Offshore Biological Environment

6.1. Benthic Subtidal Ecology

6.1.1. Introduction

This section of this Scoping Report presents the relevant benthic subtidal ecology aspects of the Array and considers the scope of assessment on benthic subtidal ecology from the construction, operation and maintenance, and decommissioning of the Array.

6.1.2. Study Area

Two study areas are defined to inform the characterisation of the baseline environment for benthic subtidal ecology:

Array benthic subtidal ecology study area, which is defined as the area encompassed by the site boundary (see Figure 6.1 Open ▸ ). The site-specific benthic subtidal ecology surveys were undertaken within this area, the results of which were used to inform the baseline characterisation and identify benthic receptors which could be potentially impacted by the Array; and
The regional benthic subtidal ecology study area, which is defined as the area encompassing the wider North Sea (see Figure 6.1 Open ▸ ). The boundaries for this regional benthic subtidal ecology study area were adapted from the SMP Assessment region: East Region, to include an area to the south of the site boundary which has the potential to be impacted by indirect effects. Desktop data sources have been used to characterise the regional benthic subtidal ecology study area, which will, overall, provide wider context to the site-specific data collected within the Array benthic subtidal ecology study area in 2022 (see Appendix 7).

6.1.3. Baseline Environment

The benthic subtidal ecology baseline environment of the Array is summarised briefly in this section, with a detailed description provided in Appendix 6. The site-specific survey data collected in 2022 (Appendix 7), and the comprehensive desktop information and data sources outlined in Appendix 6 ensures a robust and up to date characterisation of the benthic subtidal ecology baseline for the purposes of the Array Environmental Impact Assessment (EIA) Report.

Subtidal sediments

The EUSeaMap data indicate that deep circalittoral sand (JNCC Marine Habitat Classification (MHC): SS.SSa.OSa) dominates the site boundary encompassing the Array. There is one small area comprised of deep circalittoral coarse sediment (SS.SCS.OCS) located within the north-west of the site boundary. These are illustrated in Apx Figure 6.1 Open ▸ . Deep circalittoral sand is interspersed more evenly with deep circalittoral coarse sediment elsewhere in the regional benthic subtidal ecology study area, while deep circalittoral mud (SS.SMu.OMu) and circalittoral mixed sediments (SS.SMx.CMx) are mainly present along the coast and within the Firth of Forth.

Figure 6.1: Benthic Subtidal Ecology Study Areas

Limited variation in sediment composition was reported during the site-specific benthic surveys across the Array benthic subtidal ecology study area. The substrate mainly comprises sand, with several sites revealing higher gravel content. Sand was the dominant sediment fraction with an average content of 86.4%. Similarly, results of the site-specific benthic surveys indicated that two broad subtidal habitats characterised the Array benthic subtidal ecology study area: “Faunal communities of Atlantic circalittoral sand” and “Faunal communities of Atlantic circalittoral mixed sediment”.
Site-specific geophysical data have been collected across the site boundary (Appendix 7). These show that the seabed within the Array benthic subtidal ecology study area is characterised by sand, with numerous patches of gravel and occasional diamicton observed, mainly in the west ( Figure 6.2 Open ▸ ). The widespread presence of megaripples and sand waves indicated some degree of sediment mobility, while occasional furrows, mainly in the west, were indicative of erosion. The water depth ranged between 63.82 m and 88.66 m, with a general increase in depth towards the east. The seafloor gradient demonstrates gentle slopes that also generally deepen towards the east of the site boundary.

