Publication - Strategy/plan

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
3 Tidal Draft Plan Option

87 page PDF

1.4 MB

3 Tidal Draft Plan Option

TSW1

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 overlaps with Luce Bay and Sands SAC (primarily designated for habitats and sediments) and the Mull of Gallowy SAC. Furthmore it is located near 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.

Further east is the Solway Firth SAC (with Sea and 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 potential vulnerability for collision of diving birds was identified, particularly during the breeding season and in the north west part of TSW1 (near to the Rhins Peninsula). However, this vulnerability may differ for individual species.

The available distribution data indicates that Cetaceans have been sighted 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 the presence of Seals in this area. Basking sharks sightings are common around the Isle of Man and a number of recorded sightings have been made in the Firth, particularly in the vicinity of TSW1. It is believed that Basking sharks travel up the west coast of Scotland, and other species of elasmobranch are known to use this area.

Fish species found in the area might include diadromous species, such as Atlantic salmon and Sea trout, Lamprey and many commercially caught species. The region also contains important nursery grounds for several commercially important species of fish.

The coastline is a mix of intertidal rocks and sediments with the predominant habitat type shallow sub tidal sediments. Predominantly coarse sediments are found in the vicinity of the Draft Plan Option. The benthos present is expected to be conditioned to the dynamic environment of the Solway.

Potential vulnerabilities are identified for diving bird collision and displacement with tidal energy devices in relation to the Draft Plan Option, particularly during the breeding season. Any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 creation of barriers to movement, collision with the device components and associated infrastructure, and below water noise impacts during construction and operation. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

While the presence of sub-tidal sediments indicates the potential for smothering of benthic habitats, the dynamic and turbid environment in the Solway would indicate that the benthos present will likely be conditioned to dynamic environments, and as a result, the magnitude of potential impacts may be reduced. However, there are gaps in present research knowledge to establish certainty of effect relating to sediment effects from tidal energy devices.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified, particularly for important species such as Gannet. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

The western edge of the plan area in particular may coincide with routes used by Basking sharks and cetaceans.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Luce Bay, if associated grid infrastructure was to be sited in the Draft Plan Option.

Project level assessment ( EIA) that includes specific modelling and/or assessment will be required to demonstrate that there is no significant impact on the Luce bay SAC habitats as a result of changes to hydrology and sedimentation from the construction of devices. Similar work may be required to demonstrate no significant risk to diving birds and other marine fauna from the presence of tidal devices in this Draft Plan Option area.

The potential effects associated with grid infrastructure could be avoided if supporting onshore/offshore grid connections were located away from 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.

It is recommended that the boundary of the Draft Plan Option is kept under review as part of ascertaining whether the overlap with the Luce Bay and Sands SAC and the Mull of Galloway 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 SACs.

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.

Important shipping routes are identified in the Marine Atlas in this area.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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 and within Luce Bay to the north 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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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 has 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 [13]

The seabed in the vicinity of the Draft Plan Option is 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 energies 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 during the site preparation and placement of device foundations, although the scale is 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 impacts such as scour and abrasion at the site, and deposition of sediments in nearby areas and may 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 will be site specific and depend on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 near and within 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 could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

The Solway Firth and surrounding coastlines are rich in historic features, particularly the south coast of Dumfries and Galloway near the Mull of Galloway and Burrow Head where there are numerous scheduled monuments including coastal fortifications, chambered cairns and early church sites, including at Whitthorn Peninsula.

Numerous historic wrecks have been identified in or near to draft plan 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. Effects on the setting of historic assets will only arise where devices have visible above water components or support structures.

There may also be the potential for impacts on historic wreck sites if devices and supporting infrastructure are installed near to these sites.

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.

Effects on features of the historic environment 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. However, direct views to the Draft Plan Option from these may be limited to its eastern edge only.

The east and west parts of the Draft Plan Option are very close to the Dumfries and Galloway coastline, much of which is covered by local designated landscapes. These include the southern tip of the Rhins Peninsula (Rhins Coast RSA), Burrowhead (Machars Coast RSA) and within Luce Bay (Mochrum Lochs RSA).

The elements of tidal energy developments that pierce the water surface may be visible from the Luce Bay coastline and areas of local landscape designations.

It is considered unlikely that some infrastructure associated with tidal devices within the Draft Plan Option has potential to be visible from coastal NSAs.

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

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

The surface-piercing components of tidal devices within the plan option areas may be visible from the coast near Luce Bay, including from areas designated for their landscape importance. As the majority of the tidal energy device infrastructure will be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

Impacts will be more likely during construction and maintenance than in the operational phase.

Development within the Draft Plan Option would alter the current seascape, although this may depend on the type of tidal technology adopted and the height of surface-piercing components above the water surface.

Lighting of devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects on nearby coastal areas ( e.g. Luce Bay). However, the potential for visual impacts to onshore receptors could potentially be limited by undertaking construction further from the mainland and as a result of the majority of devices and development being below the water surface.

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.

TW1

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 several designated sites including the Rinns of Islay SPA (designated for a number of bird species including Chough, Greenland white-fronted goose and Whooper swan), the Oa SPA and SSSI (designated for Chough) and South-East Islay Skerries SAC (for Common seal interests).

Vulnerability of collision for diving birds was identified in winter and breeding periods, the potential for slightly higher vulnerability was identified in the south east part of TW1. However, this vulnerability may differ for individual species.

Seal density mapping and the presence of seal haul out areas indicate this is a well-used area for marine mammals, particularly for Grey seals in the north of TW1 and Common seals in the south east of TW1.

While cetacean distribution is relatively low in the vicinity of the Draft Plan Option, these species may be present in the area. Furthermore the Skerries and Causeway SAC, in Northern Irish waters, is designated for Harbour porpoise. Basking sharks have also been sighted in the vicinity of TW1, and Given the likely presence of a known 'hotspot' around Tiree and Mull to the north, these species and other elasmobranchs may also be present in the Draft Plan Option area,

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.

Sediments in the region are largely coarse ( e.g. sands, gravelly sands, gravels, etc.) and may be susceptible to hydrodynamic change. These benthic habitats are likely to contain species used to strong tidal movements.

