiversity and the presence of Basking shark and Minke whale.

The seabird maps presented in the baseline indicate low vulnerability for collision and displacement from with wind energy devices in both winter and breeding seasons. However, this vulnerability may differ for individual species.

The south east of Islay contains the South-East Islay Skerries SAC designated for Common seals. The identification of several Seal haul out areas located in Islay and Colonsay and high Seal densities in the vicinity of these areas indicates grey Seal interests in this region.

The available distribution and sighting data also indicates that there are likely to be Cetacean, elasmobranchs and fish ( e.g. Basking shark and Atlantic salmon, etc.) in the region, with important nursery grounds for a number of commercial fish species. While the Draft Plan Option is located some distance south of the Basking shark and Common skate 'hotspots' located in the vicinity of Tiree, Coll and Mull, it is expected that these species, and other elasmobranchs, may be encountered within the Draft Plan Option.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. The region is known to contain important nursery grounds for several commercially important species of fish (including Spurdog, Herring, Whiting and Anglerfish, amongst others).

Benthic habitats in the region are largely shallow and shelf subtidal coarse sediments ( e.g. sands, gravelly sands, gravels, etc.) and may be susceptible to hydrodynamic change. Benthic habitats are likely to contain species used to strong tidal movements.

Given the presence of important sites for birds located in the vicinity of the site, the potential for collision and displacement impacts remains. However, the potential for these effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Basking sharks and other elasmobranchs, Cetaceans and Seals in the vicinity of the Draft Plan Option, there may potential effects such as barriers to movement, collision with the devices and associated infrastructure, and above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats such as scouring, smothering, deposition and abrasion of seabed in areas with coarse sediments as a result of placing devices within this area. There will likely be some direct localised effect on benthic habitats from installation ( e.g. habitat loss with placement of device base, etc.).

Potential for collision for diving birds with wind devices and associated infrastructure both above and below the water surface, and potential for displacement of species. However, the significance of such impacts is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although precise effects on population cannot be ascertained at this strategic stage but should rather be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects ( e.g. collision risk) from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion). However, such effects may be limited as the existing environment is already dynamic.

Potentially significant effects to designated areas, such as those on Islay, if grid infrastructure were to be sited in the vicinity of the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate there will be no significant impacts on the birds, mobile species and important habitats in the vicinity as a result of collision with wind devices and effects during their installation. The results of monitoring from any licensed projects that are developed, has the potential to help provide greater certainty on the scale of these effects.

Further research into the potential for collision, displacement and the effects on cetaceans, seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The results of monitoring of existing and operational projects in this region have the potential to provide greater certainty on the scale of effects.

Development to the west of the Draft Plan Option and further away from Islay may reduce the potential for impacts on some bird species.

The potential for effects from grid infrastructure could be avoided if supporting onshore/offshore connections were located away from sensitive areas, such as Islay.

Population and Human Health

The waters to west and north west of Islay are used for a number of industry and recreational activities including fishing, recreational sea angling, light recreational cruising, surfing and diving.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the Draft Plan Option were classified at being of good status under the WFD in 2011.

There are two designated shellfish waters within the vicinity of the Draft Plan Option off Jurra and Colonsay.

Potential for adverse water quality impacts during installation, operation and decommissioning of developments ( e.g. increased turbidity during benthic works, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

Broadly stable coastal areas with small sections of the coastline identified as potentially being vulnerable to erosion/accretion ( e.g. sheltered beaches and bays on Islay, southern side of Colonsay and south west areas of Mull), particularly during storm events.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy although much of the coastline near the Draft Plan Option is broadly stable.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed in the vicinity of the Draft Plan Option is composed of predominantly coarse sediments ( i.e. sandy gravels and gravelly sands) with coarser materials located to the west of Islay.

While the region has relatively low wave and tidal energy across much of the Draft Plan Option, a high tidal energy zone is located immediately south of the option area, to the west and south west of Islay.

Although there are largely coarse sediments in the area, some sediment disturbance and loss of seabed habitat is still likely to occur during the site preparation and placement of device foundations. The scale of disturbance will depend on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants).

Increased turbidity is considered unlikely given the predominantly coarse sediments identified across the area.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site, with potential general impacts such as scour and abrasion at the development site, and deposition at the site or in surrounding areas. This may be of particular concern for sites near to relatively sheltered areas, and areas of high accretion ( e.g. sheltered bays along the north coast of Islay). However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area associated with installation may be permanent, although some natural regeneration may occur upon decommissioning of devices.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly given the proximity to sensitive coastal areas on Islay.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices on or into the seabed.

Historic Environment

There are a number of marine and coastal wreck sites within this region, including small clusters located near the west coast of Tiree, the west and south coasts of Islay, and along the southern and south east coasts of Kintyre.

Significant sections of coastal and marine areas in Tiree, Colonsay, Islay and Kintyre have been identified as being of potential interest for submerged archaeology.

There are also a wide range of historical features located along the shorelines or which are of coastal relevance ( e.g. designated sites such as lighthouses, listed buildings, and scheduled monuments, such as fortifications and early church sites).

The proximity of the Draft Plan Option to the coastline means there is the potential for impacts on the setting of coastal historic assets ( e.g. Iona Abbey, numerous scheduled forts along the coast in Western Islay, Dhu Heartach Lighthouse in Colonsay).

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments.

The likely presence of submerged archaeology means that there is potential for direct effects on any remains. However, development which includes archaeological survey may also have some positive effects by contributing to knowledge/understanding about the marine historic environment.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Where development is in an area considered likely to have submerged archaeology projects should seek to identify and avoid direct impacts on features.

Landscape / Seascape

The Draft Plan Option is located in proximity to the Islay coast, with the north part of the Draft Plan Option near to a local landscape designation area in north west Islay.

The islands of Oronsay, Colonsay and Mull contain a number of landscape designations and areas of wild land along coastlines that may have views to the Draft Plan Option.

Given the proximity of the Draft Plan Option to the Islay coast, there is potential for wind turbines to be visible from areas of local landscape designations.

Visibility effects may also occur during construction periods as well as operation. It is likely that construction / maintenance works and navigational aids ( e.g. marker buoys, lighting) will have visual effects.

There are a number of potential offshore receptors, including recreational boats that may sail close to the option area.

Devices and supporting infrastructure within the wind option may be visible from Islay which includes areas designated for their landscape importance.

Impacts are likely to occur during construction, maintenance and operation periods.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Development within the Draft Plan Option would likely alter the current seascape.

Visual impacts could be greater for offshore receptors, such as recreational sea users as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects. However, visual impacts to onshore receptors could potentially be limited by construction further from the mainland, in particular the west of the Draft Plan Option.

Impacts to the landscape and seascape character of Islay, and potentially Oronsay, Colonsay and Mull would also need to form part of project level assessments.

OWW2

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Tiree Wetlands and Coast SPA, and Tiree, Coll and Sleibhtean agus Cladach Thiriodh SPAs are located close to the Draft Plan Option with features including Corncrake, Oystercatcher, Polver and Geese, amongst others.

There are SACs in the vicinity of the site are designated for dune habitats, whilst the Treshnish Isles SAC is designated for Grey Seals. The south east of the Draft Plan Option overlaps with the Stanton Banks marine SAC which is designated for reef, which could have diverse benthic habitats that may be susceptible to change.

Most of the Draft Plan Option is located within the Skye to Mull MPA search area. This area is considered important for its geodiversity and the presence of Basking shark and Minke whale species.

The seabird maps presented in the baseline identifies a potential vulnerability for seabird collision and displacement with wind energy devices during breeding seasons, with a slightly higher vulnerability identified during winter seasons. However, this vulnerability may differ for individual species.

Distribution data presented in the baseline indicates that cetaceans are likely to be present within the region and the Draft Plan Option is located near to Basking shark and Common skate 'hotspots' at Tiree and Coll. Other elasmobranch species are also considered likely to be encountered in the vicinity of the Draft Plan Option. Seal survey data and the presence of Seal haul out areas around Tiree, Coll and Mull indicates this is a well-used area for marine mammals, particularly Grey seals.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

The seabed in the region largely comprises shallow and shelf subtidal coarse sediments ( e.g. sands, gravelly sands, gravels, etc.).