Subtidal benthic communities

As outlined above, site-specific survey data indicated the sediment composition comprised “Faunal communities of Atlantic circalittoral sand” and “Faunal communities of Atlantic circalittoral mixed sediment” (see paragraph 323). Grab sample data indicated the presence of two subtidal habitats within the Array benthic subtidal ecology study area. These were “Echinocyamus pusillus, Ophelia borealis, and Abra prismatica in circalittoral fine sand” (JNCC MHC SS.SSa.CFiSa.EpusOborApri), and “A. prismatica, Bathyporeia elegans, and polychaetes in circalittoral fine sand” (SS.SSa.CFiSa.ApriBatPo).
The results of the site-specific benthic survey recorded high abundances of annelids, primarily sand mason worm Lanice conchilega and the bristleworm Spiophanes bombyx. There were 196 non-colonial taxa recorded from the grab samples, with the most abundant being L. conchilega, S. bombyx, bivalve A. prismatica, bristleworm Scoloplos armiger and pea urchin E. pusillus. The colonial fauna was dominated by cnidarians and bryozoans, while echinoderms comprised the majority of the total biomass collected during grab sampling. The faunal analysis of the epibenthic beam trawling indicated that the non-colonial phyletic composition was dominated by arthropods, with 46 taxa recorded. The colonial fauna identified comprised cnidarians, bryozoans and porifera. The total fauna recorded in the trawls was dominated by chordates (i.e. fish), which contributed 67% of the total biomass, followed by echinoderms (15%) and bryozoans (7%).
Faunal presence in the drop-down video (DDV) and still photographs recorded during the site-specific benthic surveys was generally sparse and species composition consisted of the following: L. conchilega, bryozoans and cnidarians, echinoderms, sea pen Pennatula phosphorea, ocean quahog Arctica islandica, and the symbiotic hermit crab Pagarus prideaux with anemone Adamsia palliata.
An overview of the benthic communities recorded within surveys for the nearby Seagreen 1 (formerly known as Seagreen Alpha and Bravo), Berwick Bank, and Kincardine Offshore Wind Farms (located between 50 km and 62 km from the site boundary) is presented in Table 6.1 Open ▸ . Further detail on other desktop data sources from the regional benthic subtidal ecology study area is set out in Appendix 6.

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Figure 6.2: Sediment Features and Boulder Fields Within the Site Boundary

Table 6.1: Benthic Subtidal Ecology Community Overview from Seagreen 1 and Berwick Bank Site-Specific Benthic Subtidal Ecology Survey Data (Seagreen, 2012, Atkins, 2016, SSER, 2021)

Project	Community Overview
Seagreen Alpha	The sabellid polychate classes “dense Chone” and “sparse Chone”, dominate the central and eastern regions; Sabellaria, “sparse polychaetes and bivalves”, and “faunal turf” present in the western area.
Seagreen Bravo	“Dense Chone” and “rich polychaetes” present in the eastern area; Sabellaria, “rich polychaetes and bivalves”, and “epifauna with polychaetes” present in the western area.
Berwick Bank	Northern areas dominated by pea urchin, polychaete and bivalve communities and patches of super-abundant Amphiura filiformis; Bivalves dominating the central and eastern areas and a patch in the west; “Polychaete-rich deep Venus communities” were present in the western area.
Kincardine	Offshore deep circalittoral habitats with fine sands or non-cohesive muddy sands (SS.SSa.OSa) throughout the Development Area; Frequently observed species were dead man’s fingers Alcyonium digitatum, the echinoderm Asterias rubens, and bryozoans (such as Flustra foliacea).

Sediment contamination

Ten of the 80 grab samples from the site-specific benthic surveys were tested for contaminants such as metals, total organic matter (TOM), total organic carbon (TOC), total hydrocarbon content (THC), polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCBs) and organotins.
Levels for all contaminants within the site boundary were low overall, and concentrations of TOM, TOC, THC, and PAH were slightly higher in the southern and eastern regions, albeit still low. Levels of metals and PAH were below Cefas Action Level 1. Similarly, concentrations of PAH, PCBs, and organotins were below the limit of detection in most samples.

