Yell - Unst Marine Licence Application
Environmental Supporting Information
Scottish Hydro Electric Power Distribution plc
Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
Xodus Group Xodus House, 50 Huntly Street Aberdeen, UK, AB10 1RS
T +44 (0)1224 628300 E [email protected] www.xodusgroup.com
Environmental Supporting Information A100487-S01
Client: Scottish Hydro Electric Power Distribution plc Document Type: Report Document Number: A-100487-S01-REPT-001
A02 25/04/2018 Re-Issued for Use RP EH JH
A01 20/04/2018 Issued for Use RP EH JH
R01 11/04/2018 Issued for Review JH EH EH
Checked Approved Client Rev Date Description Issued By By By Approval
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 ii
CONTENTS
ACRONYMS 6
1 INTRODUCTION 8
1.1 Introduction 8 1.2 Work completed to date 9 1.2.1 Marine surveys 9 1.3 Project description 13 1.3.1 Route Overview 13 1.3.2 Submarine cable installation 16 1.3.3 Intertidal cable installation 18 1.3.4 Vessels 19 1.3.5 Schedule 19 1.4 Consent requirements and relevant legislation 19 1.4.1 Marine Licence and supporting information requirements 19 1.4.2 Scottish National Marine Plan 20 1.4.3 Shetland Islands’ Marine Spatial Plan 22 1.5 Stakeholder consultation 23 1.6 Environmental assessment scope 24
2 ECOLOGICAL PROTECTED SITES 25
2.1 Introduction 25 2.2 Consultation 25 2.3 Internationally important sites 26 2.3.1 Nature Conservation Marine Protected Areas (NCMPAs) and Special Areas of Conservation (SACs) 26 2.3.2 Special Areas of Conservation (SPAs) and Ramsar sites 30 2.4 Nationally and locally important sites 30 2.5 Potential impacts 33
3 PHYSICAL ENVIRONMENT (INCLUDING SEABED CONDITIONS) 35
3.1 Introduction 35 3.2 Legislation and policy context 35 3.3 Consultation 35 3.4 Physical environment description 35 3.5 Potential impacts 38
4 BENTHIC AND INTERTIDAL ECOLOGY 39
4.1 Introduction 39 4.2 Legislation and Policy Context 39 4.2.1 European Habitats Directive 39 4.2.2 Marine (Scotland) Act 2010 39 4.2.3 Biodiversity Action Plan (BAPs) 40 4.2.4 Shetland Islands Marine Spatial Plan 40 4.3 Consultation 40 4.4 Benthic and intertidal ecology description 40 4.4.1 Subtidal area 41 4.4.2 Intertidal areas 43 4.5 Potential impacts to benthic and intertidal ecology 46
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 iii
4.5.1 Potential impacts during cable installation 46 4.5.2 Potential impacts during cable operation 49 4.5.3 Impact, management and mitigation summary 49
5 MAMMALS, FISH, BIRDS AND OTTERS 50
5.1 Introduction 50 5.2 Legislation and Policy Context 50 5.3 Consultation 50 5.4 Receptor description 50 5.4.1 Cetaceans 50 5.4.2 Pinnipeds 53 5.4.3 Otters 54 5.4.4 Fish ecology 54 5.4.5 Ornithology 57 5.5 Summary of potential impacts 59
6 MARINE ARCHAEOLOGY 61
6.1 Introduction 61 6.2 Legislation and policy context 61 6.2.1 International/ EU legislation and policy 61 6.2.2 UK legislation and policy 61 6.2.3 Scottish legislation and policy 62 6.2.4 Local planning policy 62 6.2.5 Codes of practice, professional guidance and standards documents 62 6.3 Consultation 63 6.4 Sources of information 63 6.4.1 Desk-based assessment 64 6.5 Assessment Methodology 64 6.5.1 Desk Based Assessment 65 6.5.2 Receptor evaluation 67 6.6 Site characterisation 68 6.6.1 Potential for submerged landscapes and prehistoric sites 68 6.6.2 Shipwrecks and aircraft wrecks 68 6.6.3 Unexploded ordinance (UXO) 71 6.7 Potential Impacts 71 6.7.1 Direct damage to or destruction of known marine historic environment assets and unexploded ordnance 71 6.7.2 Direct damage to or destruction of unknown marine historic environment assets including unexploded ordnance 71 6.7.3 Direct damage to or destruction of known and unknown marine historic environment assets and unexploded ordnance 72 6.7.4 Potential indirect damage to or destruction of known and unknown marine historic environment assets including unexploded ordnance 72 6.8 Mitigation 72 6.8.1 Mitigation by design 72 6.8.2 Mitigation during installation 73 6.8.3 Mitigation during operation 73 6.9 Residual Impacts 73
7 CONCLUSIONS 75
7.1 Key receptors 75 7.1.1 Ecological protected sites 75 7.1.2 Benthic and intertidal ecology 75 7.1.3 Marine mammals, fish, birds and otters 76 7.1.4 Marine archaeology 76 7.2 Residual impacts 76 7.3 Compliance with the NMP 76
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 iv
8 REFERENCES 78
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 v
ACRONYMS AtoN Aid to navigation BAP Biodiversity Action Plan CAR Controlled activity regulation CBD Convention on Biological Diversity CIfA Chartered Institute for Archaeologists CLV Cable lay vessel CMS Convention for Migratory Species of Wild Animals DBA Desk-based assessment DECC Department of Energy and Climate Change DEFRA Department for Environment, Food and Rural Affairs DSV Dive support vessel DTI Department of Trade and Industry ECoW Ecological Clerk of Works EIA Environmental impact assessment EMF Electromagnetic fields EPS European Protected Species ERM Environmental Resources Management Ltd. ESG Environmental Scientifics Group EU European Union EUNIS European Nature Information System FLMAP Fishing Liaison Mitigation Action Plan GES Good Environmental Status HMPA Historic Marine Protected Areas HVAC Heating, Ventilation and Air Conditioning IUCN International Union for the Conservation of Nature JNCC Joint Nature Conservation Committee LDP Local Development Plan LNCS Local Nature Conservation Sites LSE Likely Significant Effects MHWS Mean High water Springs MLWS Mean Low water Springs MMO Marine Mammal Observer MMPP Marine Mammal Protection Plan MPA Marine Protected Area MSFD Marine Strategy Framework Directive
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 6
NAFC Natural Environment Research Council NBN National Biodiversity Network NCMPA Nature Conservation Marine Protected Area NMP Scottish National Marine Plan NMPI National Marine Plan Interactive NNR National Nature Reserve NRHE National Record of the Historic Environment OHL Overhead lines OSPAR Convention for the Protection of the Marine Environment of the North East Atlantic PMF Priority Marine Feature pSPA proposed Special Protection Area ROV Remotely Operated Vehicle RPSB Royal Society for the Protection of Birds SAC Special Area of Conservation SAT Shetland Amenity Trust SCANS Small Cetaceans in the European Atlantic and North Sea SEA Strategic Environmental Assessment SHEPD Scottish Hydro Electric Power Distribution plc SIMSP Shetland Islands Marine Spatial Plan SMR Shetland Sites and Monuments Record SMRU Sea Mammal Research Unit SNH Scottish Natural Heritage SPA Special Protection Area SSSI Sites of Special Scientific Interest UK United Kingdom UKBAP United Kingdom Biodiversity Action Plan UKHO UK Hydrographic Office UNCLOS United Nations Convention of the Law of the Sea UXO Unexploded Ordinance
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 7
1 INTRODUCTION
1.1 Introduction In line with Part 4 of the Marine (Scotland) Act 2010, Scottish Hydro Electric Power Distribution plc (SHEPD) is submitting an application for a Marine Licence for the installation of two replacement 33kV submarine electricity cables (hereinafter referred to as the cable or cables) from Point of Grimsetter in Yell to Ness of Wadbister in Unst within the Shetland Isles – Yell – Unst North and Yell – Unst South (the ‘Project’). The purpose of this report and the separately produced Fishing Liaison Mitigation Action Plan (FLMAP) is to provide information on the proposed works for the cable installation and present the environmental information required in support of the Marine Licence application. The environmental supporting information has been based on publicly available information including that available through the National Marine Plan Interactive (NMPI) website platform and the Scottish Natural Heritage (SNH) website. As further information becomes available through additional marine surveys planned for May to June 2018, the potential impact of the proposed cable operations on environmental sensitivities will re-evaluated. The conclusion drawn from the environmental information available is that the proposed cable operations will not significantly impact the environment or protected features in the Project area. For specifically sensitive environmental receptors mitigation plans have been produced The existing 33 kV cables between Yell and Unst were installed in 1984 and 1989 and are nearing the end of their operational life. This has been verified through our existing asset records and following recent visual inspections by Remotely Operated Vehicle (ROV) on the cable. The replacement of these cables is essential to securing SHEPD power supplies to the island of Unst. The existing cable for replacement is shown in Figure 1.1.