Potential vulnerabilities were identified for diving bird collision and displacement with tidal energy devices in relation to the Draft Plan Option, particularly in the south east part of TW1. Any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 be the potential for effects such as the creation of barriers to movement, collision with the device components and associated infrastructure, and below water noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas and the nearby SAC. Furthermore, Harbour porpoise are likely to frequent this area. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

While the presence of sub-tidal sediments indicates the potential for smothering of benthic habitats, the dynamic and turbid environment in the Solway would indicate that the benthos present will likely be conditioned to dynamic environments, and as a result, the magnitude of potential impacts may be reduced. However, there are gaps in present research knowledge to establish certainty of effect relating to sediment effects from tidal energy devices.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified, particularly for important species such as Gannet. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 SPAs and SACs in the vicinity as a result of changes to hydrology and sedimentation from the construction of devices, and from direct impacts on bird and seal species.

The results of monitoring projects currently in the application process have the potential to help provide greater certainty on the scale of these effects.

The potential effects associated with grid infrastructure could be avoided if supporting onshore/offshore grid connections were located away from Islay.

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

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

Important shipping routes are identified in the Marine Atlas in this area.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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.

There is one designated shellfish water within the vicinity of the Draft Plan Option off Jura.

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

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 sections of soft and sheltered beaches identified in the south west part of Islay as being potentially vulnerable to erosion and accretion. While no significant erosion has been identified, accretion has been identified in sheltered Laggan Bay on the south west coast, Machir Bay on the west coast and Loch Gruinard on the north coast of Islay.

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 area appears 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 largely composed of coarse sediments ( i.e. sandy gravels and gravelly sands) and may be susceptible to hydrodynamic change.

While the region has moderate to high wave and tidal energies across much of the Draft Plan Option, with several areas of strong tidal energy located immediately west and south west of Islay.

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

As such, 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. This could lead to potential general impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines ( e.g. identified areas of accretion in West Islay). However, these systems are likely to be complex and ,as such, the potential for impacts will be site specific and depend on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 in coastal areas around 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 could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

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 and south coasts of Islay.

Nearby coastal areas also contain a wide range of historical features located either on the shoreline or which are of coastal relevance ( e.g. designated sites such as lighthouses, listed buildings and, scheduled monuments such as fortifications, early church sites). Notable sites include the Rhinns of Islay Lighthouse in Orsay, and coastal chapel sites in the Oa.

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

The proximity of the Draft Plan Option to the coastline 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 coast. 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 such as the Rhinns of Islay Lighthouse in Orsay or the coastal chapel sites in the Oa. Effects on the setting of historic assets will only arise where devices have visible above water components or support structures.

There may also be the potential for impacts on historic wreck sites if devices and supporting infrastructure are installed near to these sites.

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.

Effects on features of the historic environment 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 in close proximity to the Islay coast, with the north part of the Draft Plan Option particularly close to a local landscape designation area located in north west Islay.

Areas of the coastline in the vicinity of TW1 are considered to have a high wildness value.

Given the proximity of the Draft Plan Option to the Islay coast line there is potential for visual effects on the local Islay designation and areas of wild land.

In terms of operation, the majority of tidal devices and supporting infrastructure will be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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 Draft Plan Option.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from the Islay coast. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind and wave).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology. For example residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects, particularly for parts of Islay. However visual impacts to onshore receptors could potentially be limited by construction further from the Islay coast, in particular to the west and south of the Draft Plan Option. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

TW2

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 a number of coastal SSSIs including Sanda Islands, designated for a number of bird species including Black guillemot, Cormorant, Guillemot, Puffin, and Razorbill.

The Draft Plan Option overlaps with a proposed MPA (Clyde Sea Sill) located at the southern tip of the Kintyre Peninsula. This area is proposed for its Black Guillemot and for geodiversity interests.

The seabird maps presented in the baseline indicate potential vulnerability for diving bird collision with tidal energy devices in the Draft Plan Option, particularly during winter periods. However, this vulnerability may differ for individual species.

The south east coast of Islay contains the South-East Islay Skerries SAC which is designated for common seals. Seal density mapping and the presence of a seal haul out area to the east of TW2 and the south of the Mull of Kintyre would indicate this is a well-used area for marine mammals.

The available distribution and sighting data indicates that cetaceans may be present in this area. Several Basking shark sightings have been made within the Draft Plan Option itself, and the area is known to be used by other elasmobranch species. Furthermore the Skerries and Causeway SAC, to the west of TW2 in Northern Irish waters is designated for Harbour porpoise interests.

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.

Seabed sediments in the region are largely coarse ( e.g. sands, gravelly sands, gravels, etc.) with an area of muddy sandy gravel identified southwest of the Kintyre peninsula. These sediments may be susceptible to hydrodynamic change, and these habitats are likely to contain species used to strong tidal movements.

Potential vulnerabilities were identified for diving bird collision and displacement with tidal energy devices in relation to the Draft Plan Option, particularly during winter periods, at the southern edge of the Draft Plan Option. Any potential risk is likely to vary by bird species and by device type, with species such as the Black guillemot considered to be particularly at risk. In general, collision risk will likely be greater for tidal devices with moving parts.

Given the potential 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 be the potential for effects such as creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

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. However, such impacts may be limited given the dynamic nature of the Draft Plan Option. It is noted that there are gaps in present research knowledge in establishing certainty of effect relating to sediment effects from tidal energy devices.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 priority marine species and designations in the vicinity as a result of changes to hydrology and sedimentation from the construction of devices, and from direct impacts on bird and mammal species. Monitoring from the existing tidal lease site within the Draft Plan Option help to identify potential adverse effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including Atlantic salmon) 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.

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the proposed Clyde Sea Sill MPA 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.

Population and Human Health

The waters to south west of Kintyre are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising, surfing and bathing.

Important shipping routes are identified in the Marine Atlas in this area.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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 moderate (immediately south and east of the Kintyre Peninsula) to good status (north west of the Kintyre Peninsula) 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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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 several sections of the western Kintyre coastline have been identified as being potentially vulnerable to erosion/accretion, the south west coast is largely rocky and broadly stable. No areas of significant erosion have been identified.

However, small soft coastline areas have been identified to the east of the draft plan area at the southern tip of the peninsula near ( e.g. beaches at Carskey, Dunaverty and Brunerican Bays).

Potential for mixed effects on coastal erosion and accretion caused by changes to hydrodynamics and wave energy, particularly along vulnerable sections of coastline near to the draft plan area such as beaches at Carskey, Dunaverty and Brunerican Bays.

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 coarser sediments such as sandy gravels, with a small area of muddy sandy gravel identified southwest of the Kintyre peninsula.

While the region has moderate wave and tidal resources across much of the Draft Plan Option, with dynamic coastal zones adjacent to the Kintyre peninsula and within the option area.