Designated sites

The Array does not overlap with any protected sites that have been designated for benthic subtidal features. Numerous sites have been identified as occurring within the regional benthic subtidal ecology study area (Apx. Table 6.3 and Apx Figure 6.6 Open ▸ ). These include Marine Protected Areas (MPAs), Marine Conservation Zones (MCZs) and Special Areas of Conservation (SACs). However, due to the distance between the Array and these designated sites (i.e. the closest designated site is over 25 km from the Array), impacts on benthic subtidal features of these sites are unlikely to occur.
There were no Annex I features, including stony or biogenic reefs, recorded in the site-specific benthic surveys. However, there were two habitats and 13 species of conservation importance recorded. The habitats included one Priority Marine Feature (PMF) habitat: offshore subtidal sands and gravels, and one Scottish Biodiversity List (SBL) habitat: subtidal sands and gravels. The species included the sea pen P. phosphorea and associated burrowed mud PMF, hydroid Tamarisca tamarisca (SBL), ocean quahog (PMF and OSPAR (Convention for the Protection of the Marine Environment of the North-East Atlantic) species), and dead man’s fingers A. digitatum (SBL).
The Likely Significant Effect (LSE) Screening Report will include a full screening of National and European designated sites with qualifying interest features relevant to benthic subtidal ecology, that may be impacted by the Array. The information to support the assessment of the National Site Network and transboundary European sites and features will be presented in the Report to Inform Appropriate Assessment (RIAA), as part of the Habitat Regulations Assessment (HRA) process.

6.1.4. Potential Array Impacts

Potential impacts on benthic subtidal ecology which may occur during the construction, operation and maintenance, and decommissioning phases of the Array in the absence of designed in measures have been identified in Table 6.2 Open ▸ .

Table 6.2: Potential Impacts Identified for Benthic Subtidal Ecology in the Absence of Designed In Measures