Vulnerability mapping identified potential vulnerability for collision and displacement of seabirds from wind energy. There are a number of bird interests that might be potentially affected, although the potential for such effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly elasmobranchs such as Basking sharks and Common skate, Cetaceans and Seals in the vicinity of the Draft Plan Option, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion of seabed in areas with coarse sediments. As a result of placing devices within this area. Also direct effects on benthic habitats from installation ( e.g. habitat loss with placement of device base, etc.), and the significance of such effects could increase for development in the south west portion of the Draft Plan Option area that overlaps with the Stanton Banks marine c SAC. However, there are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

There is potential for collision between seabirds and wind devices and their supporting infrastructure above and below the water, and for the potential displacement of some species. However, the significance of the impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on cetaceans, seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effects on population cannot be ascertained at this strategic stage but should be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion). However, such effects may be limited as the existing environment is already dynamic.

Potential for significant effects to designated areas, including reef habitats at Stanton Banks SAC and important coastal SACs on Tiree, associated with wind developments and grid infrastructure if it were to be sited in the vicinity of the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices. The result of monitoring from projects currently in the application process has the potential to help provide greater certainty on the scale of these effects.

Given the proximity of the Draft Plan Option to important areas for birds, development in the southern part of the Draft Plan Option may be preferred.

Further research into the potential collision risks, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The result of monitoring of wind projects currently in the application process has the potential to help provide greater certainty on the scale of effects.

It is recommended that the south west boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Stanton Banks SAC would lead to adverse effects or whether co-location is possible. Project level HRA must demonstrate development does not adversely affect the integrity of the SAC.

Furthermore, it is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Skye to Mull MPA search area will remain and would lead to adverse effects, or whether co-location is possible. Projects will need to demonstrate through the EIA process that they are compatible with the conservation objectives of the MPA.

Potential onshore effects from grid connections could be avoided if supporting onshore/offshore connections were located away from Tiree.

Population and Human Health

The waters to the west of Tiree are used for a number of industry and recreational activities including fishing, recreational sea angling, light recreational cruising, surfing and diving.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the draft plan area were classified at being of good status under the WFD in 2011.

There are some designated shellfish waters within the vicinity of the Draft Plan Option around the Isle of Mull.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

Broadly stable coastal areas although small sections of the coastline have been identified as potentially being vulnerable to erosion/accretion ( e.g. beaches on Tiree, and sheltered bays on the west and southern sides of Colonsay), particularly during storm events.

Potential increases in storm events and rising sea levels due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy although much of the coastline near the Draft Plan Option is considered to be broadly stable.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed in the vicinity of the Draft Plan Option is composed of predominantly coarse sediments ( i.e. sandy gravels and gravelly sands).

There is generally low wave and tidal energy across much of the Draft Plan Option. However, stronger wave and tidal areas have been identified to the west of Tiree, immediately east of the Draft Plan Option.

While there are largely coarse sediments in the area, some sediment disturbance and loss of seabed habitat is still likely to occur during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance that occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants).

Increased turbidity is considered to be unlikely given the predominantly coarse sediments identified across the area.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site, with potential general impacts such as scour, abrasion and deposition at development sites. The potential for increased coastal erosion or deposition in surrounding areas due to the presence of devices has also been identified. However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area from installation works may be permanent ( e.g. beneath device foundations), although some natural regeneration may occur upon decommissioning of devices.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. changes to local sediment dynamics and deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

There are a number of marine and coastal wreck sites within this region, including small clusters of wreck sites located near the west coast of Tiree.

Significant sections of coastal and marine areas in Tiree have been identified as being of potential interest for submerged archaeology.

Coastal areas also contain a wide range of historical features located on the shoreline or which are of coastal relevance ( e.g. lighthouses and numerous coastal scheduled monuments including fortifications and early church sites).

The close proximity of the site footprint to the southern tip of Tiree would suggest there is the potential for impacts on the setting of a number of coastal historic assets including scheduled fortifications and early church sites.

In particular sites in the Draft Plan Option may have the potential to impact on the setting of the Category A listed Skerryvore Lighthouse.

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments.

The likely presence of submerged archaeology means that there is potential for direct effects on any remains. However, development which includes archaeological survey may also have some positive effects by contributing to knowledge/understanding about the marine historic environment.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Where development is in an area considered likely to have submerged archaeology projects should seek to identify and avoid direct impacts on features.

Landscape / Seascape

The Draft Plan Option is located in proximity the island of Tiree. Much of Tiree is covered by local landscape designations and some sections of the Draft Plan Option may be visible from the coastline.

While the coastline of Tiree is not identified as an area of wild land, this could potentially indicate that there may be more receptors to offshore development ( e.g. recreational sea users).

The Loch na Keal NSA on the Isle of Mull may also need consideration.

Given the proximity of the Draft Plan Option to the Tiree coast there is potential for wind turbines to be visible from areas of local landscape designations.

Visibility effects may also occur during construction periods as well as operation. It is likely that construction / maintenance works and navigational aids ( e.g. marker buoys, lighting) will have visual effects.

There are a number of potential offshore receptors, including recreational boats that sail close to the option area.

Devices and supporting infrastructure within the Draft Plan Option may be visible from Tiree which includes areas designated for their landscape importance. Development within the Draft Plan Option would likely alter the current seascape.

Impacts are likely to occur during construction, maintenance and operation periods.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Visual impacts could be greater for offshore receptors, such as recreational sea users, as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects. However, visual impacts to onshore receptors could potentially be limited by construction further from the mainland, in particular, the south and east portions of the Draft Plan Option.

Impacts to the landscape and seascape character of Tiree would also need to form part of project level assessments.

Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

OWW3

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The north west of the Draft Plan Option overlaps with the Mingulay and Berneray SPA and SSSI which has a number of seabird assemblage interests (including Fulmar, Puffin, Kittiwake, Razorbill and Guillemot). To the east of WW4 is the East Mingulay marine SAC (designated for reefs), and Small Seal islands SSSI (Grey seal interests) and the Sound of Barra p SAC (marine habitat and Common seal interests) are located to the north west of the site. Several IBAs have also been identified amongst the islands immediately east and north east of WW4.

The Draft Plan Option is also located outside and to the east of the Skye to Mull MPA search area. This area is considered important for its geodiversity and the presence of Basking shark and Minke whale.

Seabird maps presented in the baseline indicates a potential vulnerability for collision and displacement of seabirds for wind energy devices, particularly during breeding periods and in the eastern part of the Draft Plan Option. However, this vulnerability may differ for individual species.

The available distribution and sighting data also indicates that there are likely Cetaceans present in the vicinity of the Draft Plan Option. Basking shark sightings have been recorded amongst the southern island of the outer Hebrides, with the area to the east of Mingulay and Barra known to be a Basking shark 'hotspot'. Other elasmobranchs are also known to use these areas. Seal density mapping, the presence of Seal haul outs and the proximity of the Draft Plan Option to an SAC designated for Common seal interests, demonstrates the importance of the area for Grey seals.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

Benthic habitats in the region are largely rocky outcrops near to Barra, and sandy and gravelly sediments further west and within the Draft Plan Option. These habitats may be susceptible to hydrodynamic change, and are likely to contain species used to strong tidal movements.

The vulnerability mapping included in the baseline identified a potential vulnerability for seabird collision and displacement during the winter and breeding seasons. There are several important sites for a number of bird species, However, the potential for such effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly elasmobranchs such as Basking sharks and skates, Cetaceans and Seals in the vicinity of the Draft Plan Option, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats such as habitat loss, scouring, smothering, deposition and abrasion of seabed in areas with coarse sediments. However, there are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

There is the potential for seabird collision with wind devices and supporting infrastructure both above and below the water, and also potential for the displacement of bird species. However, the significance of such impacts is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effects on populations cannot be ascertained at this strategic stage but should rather be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( e.g. scouring, smothering, sediment deposition and abrasion). However, such effects may be limited as the existing environment is dynamic.