Figure 1.1 Existing cables for replacement
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 8
1.2 Work completed to date
1.2.1 Marine surveys SHEPD previously appointed a Contractor to conduct marine surveys along the proposed cable route and surveys were undertaken between September and October 2015. The main objectives of the marine surveys were to identify: Seabed conditions (e.g. sand, rock, mud) to optimise the proposed cable route (avoidance of rock outcrops) Potential geological constraints, such as dykes, rock pinnacles, sand waves, incised channels etc. Locations of potential engineering constraints and/or safety hazards, such as existing pipelines and cables either in service or out of service, wrecks, marine debris, UXO etc. Areas of potential biological and ecological importance (such as biogenic and rocky reefs, priority marine features etc) to allow habitat mapping and inform the requirement for additional surveys and assessment in line with SNH comments The surveyed corridor was centred along the existing cable routes and was selected following a review of potential cable landing points on Yell and Unst, from previous ROV inspections of the existing cable and following an assessment of current and proposed sea user activities in the area. The presence of an existing fish farm to the South, tidal turbine to the North and harbour authority at Cullivoe also influenced the positioning of the survey corridor and routeing of the proposed cables. The extent of the surveyed corridor was decided taking into consideration the survey cost, impact on environmental species from the survey equipment and also disruption to sea users from the survey works. Centring the survey corridor on the existing cable provided the ability to route the proposed cables North or South of the existing cables and to allow some micro-routing following assessment of the survey data. The data acquired along the surveyed route (Figure 1.2) highlighted that rock is prevalent throughout the full extent of the surveyed corridor. This is evident from the highly tidal location which has scoured the seabed leaving minimal overlying sediment on the seabed. There are sections showing a shallow veneer of sediment, however this is insufficient for cable burial. It is evident from the marine survey data that due to the rocky geology and highly tidal nature of the area, consideration needs to be given to cable stability as this will affect cable health. The reducing water depths from the middle of the channel will present challenges with vessel positioning and underkeel clearances for the cable installation works. This will restrict the size and positioning of the installation vessels that can be used. Furthermore, rocky areas are present at the intertidal areas around the shore at both Yell (Figure 1.3 and Figure 1.4) and Unst which was verified by further site visits and site investigations. On Yell the rocky coastline extends North to the nearby harbour at Cullivoe. Further South on Yell a consented fish farm at Wick of North Garth restricts routeing of the cables to the South. Similarly, on Unst, the coastline is rocky and there are cliffs present along the coastline (Figure 1.5) limiting suitable cable landing locations for the proposed cables to the South of Ness of Wadbister. There is also a heritage area present near Loch Snarravoe which must be considered for any onshore based cable routeing or Overhead Line (OHL) works. Directly West of Loch Snarravoe is a sheltered bay (Figure 1.6) where both cables are proposed to come onshore. The presence of an existing tidal turbine within the Bluemull Sound also limits cable routeing to the North. Sub-bottom Profiling (SBP) was utilised to map the seabed surface to allow identification and definition of the extent of the sediment types. These survey methods are useful for identifying areas that may be
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 9
suitable for direct cable burial within the seabed along the route or to help inform alternative cable protection methods, if deemed required. The outcome from the SBP data indicated a lack of sediment along the length of the surveyed corridor. The extent of geotechnical surveys was therefore restricted to seabed grab sampling at selected intervals. A number of grab sample attempts during the survey works failed to recover sufficient material due to a lack of sediment. The purpose of this sampling was to carry out a benthic characterisation assessment combined with Particle Size Distribution (PSD) analysis of the material at the seabed surface. The geotechnical sampling methods were intrusive in that there is a physical interaction between the sampling device and the sediments. Further and more intrusive geotechnical surveying would normally be required where direct cable burial is required along the route. This would provide information on soil conditions and the suitability of burial equipment, however as there is minimal sediment present, direct cable burial is not achievable. Any cable protection needed would be in the form of rock placement, rock filter bags or concrete mattressing directly over the cable.
Figure 1.2 2015 Survey Bathymetry between Yell and Unst These pre-installation surveys have allowed SHEPD to optimise the cable route within the survey corridor and helped to identify feasible installation and cable protection methods. The routeing has been refined following a review of seabed conditions, bathymetry, stakeholder views, seabed use and any other identified seabed features. It has also informed the decision to undertake further marine surveys during the summer of 2018 to better refine and assess the engineering viability and environmental impact of the proposed cable route and installation works.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 10
As part of this additional survey, drop-down video and imagery surveys will also be undertaken to understand better the range of potential habitats and their geographic spread. The methodology in relation to the surveys was developed through discussion with SNH. The survey outputs from the drop- down video surveys will be shared to evidence the habitats and features present along and in the vicinity of the proposed cable. To support the marine licence and the proposed cable installation methodology a Cable Burial Risk Assessment (CBRA) and cable stability assessment will be completed to determine the level of protection needed and to evaluate the impact of the proposed cable installation. The additional surveys may influence the cable installation design and routeing to help minimise the impact on the habitats and seabed features present on the route. This will allow identification of mitigation measures in the form of cable re-routing where appropriate, crossing locations for protective habitats, areas suitable for cable burial and also areas for rock bag placement to stabilise the proposed cable to minimise movement along the seabed.
Figure 1.3 Yell Shoreline viewing North towards Cullivoe harbour
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 11
Figure 1.4 Yell Shoreline viewing South, existing cable AtoN in the background
Figure 1.5 Unst Shoreline viewing South. Existing South cable AtoN in the background
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 12
Figure 1.6 Unst sheltered bay West of Loch Snarravoe viewing West
1.3 Project description
1.3.1 Route Overview The Project aims to install two replacement 33kV HVAC cables between Yell and Unst. The existing cable routes are located from the Point of Grimsetter on Yell to Ness of Wadbister on Unst, across the Bluemull Sound (Figure 1.1). At each shore end landfall, the existing land-based distribution network will be connected to the submarine cables. The potential impacts from the onshore construction activities have been assessed separately via an Extended Phase 1 habitat survey and terrestrial ecology desk study, which will be used to inform the construction contractor of any potential environmental issues to be aware of and/or specific working methods to adhere to. Following a review of the marine survey data outlined above in Section 1.2.1, an optimum route for the proposed cables has been identified as shown in Figure 1.7. The proposed North cable will be 3.15 km in length (2.05 km within the marine environment) between the two termination points with the Overhead lines (OHL), which are located inshore from the Mean High Water Springs (MHWS) limit. However, the length of the cable to be submitted as part of the marine licence application is 2.5 km to allow for obstacle avoidance during cable lay and tolerances with the cable lay operations. The proposed South cable will be 3.15 km in length (2.23 km within the marine environment) between the two termination points with the OHL, which are located inshore from the MHWS limit. However, the application length is 2.5 km to allow for obstacle avoidance during cable lay and tolerances with the cable lay operations. The proposed cable routes lie within the survey corridor with some micro-routeing selected to avoid areas of significant bedrock, boulders and to avoid or minimise the impact on sensitive marine features identified from the marine surveys for the proposed cables. The Fetlar to Haroldswick MPA is located further South which has been considered for our proposed routeing by avoiding this area. The proposed cables retain the North cable shore end landfall at Yell. Alternative landfall positions were reviewed but discounted due the rocky coastline, harbour authority area to the North and locations of consented offshore developments. The proposed cable routes will be located adjacent to the existing North cable. An offset will be used to allow safe installation, operation, future maintenance and ongoing inspection of the cable(s).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 13
On both Yell and Unst the proposed cables will be completed with short sections of underground cabling onto the existing SHEPD OHL. The proposed cable routes and method of installation has been identified based on a combination of desk studies, marine seabed surveys and stakeholder views. Prior to the cable installation, SHEPD’s appointed contractor will undertake a final review of the marine survey to confirm the seabed conditions and finalise the exact cable route within the consented corridor and techniques to be employed. Further to this, a review of the existing shore end landfall locations and land-based infrastucture was undertaken and verified with site visits on both Yell and Unst to confirm the shore end landing points and the method of cable installation above the MLWS limits. This was necessary in order to assess the suitability for site access and the logistical constraints for plant and machinery but also to better understand the environmental and landowner contraints.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 14
Figure 1.7 Proposed Cable Routes (including marine survey corridor)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 15