Potential Impact	Justification
Construction
Temporary habitat loss and/or disturbance	There is potential for temporary direct habitat loss and/or disturbance as a result of site preparation and construction activities (e.g. cable installation) which could result in potential effects on benthic subtidal ecology.
Effects to benthic subtidal ecology due to increases in SSCs and associated deposition	Sediment disturbance may occur as a result of construction activities, such as installation of foundation mooring and anchoring systems, seabed preparation works and cable installation. These activities could result in indirect impacts on benthic communities through temporary increases in SSCs and associated sediment depositions (i.e. smothering benthic receptors). Changes in SSCs may impact benthic communities directly through changes in water clarity and reduced feeding due to increases in suspended solids, smothering, and changes to siltation rate.
Long term subtidal habitat loss	There is potential for long-term loss of benthic habitats to occur directly as a result of placement of foundation mooring and anchoring systems, scour and cable protection.
Effects to benthic subtidal ecology due to accidental pollution	There is a risk of pollution being accidentally released during construction activities from sources such as vessels/vehicles, equipment and machinery involved with construction.
Effects to benthic subtidal ecology due to increased risk of introduction and spread of invasive non-native species (INNS)	There is potential for an increased risk of introduction and spread of INNS due to vessel movements during the construction phase.
Effects to benthic subtidal ecology due to the release of sediment bound contaminants	Sediment disturbance associated with the construction activities, such as foundation mooring and anchoring systems installation and cable burial, could remobilise sediment-bound contaminants. This could cause harmful and adverse effects on benthic communities.
Operation and Maintenance
Temporary habitat loss and/or disturbance	There is potential for temporary direct habitat loss and/or disturbance during the operation and maintenance phase, such as during cable burial or repair operations. In addition, temporary habitat loss/disturbance may also occur due to movement of foundation mooring and anchoring systems or cables on the seabed during the operation and maintenance phase.
Effects to benthic subtidal ecology due to increases in SSCs and associated deposition	Sediment disturbance may occur as a result of operational and maintenance activities, such as remedial cable burial or repair operations. These activities could result in indirect impacts on benthic communities through temporary increases in SSCs and associated sediment depositions (i.e. smothering benthic receptors). Changes in SSCs may impact benthic communities directly through changes in water clarity and reduced feeding due to increases in suspended solids, smothering, and changes to siltation rate.
Long-term subtidal habitat loss	There is potential for long term loss of benthic habitats to occur directly as a result of the presence of foundation anchoring and mooring systems, scour and cable protection over the lifetime of the project.
Effects to benthic subtidal ecology due to accidental pollution	There is a risk of pollution being accidentally released during the operation and maintenance phases from sources such as vessels/vehicles, equipment and machinery involved with operation and maintenance.
Colonisation of hard structures	Artificial structures placed on the seabed (i.e. anchoring and mooring systems, foundations, cable protection and scour protection) and foundations, mooring lines and dynamic cabling in the water column are expected to be colonised by a range of marine species. This could lead to localised increases in biodiversity.
Effects to benthic subtidal ecology due to increased risk of introduction and spread of INNS	There is potential for an increased risk of introduction and spread of INNS through vessel movements required during the operation and maintenance phase and through the availability of hard structures (i.e. foundations) that are expected to be colonised by a range of marine species (see row above).
Effects to benthic subtidal ecology due to electromagnetic fields (EMF)	EMF generated by subsea electrical cabling may affect benthic subtidal ecology in the regional benthic subtidal and ecology study area by inhibiting and/or interfering with the behaviours of relevant benthic receptors. However, these are not expected to result in significant effects on benthic receptors (see Table 6.5 Open ▸ ).
Effects to benthic subtidal ecology due to changes in physical processes	The presence of structures associated with the foundations may introduce localised changes to the tidal flow and wave climate, which could potentially result in changes to the sediment transport pathways and have associated effects on benthic subtidal ecology.
Decommissioning
Temporary habitat loss and/or disturbance	There is potential for temporary direct habitat loss and/or disturbance as a result of site operations, such as decommissioning activities to remove foundations and, if required, electrical cables, which would result in potential effects on benthic subtidal ecology.
Effects to benthic subtidal ecology due to increases in SSCs and associated deposition	Sediment disturbance may occur as a result of decommissioning activities, such as foundation removal. These activities could result in indirect impacts on benthic communities through temporary increases in SSCs and associated sediment depositions (i.e. smothering benthic receptors). Changes in SSCs may impact benthic communities directly through changes in water clarity and reduced feeding due to increases in suspended solids, smothering, and changes to siltation rate.
Effects to benthic subtidal ecology due to accidental pollution	There is a risk of pollution being accidentally released during decommissioning activities from sources such as vessels/vehicles, equipment and machinery involved with decommissioning.
Effects to benthic subtidal ecology due to increased risk of introduction and spread of INNS	There is potential for an increased risk of introduction and spread of INNS due to vessel movements required during decommissioning, along with during transportation of any decommissioned floating parts, where relevant.
Effects to benthic subtidal ecology due to removal of hard substrates	As above, benthic species may colonise hard substrates, such as foundations. However, these may be removed during the decommissioning phase. Loss of species and/or habitats could therefore occur due to the removal of hard substrates.

6.1.5. Designed In Measures

The following designed in measures have been considered in the identification of potential impacts that have been scoped into the Array assessment, including how these can reduce potential for impact ( Table 6.4 Open ▸ ):

the development of, and adherence to, an appropriate Code of Construction Practice (CoCP);
the development of, and adherence to, an EMP, including a Marine Pollution Contingency Plan (MPCP) and INNSMP; and
the development of, and adherence to a Decommissioning Programme.

The significance of effects on benthic subtidal ecology may result in the requirement for additional mitigation measures. This will be consulted upon with the statutory consultees throughout the EIA process.

6.1.6. Relevant Consultations

A summary of the key points of agreement with relevant stakeholders and Statutory Nature Conservation Bodies (SNCBs) during the Array Scoping workshop undertaken in November 2022 is presented in Table 6.3 Open ▸ .

