Sectoral marine plan for offshore wind energy: strategic habitat regulations appraisal pre-screening report

Pre-Construction Survey (applies where surveys are required to inform baseline environmental descriptions to prepare for installation of devices or cables)

Trawling and borehole sampling during environmental baseline surveys

Temporary removal of, or change to, species or habitats features (e.g. biogenic reefs)

Physical Damage (indirect and temporary damage to marine habitat)

Changes to coastal and offshore habitat as result of damage from baseline surveys (e.g. boreholes/trawls); from equipment use causing abrasion, damage or smothering during installation and from maintenance and removal of cables/devices (e.g. jack-up legs, vessels, anchors, mooring chain).

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Trawling and borehole sampling during environmental baseline surveys

Temporary removal of, or change to, species or habitats features (e.g. biogenic reefs)

Physical Damage (indirect and temporary damage to marine habitat)

Reduction in quality of foraging areas as result of damage to coastal and offshore habitat from baseline surveys (e.g. boreholes and trawls); from equipment use causing abrasion, damage or smothering during installation; from maintenance and removal of cables/devices or from scour, sediment transport and hydrodynamic change, and damage from chains anchoring devices during operation.

6

Increased vessel activity during baseline surveys

Elevated collision risk for marine species especially marine mammals

Physical Damage (direct damage to species from collision risk)

Collision risk and possible mortality of species due to the presence of devices or from vessels travelling to and from the site (including above and below water collision risk and the influence of lighting); risk of entanglement following a collision with power cables or mooring elements.

8

Increased vessel activity during environmental baseline surveys

Visual disturbance of species

Non-Physical disturbance (disturbance to species)

Visual disturbance and exclusion from areas as a result of surveying, cable and device installation/operation and decommissioning activities and movements of vessels.

10

Seismic surveys; Increased vessel activity during environmental baseline surveys

Noise and vibration from seismic exploration and geophysical surveys creating underwater pressure waves that may affect/damage fish or marine mammals and or airborne noise that may affect bird species; Increased vessel activity causing elevated noise disturbance to marine mammals, birds and possibly shoreline mammals (otter)

Non-Physical disturbance (disturbance to species)

Noise/vibration disturbance and exclusion from areas as a result of vessels and other activities during survey work (e.g. seismic exploration and geophysical surveys), construction (e.g. piling, drilling, cable laying), operation (e.g. device noise), maintenance or decommissioning.

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Increased vessel activity during environmental baseline surveys

Elevated risk of spillages/releases of oil or other contaminants & toxic effects on marine species

Toxic Contamination (reduction in water quality)

Spillage of fluids, fuels and/or construction materials during installation or removal of structures (devices and cables) or during survey/maintenance.

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Increased vessel activity during environmental baseline surveys

Elevated risk of introducing non-native species as biofouling on the surfaces of vessels

Biological Disturbance (introduction of non-native species)

Introduction and ingress of invasive non-native species as biofouling species on the surfaces of vessels or construction plant.

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Device & Cable Construction and Decommissioning (applies where devices or cables would need to be installed and then, at the end of their operational life, removed)

Use of jack-up legs and other activities for the installation and decommissioning of structures (including any future ‘repowering’/upgrading activities) and cables.

Damage to vulnerable benthic habitats outside the developmental footprint from construction activities including abrasion from equipment and smothering of habitats where significant sediment is released.

Physical Damage (indirect and temporary damage to marine habitat)

Changes to coastal and offshore habitat as result of damage from baseline surveys (e.g. boreholes/trawls); from equipment use causing abrasion, damage or smothering during installation and from maintenance and removal of cables/devices (e.g. jack-up legs, vessels, anchors, mooring chain).

4

Installation and decommissioning of structures (including any future ‘repowering’/upgrading activities) and cables

Where significant changes occur to intertidal or subtidal habitats (e.g. substratum) then they can lead to impacts to species' food resources

Physical Damage (indirect and temporary damage to habitat)

Reduction in quality of foraging areas as result of damage to coastal and offshore habitat from baseline surveys (e.g. boreholes and trawls); from equipment use causing abrasion, damage or smothering during installation; from maintenance and removal of cables/devices or from scour, sediment transport and hydrodynamic change, and damage from chains anchoring devices during operation.