Potential for significant effects to designated areas, including SACs and SPAs located to the east and north east of the Draft Plan Option, associated with grid infrastructure if it were to be sited in this area.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices.

Given the proximity of the Draft Plan Option to important areas for birds and uncertainty of effects, initial development within the westernmost portion of the Draft Plan Option is recommended.

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Mingulay and Berneray SPA would lead to adverse effects on the integrity of the designation or whether co-location is possible. Project level HRA must demonstrate development does not adversely affect the integrity of the SPA.

Further research into the potential collision risks, displacement and the effects on cetaceans, seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The result of monitoring of wind projects currently in the application process has the potential to help provide greater certainty on the scale of effects.

Potential onshore effects from grid connections could be avoided if supporting onshore/offshore connections were located away from Mingulay and Barra.

Siting of developments in rocky seabed areas could limit the potential for benthic effects. However, the practicality of this mitigation measure may be influenced by other factors such as specific locations selected by developers and limitations associated with technology and engineering requirements.

Population and Human Health

The waters to the west of Barra and Mingulay are used for a number of industry activities including fishing, recreational sea angling and light recreational cruising.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the draft plan area were classified as being of high status under the WFD in 2011.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors [9]

Western beaches of the Outer Hebrides Islands are dominated by wind and wave action. The western coasts of the southern isles ( e.g. Barra, Sandray, and Mingulay) have broadly rocky coastal areas with several self-contained pocket beaches, particularly along the western coastline of Barra.

Wave erosion of the machair edge has been observed in sections of the west coast, and storm damage of the shingle edge has been observed on Vatersay. As such, some sections of the coastline have been identified as potentially being vulnerable to erosion/accretion, particularly during storm events.

The potential for increases in storm events and rising sea levels have been identified, due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly from developments located near to the coastline.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed in the vicinity of the Draft Plan Option is of variable depth (ranging from 20 - 120m), consisting mainly of rock outcrops to the immediate west of Barra. Sandy and gravelly sediments are located further west, within the Draft Plan Option, and to the south of Barra within the adjacent tidal energy plan option area.

While the region has low wave and tidal energy, it is located adjacent to and part overlaps a wave energy Draft Plan Option area to the southeast with higher energy resource.

While there are largely coarse sediments in the area, some sediment disturbance and loss of seabed habitat are still likely to occur during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants). Significant increases in turbidity are considered unlikely given the predominantly coarse sediments identified across the area.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site, with potential general impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines ( e.g. Barra, Mingulay). However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area beneath device foundations may be permanent, although some natural regeneration may occur upon decommissioning of devices.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly along sensitive coastlines in the Outer Hebrides.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

There are a number of marine and coastal wreck sites in the Outer Hebrides, including several near Barra.

The coastal areas of the islands also contain a wide range of historical features located either on the shoreline or which are of coastal relevance ( e.g. Barra Head lighthouse and a cluster of coastal sites within the southern isles of the Outer Hebrides).

The close proximity of the site footprint to the southern tip of Barra would suggest there is the potential for impacts on the setting of a number of coastal historic assets including scheduled duns and Barra Head Lighthouse.

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Landscape / Seascape

The Draft Plan Option is located close to the coastline of the southern islands in the Outer Hebrides, many of which are considered important for their natural environment and landscape qualities. The Draft Plan Option may also be visible from South Uist Machair NSA, located to the north east.

Several coastlines of the islands in this region are identified as areas of wildness value.

Given the proximity of the Draft Plan Option to these islands, there is the potential for visual effects on the local environment, wild land and potentially the South Uist Machair NSA.

Given the potential visibility of wind structures and turbine blades, there is also potential for changes to the character of the area and to the seascape.

Visual effects will occur both during construction, maintenance and operation phases. It is likely that navigational aids ( e.g. marker buoys, lighting) will have visual effects.

There are a number of potential offshore receptors including recreational boats that sail close to the option area.

Devices and, in particular, supporting infrastructure within the Draft Plan Option may be visible from local islands, including areas designated for their landscape importance and are areas of wildness.

Impacts are likely during construction, maintenance and operation phases.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Development within the Draft Plan Option would likely alter the current seascape. However, the number of human receptors in this remote area may be few.

Visual impacts could be greater for offshore receptors, such as recreational sea users as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects. However visual impacts to onshore receptors could potentially be limited by construction further from the mainland, in particular the west of the Draft Plan Option.

Impacts to the landscape and seascape character would also need to form part of project level assessments. Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

Given the high quality landscape in the vicinity of the Draft Plan Option, any development in this area should only be undertaken where significant effects can be avoided.

Development of the western parts of the Draft Plan Option could potentially reduce visual and landscape/ seascape impacts.

OWNW1

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Draft Plan Option sits between the isles of Lewis and Cape Wrath, to the north of the North Minch. There are a number of important designations in the areas, including the Cape Wrath and Handa SPAs on the Scottish mainland, and the Lewis Peatlands SPA designated for seabird assemblage interests (including Fulmar, Puffin, Kittiwake, Razorbill, and Guillemot). The Ness and Barvas SPA on Lewis is designated for Corncrakes, and Foinaven SPA on the mainland and Lewis Peatlands SPA on Lewis are also designated for Golden Eagles. Several IBAs have been identified in proximity to the Draft Plan Option.

A range of other sites, including Cape Wrath SAC, Oldshoremore and Sandwood SAC, Loch Laxford SAC and Southern Parphe SSSI are designated for coastal habitat features. In the marine environment, North Rona and Sula Sgeir SPA (designated for a number of seabird interests), and Solan Bank Reef c SAC (designated for offshore reefs) are located close to the Draft Plan Option. An SAC has also been designated at North Rona SAC for Grey seal interests. SACs on Lewis (Langavat and North Harris) and at Little Gruinard River have been designated for their Atlantic salmon interests.

The Draft Plan Option is located in close proximity to the north of the Eye Peninsula to Butt of Lewis MPA search area, proposed for Rissos dolphin, White-beaked dolphin and Sand eel interests.

The potential vulnerability for collision and displacement of seabirds from wind energy was identified, particularly during the winter in the south east corner of OWNW1 and during the breeding season in the south and north east of the Draft Plan Option. However, this vulnerability may differ for individual species.

The distribution of Cetaceans is considered to be high near the North Minch, particularly in the southern part of the Draft Plan Option area.

While no Basking shark sightings have been recorded in the Draft Plan Option, several have been recorded along the Lewis and Cape Wrath coastlines indicating the potential for encounter in this area. Other elasmobranch species are known to use these waters.

Seal density mapping and the presence of Seal haul out areas on the mainland and North Rona indicates the likely use of the area by Grey seals.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. A number of high intensity nursery grounds have been identified within the region for commercially fish species such as herring, whiting and mackerel, amongst others.

Seabed sediments in the vicinity of the Draft Plan Option are described as coarse sediments ( e.g. sands, gravelly sands and sandy gravels).

The vulnerability mapping included in the baseline identified the potential for collision and displacement of seabirds, both during the winter and breeding seasons and in areas, particularly in the south, south east and north east sections of the Draft Plan Option. However, the potential for such effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Cetaceans and Seals in this region, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

Whilst the area is not identified as a hot spot for Basking sharks they and other elasmobranchs (including priority marine features) are known to have used this area, and there remains the potential for the same impacts as listed above for Seals and Cetaceans.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats including the loss of habitat and scouring, smothering, deposition and abrasion of seabed in areas with coarse sediments from the placement of devices in this area. The potential for impacts on the Solan Bank Reef c SAC reef site has also been identified as a result of sediment movement from the installation of wind devices. However, there are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

There is potential for collision between seabirds and wind devices and associated infrastructure, and the potential for displacement of bird species. However, the exact significance of the impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effects on populations cannot be ascertained at this strategic stage but should rather be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( e.g. scouring, smothering, sediment deposition and abrasion). However, such effects may be limited as the existing environment is already dynamic.