Some sediment disturbance and loss of seabed habitat is likely during site preparation and placement of device foundations. The scale of such disturbance 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 impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines ( e.g. southern tip of the Kintyre Peninsula). However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and depend on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are a number of marine and coastal wreck sites within this region, including small clusters of wreck sites located around the southern tip of the Kintyre peninsula.

Nearby coastal areas also contain a wide range of historical environment sites located either on the shoreline or which have coastal relevance. These include scheduled monuments such as forts and duns. The most notable is the A-listed Mull of Kintyre Lighthouse, and the B-listed St. Ninian's Chapel located on Sanda Island.

Significant sections of coastal areas around the Kintyre peninsula have also been identified as being of potential interest for submerged archaeology.

The proximity of the Draft Plan Option to the coastline means that there is the potential for impacts on the setting of coastal historic environment sites ( e.g. Mull of Kintyre Lighthouse, and St. Ninian's Chapel).

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

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.

Effects on features of the historic environment 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

The southern end of the Mull of Kintyre contains numerous local landscape designations, illustrating the high value attributed to landscapes in this part of Scotland.

The eastern side of the Mull of Kintyre has a high wildness value.

The Draft Plan Option skirts close to the Mull of Kintyre local landscape designation and the wild land character of the peninsula. Tidal energy developments in the Draft Plan Option, at least those elements that pierce the water surface, may be visible from the coast.

In terms of operation, the majority of tidal devices components and supporting infrastructure will likely be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. It is likely that navigational aids ( e.g. marker buoys, lighting) may also have visual effects.

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

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from the Kintyre coast. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology. For example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects, particularly for coastal areas on the Kintyre peninsula. However visual impacts to onshore receptors could potentially be limited by construction further from the mainland, for example, to the west and south. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

TN1

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 the Pentland Firth, to the east of Thurso. Key relevant designations in the area include a number of SSSI, IBA and SPA sites at Hoy, North Caithness Cliffs, Pentland Firth Islands, and Switha, amongst others. These sites are all designated for their seabird assemblage interest, demonstrating the presence of species such as Fulmar, Arctic Tern, Puffin, Kittiwake, Razorbill, Guillemot, Skua, and Greenland Barnacle goose in the area.

Other designations, such as Hoy SAC (designated for its vegetated cliffs amongst other features) and River Thurso SAC (for Atlantic salmon interests) have also been identified in the vicinity of the Draft Plan Option.

A small section of the boundary of the Draft Plan Option overlaps with Hoy SPA and North Caithness Cliffs SPA. The Pentland Firth Islands SPA is contained within the Draft Plan Option.There are bird interests within the area and potential collision vulnerability for diving birds was identified, particularly in the breeding season. However, this vulnerability may differ for individual species.

Cetacean distribution in the region is considered to be low, although there is the potential for encounters within the Draft Plan Option. Several Basking shark sightings have been recorded within the Pentland Firth, indicating the potential for encounters in TN1. Other elasmobranch species are also known to use this area. Seal density mapping and the presence of seal haul out areas within the Pentland Firth and amongst the Orkney Islands, illustrates the importance of this area for both Grey and Common Seals.

The north region is known to be used by a range of fish species, including diadromous species, such as Atlantic salmon, and others including many commercially caught species. The Orkney and Shetland region also contains important nursery grounds for several commercially important species of fish.

The seabed within the Pentland Firth consists of undifferentiated rock in the narrow section of the Firth between Orkney and the mainland, with coarse sediments ( e.g. sandy gravels, gravelly sands and sands) to the west along the North Sutherland Coast and to the east of the Pentland Firth. These benthic habitats are likely to contain species conditioned to strong tidal movements and currents.

Potential vulnerabilities were identified for diving bird collision and displacement with tidal energy devices in relation to the Draft Plan Option. Any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for Seals given the proximity to haul out areas in the Firth and in Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this will depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion of seabed in sections of the Firth underlain by coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments. The dynamic and turbid environment in the Pentland Firth would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on marine mammals, particularly cetaceans and seals, such as the creation of barriers to movement, collision with infrastructure, and noise impacts.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 as a result of changes to hydrology and sedimentation from the construction of devices, and from direct impacts on bird and mammal species (particularly seals). Monitoring from the existing tidal lease sites within the Draft Plan Option help to identify potential adverse effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including Atlantic salmon) will help to identify the potential for significant effects. Monitoring should identify on the potential for devices to attract seals.

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.

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the Hoy, North Caithness Cliffs, and Pentland Firth Islands SPAs, 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 SPAs.

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

Siting of developments in rocky seabed areas within the Pentland Firth could limit the potential for benthic effects and impacts to sediment dynamics. 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 Pentland Firth and adjacent coastal regions in Orkney and the North Sutherland Coast are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising, sailing, surfing, diving and bathing.

Important shipping routes are identified in the Marine Atlas in this area.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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 to 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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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.

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

Several sections of the Pentland Firth coastline, largely comprising sandy beaches between Gill's Bay and John O'Groats, and small sheltered inlets in the southern Orkney Isles, have been identified as being potentially vulnerable to coastal erosion. In some localised sections of this coastline near John O'Groats, erosion has been previously observed.

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 coastlines and long term coastal retreat observed in this area.

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 of undifferentiated rock in the narrow section of the Firth between Orkney and the mainland, with coarse sediments ( e.g. sandy gravels, gravelly sands and sands) to the west along the North Sutherland Coast and to the east of the Pentland Firth.

Depths vary from 20 - 100m in the Pentland Firth and off the North Sutherland coast, although the narrows of the Firth provide the shallowest part of this area.

The area has generally moderate wave and strong tidal energy resources, particularly within the Draft Plan Option in the narrowest part of the Firth.

Some seabed disturbance and loss of habitat is likely during site preparation and placement of device foundations. The scale of such disturbance 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.

As such significant increases in turbidity are unlikely given the largely coarse sediments within the Draft Plan Option and the high tidal energies present within the Pentland Firth.

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 impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines ( e.g. identified areas of accretion on the North Sutherland Coast). However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and dependent on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 for areas known to be susceptible to coastal erosion.

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

Mitigation measures could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are a number of marine wreck sites within the Pentland Firth, and near to the adjacent Orkney and North Sutherland coastlines. In particular there is a large cluster of wreck sites, including designated sites within Scapa Flow to the north of the Draft Plan Option.