6

Installation and decommissioning of cables through intertidal habitats

Temporary damage to seal haul out locations during the installation and decommissioning processes

Physical Damage (direct and temporary damage to habitat)

Damage to seal haul out locations during the installation, decommissioning and operation of the cables and cable armouring

7

Increased vessel activity during installation of devices and arrays

Elevated collision risk for marine species especially marine mammals

Physical Damage (direct damage to species from collision risk)

Collision risk and possible mortality of species due to the presence of devices or from vessels travelling to and from the site (including above and below water collision risk and the influence of lighting); risk of entanglement following a collision with power cables or mooring elements.

8

Increased vessel activity during installation of devices and arrays

Visual disturbance of species

Non-Physical disturbance (disturbance to species)

Visual disturbance and exclusion from areas as a result of surveying, cable and device installation/operation and decommissioning activities and movements of vessels.

10

Noise and vibration generated by turbine installation (especially with percussive piling, percussive demolition or the use of explosives)

Underwater noise disturbance that may affect/damage/disturb fish or marine mammals and or airborne noise that may affect bird species

Non-Physical disturbance (disturbance to species)

Noise/vibration disturbance and exclusion from areas as a result of vessels and other activities during survey work (e.g. seismic exploration and geophysical surveys), construction (e.g. piling, drilling, cable laying), operation (e.g. device noise), maintenance or decommissioning.

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Increased vessel activity during installation and decommissioning of devices and arrays

Elevated risk of spillages/releases of oil or other contaminants & toxic effects on marine species

Toxic Contamination (reduction in water quality)

Spillage of fluids, fuels and/or construction materials during installation or removal of structures (devices and cables) or during survey/maintenance.

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Increase in suspended sediments with associated contaminant from construction work especially in environments with fine sediments (e.g. cable trenching)

Toxic effects on marine species

Toxic Contamination (reduction in water quality)

Release of contaminants associated with the dispersion of suspended sediments during installation or removal of structures (devices and cables).

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Increase in suspended sediments from construction work especially in environments with fine sediments (e.g. cable trenching)

Adverse effects on marine species

Non-Toxic Contamination (elevated turbidity)

Increase in turbidity associated with the release of suspended sediments during installation or removal of structures (devices and cables).

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Increased vessel activity during installation of devices and arrays

Introduction of invasive non-native species from biofouling on vessels and plant

Biological Disturbance (introduction of non-native species)

Introduction and ingress of invasive non-native species as biofouling species on the surfaces of vessels or construction plant.

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Device & Cable Operation (the operation of a wind energy device and the presences of power cables)

Permanent (operational period) presence of device locations on the seabed

Loss of seabed habitat and species from the placement of turbines, arrays and/or cables

Physical Loss/Gain of habitat (loss of habitat in development footprint)

Loss of coastal and offshore habitat under the footprint of devices, cables and cable armouring from the installation, operation and decommissioning of these structures.

1

Permanent (operational period) presence of device locations on the seabed

Where significant losses occur to intertidal or subtidal habitats (e.g. substratum) then they can lead to impacts to species' food resources

Physical loss/gain of habitat (direct change to habitat within development footprint)

Loss of foraging areas from reduction in coastal and offshore habitat due to installation of devices and cable armouring both at the development footprint and outside these areas from associated scour and indirectly from changes to the hydrodynamic regime, as well as from chains anchoring devices disturbing seabed habitat during operation.

2

Permanent (operational period) presence of device locations on the seabed

Change to habitat composition (e.g. substratum) at developmental footprint and resulting changes to prey availability and species behaviour (e.g. fish aggregation, artificial reef or bird roosting)

Physical loss/gain of habitat (direct change to habitat around the development footprint)

Presence of structures on seabed for the duration of the project resulting in changes to prey and species behaviour (e.g. acting as FAD (Fish Aggregating Device), artificial reef or bird roost).

3

Use of jack-up legs and other activities for the maintenance of marine structures and cables.

Regular disturbance to, or damage of, seabed habitat features

Physical Damage (direct and temporary damage to habitat)

Changes to coastal and offshore habitat as result of damage from baseline surveys (e.g. boreholes/trawls); from equipment use causing abrasion, damage or smothering during installation and from maintenance and removal of cables/devices (e.g. jack-up legs, vessels, anchors, mooring chain).