Potentially significant effects to designated areas, particularly those in northern Lewis and remote areas near Cape Wrath, associated with grid infrastructure if it were to be sited near this location.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate that there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices and associated infrastructure.

Further research into the potential collision risks, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The results of monitoring of wind projects currently in the application process have the potential to help provide greater certainty on the scale of effects.

Potential effects of supporting onshore/offshore grid connections will need to be considered to avoid adverse effects on coastal areas.

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether proximity to the Eye Peninsula to Butt of Lewis proposed MPA would lead to adverse effects or whether co-location is possible. Projects will need to demonstrate through the EIA process that they are compatible with the conservation objectives of the MPA.

Population and Human Health

The waters at the North Minch and nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, light recreational cruising and surfing. The areas remoteness is considered to be a key attraction for many recreational visitors.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment [10]

The coastal waters in the vicinity of the Draft Plan Option were classified at being of good status under the WFD in 2011.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

The coastline of the Butt of Lewis is dominated by cliffs with no significant beaches. This alters to the south, where sheltered sandy beaches are located amongst sandstone and soft conglomerate cliffs.

As such, several areas of potential erosion and accretion have been identified on the north east coast, with accretion observed within several sheltered and sandy bays. Erosion is largely occurring due to wave action, although is limited to high water times at several locations.

The coastline to the east and south of Cape Wrath consists largely of high cliffs separating sheltered sandy bay and loch-head beaches. Several of these beaches have been identified as being potentially vulnerable to erosion/accretion, with wave action having been identified as causing some erosion on most beach systems

The potential for increases in storm events and rising sea levels have been identified, due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly from those developments located near to potentially vulnerable coastlines ( e.g. accretion at nearby Lewis coastlines and potential for erosion of sandy beaches located in the north west Scottish mainland).

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development. Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed at the North Minch bordered by Cape Wrath to the south east and Lewis to the south west, consists largely of coarse sediments ( e.g. sands, gravelly sands and sandy gravels).

Depths vary from 50 - 140m across the area, with the deeper areas generally located within the western part of the Draft Plan Option and in the central and western parts of the North Minch.

The area has generally moderate wave and tidal energies.

Some seabed disturbance and loss of habitat are likely to occur during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants), particularly in areas of fine sediments. However, significant increases in turbidity are considered unlikely given the largely coarse sediments and rock seabed formations within the option area.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site, with potential general impacts such as scour, deposition and abrasion identified. However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area beneath device foundations may be permanent, although some natural regeneration may occur upon decommissioning of devices and removal of infrastructure.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

There are a number of marine wreck sites within the Draft Plan Option, and coastal wreck sites have been identified to the south east and south west of it. This includes several wrecks on the north west coast of the Scottish mainland, including one designated wreck site which is also classified as an HMPA, and another which is a proposed HMPA.

There are also a significant number of concentrated scheduled monuments, (including duns, cairns and forts in Port Nis, the scheduled early monastic site of St Ronan's Church and the Butt of Lewis Lighthouse) to the south west, and the A-listed Cape Wrath lighthouse is located on the Scottish Mainland to the east.

The close proximity of the site footprint to Lewis and Barra, and the general remoteness of this region would suggest there is the potential for impacts on the setting of a number of coastal historic assets.

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Landscape / Seascape

The Draft Plan Option is located close to a number of landscape designations near Cape Wrath and along the northern and western coasts of the mainland. These include the Assynt - Coigach NSA, North West Sutherland NSA and Wester Ross NSA. The Sutherland coast is also designated as part of the North West Highlands Geopark.

Large parts of the Sutherland and Lewis coastlines have a high wildness level.

The Draft Plan Option is likely to be visible from the isle of Lewis to the south west and the Scottish mainland to the east and south. Large sections of the coastline are designated at local and NSA level, with many areas also noted as being wild land.

There is potential for changes to the character of the seascape and potentially on the setting of these designations, particularly the NSAs.

Visibility effects may occur during construction and maintenance periods as well as during operation. It is also likely that navigational aids ( e.g. marker buoys, lighting) will also have visual effects.

There are a number of potential offshore receptors including recreational boats that sail close to the option area.

Wind devices within the wind option may be visible from both Lewis and the mainland, including areas designated for landscape importance at a national level and areas of wildness.

Impacts are likely during construction, maintenance and operation phases.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Development within the Draft Plan Option would likely alter the current seascape. However the number of human receptors in these areas may be low.

Visual impacts could be greater for offshore receptors, such as recreational sea users, as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects. Impacts to the landscape and seascape character would also need to form part of project level assessments.

However visual impacts to onshore receptors could potentially be limited by construction further from the mainland, in particular to the north of the Draft Plan Option.

Given the high quality landscape identified, any development in this area should only be undertaken where significant effects can be avoided.

Development of the northern parts of the plan option could reduce visual and landscape/ seascape impacts.

Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

OWN1

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Draft Plan Option covers a large section of the waters immediately north west of the Orkney Isles, and there are a number of important designations in this area. Coastal SPAs on the Orkney isles include Hoy SPA, Marwick Head SPA, Rousay SPA, West Westray SPA, Papa Westray (North Hill and Holm) SPA, Calf of Eday SPA, all designated for their seabird assemblage interests (including Fulmar, Skua, Puffin, Kittiwake, Razorbill, Guillemot, Red Throated Diver, Cormorant, Gull, Tern, and Peregrine). Located between Orkney and Shetland is Fair Isle SPA, which has been designated for similar species.

Orkney also contains the Sanday SAC (designated for sandflats, reefs and Common seal), Faray and Holm of Faray SAC (designated for Grey Seal) and Stromness Heaths and Coast SAC (designated for its vegetated cliffs).

The Draft Plan Option is almost completely within the North West Orkney proposed MPA, designated for sand eels and marine geomorphology of the Scottish shelf seabed.

The seabird maps indicated a potential vulnerability for seabird collision and displacement from wind energy devices during breeding season, particularly in the south and east portions of the Draft Plan Option. However, this vulnerability may differ for individual species.

Cetacean distribution is high in a portion of the Draft Plan Option. Several Basking shark sightings have been recorded in the Orkney Islands, indicating the potential for encounters within the Draft Plan Option. Other elasmobranch species are also known to use these waters. The importance of the area for Seals is demonstrated by the presence of numerous Seal haul out areas located amongst the islands, and density mapping showing the presence of both Grey and Common seals in this area.

While having no designated sites for Atlantic salmon in Orkney, the area is known to be used by a wide range of fish species, including diadromous species such as Atlantic salmon, and many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

The seabed in the vicinity of the Draft Plan Option consists mainly of coarse sediments such as sandy gravels and gravelly sands. These benthic habitats are likely to contain species used to strong wave and tidal movements.

Vulnerability mapping indicates that there is the potential for collision and displacement impacts for birds, particularly during the breeding season. However, the potential for such effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Cetaceans and Seals in Scotland's northern waters, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

Whilst the area is not identified as a hot spot for Basking sharks they and other elasmobranchs (including priority marine features) are known to have used this area of the sea. Therefore there remains potential for the same impacts as listed above for Seals and Cetaceans.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats including loss of habitat, scouring, smothering, deposition and abrasion of seabed in areas with coarse sediments as a result of placing devices and their supporting infrastructure within this area. Of particular note is the potential for impacts to SACs in the area designated for their valued and vulnerable coastal and reef habitats.

While the potential for sediment movement from the installation of wind devices has been identified, this will likely depend on the type of foundation and installation technologies used.

There is potential for collision between seabirds and wind devices and their supporting infrastructure, and potential for displacement of bird species. However, the significance of the impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effect on populations cannot be ascertained at this strategic stage but should be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( e.g. scouring, smothering, sediment deposition and abrasion). However, it is expected sedimentation impacts may be limited as the existing environment is already dynamic.

Potential for significant effects to designated areas associated with grid infrastructure if it were to be sited in the vicinity of the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment, will be required to demonstrate that there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices.