Both the Orkney and North Sutherland coastlines contain a number of sensitive coastal historic environment sites. The most notable are the A-listed Pentland Skerries Lighthouse, various scheduled monuments on the Island of Stroma, and the A-listed Castle of Mey together with its garden and designed landscape which is included on the national Inventory.

Sections of these nearby coastlines have been identified as potentially containing submerged archaeology.

There is the potential for significant impacts on the setting of coastal historic environment sites, particularly for the Pentland Skerries Lighthouses, sites on the Island of Stroma, and the Castle of Mey. The significance of effects will depend on the location and type of technologies deployed, and will be more severe where devices have large visible above water components.

There may be the potential for impacts on historic wreck sites from installation and operation of these sites.

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.

Effects on features of the historic environment 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

There are several local landscape designations close to the Draft Plan Option area, including Dunnet Head and Duncansby Head SLAs. The western portion of the Draft Plan Option may be visible from the Hoy and West Mainland NSA located in Orkney.

While a valued landscape and heritage area, the wildness value of the mainland coast and the coastline of Hoy and South Ronaldsay is considered to be relatively low.

The Draft Plan Option skirts close to the mainland Hoy and South Ronaldsay and the Draft Plan Option will likely be visible from the coast. However, the area is unlikely to be visible from most areas designated for landscape quality, bar a small portion of the Hoy and West Mainland NSA.

In terms of operation, the majority of tidal devices components and supporting infrastructure will be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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 ferries, recreational users and shipping that sail close to the Draft Plan Option.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from the North Sutherland and Orkney coasts. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology, for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects on nearby coastal areas. However visual impacts to onshore receptors could potentially be limited by construction away from valued sites, in particular to the east of the Draft Plan Option. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

The Pentland Firth is a busy shipping channel and the development of additional infrastructure in this area will need to consider this in the context of landscape effects.

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

TN2

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 several designations in the area including a number of SSSI, IBA and a number of SPAs including Roussay, West Westray and Calf of Eday. These are all designated for their seabird assemblage interests (including Guillemot, Kittiwake, Arctic skua, Arctic tern, Fulmar, Razorbill and Great black-backed gull).

Other designations, such as the Faray and Holm of Faray SAC (designated for Grey seal) are also located near to the Draft Plan Option, and Rousay SPA with which it overlaps. The Draft Plan Option overlaps with the proposed Wyre and Rousay Sounds MPA, designated for kelp and seaweed communities on sublittoral sediment, Maerl beds and marine geomorphology.

While there are bird interests within the area, diving bird collision vulnerability to tidal energy devices is considered to be reasonably low. However, vulnerability may differ for individual species.

Cetacean distribution in the region is considered to be low, although there is the potential for encounters within the Draft Plan Option. Several Basking shark sightings have been recorded within Orkney and in TN2, indicating the potential for encounters in this area. Other elasmobranch species are known to use this area. Seal density mapping and the presence of Seal haul out areas amongst the Orkney Islands illustrates the importance of this area for both Grey and Common 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 surrounding Orkney consists largely of coarse sediments. These benthic habitats are likely to contain species conditioned to strong tidal movements and currents

Potential vulnerabilities were identified for collision and displacement of diving birds from tidal energy devices. However, any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 the creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas around Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this will depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion in seabed areas containing coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments.

The dynamic and turbid environment in the area would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 bird species. There is likely a potential risk to seals in this area (particularly cumulatively) and any tidal developments should demonstrate avoidance of adverse effects. The results of monitoring from existing tidal lease sites in this region currently in the application process have the potential to help provide greater certainty on the scale of these effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including Atlantic salmon) 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.

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

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the proposed Wyre and Rousay Sounds MPA will remain and would lead to adverse effects on benthic habitats, 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.

It is further recommended that the boundary of the Draft Plan Option is reviewed as part of ascertaining whether the overlap with the Rousay SPA, 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 SPA.

Population and Human Health

The draft plan area and surrounding waters and coastal areas in Orkney are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising, sailing, surfing and diving.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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.

There is one designated shellfish water within the vicinity of the draft plan off the coast of mainland Orkney.

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

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 potential for coastal erosion and accretion has been identified along sheltered coastlines in the vicinity of the draft plan area. In several sections of coastline, erosion and accretion has been previously observed.

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.

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 likely consists of coarse sediments ( e.g. sandy gravels, gravelly sands and sands).

Depths are reasonably shallow, reaching up to 40m in some parts of the strait between Eday and Orkney Islands.

The area has generally moderate wave and strong tidal energy resources, particularly within the Draft Plan Option at the narrowest point between Eday and Orkney Islands.

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

As such, significant increases in turbidity are unlikely given the largely coarse sediments within the Draft Plan Option and the high tidal energies present within the area of search and surrounding waters.

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 impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines. However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and depend on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 for sheltered coastlines near to the plan option area.

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

Mitigation measures could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are a number of coastal wreck sites located near to the Draft Plan Option.

Nearby areas contain a variety of sensitive coastal historic environment sites, the most notable being various scheduled broch sites and Stackel Brae castle on Eday.

Sections of nearby coastlines have also been identified as potentially containing submerged archaeology.

There is the potential for significant impacts on the setting of coastal historic environment sites, particularly for the Stackel Brae Castle. The significance of these effects will depend on the type and location of technologies deployed, and will be more severe where devices have large visible above water components.

There may be the potential for impacts on nearby historic wreck sites from the installation and operation of these sites.

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.

Effects on features of the historic environment 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 identified and seek to mitigate accordingly.

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

Landscape / Seascape

There are some local landscape designations in coastal areas near to the Draft Plan Option area.

However, the wildness value of the surrounding area is considered to be relatively low.

The Draft Plan Option is located amongst several Orkney Islands, and as a result, is likely to be visible from nearby coastlines.

In terms of operation, the majority of tidal devices components and supporting infrastructure will likely be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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 ferries and recreational boats that sail close to the option area.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from nearby coastal areas. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology , for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects on nearby coastal areas. However, the potential for visual impacts on the settings of protected landscapes in this area is considered to be low. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

TN3

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 several designations in the area including a number of SSSI, and SPAs including West Westray, Calf of Eday, Papa Westray (North Hill and Holm), all designated for their seabird assemblage interests (including Guillemot, Kittiwake, Arctic skua, Razor bill, Arctic tern, Fulmar, Cormorant and Great black-backed gull).