1.3.2 Submarine cable installation Two new distribution submarine electricity cables are proposed to be laid on the seabed between MLWS on the Yell and Unst coasts. As described in Section 1.3.1., the new cables will be laid along a similar route to the North and South of the existing cables to allow for safe installation and inspection. The new cables will have an outer diameter of 118 mm and will be installed from a Cable Lay Vessel (CLV). They will be installed each within their own defined corridors anticipated to be 200 m width (100 m either side of the new cable route), to allow for any unforeseen difficulties that arise during installation, to enable more scope for in-situ micro-routing during installation and to avoid sensitive environmental habitats or potential marine archaeology. During cable lay activities additional smaller support vessels will be required at each of the shallower shore locations; this is likely to be a multicat/DSV. This may require an anchoring system to be laid out prior to and during works in the nearshore region. In this instance, an anchor handling vessel would be required to lay out the anchors. A guard vessel is also likely to be used during the cable lay operations to ensure other vessels remain outside the area of operations to reduce collision risk. Initially, the proposed submarine cable will be surface laid on the seabed across the length of the route. Due to the strong tidal currents the majority of the proposed cable routes will be across rocky seabed with very little overlying sediment. Due to the limited sediment direct cable burial will not be possible. By initially surface laying the cables this minimises the footprint in these areas, however cable mobility on the seabed may increase the footprint and impact on the seabed habitat. To minimise the impact of the cables on the seabed during and after installation, SHEPD plan to lay rock filter bags (each with a seabed footprint of approximately 2.0 m by 2.0 m), as shown in Figure 1.8, or concrete mattresses (each with a seabed footprint of approximately 3.0 m by 6.0 m), as shown in Figure 1.9, in spot locations on the cable to pin the cables to the seabed. Only clean washed stone will be used to fill the rock bags and no cementitious material will be used. Each bag will be no more than 1 m high when installed. The rock filter bags have been proven to provide a habitat for aquatic species and mould to the seabed contours where installed. Positioning of the rock bags / mattresses will help stabilise the cables. A cable stability assessment will be undertaken to provide information on cable stability throughout the proposed routes with a view to minimising the amount of rock bags / mattresses required to pin the cable whilst ensuring cable stability following the installation. For both cables from Yell, rock filter bags / mattresses will be placed on the cable at roughly 50 m intervals within the marine environment. A maximum of 95 rock filter bags / mattresses will be used on each cable. Example rock filter bags and mattresses are shown in Figure 1.8 and Figure 1.9 respectively. The risk of installing the rock bags / mattresses directly onto the cable could cause subsequent damage from point loading dependent on the seabed and lay of the cable. A post lay inspection of the cable after it is installed will identify the potential risk to placement of the rock filter bag / mattresses directly onto the cable and confirm exact locations.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 16
Figure 1.8 Example rock filter bag
Figure 1.9 Example protection mattress
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 17
1.3.3 Intertidal cable installation Due to the suitability of the existing shore end landfall locations and following assessment of alternative areas, the proposed cable will be installed adjacent to the existing cable at both Yell and Unst. It is proposed to install the cable by using an open-cut trench method of installation inshore from the MLWS tidal limits at both shore end landfall locations. At Yell and Unst, to complete the shore end installation works there will be some underground cabling from the transition joint location with the marine cable and minor modifications to the existing 33kV OHL. It is proposed to install the cable by using an open-cut trench method of installation inshore from the MLWS tidal limits at both shore end landfall locations. An open cut trench will be excavated to install and bury the cable. This will utilise traditional terrestrial based plant including excavators at low tide. The typical underground cable trench is illustrated below in Figure 1.10. To allow for micro-routing during cable installation the landfall excavation works will take place within 100 m either side of the cable landfall positions shown in Figure 1.7. The trench will be excavated alongside the cables using a terrestrial-based mechanical excavator during low spring tide. The excavated material will be placed to one side of the trench for later reinstatement. Using a mechanical winch and cable rollers, the cable will be manoeuvred into the bottom of the trench and then covered with the excavated material using the mechanical excavator. The trench width will be minimised where possible however will be dependent on ground stability but will typically be 1 m wide. The target depth of the trench will be 1.25 m. Temporary trench shoring may be required to prevent collapse of the trench wall. The footprint of the excavator may be up to 5 m, and a working width, including for the temporary storage of removed material, would be in the order of 10 m. On either shore where sufficient burial cannot be achieved, cast iron split pipe will be fitted around the cables for additional protection in the event of exposure. This will be installed down to MLWS mark. It is proposed to install a maximum of 100 m of split pipe protection on each shore from MWHS to MLWS in the event that sufficient cable burial cannot be achieved to protect the cable. The split pipe is an articulated cast iron shell design that locks around the cable and fixed with bolted end clamps. Each shell has 8 mm wall thickness, with an effective length of 391 mm.
Figure 1.10 Typical open cut trench cross-section inshore of MLWS.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 18
The submarine cables crossing the intertidal area will be connected to the terrestrial cable in a transition joint pit (TJP) buried in the ground located above the MHWS limit at each end. At the Yell end, from the MHWS limit the cable will be buried onshore for approximately 150 m connect into the existing OHL. On the Unst shore, from the MHWS limit the cable will be buried for approximately 900 m through the field and connect in to the OHL. This will permit the dismantling several spans of existing OHL. On completion of jointing and cabling works, spoil material will be backfilled into the trenches and the shore will be reinstated; grassed areas will be left to re-seed naturally. At each shore landfall location, to facilitate the onshore works and ensure compliance with the Construction (Design and Management) Regulations 2015, a temporary site area will be required, approximately 30 m x 30 m in size, to provide welfare facilities and parking during the works. To minimise ground disturbance, ease reinstatement and recovery, the area will be covered with a membrane material and levelled with rock chippings The SHEPD Project Description (SHEPD Section ID151-152, Project Description Yell – Unst North (1), Yell -Unst South (2), undated) provides further details on the proposed methods to install the two cables between Yell and Unst.
1.3.4 Vessels For the cable laying activities, a standard small cable lay vessel will be used. An additional smaller support vessel is likely to be required at each of the shallower shore locations; this is likely to be a multicat / DSV. This may require deployment of an anchor spread, such as a four-point anchor system, prior to and during the works in the nearshore region. An anchor handling vessel will be required to lay out the anchors, which would be within a radius of 100 m from the DSV. Where there is sensitive habitat close to shore, the anchor pattern would be designed so that it targets areas where sensitivity is reduced, thereby minimising the potential impact. A guard vessel is also likely to be used during the cable lay operations to ensure other vessels remain outside the area of operations, thereby reducing collision risk. The design of the anchor spread and the area to be impacted is discussed further in Section 4.5.1.
1.3.5 Schedule The planned duration of works is no greater than 30 days, exclusive of weather. A Marine Licence is required for the period of October 2018 to March 2019. The onshore cabling works on both Yell and Unst will be completed prior to the main submarine cable installation works. The minor modifications required to the existing OHL networks will be carried out during commissioning of the submarine cable to the SHEPD network.
1.4 Consent requirements and relevant legislation
1.4.1 Marine Licence and supporting information requirements Under Part 4 of the Marine (Scotland) Act 2010, a Marine Licence is required for the installation and operation of submarine cables in Scottish waters. However, submarine cables do not require a formal Environmental Impact Assessment (EIA) as they are not listed on either Schedule 1 or Schedule 2 of the Marine Works (Environmental Impact Assessment) Regulations 2017. Although a formal EIA is not required for submarine cables, Marine Scotland advises, in their Guidance for Marine Licence Applicant Version 2 June 2015 (Marine Scotland, 2015) that “applicants for marine licences for submarine cables should consider the scale and nature of their projects and give consideration to the need for a proportionate environmental assessment”. For larger projects, where there is potential for the subsea cable to impact key environmental receptors, it is recommended by Marine Scotland (Marine Scotland, 2015) that an assessment of potential impacts on these receptors is carried out. Results from this assessment along with other relevant information about the Project should then be provided to support the Marine Licence application.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 19
This document forms part of a suite of documents that have been produced to support the Marine Licence application for the Yell - Unst Cable Replacement Project and will be used to implement environmental management measures for the Project. The aim of this report is to provide sufficient environmental information to support the Marine Licence application, by identifying the environmental receptors in the area and undertaking an assessment of the potential impacts to those that are considered particularly sensitive to the proposed works. Survey works along the proposed cable route are ongoing, therefore this document provides the results of a desk based environmental assessment.