Further research into the potential collision risks, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The result of monitoring of wind projects currently in the application process has the potential to help provide greater certainty on the scale of effects.

There is considered to be a potential risk to Seals in this area, particularly the potential for cumulative effects, and future developments should seek to demonstrate avoidance of effects.

Potential effects of supporting onshore/offshore grid connections will need to be considered to avoid effects on valued marine and coastal areas.

Impacts on important coastal and reef habitats should be monitored.

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether overlap with the North West Orkney proposed MPA would lead to adverse effects or whether co-location is possible. Projects will need to demonstrate through the EIA process that they are compatible with the conservation objectives of the MPA.

Population and Human Health

The waters to the north west of Orkney and nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising, sailing, diving and surfing.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the draft plan area were classified as being of good status under the WFD in 2011.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning, is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

Long-term coastal retreat and cliff erosion is occurring around the Orkney coast, this is likely due to the high energy coastlines present. Several coastlines, largely sheltered beaches and soft coasts, have been identified as being vulnerable to coastal erosion.

The potential for increases in storm events and rising sea levels have been identified, due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy. However it is unlikely that this would be significant given the high energy along coastlines and long term coastal retreat already observed.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed in the vicinity of the Draft Plan Option consists mainly of coarse sediments such as sandy gravels and gravelly sands. The depth of the seabed varies from 30 - 170m within the option area, with deeper areas located further to the north west.

The area has generally strong wave and tidal energy resources, particularly the northern portion of the option area.

Some seabed disturbance and loss of habitat are likely to occur during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants), particularly in areas of fine sediments. However, significant increases in turbidity are considered unlikely given the largely coarse sediments within the Draft Plan Option.

There may be the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site, with potential general impacts such as scour, deposition and abrasion identified. Associated impacts to vulnerable coastlines, such as those in Orkney's northern islands may occur ( e.g. coastal erosion, accretion). However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area beneath device foundations may be permanent, although some natural regeneration may occur upon decommissioning of devices.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly given the proximity to several eroding coasts in Orkney.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

There are a significant number of concentrated scheduled monuments, including numerous wrecks, brochs, cairns and fortification, within marine and coastal areas located near to the Draft Plan Option.

The most notable site is the Heart of Neolithic Orkney World Heritage Site which is located to the south of the area, however, much of the Orkney's coastal waters have been identified for their potential for submerged archaeology.

There is a potential for impacts on the setting of historic features including the Heart of Neolithic Orkney World Heritage Site.

The likely presence of submerged archaeology means that there is potential for direct effects on any remains. However, development which includes archaeological survey may also have some positive effects by contributing to knowledge/understanding about the marine historic environment.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites and seek to mitigate accordingly.

Where development is in an area considered likely to have submerged archaeology projects should seek to identify and avoid direct impacts on features.

Development in this area must demonstrate no adverse effects on the Heart of Neolithic Orkney World Heritage Site.

Landscape / Seascape

The southern end of the Draft Plan Option is likely to be visible from the Hoy and West Mainland NSA, from locally designated landscapes, and from the coastal edge of the Heart of Neolithic Orkney WHS. Parts of the the Draft Plan Option may also be visible from the Shetland NSA.

Large parts of the Hoy coastline have a high wildness level, and the coastal edges of the Scottish mainland, while located well south of the Draft Plan Option, also have sections of wild land.

The Draft Plan Option, particularly in the south, is likely to be visible from designated and wild parts of the Orkney coastline.

There is the potential for changes to the character of the seascape in this area, and also on the setting of the identified designations, particularly the NSA and WHS.

Visibility effects may occur during construction and maintenance periods as well as during operation. It is likely that navigational aids ( e.g. marker buoys, lighting) will also have visual effects.

There are a number of potential offshore receptors including recreational boats that sail close to the option area.

Wind energy devices and supporting infrastructure within the Draft Plan Option is likely to be visible from Orkney, including from areas designated for its landscape importance at a national level, and as areas of wildness. The significance of potential visual effects in these areas can be greater than for other parts of the coastline.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Development in the plan option would alter the current seascape and potentially affect its character in some areas.

Visual impacts could be greater for offshore receptors, such as recreational sea users, as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects. However visual impacts to onshore receptors could potentially be limited by construction further from the Orkney coastline, in particular to the west and north of the Draft Plan Option.

Impacts to the landscape and seascape character would also need to form part of project level assessments.

Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

Development of the western and northern parts of the Draft Plan Option could reduce potential visual and landscape/ seascape impacts.

OWN2

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Draft Plan Option covers a large section of the waters to the south east of the Shetland Isles. There are a number of important designations in the area including coastal sites such as Noss SPA, Fetlar SPA and Sumburgh Head SPA, which are all designated for seabird assemblage (including Fulmar, Skua, Puffin, Kittiwake, Guillemot). Between Shetland and Orkney lies Fair Isle SPA, designated for similar bird species to these sites. Mousa SPA, located west of OWN2 is designated for Storm petrel and Arctic tern.

Other designations near to the area include Mousa SAC (designated for reefs, caves and Common seal), Yell Sound Coast SAC (designated for otter and Common seal) and Pobie Bank c SAC which overlaps the northern boundary of OWN2 (proposed for its reef habitats).

There is a large amount of bird interests in the area, and hence some seabird vulnerability for collision and displacement with wind energy. However, this vulnerability may differ for individual species.

Cetacean distribution is considered high, particularly to the west of the draft plan area. A number of Basking shark sightings have been recorded along the eastern coast of Shetland indicating the potential for encounters in this area. Other elasmobranch species are known to use this area.

The importance of the area for both Grey and Common seals is demonstrated by the presence of Seal haul out areas located amongst the islands, and the findings of Seal density surveys undertaken in the area indicating their use of waters around the Draft Plan Option.

While there are no SAC sites designated for Atlantic salmon in Shetland, the area is known to be used by a wide range of fish species, including diadromous species, and by many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

The seabed surrounding Shetland consists mainly of gravelly sands and circallittoral coarse sediments. These benthic habitats are likely to contain species used to strong wave and tidal movements, particularly in the south west portion of OWN2.

Vulnerability mapping indicates that there may be the potential for collision and displacement of birds during both winter and breeding seasons. The potential for such effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Cetaceans and Seals in Scotland's northern waters, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

Whilst the area is not identified as a hot spot for Basking sharks they and other elasmobranchs (including PMFs) are known to have used this area of the sea. Therefore, there remains potential for the same impacts as those listed above for Seals and Cetaceans.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats including habitat loss, scouring, smothering, deposition and abrasion of seabed in areas with coarse sediments as a result of placing devices and their supporting infrastructure within this area.

The potential for impacts to features of the c SAC, designated for reef habitats, overlapping with the Draft Plan Option. Direct impacts from activities such as installing devices in the north of the Draft Plan Option, and indirect effects from sediment movement on benthic habitats are have been identified. However, this will likely depend on factors including the type of foundations and installation technologies used. There are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

There is potential for collision between seabirds and wind devices, and also for the displacement of bird species. However, the exact significance of the impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effect on populations cannot be ascertained at this strategic stage but should be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( e.g. scouring, smothering, sediment deposition and abrasion). It is expected sedimentation impacts may be limited as the existing environment is already dynamic.

Potential for significant effects to designated areas associated with installation of grid infrastructure if it were to be sited in the vicinity of the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate that there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices.

Further research into the potential collision risks, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The results of monitoring of wind projects currently in the application process have the potential to help provide greater certainty on the scale of effects.

It is recommended that the northern boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Pobie Bank c SAC would lead to adverse effects on its integrity or whether co-location is possible. Project level HRA must demonstrate development does not adversely affect the integrity of the c SAC.

The potential effects of supporting onshore/offshore grid connections will need to be considered to avoid impacts on coastal areas.

Impacts on important coastal and reef habitats should be monitored.

Population and Human Health

The waters to the south east of Shetland and nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising and sailing.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value.

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the draft plan area were classified at being of good status under the WFD in 2011.