Orkney also contains Faray and Holm of Faray SAC (designated for Grey Seal) and Sanday SAC (designated for Common Seal), amongst others. The Draft Plan Option overlaps with the Papa Westray (North Hill and Holm) SPA and the proposed Papa Westray MPA, designated for Black guillemot and the Marine Geomorphology of the Scottish Shelf Seabed.

There are bird interests within the area, and collision vulnerability for diving birds with tidal energy devices is likely although currently considered reasonably lower than some locations. However, this vulnerability may differ for individual species.

Cetacean distribution in the vicinity of the Draft Plan Option is relatively low, although they may be present in the Draft Plan Option. While no Basking shark sightings have been recorded in TN3, several have been recorded in the Orkney Islands, indicating the potential for encounters within the Draft Plan Option. 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.

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

The seabed surrounding Orkney consists of largely coarse sediments. These benthic habitats are likely to contain species used to strong tidal movements and currents.

Potential vulnerabilities were identified for collision and displacement for diving birds with tidal energy devices in relation to the Draft Plan Option. However, any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 the creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for Seals given the proximity to haul out areas located around Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this will depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion in seabed areas containing coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments.

The dynamic and turbid environment in the area would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 bird species. There is potentially a risk to seals in this area (particularly cumulatively) and any tidal developments should demonstrate avoidance of adverse effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including elasmobranchs and Atlantic salmon) 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.

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the proposed Papa Westray MPA 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.

It is further recommended that the boundary of the Draft Plan Option is reviewed as part of ascertaining whether the overlap with the Papa Westray (North Hill and Holm) SPA 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 SPA.

Population and Human Health

The draft plan area in the northern Orkney Islands and surrounding coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising and sailing.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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 potential for coastal erosion and accretion has been identified along soft and exposed coastlines in the vicinity of the draft plan area ( e.g. Westray and Papa Westray). Little long-term erosion has been observed, it is likely that several localised sections of coastline have been observed to be subject to 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.

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 likely consists of coarse sediments ( e.g. sandy gravels and gravelly sands).

Depths are shallow, near shore, reaching up to 50m to the north of Papa Westray, with greater depths found further offshore to the north of the option area.

The area has generally moderate wave and tidal energies, particularly within the southern portion of the Draft Plan Option near to Papa Westray.

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

As such significant increases in turbidity are unlikely given the largely coarse sediments within the Draft Plan Option and the wave and tidal energies present within the area of search and in surrounding waters to the north.

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 impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines ( e.g. Westray and Papa Westray). However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and dependent on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 for localised areas of erosion along nearby coastlines.

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

Mitigation measures could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are no wreck sites located near to the Draft Plan Option.

However, several scheduled monuments located in Papa Westray have coastal interests

Sections of nearby coastlines have also been identified as potentially containing submerged archaeology.

There is the potential for significant impacts on the setting of coastal historic environment sites in Papa Westray. The significance of effects will depend on the location and type of technologies deployed, and will be more severe where devices have large visible above water components.

There may be the potential for impacts on nearby historic wreck sites from the installation and operation of these sites.

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.

Effects on features of the historic environment 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.

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

Landscape / Seascape

There are some local landscape designations in coastal areas near to the Draft Plan Option area, the most notable being on Papa Westray.

The wildness value of the surrounding area appears to be relatively low.

The Draft Plan Option is located off Papa Westray and is likely to be visible from nearby Westray and Papa Westray coastlines.

In terms of operation, the majority of tidal devices components and supporting infrastructure are likely to be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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 ferries and recreational boats that sail close to the option area.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from nearby coastal areas. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology, for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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, particularly for the locally designated site at Papa Westray. However, the potential for visual impacts on the settings of nationally designated landscapes are considered to be low in this area. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

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

TN4

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 several designations in the area including a number of SSSI, and SPAs including West Westray, Calf of Eday, Papa Westray (North Hill and Holm) and, to the east, Fair Isle SPA. These sites are all designated for their seabird assemblage interests (including Guillemot, Kittiwake, Arctic skua, Razor bill Arctic tern, Fulmar, Cormorant and Great black-backed gull).

Orkney also contains Faray and Holm of Faray SAC (designated for Grey seal) and Sanday SAC (designated for Common seal), amongst others. The Draft Plan Option overlaps with the

East Sanday Coast SPA and Ramsar and the Sanday SAC. Furthermore the is an overlap with the North West Orkney proposed MPA search area, designated for Black guillemot and the Marine Geomorphology of the Scottish Shelf Seabed.

While there are bird interests within the area, diving bird collision vulnerability for diving birds with tidal energy devices have been identified as lower than some other locations. However, this vulnerability may differ for individual species.

While cetacean distribution in the vicinity of the Draft Plan Option is relatively low they may still be present within the Draft Plan Option. While no Basking shark sightings have been recorded in TN4, several have been recorded in the Orkney Islands, indicating the potential for encounters within the Draft Plan Option. Other elasmobranchs are known to use these waters. 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.

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

The seabed surrounding Orkney largely consists of coarse sediments. These benthic habitats are likely to contain species used to strong tidal movements and currents.

Potential vulnerabilities were identified for collision and displacement of diving birds with tidal energy devices in relation to the Draft Plan Option. However, any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 the creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas located around Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this would likely depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion in seabed areas containing coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments.

The dynamic and turbid environment in the area would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 bird species. There is likely a potential risk to seals in this area (particularly cumulatively) and any tidal developments should demonstrate avoidance of adverse effects. The results of monitoring from existing tidal lease sites in this region currently in the application process have the potential to help provide greater certainty on the scale of these effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including elasmobranchs and Atlantic salmon) 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.

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

It is recommended that the boundary of the Draft Plan Option is kept under review as part ascertaining whether the overlap with the North West Orkney proposed MPA 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.

It is further recommended that the boundary of the Draft Plan Option is reviewed as part of ascertaining whether the overlap with the East Sanday SPA and Ramsar site and Sanday 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 designations.

Population and Human Health

The draft plan area in the north east Orkney Islands and surrounding coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, medium recreational cruising and sailing.

Important shipping routes are identified in the Marine Atlas in this area.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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 potential for coastal erosion and accretion has been identified along soft and exposed coastlines in the vicinity of the draft plan area ( e.g. sections of coast in Sanday and North Ronaldsay). While little long-term erosion has been observed, it is likely that several localised sections of coastline have been previously subject to 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, particularly in vulnerable areas of 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 likely consists of coarse sediments ( e.g. sandy gravels and gravelly sands).

Depths are shallow, near shore, reaching up to 100m to the north and east of North Ronaldsay.