Table 6.3: Summary of Key Consultation on the Scoping Assessment for the Array

Date	Consultee(s)	Type of Consultation	Summary of Consultation	Where Addressed
14 November 2022	NatureScot, MS-LOT, MSS	Scoping workshop	Scoping out effects to benthic ecology due to SSCs and associated deposition, changes to physical processes, and INNS were discussed. No objection was raised to scoping these out subject to presentation of the information within this Scoping Report. Scoping out effects to benthic ecology due to EMF was also discussed, with further evidence to support this provided in Table 6.5 Open ▸ .	Table 6.5 Open ▸

6.1.7. Potential Impacts After the Implementation of Designed In Measures

Table 6.4 Open ▸ outlines the impacts which have been scoped into the Array assessment alongside a description of any additional analyses (e.g. modelling) that will be required to enable a full assessment of the impacts.
Table 6.5 Open ▸ describes the potential impacts to benthic subtidal ecology that are proposed to be scoped out of the assessment at this stage.

Table 6.4: Impacts Proposed to be Scoped Into the Array Assessment for Benthic Subtidal Ecology. Project Phase Refers to Construction (C), Operation and Maintenance (O) and Decommissioning (D) Phase of the Array

Impact	Project Phase			Justification (including consideration of designed in measures)	Data Collection and Analysis Required to Characterise the Baseline Environment for the EIA	Summary of Proposed Approach to Assessment
Impact	C	O	D			Summary of Proposed Approach to Assessment
Temporary habitat loss and/or disturbance				There is potential for temporary direct habitat loss and/or disturbance as a result of activities during the construction, operation and maintenance (including movement of mooring and anchoring systems) during operation and maintenance phase), and decommissioning phases (see Table 6.2 Open ▸ ). There are no designed in measures applicable to this impact.	Site-specific benthic subtidal surveys were undertaken to collect data to characterise the benthic subtidal ecology study area. These surveys consisted of DDV, grab sampling, and epibenthic beam trawling, and were designed using best practice guidelines after being discussed and agreed upon with NatureScot and Marine Scotland. Further detail is provided in Appendix 6.	There is no specific modelling required to inform this impact assessment. However, a quantitative assessment will be undertaken, based on information derived from the PDE (e.g. based on the maximum seabed footprint affected), and presented in the Array EIA Report. The significance of effects upon benthic receptors will be determined by correlating the magnitude of impact and sensitivity of the receptor. The magnitude of impact will be quantified for the MDS, wherever possible. A combination of Marine Evidence Based Sensitivity Assessment (MarESA) and Feature Activity Sensitivity Tool (FeAST; see section 6.1.8) will be used to determine the sensitivity of receptors.
Long term subtidal habitat loss				The presence of foundation structures (including mooring and anchoring systems) and scour and cable protection could result in long term loss of subtidal habitats during the operation and maintenance phase. This impact is also relevant to the construction phase, as these structures will be installed within the construction phase. There are no designed in measures applicable to this impact.		There is no specific modelling required to inform this impact assessment. However, a quantitative assessment will be undertaken, based on information derived from the PDE (e.g. based on the maximum seabed footprint affected), and presented in the Array EIA Report.
Colonisation of hard structures				It is expected that a range of marine species will colonise artificial structures in the water column and infrastructure placed on the seabed (e.g. foundation mooring and anchoring systems, and cable and scour protection). This could lead to localised increases in biodiversity and may also facilitate the spread of INNS (see Table 6.5 Open ▸ below). The designed in measures applicable to this impact include an INNS Management Plan (INNSMP; see Table 6.5 Open ▸ below).		There is no specific modelling required to inform this impact assessment. However, a quantitative assessment will be undertaken, based on information derived from the PDE (i.e. maximum area of habitat created), and presented in the Array EIA Report.
Effects to benthic subtidal ecology due to the removal of hard substrates				As above, benthic species may colonise hard substrates, such as foundations and cable and scour protection. However, these may be removed during the decommissioning phase. Therefore, loss of species and/or habitats colonising these structures could potentially occur during the decommissioning phase. The designed in measure for this impact is adherence to a Decommissioning Programme.		There is no specific modelling required to inform this impact assessment. Therefore, a qualitative assessment will be undertaken, based on information derived from the PDE, and presented in the Array EIA Report.