There are a number of designated shellfish waters within the vicinity of the Draft Plan Option around the isles of Shetland.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

While littoral processes in Shetland are dominated by wave action, few areas within the south east of the Isles are considered vulnerable to coastal erosion or accretion, with the exception of a small number of sheltered beaches identified at the southern tip of the isles.

The potential for increases in storm events and rising sea levels have been identified, due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly to soft and sandy coastlines located north of Aberdeen.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed in the vicinity of the Draft Plan Option consists mainly of coarse sediments ( i.e. sandy gravels, gravelly sands and sands).The depth of the seabed is generally constant across the Draft Plan Option, ranging between 100 - 140m in depth.

While the area, has generally low wave and tidal energy resources, a moderate tidal area is located off Sumburgh Head at the southern point of the Shetland Islands.

Some seabed disturbance and loss of habitat are likely to occur during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants), particularly in areas of fine sediments. Significant increases in turbidity are unlikely given the largely coarse sediments within the Draft Plan Option.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site, with potential general impacts such as scour, deposition and abrasion identified at the site. There may be the potential for adverse impacts to coastal areas ( e.g. erosion of vulnerable coasts, accretion). However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area beneath device foundations may be permanent, although some natural regeneration may occur upon decommissioning of devices.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

The Draft Plan Option is close to the southern part of mainland Shetland, Mousa and Bresay, areas which are particularly rich in historic assets including scheduled prehistoric houses, brochs and settlements. In general terms, the coastline of Shetland is particularly sensitive with many scheduled brochs, forts and other sites along its coast. The most notable is the A-listed Sumburgh Head Lighthouse at the southern tip of the islands.

Numerous SSMEI protected wrecks are located along the south east coastline of the islands

There is the potential for impacts on the setting of a number of coastal historic assets including the Sumburgh Head Lighthouse.

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of sites including the Sumburgh Head Lighthouse and seek to mitigate accordingly.

Landscape / Seascape

There are a limited number of landscape features on the south west coastline of Shetland. The Draft Plan Options location off the western Shetland coast would mean that a large portion of this would not be visible from the Shetland NSA. Views of the southern plan option from the south of the NSA are possible but may be too be minimal. The Draft Plan Option may however be visible from the Shetland NSA.

Parts of the Shetland coastline have a high wildness level.

Whilst there is potential for changes to the character of the seascape, there are few landscape designations in proximity to the Draft Plan Option. However, the option may be visible from some coastal communities between Lerwick and Sumburgh airport.

Visibility effects may occur during construction and maintenance periods as well as operation. It is likely that navigational aids ( e.g. marker buoys, lighting) will also have visual effects.

There are a number of potential offshore receptors including recreational boats that sail close to the option area.

Wind devices and their supporting infrastructure in this area may be visible from the Shetland coastline.

Impacts are likely during construction, maintenance and operational phases.

Development in the plan option would alter the current seascape and potentially affect its character in some areas.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Visual impacts could be greater for offshore receptors, such as recreational sea users.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects, however visual impacts to onshore receptors could potentially be limited by construction further from the coast, in particular the south and east of the Draft Plan Option.

Impacts to the landscape and seascape character would also need to form part of project level assessment.

Development that will affect NSA should avoid adverse effects on the integrity of the area or the qualities for which it has been designated.

OWNE1

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Draft Plan Option is in proximity to a number of designated sites, including Buchan Ness to Collieston SPA, Fowlsheugh SPA, Loch of Strathbeg SPA, and Ythan Estuary, Sands of Forvie and Meikle Loch SPA, all of which are designated for seabird assemblages (including Guillemot, Kittiwake, Fulmar, Terns, Gulls and Geese, amongst others).

Furthermore it is likely that seabirds originating from the Firth of Tay and Eden Estuary SPA and, Troup, Pennan and Lion's Head SPA, Firth of Forth SPA, and Common Seals originating from the Firth of Tay and Eden Estuary SAC may travel to use these offshore waters. SACs at the Rivers Spey, Dee and South Esk located within the north east region have all been designated for Atlantic salmon interests.

A number of important coastal sites are also located in proximity to the site, including Foveran Links SSSI known for sand dunes and coastal geomorphology.

The Draft Plan Option overlaps with the Southern Trench MPA search area, which has Minke whale, White-beaked dolphin and geodiversity interests.

The seabird maps in the baseline show a potential a collision and displacement vulnerability for seabirds from wind energy devices, particularly in the west and east of the Draft Plan Option during breeding season. However, this vulnerability may differ for individual species.

The distribution of Cetaceans is considered to be high in the southern portion of the Draft Plan Option. While no Basking shark sightings have been recorded in the Draft Plan Option, several have been recorded along the north east coast, indicating the potential for encounters in this area. Other elasmobranch species are also known to use this area. Seal density mapping indicates the likely use of the area Seals, particularly Grey seals. There are seal haul out areas located along the coast to the west in the Inner Moray Firth.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

Benthic habitats in the region largely consist of sand near to the coast, with coarser sediments including gravelly sands further offshore. These habitats may be susceptible to hydrodynamic change.

Vulnerability mapping indicates there is the potential for collision and displacement of birds, particularly during the breeding season and in areas to the west and east of the Draft Plan Option. The potential for such effects will depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Cetaceans, Seals and Atlantic salmon along Scotland's north-east coastline, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

Whilst the area is not identified as a hot spot for Basking sharks they and other elasmobranchs (including priority marine features) are known to have used these waters. As such, there remains potential for the same impacts as listed above for Seals and Cetaceans.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats including loss of habitat as a result of placing devices on the seabed and from scouring, smothering, deposition and abrasion of seabed in areas with muddy sediments. However, there are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

There is potential for collision between seabirds and wind devices, and also the potential for displacement of bird species. There is also the potential for cumulative effects for highly mobile birds and mammals as a result of developing the Draft Plan Options and planned infrastructure. However, the significance of the impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish include barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effect on populations cannot be ascertained at this strategic stage but should be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( e.g. scouring, smothering, sediment deposition and abrasion).

Potential for significant effects to designated areas associated with the installation of grid infrastructure if it were to be sited in the vicinity of the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate that there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices.

Further research into the potential collision risks, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The results of monitoring of wind projects currently in the application process have the potential to help provide greater certainty on the scale of effects.

Monitoring and information to inform the developing Southern Trench MPA search area status could also add greater clarity to potential effects as the consultation process on MPAs develops.

It is recommended that the southern edge of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Southern Trench MPA search area would lead to adverse effects or whether co-location is possible. Projects will need to demonstrate through the EIA process that they are compatible with the conservation objectives of the MPA.

Potential onshore effects of supporting grid connections will need to be considered to avoid effects on the sensitive coastal areas.

Population and Human Health

The waters to the north east of Aberdeenshire and nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising, bathing and surfing.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the draft plan area were classified at being of good (off Aberdeen and to the south) to high status (north of Aberdeen) under the WFD in 2011.

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

Significant sections of the Aberdeenshire coastline near the draft plan area have been identified as being potentially vulnerable to erosion or accretion, particularly to the north of Aberdeen between the city and Newburgh. Erosion has been observed in this area, with accretion observed further to the north (River Ythan), although the sediment transport patterns are complex around the Don and Ythan Estuaries. Dune erosion has also been observed along sections of the coastline.

The potential for increases in storm events and rising sea levels have been identified, due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly to soft and sandy coastlines located north of Aberdeen.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed off the east Aberdeenshire coast consists predominantly of sand near to the coast, with coarser sediments such as gravelly sands further offshore. Depths vary from with depths ranging from around 60 - 110m offshore.

The area has generally low to moderate wave and tidal energy resources, increasing nearer to the north east part of the Scottish Mainland.

Some seabed disturbance and loss of habitat are likely during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants), particularly in areas of fine sediments. Significant increases in turbidity are unlikely given the largely coarse sediments within the option area, and moderate wave and tidal energies present.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site. The potential for general impacts such as scour, deposition and abrasion have been identified in the area, and also related impacts to vulnerable coastlines ( e.g. between Aberdeen and the River of Don). However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area may be permanent beneath device foundations, although some natural regeneration may occur upon decommissioning of devices and removal of infrastructure.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly along important sections of the Aberdeenshire coastline ( e.g. Ythan Estuary, etc.).