4

Presence and operation of sub-surface structures

Changes to the hydrodynamics causing seabed disturbance through local scour and more distant erosion and smothering by re-deposition of mobilised sediment

Physical Damage (indirect and longer-term damage to habitat)

Changes to coastal and offshore habitat as a result of alterations to the wave climate or hydrodynamic regime from the presence of devices or cable armouring causing physical changes (including changes to sediment transport and/or sediment scour.

5

Use of jack-up legs and other activities for the maintenance of marine structures and cables.

Where significant changes occur to intertidal or subtidal habitats (e.g. substratum) then they can lead to impacts to species' food resources

Physical Damage (indirect and longer-term damage to habitat)

Reduction in quality of foraging areas as result of damage to coastal and offshore habitat from baseline surveys (e.g. boreholes and trawls); from equipment use causing abrasion, damage or smothering during installation; from maintenance and removal of cables/devices or from scour, sediment transport and hydrodynamic change, and damage from chains anchoring devices during operation.

6

Presence of cables and armouring intertidal habitats

Impacts to seal haul out locations where any structures remain permanently present across intertidal areas (possibly also causing scour across adjacent areas)

Physical Damage (indirect and longer-term damage to habitat)

Damage to seal haul out locations during the installation, decommissioning and operation of the cables and cable armouring

7

Presence and operation of turbine structures and increased maintenance vessel activity

Collision risk from vessel movements

Physical Damage (direct damage to species from collision risk)

Collision risk and possible mortality of species due to the presence of devices or from vessels travelling to and from the site (including above and below water collision risk and the influence of lighting); risk of entanglement following a collision with power cables or mooring elements.

8

Presence and operation of sub-surface structures

Behavioural effects through the physical presence of devices/arrays that causes avoidance or creates barrier to movements

Non-Physical disturbance (barrier to species movement)

Presence of structures or disturbance (noise or visual) resulting in an exclusion/displacement and presenting a barrier to movement, migratory pathways and/or access to feeding grounds depending on array design.

9

Increased vessel movements and other activities during maintenance of devices and arrays

Visual disturbance of species

Non-Physical disturbance (disturbance to species)

Visual disturbance and exclusion from areas as a result of surveying, cable and device installation/operation and decommissioning activities and movements of vessels.

10

Noise and vibration greater by operating turbines and maintenance vessels

Noise disturbance that may affect/damage/disturb fish or marine mammals

Non-Physical disturbance (disturbance to species)

Noise/vibration disturbance and exclusion from areas as a result of vessels and other activities during survey work (e.g. seismic exploration and geophysical surveys), construction (e.g. piling, drilling, cable laying), operation (e.g. device noise), maintenance or decommissioning.

11

Operation of subsea cables

Electromagnetic fields and heat generated by cables potentially affecting sensitive species and interfering with prey location and mate detection in some species

Non-Physical disturbance (disturbance to species)

Impacts from Electromagnetic Fields ( EMF) and thermal emissions on benthic invertebrates and electromagnetically sensitive fish and cetaceans interfering with prey location and mate detection in some species and creating barriers to migration.

12

Presence and operation of sub-surface structures

Behavioural effects through the physical presence of devices/arrays that causes exclusion/displacement

Non-Physical disturbance (exclusion/ displacement of species)

Presence of structures resulting in an exclusion/displacement of a species from the area.

13

Increased vessel activity during maintenance of devices and arrays

Elevated risk of spillages/releases of oil or other contaminants & toxic effects on marine species

Toxic Contamination (reduction in water quality)

Spillage of fluids, fuels and/or construction materials during installation or removal of structures (devices and cables) or during survey/maintenance.

14

Presence and operation of sub-surface structures

Introduction and colonisation of invasive non-native species on the hard substrata of the subsea infrastructure as stepping stones

Biological Disturbance (introduction of non-native species)

Introduction of new structures providing new substratum that facilitates the colonisation and ingress of invasive non-native species.

17

Presence and operation of sub-surface structures

Introduction of invasive non-native species from biofouling on vessels, plant or on the hard substrata of turbine bases

Biological Disturbance (introduction of non-native species)

Introduction and ingress of invasive non-native species as biofouling species on the surfaces of vessels or construction plant.

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