The area has generally moderate wave and tidal energy resources, particularly between North Ronaldsay and Sanday, and to the north of North Ronaldsay.

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

As such significant increases in turbidity are unlikely given the largely coarse sediments within the Draft Plan Option and the wave and tidal energies present within the area of search and in surrounding waters to the north.

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 result in general impacts such as scour, deposition and abrasion in the area, and the potential for related impacts to vulnerable coastlines ( e.g. soft coastlines on North Ronaldsay and Sanday). However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and dependent on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are a number of coastal wreck sites located within and near to the Draft Plan Option.

There are a significant number of scheduled monuments on nearby North Ronaldsay, including brochs, settlements and two lighthouses.

Sections of nearby coastlines have also been identified as potentially containing submerged archaeology.

There is the potential for significant impacts on the setting of the coastal historic environment sites in North Ronaldsay The significance of effects will depend on the location and type of technologies deployed, and will be more significant where devices have large visible above water components.

There may be the potential for impacts on nearby historic wreck sites from the installation and operation of these sites.

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.

Effects on features of the historic environment 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 identified in the baseline and seek to mitigate accordingly.

Landscape / Seascape

There are several local landscape designations in coastal areas near to the Draft Plan Option area. However, Fair Isle (part of the Shetland NSA) is likely to be too great a distance from the Draft Plan Option for it to be visible.

The wildness value of the surrounding area appears to be relatively low.

The Draft Plan Option is likely to be visible from Sanday and from areas designated for local landscape quality on North Ronaldsay.

In terms of operation, the majority of tidal devices components and supporting infrastructure will likely be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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 ferries, recreational boats and shipping that sail close to the Draft Plan Option.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from nearby coastal areas. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology, for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects, particularly relating to Sanday and North Ronaldsay.

However visual impacts to onshore receptors could potentially be limited by construction further from the coast, in particular the east of the Draft Plan Option. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

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

TN5

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 number biodiversity designations such as SSSI, SACs and a number of SPAs. These include Fair Isle SPA, Foula SPA and Sumburgh Head SPA considered important for their bird interests (including Guillemot, Kittiwake, Arctic skua, Razor bill, Arctic tern, and Fulmar, amongst others). The Mousa SAC is also nearby and is designated for Common seal interests.

The Draft Plan Option overlaps with the Sumburgh Head SPA.

There are seabird and diving bird interests within the area, and vulnerability of diving birds to collision with tidal energy devices has been identified near the Draft Plan Option. However, this vulnerability may differ for individual species.

Cetacean distribution in the vicinity of the Draft Plan Option is considered to be high, indicating their potential presence in this area. Similarly, several recorded Basking shark sightings near to the TN5 and around the Shetland coastline indicate 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 around the Shetland Isles and by Seal density mapping, indicating the frequent use of this area by Common seals in particular.

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

The seabed surrounding Shetland consists of sandy gravels and gravelly sands. These benthic habitats are likely to contain species conditioned to strong tidal movements and currents.

The area contains important seabird interests, demonstrated by the presence of numerous designated sites near to the Draft Plan Option. Potential vulnerabilities were identified for diving bird collision and displacement with tidal energy devices in relation to the Draft Plan Option. However, any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 the creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas located around Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this would likely depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion in seabed areas containing coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments.

The dynamic and turbid environment in the area would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 bird species. There is likely a potential risk to seals in this area (particularly cumulatively) and any tidal developments should demonstrate avoidance of adverse effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including elasmobranchs and Atlantic salmon) 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.

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

It is recommended that the boundary of the Draft Plan Option is kept under review as part of ascertaining whether the overlap with the Sumburgh Head SPA would lead to adverse effects on its integrity or whether co-location is possible.

Population and Human Health

The draft plan area off Sumburgh Head and the nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling, light recreational cruising, sailing and bathing.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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.

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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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

Several sheltered beaches identified at the southern tip of the isles ( i.e. Sumburgh Head) have been identified as being potentially vulnerable to coastal erosion or accretion. Wave erosion has been observed on most sand beaches in the isles, and varying degrees of cliff erosion depending on the rock type.

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 like those near Sumburgh Head.

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 and gravels).

The depth of the seabed increases sharply from the shoreline near Sumburgh Head to the south west, south and south east. Depths reach up to around 90m within the option area.

While the area has generally moderate wave and moderate tidal energy resources, the strongest tidal energies are found just offshore and south west of Sumburgh Head.

Some seabed disturbance and loss of habitat is likely during site preparation and placement of device foundations. The scale of such disturbance 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.

As such significant increases in turbidity are unlikely given the coarse sediments within the Draft Plan Option and the wave and tidal energies 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. This could result in potential general impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines. However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and dependent on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

In general terms, the coastline of Shetland is particularly sensitive to development with many scheduled monuments including brochs and forts along its coast. This Draft Plan Option area sits close to the southern part of the Shetland Isles, in an area containing numerous historic environment features. The most notable is the A-listed Sumburgh Head Lighthouse.

Several marine and coastal wrecks are located in and adjacent to the Draft Plan Option, including a cluster immediately to the south east of the area.

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

There may be the potential for impacts on nearby historic wreck sites from the installation and operation of offshore energy sites.

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.

Effects on features of the historic environment 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 identified in the baseline and seek to mitigate accordingly.

Landscape / Seascape

The Draft Plan Option is likely to be visible from the Shetland NSA and the Sumburgh Peninsula. These areas are also considered to have a relatively high wildness value.

Fair isle (part of the Shetland NSA) is likely to be too great a distance from the Draft Plan Option for it to be visible.

The site is likely to be visible from coastal areas designated for landscape quality, including the Shetland NSA and on areas considered to have wildness value.

In terms of operation, the majority of tidal devices components and supporting infrastructure will likely be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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, ferries, and recreational boats that sail close to the Draft Plan Option.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from Sumburgh Head and nearby coastal areas. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology, for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects on nearby coastal areas. However visual impacts to onshore receptors could potentially be limited by construction further from the coast, in particular the south of the Draft Plan Option. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

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

TN6

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 range of biodiversity designations including numerous SSSI, and SPAs. These include Otterswick and Graveland SPA, and Fetlar SPA which are considered important for seabird assemblage (including Red-necked phalarope, Whimbrel, Arctic skua, Arctic tern, Dunlin, Fulmar and Great skua, amongst others). Sullom Voe SAC, (designated for its reefs, lagoons, shallow inlets and bays). Yell Sound Coast SAC (includes Otter and Common seal features) and overlaps withthe Draft Plan Option.