Table 6.5: Impacts Proposed to be Scoped Out of the Array Assessment for Benthic Subtidal Ecology

Impact	Justification
Construction
Effects to benthic subtidal ecology due to accidental pollution	Pollution could potentially be accidentally released during the construction phase from source such as vessels/vehicles and equipment and machinery. However, the potential risk of accidental release of pollutants is minimised by designed in measures, such as the development of, and adherence to, an appropriate CoCP, and EMP which includes MPCP. These designed in measures include planning for accidental spills, outline all potential contaminants that could be released, and include key emergency contact details. They will also outline good industry practice and OSPAR, International Marine Organisation (IMO), and MARPOL (International Convention for the Prevention of Pollution from Ships) guidelines for preventing pollution at sea. Due to these measures, the likelihood of an accidental spill is very low, and the magnitude will be minimised in the unlikely event that it does occur. Based on this, and subject to consultation with SNCBs and feedback to be received on this Scoping Report, it is proposed to scope this impact out of further consideration within the EIA for benthic subtidal ecology.
Effects to benthic subtidal ecology due to increased SSCs and associated deposition	FeAST and MarESA were used to assess the sensitivities of the biotopes present within the Array to increased SSCs and associated deposition. Using FeAST, the biotope ‘continental shelf mixed sands’ was determined as having medium sensitivity to siltation changes and low smothering and is considered not sensitive to water clarity changes. Similarly, the biotope ‘continental shelf mixed sediments’ was determined as not sensitive to siltation changes and low smothering and medium sensitivity to water clarity changes. Using MarESA the biotopes ‘A. prismatica, B. elegans, and polychaetes in circalittoral fine sand’ and ‘E. pusillus, O. borealis and A. prismtica in circalittoral fine sand’ were assessed as having low sensitivity to siltation changes, low smothering and water clarity changes. Indirect impacts resulting from increased SSCs could occur during installation of mooring and anchoring systems, cable laying and burial, and installation of fixed foundations for Offshore Substation Platforms (OSPs), however, these activities will be short term with any increased SSC returning to background levels following installation. It is anticipated based on modelling reported from other wind farms in the region that increased SSC will be spatially limited with and will settle out of suspension quickly and well within one tidal ellipse of the Array. Therefore, it is proposed to scope this impact out of further consideration within the EIA for benthic subtidal ecology.
Effects to benthic subtidal ecology due to Increased risk of introduction and spread of INNS	There is potential for an increased risk of introduction and spread of INNS through vessel movements during the construction, operation and maintenance, and decommissioning phases, and through the availability of hard structures (i.e. foundations) that are expected to be colonised by a range of marine species (see ‘colonisation of hard structures’ in Table 6.4 Open ▸ above).However, the designed in measure for this impact is an INNSMP, which will ensure that the risk of potential introduction and spread of INNS is minimised. Management included in the INNSMP may include vessel inspections and adherence to the IMO guidelines for the control and management of ships’ ballast water and sediments (IMO, 2022). Significant effects to benthic subtidal ecology are not considered likely under adherence to an INNSMP, therefore, it is proposed to scope this impact out of further consideration within the EIA.
Effects to benthic subtidal ecology due to the release of sediment bound contaminants	As outlined in Table 6.2 Open ▸ above, if sediment bound contaminants are present within seabed sediments in the site boundary, there is potential for these to be released into the water column during the construction phase of the project (e.g. due to installation of infrastructure). However, due to the low levels of contaminants recorded during site specific surveys (i.e. all contaminants were below Cefas Action Level 1 or below limit of detection at all locations; see Appendix 6 and Appendix 7), there is no potential for significant effects on benthic receptors from this impact. As such it is proposed to scope this impact out of further consideration within the EIA for benthic subtidal ecology.
