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

Results of the pre-screening stages of the habitat regulations appraisal.


Table A2: Impact matrix for the draft Plan showing the activities, changes, standard sensitivities categories and affected features for each environmental impact pathway

Feature

Project Phase

Activity

Change

Sensitivity Category (Using standard 'categories of operations which may cause deterioration or disturbance’ ( UK Marine SAC project, 2001))

Summary Impact Pathway Description (see Note at the bottom of the table describing sources and HRA precedents)

Pathway Ref. No. (see Table A1 for list)

Coastal, Intertidal and Subtidal Habitats and Associated Species

Bird Species

Marine Mammals (seals, cetaceans and otters)

Migratory Fish and Freshwater Pearl Mussel

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).

4

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.

11

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.

14

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.

18

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

Seal

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.

11

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.

14

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).

15

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).

16

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.

18

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

Seal

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

Cetaceans

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.

18

This list of impact pathways is based on those which were originally developed during the HRA process for the Pentland Firth Strategic Area ( PFSA) Wave and Tidal Energy plan (ABPmer, 2010a; b) and which were, in turn informed by previous impact pathways identified in the R3 Offshore Wind farm, (R3 OWF) HRA (Entec, 2009a; b). For the draft Plan, this list has been revisited and updated to take account of additional relevant pathways that were identified during the HRA process for more recent plan-level HRAs, including in particular for the Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish waters (ABPmer, 2017) and for the Offshore Wind Energy ( OWE) Plan (ABPmer 2011). The list also includes potentially significant environmental effects identified in the Environmental Statements for recent floating offshore wind farm developments, namely Hywind, Kincardine Offshore Wind Farm and Dounreay Trì Wind (Statoil, 2015; Atkins, 2016; Dounreay Trì Limited, 2016).

References

ABPmer, 2010a. Screening and Scoping Review for the Pentland Firth Strategic Area ( PFSA) Leasing Round Habitats Regulations Assessment. Report for The Crown Estate, ABPmer Report No: R.1601. January 2010.
ABPmer, 2010b. Report to Inform Appropriate Assessment for the Pentland Firth Strategic Area ( PFSA) Leasing Round. Report for The Crown Estate, ABPmer Report No: R.1602. February 2010.
ABPmer. 2011a. Habitats Regulations Appraisal of Draft Plan for Offshore Wind Energy in Scottish Territorial Waters. Report for the Scottish Government, ABPmer Report No: R. 1722a-c. January 2011.
ABPmer. 2011b. Habitats Regulations Appraisal of National Infrastructure Renewables Plan ( N-RIP). Report for the Scottish Government, ABPmer Report No: R1772a-b. January 2011.
ABPmer, 2013. Habitats Regulations Appraisal of Draft Plan for Wave and Tidal Energy in Scottish Waters. Reports for Marine Scotland, ABPmer Report No. R.1863a-c. January 2013.
ABPmer, 2014. Habitats Regulations Appraisal for the Wave and Tidal Further Leasing. Reports for The Crown Estate, ABPmer Report No: R.2160a-c. April 2014.
ABPmer, 2015. Habitats Regulations Appraisal of the Marine Renewables Infrastructure Plan. Report for the Highlands and Islands Executive, ABPmer Report No: R.2340a-c. March 2015.
ABPmer, 2017. Habitats Regulations Appraisal of the Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters. Reports for Marine Scotland, ABPmer Report No: R.2121a-c. 5 May 2017.
AECOM and ABPmer, 2015. Habitats Regulations Appraisal for the Irish Scottish Links on Energy ( ISLES) Spatial Plan. Report for the ISLES project partners (Scotland, Northern Ireland and Republic of Ireland), ABPmer Report No: R.2308a-b.
Atkins, 2016. Kincardine Offshore Windfarm Environmental Statement. March 2016. David Tyldesley and Associates. 2009a. Revised Draft Guidance, The Habitats Regulations Assessment of Local Development Documents. Report for Natural England, February 2009.
Dounreay Trì Limited, 2016. Dounreay Trì Floating Wind Demonstration Project Environmental Statement. 16th September 2016. Doc. Ref. 03363-001010 Ver. no. 7.
Entec, 2009a. Habitats Regulations Assessment of the Round 3 Plan. Screening Report. Report for The Crown Estate. October 2009.
Entec, 2009b. Habitats Regulations Assessment of the Round 3 Plan. Information to Inform an Appropriate Assessment. Report for The Crown Estate. December 2009.
Statoil, 2015. Hywind Scotland Pilot Park Environmental Statement, April 2015.

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