There are bird interests within the area and the vulnerability of diving birds to collision with tidal energy devices has been identified. However, this vulnerability may differ for individual species.

The cetacean distribution maps for the area indicate their potential presence of near to TN6. Similarly, several recorded Basking shark sightings within the Draft Plan Option and around the Shetland coastline indicates there is the potential for encounters in this area. Other elasmobranch species are also known to use these waters. The importance of the area for seals and the likely presence of both Grey and Common seals is demonstrated in the location of several Seal haul out areas in close proximity to the Draft Plan Option.

The area is known to be used by fish species, including diadromous species, such as Atlantic salmon, and others including 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 ( i.e. sandy gravels and gravels) with some areas of muddy ands and gravels located within Yell Sound. The benthic habitats in this area are likely to contain species used to strong tidal movements and currents.

The area contains important seabird interests, demonstrated by the presence of numerous designated sites near to the Draft Plan Option. Potential vulnerabilities were identified for diving bird collision and displacement with tidal energy devices. However, any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 the creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas located around Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this would likely depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion of seabed in in seabed areas containing coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments.

The dynamic and turbid environment in the area would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 bird species. There is likely a potential risk to Seals in this area (particularly cumulatively) and any tidal developments should demonstrate avoidance of adverse effects. The results of monitoring from existing tidal lease sites in this region currently in the application process have the potential to help provide greater certainty on the scale of these effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including elasmobranchs and Atlantic salmon) 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.

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

It is recommended that the boundary of the Draft Plan Option is reviewed as part of ascertaining whether the overlap with the Yell Sounds Coast 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.

Population and Human Health

The draft plan area in yell Sound and in nearby coastal areas are used for a number of industry and recreational activities including fishing, recreational sea angling and sailing.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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.

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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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

Wave erosion has been observed on most sand beaches in the isles, and varying degrees of cliff erosion depending on the rock type. Several areas of coastline between Shetland and Yell Islands and along Yell Sound near to the draft plan area have been identified as potentially susceptible to coastal erosion. Coastal erosion has been observed along several sheltered sections of soft coast on the eastern side of Shetland Island, located to the south west of the draft plan area.

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 like those located along the western (Shetland Island) side of Yell Sound.

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 and gravels) with some areas of muddy ands and gravels located within Yell Sound near to or within the option area.

The area has been included as a plan option area based on its tidal energy resources.

Some seabed disturbance and loss of habitat is likely with 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 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.

As such significant increases in turbidity are unlikely given the coarse sediments within the Draft Plan Option and the tidal energies 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. This could result in potential general impacts such as scour, deposition and abrasion in the area and related impacts to vulnerable coastlines within yell Sound. However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and dependent on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 within sheltered bays and areas near Yell Sound.

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

Mitigation measures could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are a number of coastal wreck sites located within and near to the Draft Plan Option.

There are a significant number of important historic environment assets, including several scheduled brochs and listed buildings, in coastal areas adjacent to the Draft Plan Option.

Sections of nearby coastlines have also been identified as potentially containing submerged archaeology, with some sections of known coastal archaeology identified as being at risk of coastal erosion.

There is the potential for significant impacts on the setting of the coastal historic environment assets adjacent to Yell Sound.

There is also the potential for exacerbation of coastal erosion issues in the area caused by the installation and operation of tidal devices and their associated infrastructure.

However in both cases, effects will depend on the technologies deployed. Effects on the setting of assets will be more significant where devices employed have visible above water components.

There may be the potential for impacts on nearby historic wreck sites from the installation and operation of these sites.

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.

Effects on features of the historic environment 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 identified in the baseline and seek to mitigate accordingly.

Landscape / Seascape

The Draft Plan Option is likely to be visible from the Shetland NSA component located at the top of Yell sound and along the coastlines within the sound itself. This region of the Shetland Islands also has a relatively high wildness value.

The site is likely to be visible from areas designated for landscape quality including the Shetland NSA and on areas with wildness value.

In terms of operation, the majority of tidal devices components and supporting infrastructure will likely be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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, ferries, and recreational boats that sail close to the Draft Plan Option.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from coastal areas within Yell Sound. As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology, for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

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 landscape and seascape effects on nearby coastal areas, particularly to the NSA located to the north west of the Draft Plan Option. However, the potential for visual impacts on settings of protected landscapes are likely to be low in this area. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

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

TN7

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 several biodiversity designations. It overlaps with the Hermaness, Saxa Vord and Valla Field SPA designated for Seabird assemblage (including, Guillemot, Kittiwake, Puffin, Red-throated diver, Shag, Fulmar, Great skua, and Gannet). This site is also designated as a SSSI. Fetlar SPA is also located in the general vicinity of TN7, and is designated for a similar range of bird species. South of the Draft Plan Option is Otterswick and Graveland SPA (designated for Red-throated diver).

The Draft Plan Option TN7 overlaps with the Hermaness, Saxa Vord and Valla Field SPA.

Clearly there are bird interests within the area and the vulnerability of diving birds to collision with tidal energy devices has been identified, particularly in winter. However, this vulnerability may differ for individual species.

The Cetacean distribution maps for the area indicate the potential presence of Cetaceans near to TN7. Basking shark sightings within the Draft Plan Option and around the Shetland coastline indicates there is also the potential for encounters in this area. Other elasmobranch species are known to use these waters. The importance of the area for seals and the likely presence both Grey and Common seals is demonstrated by the seal density mapping and the presence of seal haul out areas around the Shetland Isles.

The area is known to be used by fish species, including diadromous species such as Atlantic salmon, and others including 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 ( i.e. sandy gravels and gravelly sands). These benthic habitats are likely to contain species used to strong tidal movements and currents.

The area contains important seabird interests, demonstrated by the presence of numerous designated sites near to the Draft Plan Option. Potential vulnerabilities were identified for diving bird collision and displacement with tidal energy devices. However, any potential risk is likely to vary by bird species and by device type. In general, collision risk will likely be greater for tidal devices with moving parts.

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 the creation of barriers to movement, collision with the device components and associated infrastructure, and underwater noise impacts during construction and operation. This is particularly relevant for seals given the proximity to haul out areas located around Orkney. However, there are gaps in present research knowledge to establish certainty of impact.

The review of tidal technologies identified the potential effects from EMF on elasmobranchs and fish. However, the magnitude of these effects is unknown at this stage.

Sediment movement from the installation of tidal devices could be possible although this would likely depend on the type of installation technology used.