1.4.2 Scottish National Marine Plan The Scottish Government adopted the National Marine Plan (NMP) in early 2015 (Scottish Government, 2015) to provide an overarching framework for marine activity in Scottish waters, with an aim to enable sustainable development and the use of the marine area in a way that protects and enhances the marine environment whilst promoting both existing and emerging industries. This is underpinned by a core set of general policies which apply across existing and future development and use of the marine environment. Sectoral policies are also outlined in the Plan where a particular industry brings with it issues beyond those set out in the general policies. For the Project, the policies covering sea fisheries and submarine electricity cables are of particular relevance. SHEPD has taken all the policies outlined below into consideration when developing the replacement cable route and assessing the potential environmental and socio-economic impacts. Discussion on how compliance and alignment with the NMP has been achieved is provided in the Conclusions (section 7.3 of this report). General Planning The general planning policies of particular relevance to the Project include: General planning - There is a presumption in favour of sustainable development and use of the marine environment when consistent with the policies and objectives of the Plan; Economic benefit - Sustainable development and use which provides economic benefit to Scottish communities is encouraged when consistent with the objectives and policies of this Plan; Co-existence - Proposals which enable coexistence with other development sectors and activities within the Scottish marine area are encouraged in planning and decision making processes, when consistent with policies and objectives of this Plan; Climate change - Marine planners and decision makers must act in the way best calculated to mitigate, and adapt to, climate change; Natural heritage - Development and use of the marine environment must: . Comply with legal requirements for protected areas and protected species;
. Not result in significant impact on the national status of Priority Marine Features (PMF); and
. Protect and, where appropriate, enhance the health of the marine area.
Noise: Development and use in the marine environment should avoid significant adverse effects of manmade noise and vibration, especially on species sensitive to such effects; Engagement: Early and effective engagement should be undertaken with the general public and interested stakeholders to facilitate planning and consenting processes; and
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 20
Cumulative impacts: Cumulative impacts affecting the ecosystem of the Marine Plan area should be addressed in decision-making and Plan implementation. Sea Fisheries With respect to sea fisheries, the NMP sets out a number of policies. Those that are relevant to the Project include: 'Fisheries 1': Taking account of the EU’s Common Fisheries Policy, Habitats Directive, Birds Directive and Marine Strategy Framework Directive, marine planners and decision makers should aim to ensure: Existing fishing opportunities and activities are safeguarded wherever possible; Protection for vulnerable stocks (in particular for juvenile and spawning stocks through continuation of sea area closures where appropriate); That other sectors take into account the need to protect fish stocks and sustain healthy fisheries for both economic and conservation reasons; and Mechanisms for managing conflicts between fishermen and/or between the fishing sector and other users of the marine environment. 'Fisheries 2': The following key factors should be taken into account when deciding on uses of the marine environment and the potential impact on fishing: The cultural and economic importance of fishing, in particular to vulnerable coastal communities; The potential impact (positive and negative) of marine developments on the sustainability of fish and shellfish stocks and resultant fishing opportunities in any given area; The environmental impact on fishing grounds (such as nursery, spawning areas), commercially fished species, habitats and species more generally; and The potential effect of displacement on: fish stocks; the wider environment; use of fuel; socio- economic costs to fishers and their communities and other marine users. 'Fisheries 3': Where existing fishing opportunities or activity cannot be safeguarded, a Fisheries Management and Mitigation Strategy should be prepared by the proposer of development or use, involving full engagement with local fishing interests (and other interests as appropriate) in the development of the Strategy. All efforts should be made to agree the Strategy with those interests. Those interests should also undertake to engage with the proposer and provide transparent and accurate information and data to help complete the Strategy. The Strategy should be drawn up as part of the discharge of conditions of permissions granted. The content of the Strategy should be relevant to the particular circumstances and could include: An assessment of the potential impact of the development or use on the affected fishery or fisheries, both in socio-economic terms and in terms of environmental sustainability; A recognition that the disruption to existing fishing opportunities/activity should be minimised as far as possible; Reasonable measures to mitigate any constraints which the proposed development or use may place on existing or proposed fishing activity; and Reasonable measures to mitigate any potential impacts on sustainability of fish stocks (e.g. impacts on spawning grounds or areas of fish or shellfish abundance) and any socioeconomic impacts.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 21
Submarine Cables With respect to submarine cables, the NMP sets out a number of key objectives. Those that are relevant to the Project include: Protect submarine cables whilst achieving successful seabed user co-existence; Achieve the highest possible quality and safety standards and reduce risks to all seabed users and the marine environment; and Support the generation, distribution and optimisation of electricity from traditional and renewable sources to Scotland, UK and beyond. There are four marine planning policies laid out in the NMP that are relevant to the Project: 'Cables 1': Cable and network owners should engage with decision makers at the early planning stage to notify of any intention to lay, repair or replace cables before routes are selected and agreed. When making proposals, cable and network owners and marine users should evidence that they have taken a joined-up approach to development and activity to minimise impacts, where possible, on the marine historic and natural environment, the assets, infrastructures and other users. Appropriate and proportionate environmental consideration and risk assessments should be provided which may include cable protection measures and mitigation plans. Any deposit, removal or dredging carried out for the purpose of executing emergency inspection or repair works to any cable is exempt from the marine licensing regime with approval by Scottish Ministers. However, cable replacement requires a marine licence. Marine Licensing Guidance should be followed when considering any cable development and activity. 'Cables 2': The following factors will be taken into account on a case by case basis when reaching decisions regarding submarine cable development and activities: Cables should be suitably routed to provide sufficient requirements for installation and cable protection; New cables should implement methods to minimise impacts on the environment, seabed and other users, where operationally possible and in accordance with relevant industry practice; Cables should be buried to maximise protection where there are safety or seabed stability risks and to reduce conflict with other marine users and to protect the assets and infrastructure; Where burial is demonstrated not to be feasible, cables may be suitably protected through recognised and approved measures (such as rock or mattress placement or cable armouring) where practicable and cost-effective and as risk assessments direct; and Consideration of the need to reinstate the seabed, undertake post-lay surveys and monitoring and carry out remedial action where required. 'Cables 4': When selecting locations for land-fall of power and telecommunications equipment and cabling, developers and decision makers should consider the policies pertaining to flooding and coastal protection in Chapter 4 (of the NMP), and align with those in Scottish Planning Policy and Local Development Plans.
1.4.3 Shetland Islands’ Marine Spatial Plan The Shetland Islands Marine Spatial Plan (SIMSP) provides an overarching policy framework to guide marine development and activity. This SIMSP is based on Scottish Ministers’ commitment to making marine management more efficient, inclusive and accessible. Areas of constraint and/or opportunities for development have been identified in order to reduce potential conflicts between marine activities and encourage co-existence between multiple users. The SIMSP aims at providing an approach to the management of the sea around Shetland; facilitating an integrated and better informed decision-making process regarding the future distribution of activities and resources; and enabling the long-term protection and use of the marine environment.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 22
Section 4 of the SIMSP sets out the legislative requirements that need to be considered for any development proposal. This section covers marine and works licences, planning permission, controlled activity regulation (CAR) authorisation, seabed agreement for lease, electricity regulations, EIA, cumulative impacts and consultation with stakeholders. Section 5 of the SIMSP sets out a number of general policies that ensure that the SIMSP is contributing to the high-level government targets that are supporting a clean and safe, healthy and diverse, and productive marine environment. Those that are most relevant to this Project include: underwater noise, navigational safety, cables and pipelines, climate change, coastal defence and flood protection, protected species, nature conservation designations, marine recreation and invasive non-native species.
1.5 Stakeholder consultation During the planning of the cable installation works and preparation of the Marine Licence application and supporting documentation, SHEPD has undertaken consultation with a number of different parties. Key to this was a series of “Pre-application Consultation Events” which were held to enable any interested party to comment upon the cable replacement process. SHEPD targeted events at legitimate sea users, SHEPD customers, public sector and non-governmental organisations and statutory consultees. The timing and content of these consultations are summarised below, with topic specific issues summarised as appropriate in the impact assessment. Full details of the Pre-application Consultation Events is provided in Pre-application Consultation Report Yell-Unst 1 and Pre-application Consultation Report Yell-Unst 2.