Operation and Maintenance
Effects to benthic subtidal ecology due to accidental pollution	As above for the construction phase.
Effects to benthic subtidal ecology due to increased SSCs and associated deposition	As above for the construction phase.
Effects to benthic subtidal ecology due to Increased risk of introduction and spread of INNS	As above for the construction phase
Effects to benthic subtidal ecology due to EMF	EMF generated by subsea electrical cabling has the potential to affect benthic receptors in the site boundary in close proximity to cable infrastructure. However, there is limited information on the effects of EMF on benthic receptors, with the majority of research concentrated on fish. A recent study by Hutchinson et al., (2020) demonstrated behavioural changes in American lobsters Homarus americanus during the presence of EMFs, however, this species is not present within the regional benthic subtidal ecology study area. Similarly, other benthic invertebrates have been demonstrated to use the earth’s magnetic fields for navigation, such as the amphipods Idotea baltica basteria and Gondogenia antarctica, and crustacean, the spiny lobster Panulirus argus (Herrnkind and McLean, 1971, Lohmann et al., 1995, Ugolini and Pezzani, 1995, Boles and Lohmann, 2003, Tomanová and Vácha, 2016). However, Bochert and Zettler (2006) studied the effects of EMF on the survival and physiology of various crustaceans, marine worms, and echinoderms in the context of cables associated with offshore wind farms in the Baltic Sea and demonstrated no significant effects for any species after three months of exposure. Furthermore, there were no differences between benthic community assemblages observed in visual surveys of wind farm subsea cables and their peripheral areas (Wilhelmsson et al., 2010). Finally, the presence of diverse and seemingly healthy benthic communities on existing offshore wind farm structures indicates that EMF is unlikely to cause a long-term significant effect upon benthic receptors (Linley et al,. 2007; Walker et al., 2009). In addition, a recent review of evidence of the effect of EMF on benthic receptors undertaken for Berwick Bank (SSER, 2022) indicated that any effects, should any occur at all, would affect a very limited area (e.g. in the immediate vicinity of electrical cables) and, therefore, would not lead to significant adverse effects. On the basis of the information presented here, it is proposed to scope this impact out of further consideration within the EIA for benthic subtidal ecology.
Effects to benthic subtidal ecology due to changes in physical processes	As all potential changes to physical processes are proposed to be scoped out (see section 5), adverse effects to benthic subtidal ecology are unlikely to occur. Furthermore, FeAST and MarESA were used to assess the sensitivities of the biotopes present within the Array to changes in local water flow (i.e. tidal current). Using FeAST, the biotopes ‘continental shelf mixed sands’ and ‘continental shelf mixed sediments’ were determined as having low sensitivity to changes in local water flow. Similarly, using MarESA, the biotopes ‘A. prismatica, B. elegans, and polychaetes in circalittoral fine sand’ and ‘E. pusillus, O. borealis and A. prismatica in circalittoral fine sand’ were assessed as being not sensitive to changes in local water flow. Therefore, it is proposed to scope this impact out of further consideration within the EIA for benthic subtidal ecology.
Decommissioning
Effects to benthic subtidal ecology due to accidental pollution	As above for the construction phase.
Effects to benthic subtidal ecology due to increased SSCs and associated deposition	As above for the construction phase.
Effects to benthic subtidal ecology due to Increased risk of introduction and spread of INNS	As above for the construction phase.

6. Offshore Biological Environment

6.1. Benthic Subtidal Ecology

6.1.1. Introduction

6.1.2. Study Area

6.1.3. Baseline Environment

Subtidal sediments

Subtidal benthic communities

Sediment contamination

Designated sites

6.1.4. Potential Array Impacts

6.1.5. Designed In Measures

6.1.6. Relevant Consultations

6.1.7. Potential Impacts After the Implementation of Designed In Measures