There is potential for impacts on benthic habitats as a result of scouring, smothering, deposition and abrasion of seabed in seabed areas containing coarse sediments as a result of placing devices and their supporting infrastructure within this area. These may be lower than in areas with more sandy sediments.

The dynamic and turbid environment in the area would indicate that the benthos present will be conditioned to dynamic environments and as a result impact magnitude may be reduced. However, there are gaps in present research knowledge to establish certainty of effect.

The potential for collision and displacement of diving birds with underwater tidal devices has been identified. However, the significance of any impact is uncertain as effects on the population viability of individual species present in the area are not known.

There is the potential for effects on cetaceans, seals, fish and elasmobranchs from the creation of barriers to movement, potential collision with infrastructure, and noise impacts during construction and operation.

Elasmobranchs and fish may be impacted as a result of EMF associated with tidal energy devices and associated infrastructure. Indirect effects may include altered migratory pathways with unknown energetic/biological consequences.

While effects associated with construction would likely be temporary, the potential for longer term effects from tidal devices with significant underwater infrastructure remains.

There is the potential for direct benthic effects associated with the siting and installation of tidal devices, and for indirect effects including sediment movements ( i.e. scouring, smothering, sediment deposition and abrasion) from their presence in the marine environment. However, it is expected sediment deposition impacts at this location will be limited as the existing environment is already dynamic.

There may be the potential for significant effects to designated areas in locations such as Islay, if associated grid infrastructure was to be sited in 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 bird species. There is likely a potential risk to seals in this area (particularly cumulatively) and any tidal developments should demonstrate avoidance of adverse effects.

Further research into the potential collision, displacement and the effects on cetaceans, seals elasmobranchs and fish (including elasmobranchs and Atlantic salmon) 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.

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

It is recommended that the boundary of the Draft Plan Option is kept under review as part of ascertaining whether the overlap with the Hermaness, Saxa Vord and Valla Field SPA would lead to adverse effects on its integrity or whether co-location is possible.

Population and Human Health

The Draft Plan Option is located at the northern tip of the Shetland Islands. Nearby coastal waters are used for a number of industry and recreational activities including fishing, recreational sea angling and sailing.

Whilst tidal devices will be constructed under the water surface there may be some elements of tidal devices that could be above the water. It is these elements that carry some collision risk both during operation and installation.

The presence of tidal turbines and supporting infrastructure should have minimal impacts on recreational use, as vessels should be able to travel over the technology. If devices and supporting infrastructure pierce the surface there is some potential to displace some existing recreational activities, through limiting access to areas of the sea and potential disruption to perceived amenity value. However given the likely area of exclusion this effect is considered minimal.

Commercial ships with bigger hulls could have a higher risk of collision with devices, and in particular with operational and maintenance vehicles and infrastructure.

Any collision could directly affect vessels and passengers, however it is not expected that tidal 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 occur, 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. However, it is anticipated that in many instances tidal devices and recreational boating could collocate.

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.

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 associated with anchoring of devices, contamination from their installation and maintenance vessels).

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

Wave erosion has been observed on most sand beaches in the isles, and varying degrees of cliff erosion depending on the rock type and coastal energies. However, no areas of coastline near to the draft plan area have been identified as being potentially susceptible to coastal erosion or accretion.

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, based on the high energy coastlines and the absence of observed erosion in this area, it is unlikely that this would be significant.

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 climate related changes to the marine environment when assessing impacts on the coastal environment.

Marine Geology and Coastal Processes

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

The area has been included as a plan option area based on its tidal energy resources.

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

As such significant increases in turbidity are unlikely given the coarse sediments and the tidal energies 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. This could result in potential general impacts such as scour, deposition and abrasion in the area and the potential for related impacts to vulnerable coastlines. However, these systems are likely to be complex, and as such, the potential for impacts will be site specific and dependent on factors such as the type and size of the devices and their foundations/anchors.

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

Loss of small areas of seabed associated with the installation of foundations/anchors may occur, although some natural regeneration may occur upon decommissioning of devices and removal of anchors.

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 could include the design and use of rock scour protection (if required) around the base of any anchors or foundations used.

Historic Environment

There are few coastal wreck sites located in the vicinity of the Draft Plan Option, however a SSMEI protected wreck is located to the south east.

There are a number of important historic environment assets in coastal areas adjacent to the Draft Plan Option, including Muckle Flugga lighthouse and the scheduled monument, Inner Skaw houses and field system, which are located on North Unst.

Sections of nearby coastlines and marine areas within and adjacent to this option area have also been identified as potentially containing submerged archaeology.

There is potential for significant impacts on the setting of the coastal historic environment assets such as Muckle Flugga lighthouse and the scheduled monument, Inner Skaw houses and field system, in North Unst. Impacts on the setting of sites will be more significant where devices employed have visible above water components.

There may be the potential for impacts on nearby historic wreck sites from the installation and operation of sites.

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.

Effects on features of the historic environment 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 any valued sites, including the Muckle Flugga lighthouse, and seek to mitigate accordingly.

Landscape / Seascape

The Draft Plan Option is likely to be visible from the Shetland NSA component at the top of Unst. This part of the Shetland Isles also has a relatively high wildness value.

The site is likely to be visible from areas designated for landscape quality including the adjacent NSA and on areas with wildness value.

In terms of operation, the majority of tidal devices components and supporting infrastructure will likely be below the water surface, and as a result, visual impacts may be minimised. However, this will depend on the type of tidal technologies taken forward.

Visibility may be greater during construction and maintenance periods more than during the operational phase. 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 users and shipping that sail close to the Draft Plan Option.

The surface-piercing components of tidal devices and their supporting infrastructure (if any) within the plan option areas may be visible from nearby coastal areas ( e.g. Unst). As the majority of the tidal energy device infrastructure is expected to be submerged, the significance of effects may be lower than for other technologies ( e.g. wind).

The plan option could alter the current seascape and potentially affect its character. However, this will depend on the technology, for example, residual visual effects for some technologies could be minimal once constructed.

Lighting of tidal devices and marker buoys may result in some visual effects during day and night, particularly those in near shore waters. The significance of effects will depend on the visibility of devices which needs to be established at the project level.

Visual impacts could be greater for offshore receptors, such as shipping and 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 landscape and seascape effects on nearby coastal areas. However visual impacts to onshore receptors could potentially be limited by construction further from the coast, in particular to the north east of the Draft Plan Option. In addition effects may be limited as a result of the majority of devices and development being below the water surface.

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


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