Timing Organisation Consultation undertaken August Legitimate sea users, SHEPD customers, public Open door event held in Cullivoe Hall, Yell 2016 sector and non-governmental organisations August Legitimate sea users, SHEPD customers, public Open door event held at the Shetland Power 2016 sector and non-governmental organisations Station, Lerwick August Legitimate sea users, SHEPD customers, public Open door event held in Mossbank Hall 2016 sector and non-governmental organisations August Legitimate sea users, SHEPD customers, public Open door event held in Baltasound Hall, 2016 sector and non-governmental organisations Unst October Scottish Natural Heritage Clarification meeting to discuss issues raised 2016 in communications to date October Maritime Coastguard Agency Inform of project details prior to submission of 2016 applications November Scottish Fishermen’s Federation Inform of project details prior to submission of 2016 applications November Commissioners of the Northern Lighthouse Board Inform of project details prior to submission of 2016 Meeting applications November Scottish Environment Protection Agency Inform of project details prior to submission of 2016 applications January Crown Estate Inform of project details prior to submission of 2017 applications April 2017 Legitimate sea users, SHEPD customers, public Open door event held at the Shetland sector and non-governmental organisations Museum, Lerwick April 2017 Legitimate sea users, SHEPD customers, public Open door event held at the Shetland sector and non-governmental organisations Museum, Lerwick April 2017 Legitimate sea users, SHEPD customers, public Open door event held in Cullivoe Hall, Yell sector and non-governmental organisations April 2017 Legitimate sea users, SHEPD customers, public Open door event held in Baltasound Hall, sector and non-governmental organisations Unst
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 23
1.6 Environmental assessment scope The following sections of this environmental supporting information document provide information on: The identification of potential impacts on protected sites and key receptors associated with those sites; The identification of potential impacts on other key receptors and an assessment of the potential for those impacts to be significant; and Mitigation measures that will be implemented to avoid or minimise any potential impacts (these include mitigation measures that are inherent to the Project design). Ongoing liaison between the SHEPD Project team and the environmental consultants during the course of the impact assessment work has allowed for environmental considerations to be incorporated into the Project design as appropriate. The cable routes from Yell to Unst has a small discrete footprint in Bluemull Sound. The proposed works are also temporary in nature and will be short term. However, a small number of potential impacts on the following key receptors have been considered to demonstrate that impacts are either inherently sufficiently limited in nature or that sufficient control measures will be implemented to ensure impacts are not significant1: Protected sites and species associated with those sites; Physical environment; Benthic and intertidal ecology; and Other species, including mammals, fish, shorebirds and otters. Fisheries and other sea users are considered in the FLMAP and are not discussed further in this document.
1 Note: The 2017 change to EIA legislation give effect to the amended European Union EIA Directive (1), which clarifies that ‘population and human health’ factors should be included in the environmental topics considered by EIA. As a result of the limited scale of the proposed activities, and given that the proposed activities are routine and are well-controlled by Industry-standard procedures, no potential impacts on public health have been identified. Therefore, no further discussion on population and human health factors is presented herein.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 24
2 ECOLOGICAL PROTECTED SITES
2.1 Introduction This section of the report provides detail on the protected sites and their qualifying features in the vicinity of the Project, as well as the relevant legislation applicable to each site, and the relevant consultation advice that has been provided to SHEPD by key stakeholders. It then assesses the potential impacts on the sites that could be impacted from the proposed activities and discusses the mitigation and management measures that will be undertaken in order to ensure impacts are avoided or minimised and provides a conclusion of the significance of potential impacts. There is one protected site with marine components located in the immediate vicinity of the replacement cable routes and landfall locations, namely the Fetlar to Haroldswick Nature Conservation Marine Protected Area (NCMPA) (Figure 2.1). The site, that extends along the east coast of Unst down to Yell, and surrounds the isle of Fetlar, is designated for the breeding black guillemot (Cepphus grylle), for the presence of benthic features including circalittoral sand and coarse sediments, horse mussel beds, kelp and seaweed communities on sublittoral sediments, maerl beds, shallow tide-swept coarse sands with burrowing bivalves, and for the geomorphology of the Scottish shelf seabed (SNH, 2014). There is also another protected site, the Yell Sound Coast Special Area of Conservation (SAC) for which the qualifying harbour seal could potentially be impacted during cable installation activities.
2.2 Consultation SHEPD has undertaken consultation with statutory and non-statutory bodies. Correspondence of relevance to ecologically protected sites is summarised below in Table 2.1 (taken directly from the written correspondence). Table 2.1 Consultation Summary
Consultee Consultation Comment
Ecological protected sites
SNH have been consulting on whether the Blue Mull and Colgrave Sounds should become a Special Protection Area (SPA) as it is an important foraging area for breeding red- throated divers. SNH advised that there is likely to be no significant effects because the cable is not passing through 5th October 2016, SNH a high density feeding ground as cable deeper that they Inverness usually like to dive.
Birds are breeding in this area between May and July. Supportive of commitment to undertake works, onshore and in water, outside the months of May and July.
Bird and otter surveys should be undertaken at landfall sites. SHEPD attended SNH's consultation event on Yell to understand if the proposed SPA designation would require adopting different cable SNH consultation installation and protection methods to the current approach; and if th SNH event on SPAs, 17 any additional environmental surveys were required. However, SNH August 2016, Yell declined to comment before formal submission of the Marine Licence Application at which point they will response in accordance with statue.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 25
2.3 Internationally important sites
2.3.1 Nature Conservation Marine Protected Areas (NCMPAs) and Special Areas of Conservation (SACs) The Scottish National Marine Plan incorporates 30 nature conservation Marine Protected Areas (NCMPAs) of which 17 are in territorial waters. The closest NCMPA is the Fetlar to Haroldswick NCMPA, located 1.6 km south of the Project area as listed in Table 2.1 and shown on Figure 2.1. The site is protected for the following features: Black guillemot (Cepphus grylle) (breeding); Circalittoral sand and coarse sediments; Horse mussel beds; Kelp and seaweed communities on sublittoral sediments; Maerl beds; Shallow tide-swept coarse sands with burrowing bivalves; Geomorphology of the Scottish shelf seabed (SNH, 2014). Horse mussel beds, kelp and seaweed communities on sublittoral sediments and maerl beds are designated as Priority Marine Features (PMFs) in Scottish waters (Tyler-Walters, 2016). Due to the distance to the NCMPA (1.6 km) and the small discrete footprint and short-term nature of the proposed works between Yell and Unst, impacts on these benthic features are unlikely. The black guillemot is protected during the breeding season (May to July) within the NCMPA, when they spend more time ashore at the nesting sites (Ewins, 1985). However, the proposed works are planned to occur between October 2018 and March 2019, which is outwith the breeding season for black guillemot, therefore any impacts on breeding guillemot are unlikely. The EC Habitats Directive comprises a list of priority habitat types and species that require measures for protection in Europe. In the UK, 76 habitat types and 61 species listed in the Directive have been recorded in the UK (McLeod et al., 2005). There are currently 10 Special Areas of Conservation (SACs) in Shetland that are designated for the presence of Annex I habitats and Annex II species, 6 of which have a marine component: Yell Sound Coast, Papa Stour, Sullom Voe, The Vadills, Mousa and Fair Isle. The closest offshore SAC to the Project are is the Yell Sound Coast SAC, located approximately 24 km south-east of the Project area. The features that are primary reasons for designating these sites are presented in Table 2.2. Scotland is recognised as a stronghold for the otter in Europe, and is the most significant terrestrial mammal in Shetland. Along with the harbour seal (Phoca vitulina), the Yell Sound Coast SAC has been designated for the presence of European otter (Lutra lutra). The site supports approximately 80 otters with the highest densities in Britain, thus representing 2.5% of the UK population. Three sightings of otter (L. Lutra) have been recorded from a recorded position approximately 760 m to the north of the proposed Yell landfall in 1979, 1991 and 2015 (NBN Atlas, 2018). A site survey was conducted at Yell and Unst landfalls for the north cable route on 26th January by the Shetland Amenity Trust (ERM, 2018a, 2018b). At Yell, high levels of otter activity were recorded along the coast. However, no holts were recorded within 200 m of the proposed North cable route (ERM, 2010a) and within 100 m of the South cable route (ERM, 2018b) (Figure 2.2). At Unst, one otter holt was found on a coastal sandy bank, approximately within 20 m of the South cable landfall location (Figure 2.3). Another two active holts were found on the stretch of coastline at Snarra Voe, the bay where the cable landfalls are located, however these were over 100 m from the landfall sites (ERM, 2010b). One otter holt was observed 100 m of the proposed North cable route at Unst on a coastal sandy bank (Figure 2.3) (ERM, 2010a).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 26