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

There are a number of sensitive coastal sites in the vicinity of the Draft Plan Option, including the A-listed Girdle Ness Lighthouse, Castle Cowie and Dunnottar Castle amongst others.

Numerous wrecks sites are located around the north east coastline of the Scottish mainland, both within the Draft Plan Option, between the area and the coast, and in nearby areas to the north. However, none of these wrecks have been designated.

There is the potential for impacts on the setting of a number of coastal historic assets including Girdle Ness Lighthouse and several castles located along the coastline.

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments, particularly those in benthic areas susceptible to erosion or accretion.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of the sites identified in the baseline and seek to mitigate accordingly.

Landscape / Seascape

There are no national level designations in the vicinity of the Draft Plan Option. While the Draft Plan Option is located near to a number of important local landscape areas along the Aberdeenshire coast [11] .

The wilderness value of the coastline near the Draft Plan Option is considered to be low.

The Draft Plan Option is potentially visible from several settlements along the coastline including areas around Aberdeen city.

There is potential for changes to the character of the seascape and potentially on the setting of important local landscape areas. However, the coastline has a number of existing shipping movements and infrastructure, and as a result, the scale of any effect may be reduced.

Visibility effects may occur during construction and maintenance periods as well as during operation. It is likely that navigational aids ( e.g. marker buoys, lighting) will also have visual effects.

There are a number of potential offshore receptors including recreational boats that sail close to the option area.

Wind devices within the Draft Plan Option may be visible from local landscape quality areas. However much of the area is undesignated, has very little wild land and is already busy in terms of shipping movements. Whilst plan option would alter the current seascape and potentially the character of seascape the significance of effects is considered to be limited as a result.

Impacts are likely during both the construction and operation.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Visual impacts could be greater for offshore receptors, such as recreational sea users as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects, however visual impacts to onshore receptors could potentially be limited by construction further from the mainland, in particular the east of the Draft Plan Option.

Impacts to the landscape and seascape character would also need to form part of project level assessment.

OWNE2

SEA Topic

Summary of Key Baseline Evidence

Potential for effects

Characteristics

Mitigation available and potential residual effects

Biodiversity, Flora and Fauna

The Draft Plan Option is located in proximity to a number of designated sites, including Buchan Ness to Collieston SPA, Loch of Strathbeg SPA, and Troup, Pennan and Lion's Heads SPA; all of which are designated for seabird assemblages (including Guillemot, Kittiwake, Fulmar, terns, gulls and geese amongst others). Far to the west is a number of designated sites, including the Moray Firth SAC which is designated for mobile Bottle-nosed dolphins amongst other features. SACs at the Rivers Spey, Dee and South Esk located within the north east region have all been designated for Atlantic salmon interests.

A number of important coastal sites are also located in proximity to the site, including Rosehearty to Fraserburgh Coast SSSI and Gamrie and Pennan Coast SSSI, with bird and/or coastal geological interests.

Furthermore, it is likely that seabirds originating from the Firth of Tay and Eden Estuary SPA and; and Common seals originating from the Firth of Tay and Eden Estuary SAC may travel to use these offshore waters.

The Draft Plan Option overlaps with the Southern Trench MPA search area, which has Minke whale, White-beaked dolphin and geodiversity interests.

A potential vulnerability for seabirds to collision and displacement from wind energy was identified in the south west portion of the plan option, particularly during breeding season. However, this vulnerability may differ for individual species.

Cetacean distribution data indicates the possibility of Cetacean encounters in the Draft Plan Option, particularly in the southern part of the area. Several Basking shark sightings have been recorded along the northern Aberdeenshire coastline, indicating the potential for encounters in this area. Other elasmobranch species are also known to use this area. Seal density mapping and the presence of Seal haul out areas to the west of OWNE2 in the Inner Moray Firth, indicates the importance of the area to Grey seals and their likely presence in the vicinity of the Draft Plan Option.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including Sea trout and many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

Benthic habitats in the region are largely sandy or gravelly based.

Vulnerability mapping included in the baseline indicates there is the potential for collision and displacement for birds, particularly in south west portion of the plan option and particularly during breeding season. However, the potential for such effects likely depend on a range of factors including the bird species considered ( e.g. vulnerability varies for different bird species), and the size and design of wind energy devices ( e.g. some species are known to be more susceptible to collision with larger devices, and others with devices with lower clearance above the water surface).

Given the likely presence of marine mammals and fish, particularly Cetaceans, Seals and Atlantic salmon along Scotland's north-east coastline, there may be the potential for effects such as barriers to movement, collision with the devices and associated infrastructure, above and below water noise impacts during construction and operation, and aggregation effects ( e.g. aggregation of predators near structures). However, there are currently gaps in research knowledge which mean it is difficult to establish the likelihood of impact.

Whilst the area is not identified as a hot spot for Basking sharks they and other elasmobranchs (including priority marine features) are known to have used this area of the sea. Therefore, there remains potential for the same impacts as those listed above for Seals and Cetaceans.

The review of technologies identified potential effects from EMF on fish and elasmobranchs although research into the magnitude of effects demonstrates that this is uncertain.

There is potential for impacts on benthic habitats including loss of habitat from placement of devices on the seabed, and from scouring, smothering, deposition and abrasion of seabed. However, there are currently gaps in research knowledge which make it difficult to establish certainty of such effects.

There is potential for collision between seabirds and wind devices, and potential for displacement of bird species. There is also the potential for cumulative effects for highly mobile birds and mammals as a result of developing the Draft Plan Options and planned infrastructure. However, the significance of the impact is uncertain as effects on the population viability of individual species are not known.

Potential effects on Cetaceans, Seals, elasmobranchs and fish including barriers to movement, collision with infrastructure, and possible noise impacts as a result of piling activities associated with installing devices. These effects may range from changes to existing feeding behaviour to mortality, although the precise effect on populations cannot be ascertained at this strategic stage but should be a consideration at the project level ( e.g. in monitoring).

Effects associated with construction activities, such as fauna disturbance from underwater noise associated with piling for monopile or jacket devices, would be temporary but longer term effects from wind devices with underwater infrastructure remain.

Potential for EMF impacts on fish and elasmobranchs from electricity cables associated with wind energy devices. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

Potential for direct benthic effects associated with the siting and construction of devices, and indirect effects including sediment movements ( e.g. scouring, smothering, sediment deposition and abrasion).

Potentially significant effects to designated areas associated with grid infrastructure if it were to be sited in the vicinity of the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment, will be required to demonstrate that there will be no significant impacts on the birds and mobile species in the vicinity as a result of collision with wind devices. The result of monitoring from projects in this region currently in the application process has the potential to help provide greater certainty on the scale of these effects.

Further research into the potential collision risks, displacement and the effects on Cetaceans, Seals elasmobranchs and fish will help to identify the potential for significant effects.

To date research has indicated that there are uncertain effects of EMF and noise on fish and elasmobranchs. The result of monitoring of wind projects currently in the application process has the potential to help provide greater certainty on the scale of effects.

Monitoring and information to inform the developing Southern Trench MPA status could also add greater clarity to potential effects as the consultation process on MPAs develops.

It is recommended that the southern edge of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Southern Trench MPA search area would lead to adverse effects or whether co-location is possible. Projects will need to demonstrate through the EIA process that they are compatible with the conservation objectives of the MPA.

Potential onshore effects of supporting onshore/offshore grid connections will need to be considered to avoid effects on areas on sensitive coastal areas.

Population and Human Health

The waters to the east of Aberdeenshire and nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising, bathing and surfing.

During adverse conditions recreational craft are recommended to stay 2-3 miles offshore of Kinnaird Head and Rattray Head which might bring craft closer to the boundary of this option.

There is potential for collisions between recreational vessels and offshore energy infrastructure and supporting vessels, particularly during installation. However, given the height of wind turbines these would be highly visible during most conditions which should reduce collision risk.