Based on the current design, the proposed South cable routes is located in close proximity to otter holts (within 30 m) on Unst. A route towards and into the Bay of Ulsta on Unst has previously been determined as less favourable for a new submarine cable due to unfavourable tidal currents, seabed conditions and interactions with other marine users. The tidal conditions are more extreme further north which in turn would have a detrimental effect on the cable in terms of movement and abrasion and would result in a higher likelihood of future fault. Likewise, the seabed conditions to the south of this Bay of Ulsta are naturally more undulating and together with the charted ‘spoil ground’ just south of this bay, which would indicate the potential for unknown material and increased tendency for unstable seabed levels, it was considered preferable to avoid this area on the basis of cable integrity. Additionally, the presence of passenger ferry and other recreational vessel movements between Tofts Voe and Bay of Ulsta would present difficulties during installation and expose any new cable in this vicinity to risks associated with anchor deployment. However, several mitigation measures are proposed to avoid otter holts. The proposed cable routes between Yell and Unst remain flexible in the design route such that the 100 m wide working corridor in the onshore section (± 50 m from the centre of the cable routes) and the 500 m corridor (± 250 m) in the offshore section would allow for micro-routing and avoidance of known holt location. An Ecological Clerk of Works (ECoW) would most likely be present on site to ensure that buffer areas are enforced and check any new otter activity. If there are any activities close to areas of high otter density, as found during the SAT survey at the cable landfalls, the Marine Mammal Observer (MMO) will also monitor for the presence of otters the water, and delay the start of the activities if any are seen within 100 m of the vessels. Considering the mitigation measures to avoid otter holts and prevent disturbance of otters whilst in the water, and that otters are known to accommodate a discrete, and short-term disturbance (the proposed works are expected to extend over approximately 30 days per cable), no significant impact on otters are expected. Table 2.2 SACs and NCMPAs located in the vicinity of the Project area
Distance and Potential connectivity Site name Description and qualifying features direction from with the Project Project Black guillemot C. grylle (breeding); No Proposed activities will Circalittoral sand and coarse not impact this site. sediments; Horse mussel beds; Fetlar to Kelp and seaweed communities on Haroldswick sublittoral sediments; 1.6 km south NCMPA Maerl beds; Shallow tide-swept coarse sands with burrowing bivalves; and Geomorphology of the Scottish shelf seabed Yes2 Yell Sound Otter L. lutra; and 24 km south-east (28 The site is within foraging Coast SAC Harbour seal P. vitulina km by sea) range of harbour seal. No Sullom Voe Large shallow inlets and bays 25 km south-east (36 Proposed activities will SAC (Annex I habitat) km by sea) not impact this site. Pobie Bank Annex I Reefs No Reef SAC 34 km E of the Project Proposed activities will area not impact this site.
2 Harbour seal foraging distance is typically 40-50 km (SCOS, 2014).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 27
Figure 2.1 Ecological protected sites around Yell and Unst in Shetland (NMPI, 2018)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 28
Figure 2.2 Otter holts recorded in the vicinity of the Figure 2.3 Otter holts recorded in the vicinity of the Unst Yell landfall for the North and South cable routes (ERM, 2018a) landfall for the North and South cable routes (ERM, 2018a)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 29
2.3.2 Special Areas of Conservation (SPAs) and Ramsar sites The waters around Shetland support national and international populations of seabirds. Under the EC Birds Directive, breeding (Annex I) or regularly occurring migratory populations of seabird and marine waterfowl are protected through the designation of SPAs. In the Shetland Islands, there are 12 designated SPAs, 11 of which protect seabirds with a marine component. The closest SPA to the Project area is the Fetlar SPA, located approximately 3.6 km to the south of the Project area. The Hermaness, Saxa Vord and Valla field SPA is located approximately 3 km north-east of the Project area, the Fetlar SPA located 3.5 km south, and the Noss SPA is located 58 km south (Figure 2.1). The proposed cable routes are also located within the Blue Mull and Colgrave Sounds proposed SPA (pSPA), which lies between the islands of Unst, Yell and Fetlar in the north-east of Shetland. This has been proposed as a protected site for the presence of breeding red-throated diver (Gavia stellate), which nest at the edges of freshwater lochs and peatland pools and forage by surface diving for small fish, shellfish and marine worms. Since the proposed works will occur outwith the breeding season for red-throated diver (April to mid-September), this species is unlikely to be impacted during cable installation works. The red-throated diver typically breeds in small waterbodies within areas of open moorland, and nesting occurs in lightly forested areas (JNCC, 2012). Its breeding season extends from April to mid-September (Table 5.2). Since the works are planned to occur between October 2018 and March 2019, the breeding season for red-throated diver will be avoided and any disturbances to these birds during breeding season are unlikely. Due to the limited number of vessels involved in the Project (cable lay vessel, dive support vessel, anchor handling vessel and guard vessel), the temporary and short-term nature of the works, although birds from SPAs could be present in the Project area, the potential for Likely Significant Effects (LSE) on birds from SPAs is negligible. There is one Ramsar site designated under the Convention on Wetlands of International Importance for wetland habitats and wetland species in Shetland, the Ronas Hill-North Roe and Tingon site (NAFC Marine Centre, 2013). However, given the distance to this protected wetland from the Project area (23 km south-west), no further consideration is given to this site.
2.4 Nationally and locally important sites Under Section 117 of the Marine (Scotland) Act 2010, Scottish Ministers, in consultation with the Natural Environment Research Council (NAFC), have formally designated a number of seal haul-out sites to provide additional protection for seals from intentional or reckless harassment under the Protection of Seals (Designated Seal Haul-Out Sites (Scotland) Order 2014. A total of 194 designated seal haul- outs occur around the Scottish coast (Scottish Government, 2017). The seal haul-outs occurring in the vicinity of the proposed works are presented in Table 2.2 and shown in Figure 2.2. The majority of sites are located at significant distance from the area of works (closest 2 km to the North) and vessels associated with the Project will not be present in the waters adjacent to these sites. Harbour seal density is estimated as very low along the proposed cable routes, between 0 and 1 animals per 25 km2 (Jones et al., 2015; NMPI, 2018). Grey seal density is estimated as low (1 - 5 animals per 25 km2) along the entire proposed cable routes (Jones et al., 2015; NMPI, 2018).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 30
Table 2.2 Seal haul outs and pupping sites located in the vicinity of the Project area (NMPI, 2018) (see Figure 2.2)
Site name Designated features Distance by sea from the Project Westing Seal haul-out 2 km north Grey seal3 Fetlar North West islands Seal Harbour seal4 7.2 km south-east haul-out
2 North West Fetlar & Haaf Gruney Grey seal 7.8 km south-east Grey seal pupping site
2 Skerries of Neapaback Seal haul- Grey seal 24 km south out Harbour seal3 There is a designated National Nature Reserve (NNR) in the north of Unst, the Hermaness NNR, which is one of the two NNRs designated in Shetland (NMPI, 2018; NAFC Marine Centre, 2015). These sites highlight important natural heritage areas and have conservation objectives for habitats and species of national and international importance (NAFC Marine Centre, 2015). The Hermaness site is of particular importance for great skuas, fulmars, gulls, shags, gannets, puffins and kittiwakes. As highlighted above although could be present in the Project area, the potential for significant impacts is negligible. Nationally important sites include Sites of Special Scientific Interest (SSSI). There are 78 SSSIs in Shetland, including 31 for marine biological features and 36 coastal sites for geological and morphological features, although for five of these the geological interest does not extend down to mean high water spring (MHWS) (NAFC Marine Centre, 2015). A further two geological sites are within 100 m of MHWS (NAFC Marine Centre, 2015). The closest SSSI is the North Fetlar SSSI, located 6 km to the south-east of the proposed Yell – Unst cable routes. This site is designated as SSSI for the protection of a number of breeding seabirds and land birds, grey and harbour seals, and for the presence of Calaminarian grassland and serpentine heath (SNH, 2014).
3 Grey seal foraging rage is typically over 100 km (SCOS, 2014). 4 Harbour seal foraging range is typically 40 – 50 km (SCOS, 2014).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 31
Figure 2.4 Designated seal haul outs in the vicinity of the Project (NMPI, 2018)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 32
There are eight RSPB Reserves in Shetland, the closest of which is Yell (3.4 km south) (NMPI, 2018). As previously discussed birds from this site will not be impacted by the Project and therefore no further consideration is required on its conservation interests. Additionally, there are 49 designated Local Nature Conservation Sites (LNCS) in Shetland, highlighting sites with natural heritage features considered of national importance. The closest LNCS is located approximately 340 m to the north of the Project area, and is designated for land geodiversity features (NAFC Marine Centre, 2015).
2.5 Potential impacts Based on the summary of protected sites provided above together with the consultation responses received with regards to protected sites, the table below summarise those sites which could potentially be impacted as a result of the Project. Table 2.3 Potential impacts on ecological protected sites and mitigation measures
Environmental Management and mitigation and overall impact Potential impacts receptor significance
There is not considered to be the potential for Likely Significant Effects (LSE) on harbour seals and otters from the Yell Sound SAC that may be present in the Project area due to the following: Marine (vessel) activities will be temporary (approximately 30 days per cable); Slow speed of vessels (maximum of few knots per hour) will minimise disturbance impacts; Pre-construction surveys undertaken to confirm Harbour seals and otters presence or absence of otters in the vicinity of the from this SAC could landfall works; potentially be present in An EcoW will ensure distance to otter holts is at least the Project area and be 30 m from the proposed works, and will look for any temporarily disturbed by evidence of new otter activity; Yell Coast SAC – vessel presence and Harbour seal noise. Potential for accidental release of pollutants is very interests low; Risk from accidental pollution e.g. from oil In the event that potential impacts on otters at the seepage, hydraulic fluid cable landfall cannot be avoided, any disturbance release, vessel fuel will require a European Protected Species (EPS) release licence and specific mitigation implemented in order to minimise impacts, such as the implementation of an otter species protection plan; Implementation of a Marine Mammal Protection Plan (MMPP), which will include a 100 m mitigation zone for seals; Vessel SOPEP details procedures and description of actions to be taken in the event of an oil pollution incident; Operating instructions in place for all hazardous substances including hydraulic oil. There is not considered to be the potential for Likely Significant Effects (LSE) on red-throated diver from the Blue Blue Mull and Disturbance of breeding Mull and Colgrave Sounds pSPA, due to the following: Colgrave Sounds red-throated diver at pSPA their foraging sites Cable installation works will occur between October 2018 and 31st March 2019 to avoid most of the breeding season for red-throated diver.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 33
Environmental Management and mitigation and overall impact Potential impacts receptor significance
No potential for significant impacts on seals, due to:
SHEPD will ensure the Contractor is aware of the Grey and harbour seals Scottish Government advice and responsible Westing could be disturbed from behaviour around designated seal haul outs which designated seal their haul due to states “New activities taking place near seal haul- haul out for activities in adjacent outs, which present no significant disturbance to the protection for grey waters – however the seals, or where the disturbance is low level (a few and harbour seals vessels involved in the seals) and/or short term (over a short time period), coming ashore to decommissioning works will normally be acceptable. This may require some rest, mould or will not require to move monitoring of the seals to avoid the risk of potentially breed (2 km to the this far from the work causing a significant proportion of seals on a haul- north of the Project area during the out site to leave that site either more than once or area) decommissioning repeatedly or, in the worst cases, to abandon it activities and therefore permanently.” no impacts are predicted (http://www.gov.scot/Resource/0045/00452869.pdf). Marine Mammal Protection Plan (MMPP) has been developed for the Project
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 34
3 PHYSICAL ENVIRONMENT (INCLUDING SEABED CONDITIONS)
3.1 Introduction This section of the report provides detail on the physical environment in the vicinity of the Project, as well as the relevant legislation applicable to each site, and the relevant consultation advice that has been provided to SHEPD by key stakeholders. It then assesses the potential impacts on the sites that could be impacted from the proposed activities and discusses the mitigation and management measures that will be undertaken in order to ensure impacts are avoided or minimised and provides a conclusion of the significance of potential impacts
3.2 Legislation and policy context The EU Marine Strategy Framework Directive 2008/56/EC (MSFD) was formally adopted in July 2008 and was transposed into UK Legislation under the Marine Strategy Regulations 2010 on 15th July 2010. The Directive is the environmental pillar of the Integrated European Maritime Policy which focuses on the development of a coherent, co-ordinated and integrated approach to the management of marine environment through marine planning. The MSFD constitutes a vital environmental component of the European Union’s future maritime policy and is designed to achieve full economic potential of oceans and seas in harmony with the marine environment (MSFD, 2015). An updated Marine Strategy Part One will be published in 2018 following a public consultation in 2017. The main requirement of the MSFD is for Member States to prepare national strategies, including marine spatial plans, to manage their seas to achieve Good Environmental Status (GES) by 2020 at the latest. The key requirements of the Directive are to undertake an assessment of the current state of UK seas, and a detailed description of what GES means for UK waters, with a set of associated targets and indicators (Scottish Government, 2016). In December 2012, the UK Marine Strategy Part 1 was published. This included an assessment of UK marine waters; proposals on defining Good Environmental Status (GES) and developing targets and indicators for achieving and monitoring GES. Provisions for Scotland to work with other UK administrations towards achieving GES are set out under the MSFD (DEFRA, 2012). In July 2014, Part two of the Marine Strategy was published by the UK government to establish and implement coordinated monitoring programmes for the ongoing assessment of the environmental status of marine waters around the UK (DEFRA, 2014). Part 3 of the Marine Strategy was published in December 2015. It sets out a programme of measures to enable the achievement of GES (DEFRA, 2015).
3.3 Consultation SHEPD has undertaken consultation with statutory and non-statutory bodies. There were no issues raised of relevance to the physical environment during the consultation events.
3.4 Physical environment description Strong winds are the main characteristic of the Shetland climate. The mean wind speed is 6.5 – 7.5 m/s during the year, with gales occurring on an average of 58 days per year. During the period 1965- 1973, 75% of the time the hourly mean wind speed was more than 4.25 m/s, and for 0.1% of the time it was more than 21.5 m/s, which are the highest wind speed values recorded in Britain. Predominant winds come from south and west, and there is a pronounced minimum for easterly winds. Northerly winds are commonest in summer and southerly winds in winter (Barne et al., 1997). Tidal streams around the Shetland Islands generally move southwards on the flood tide, and northwards on the ebb, at speeds ranging between 0.5 to 1.25 m/s. In some places, notably the Bluemull Sound where the proposed Yell to Unst cable routes are located, Muckle Flugga, Yell Sound, Linga Sound,
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 35
and near Sumburgh Head, tidal streams can reach considerably higher velocities up to 4 m/s (Barne et al., 1997; Wolf et al., 2015). The tides in the Shetland Islands are the result of interaction between the two independent tidal systems in the North Atlantic and the North Sea. The mean spring tidal range is approximately 1.5 m in Shetland, with variations in the tidal bays and enclosed areas (Barne et al., 1997). The coastline of Shetland offers a wide range of exposure, with the west coast of Shetland being exposed to much stronger wave action than most of the Scottish coast. The mean significant wave height recorded 10% of the time directly to the west coast of Shetland was 3.0 m, and 2.5 m to the east coast. However, 75% of the time mean wave height 1.5 m to the west of Shetland and was 0.5 m directly to the east (Barne et al., 1997). The Shetland Islands are surrounded by waters with salinity exceeding 35 g / kg in both winter and summer, reflecting the Atlantic Ocean origin of these waters. The land area is too small for freshwater runoffs to have significant impacts on salinity, dilution of waters only occurring in surface waters in enclosed areas during periods of heavy rain (Barne et al., 1997). The mean surface temperature in summer is 12.5°C along the east coast of the Shetland islands. In winter, mean surface temperature to the south of Shetland is 7.0°C, and 7.5°C in waters surrounding the northern islands of Shetland (Barne et al., 1997). The seabed slopes steeply away from the mainland and the northern islands of Shetland to 80 m depth, marking the base of the submerged Shetland hillsides and the limit of the islands as a feature on the continental shelf. Beyond 10 km from the islands the sea floor lies more than 100 m below mean sea level, with local depression exceeding 140 m depth (Barne et al., 1997). Within the Bluemull Sound, where the proposed Yell to Unst cable routes are located, a bathymetric contour indicates a water depth of 40 m closer to the Unst coastline (Barne et al., 1997). A hydrographic, geophysical and geotechnical survey was undertaken in 2015 along the existing cable routes between Yell and Unst. The survey included multibeam echosounder, seismic profiling, Hamon grab sampling and topographic surveys at the landfalls. Bathymetry data were obtained along with data on geology, benthic sediments and fauna (ESG, 2015). Figure 3.1 shows the bathymetry between the Yell and Unst landfalls.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 36
Figure 3.1 Bathymetry between Yell and Unst landfalls (ESG, 2015)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 37
Potential impacts and mitigation and management measures with regards to the physical environment are summarised in Table 3.1.