The presence of offshore wind turbines has the potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value.

Any collision could directly affect vessels and passengers, however it is not expected that wind developments would result in a significant increase in collisions.

It is difficult to predict the precise impact of potential changes to amenity on recreational use of the area. Some displacement could be permanent leading to recreational activities being discontinued. However it is likely that most activities could continue within a smaller range or in other nearby locations.

Potential mitigation for collisions through the inclusion/mapping of offshore energy developments on navigational charts and the use of navigational aids (such as marker buoys and lighting, etc.) in the vicinity of the infrastructure.

When planning projects, developers could work with the recreation sector to consider best how recreational activities might continue within the option boundary. Early consultation can also help to reduce impacts on important cruising routes.

There may be the requirement for commercial shipping to be excluded from developed areas. This would be determined through further engagement between MS- LOT and the relevant navigation authorities at the project level.

Water and the Marine Environment

The coastal waters in the vicinity of the draft plan area were classified as being of high status under the WFD in 2011, with the exception of waters off the Fraserburgh coast (moderate status) and off Peterhead (good status).

Potential for adverse water quality impacts during installation, operation and decommissioning of the developments ( e.g. increased turbidity caused by works on the seabed, contamination from installation and maintenance vessels).

Wind turbines that use gravity based foundations that use sediment as fill, may carry a pollution risk depending on where the sediment is sourced.

Impacts associated with any contamination from seabed material disturbed during installation or potentially decommissioning is likely to be of localised and temporary nature, with the significance of effects dependant on the level of contamination. Impacts during operation and maintenance are considered less likely.

The significance and characteristic of impacts associated with contamination from vessels is uncertain and cannot be described beyond the potential for it to occur.

Pollution risks associated with installation, maintenance and decommissioning of devices should be reduced and limited through building mitigation into construction procedures, to avoid discharges of harmful material and substances.

Further assessment work may be required to reduce uncertainty regarding potential impacts on water quality, particularly on including shellfish waters. This includes a recommendation for hydrodynamic and water quality modelling as part of project level assessment

Climatic Factors

Significant sections of the north east Scottish coastlines northern have been identified as being potentially vulnerable to erosion or accretion, particularly between Fraserburgh and Peterhead Combs. Both erosion and accretion has been observed in this area, with wave action also identified eroding dune systems near St Combs.

The potential for increases in storm events and rising sea levels have been identified, due to the effects of climate change.

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy particularly for soft coastlines between Fraserburgh and St. Combs.

Likely contributions to achieving GHG reductions through replacing energy generation from non-renewable sources to renewable sources.

Significance and character of effects are unknown. Depending on how offshore infrastructure affects hydrodynamics the effects on coastal erosion and accretion could be positive or negative. However any effects that do occur are likely to depend on the specific nature and location of the proposed development.

Effects on the coastline are likely to be indirect.

Project level assessment of hydrodynamic changes, as a result of renewables development, should include any relevant climate related changes to the marine environment when assessing impacts.

Marine Geology and Coastal Processes

The seabed off the north east Aberdeenshire coast is more variable than that to the south, consisting of sandy gravel near the coastline, interspersed with large pockets of slightly gravelly sand and gravelly sand near to the tip, and sandy gravel, sand and muddy sand areas to the west towards the Moray Firth.

There is a sharp increase in depth to the north of the Draft Plan Option, ranging between 60 - 200m at its deepest due to the presence of the Moray Firth trench.

The area has generally moderate wave and tidal energy resources, particularly off the coast between Fraserburgh and Peterhead.

Some seabed disturbance and loss of habitat is likely during the site preparation and placement of device foundations. The scale of such disturbance is likely dependent on the type and size of the device.

Sediment disturbance which occurs during the installation process could also lead to secondary impacts ( e.g. smothering, release of existing contaminants), particularly in areas of fine sediments. Significant increases in turbidity are unlikely given the largely coarse sediments within the Draft Plan Option.

There is the potential for offshore developments within the Draft Plan Option to alter sediment dynamics and tidal flow fluxes in the vicinity of the site. The potential for general impacts such as scour, deposition and abrasion have been identified in the area, and also related impacts to vulnerable coastlines ( e.g. Fraserburgh and St Combs). However, these systems are likely to be complex, and as such, the potential for impacts is likely to be site specific and dependent on factors such as the type and size of the devices and their foundations.

Direct impacts such as disturbance of the seabed during installation are likely to be temporary and localised.

Loss of seabed area may be permanent beneath device foundations, although some natural regeneration may occur upon decommissioning of devices and removal of infrastructure.

Changes in sediment dynamics and direct impacts such as scour, deposition and abrasion of seabed sediments are likely to be limited to the installation and operation phases of developments. However, in some circumstances, the effects of such changes may have long-term effects in coastal areas ( e.g. the deposition of sediments in nearby coastal areas).

When projects are in the design process, consideration should be given to the location and arrangement of devices in order to build in mitigation to avoid potential impacts on marine geology and coastal processes, particularly given the proximity to important and eroding dune systems in the North East region.

It is recommended that sediment dynamic modelling is undertaken at project level to demonstrate potential effects in order to consider appropriate mitigation.

Mitigation measures should include the design and use of rock scour protection around the base of gravity-based foundations, jacket and monopile devices placed on or into the seabed.

Historic Environment

There are a number of important coastal sites in the vicinity of the Draft Plan Option, including a range of listed castles and churches. These sites include the scheduled Kinnaird Head Castle and Lighthouse, and a various castles and churches located near Fraserburgh.

Numerous wrecks sites are located around the north east coastline of the Scottish mainland, both within the Draft Plan Option, between the area and the coast, and in nearby areas to the south and south east. However, none of these wrecks have been designated.

There is the potential for impacts on the setting of a number of coastal historic assets including Kinnaird Head Castle and Lighthouse, and important castles and churches located near Fraserburgh.

Potential impacts on historic wreck sites in the vicinity of the developments from installation and operation of offshore energy developments, particularly those in benthic areas susceptible to erosion or accretion.

Direct effects on historic assets e.g. loss of assets caused by changes to coastal processes or the siting of offshore developments, would likely be permanent. The significance of the effects would, depend on the significance of the receptor.

Effects on the setting of historic environment features would be indirect, and last for the lifespan of the development.

Direct effects on historic environment features can be avoided through appropriate siting of devices away from vulnerable coastlines and known historic marine features.

Project level assessments should consider the potential for impacts on the setting of the sites identified in the baseline and seek to mitigate accordingly.

Landscape / Seascape

There are no national level designations in the vicinity of the Draft Plan Option. While the Draft Plan Option is located near to a number of important local landscape areas along the Aberdeenshire coast [12] .

The wilderness value of the coastline near the Draft Plan Option is low.

The Draft Plan Option is potentially visible from several settlements along the coastline.

There is potential for changes to the character of the seascape and potentially on the setting of important local landscape areas. However, the coastline has a number of existing shipping movements and infrastructure, and as a result, the scale of any effect may be reduced.

Visibility effects may occur during construction and maintenance periods as well as during operation. It is likely that navigational aids ( e.g. marker buoys, lighting) will also have visual effects.

There are a number of potential offshore receptors including recreational boats that sail close to the option area.

Wind devices within the Draft Plan Option may be visible from local landscape quality areas. However much of the area is undesignated, has very little wild land and is already busy in terms of shipping movements. Whilst plan option would alter the current seascape and potentially the character of seascape the significance of effects is considered to be limited as a result.

Impacts are likely during both the construction and operation.

Lighting of wind devices may result in visual effects during day and night, although the scale of any effects for onshore receptors is expected to decrease with greater distance from the light source.

Visual impacts could be greater for offshore receptors, such as recreational sea users as their proximity to devices would be greater than onshore receptors.

Full visual impact assessment will be required at the project level ( EIA) to establish the visual envelope and significance of effects. However visual impacts to onshore receptors could potentially be limited by construction further from the mainland, in particular to the north and east of the Draft Plan Option.

Impacts to the landscape and seascape character would also need to form part of project level assessments.


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