3.5 Potential impacts Based on the summary of the physical environment provided in Section 3.4, Table 3.1 summarises potential impacts on each receptor as a result of the Project. Table 3.1 Potential impact on the physical environment surrounding the Project area
Environmental Management and mitigation and overall impact Potential impacts receptor significance
Bathymetry and No potential impacts hydrology N/a
No potential for significant impacts on water quality, Increased suspended sediment due to: in the water column over the Cable installation activities will last approximately 30 short period of the underwater days per cable and any increase in suspended activities resulting from cable sediments will quickly revert back to background levels installation activities (estimated to be no more than 25% of the All cable landfall works undertaken in line with standard cable routes) best practice and general environmental management plans provided by SHEPD (further details in CEMP)
Water quality No potential for significant impacts on water quality, due to:
Pollution prevention measures in place (further details Risk from accidental pollution in CEMP) e.g. from oil seepage, hydraulic Potential for accidental release of pollutants is very low. fluid release, vessel fuel Vessel SOPEP details procedures and description of release actions to be taken in the event of an oil pollution incident (further details in CEMP)
Operating instructions in place for all hazardous substances including hydraulic oil
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 38
4 BENTHIC AND INTERTIDAL ECOLOGY
4.1 Introduction This section of the report provides detail on the benthic and intertidal habitats in the vicinity of the Project, as well as the relevant legislation and policy guidance. It then assesses the potential impacts on benthic and intertidal ecology and the management and mitigation measures that will be undertaken in order to ensure impacts are minimised.
4.2 Legislation and Policy Context With respect to benthic and intertidal ecology, in order to identify potential constraints to routing a subsea cable and identifying potential landfall locations, it is necessary to identify potential habitats and species of conservation importance that could potentially be present in the Project study area and along potential subsea cable route corridors. There are a number of different statutes and guidance that are relevant in this regard. These include: European Habitats Directive (Directive 92/43/EEC); The Habitats (Scotland) Regulations 1994 (as amended) which implements species protection requirements of the Habitats Directive in Scotland, on land and in inshore waters (within 12 nm); The Convention for the Protection of the Marine Environment of the North East Atlantic (known as the OSPAR Convention); Marine (Scotland) Act 2010 and Marine and Coastal Access Act (2009); and UK Post-2010 Biodiversity Framework (July 2012) – this supersedes the UK Biodiversity Action Plan (UKBAP) which was the UK Governments Response to the Convention on Biological Diversity (CBD), which the UK signed up to in 1992 in Rio de Janeiro.
4.2.1 European Habitats Directive The European Habitats Directive lists 15 marine and coastal habitats and eight marine species in Annexes I and II respectively. To meet the requirements outlined in Article 3 of the European Habitats Directive, SACs have been designated in UK waters to contribute to the European network of important high-quality conservation sites that will make a significant contribution to conserving these species and habitats. There are no records of marine and coastal habitats as listed in Annex I of the Directive within the Project area.
4.2.2 Marine (Scotland) Act 2010 On behalf of the Scottish Government; JNCC, SNH and Marine Scotland have together developed recommended lists of PMFs in Scotland’s seas (SNH & JNCC, 2014). The list of PMFs has not been developed in accordance with any specific legislation, agreement or convention; it was developed to guide policy decisions regarding the conservation of Scotland’s seas, through the identification of priority species and habitats. The list of recommended PMFs in Scotland’s offshore waters was adopted in 2014 and contains 81 habitats and species considered to be of conservation importance (SNH & JNCC, 2014). Howson et al. (2012) have also developed an equivalent list for Scotland’s territorial waters which comprises 56 PMFs, including 8 habitats and species groups, 11 individual habitats and 37 individual species. The Scottish PMFs that have been identified within the Project area are kelp beds. These are also designated features of the Fetlar to Haroldswick NCMPA located 1.6 km south of the Project area.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 39
4.2.3 Biodiversity Action Plan (BAPs) The UK Biodiversity Action Plan (UKBAP) was launched in 1994 as a means of meeting the UK’s obligations under the Biodiversity Convention (signed by the UK and over a hundred other countries at the Rio Earth Summit in 1992) to “develop national strategies, plans or programmes for the conservation and sustainable use of biological diversity”. The stated goal of the UK BAP is to “conserve and enhance biological diversity within the UK, and to contribute to the conservation of global diversity through all appropriate mechanisms”. UK BAP priority species were those identified as being the most threatened and requiring conservation action under the UK BAP. As a result of devolution, and new country-level and international drivers and requirements, much of the work previously carried out by the UK BAP is now focused at a country-level rather than a UK-level, and in July 2012 the UK BAP was succeeded by the UK Post-2010 Biodiversity Framework'. The UK list of priority species, however, remains an important reference source and has been used to help draw up statutory lists of priorities in Scotland.
4.2.4 Shetland Islands Marine Spatial Plan The Shetland Islands Marine Spatial Plan (SIMSP) provides an overarching policy framework to guide marine development and activity. This SIMSP is based on Scottish Ministers’ commitment to making marine management more efficient, inclusive and accessible. Areas of constraint and/or opportunities for development have been identified in order to reduce potential conflicts between marine activities and encourage co-existence between multiple users. The SIMSP aims at providing an approach to the management of the sea around Shetland; facilitating an integrated and better-informed decision-making process regarding the future distribution of activities and resources; and enabling the long-term protection and use of the marine environment. Section 4 of the SIMSP sets out the legislative requirements that need to be considered for any development proposal. This section covers marine and works licences, planning permission, controlled activity regulation (CAR) authorisation, seabed agreement for lease, electricity regulations, EIA, cumulative impacts and consultation with stakeholders. Section 5 of the SIMSP sets out a number of general policies that ensure that the SIMSP is contributing to the high-level government targets that are supporting a clean and safe, healthy and diverse, and productive marine environment. Those that are most relevant to this Project include: underwater noise, navigational safety, cables and pipelines, climate change, coastal defence and flood protection, protected species, nature conservation designations, marine recreation and invasive non-native species.
4.3 Consultation SHEPD has undertaken consultation with statutory and non-statutory bodies. Correspondence of relevance to ecologically protected sites is summarised below in Table 3.5 (taken directly from the written correspondence). Table 3.5 Consultation Summary
Consultee Consultation Comment
Benthic environment
5th October 2016, SNH SNH have no benthic data along the cable route but expect to see Inverness horse mussel beds there.
4.4 Benthic and intertidal ecology description This section provides a detailed description of the intertidal and benthic habitats along the proposed cable routes corridors. This is based on published resources as the collection of seabed survey data
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 40
is ongoing (marine surveys scheduled for May to June 2018, therefore this assessment will be reviewed once survey data have been obtained in order to better quantify existing and/or identify further impacts and mitigation measures.
4.4.1 Subtidal area The northern end of the Bluemull Sound is characterised by deep rock dominated by extensive stands of the soft coral Alcyonium digitatum with a rich associated flora and fauna. In weaker currents, horse mussels can be found, with brittle stars. In the centre of the Bluemull Sound, boulders on sand support kelp forests, and in deeper waters, hydroids are found on pebbles and cobbles, associated with amphipods (Barne et al., 1997). The EUSeaMap 2016 is a broad-scale seabed habitat map covering European waters, which uses the European Nature Information System (EUNIS) habitat classification and Marine Strategy Framework Directive (MSFD) predominant habitat classification systems. This map allowed identifying predominant habitat types in the subtidal area of the Project between the Yell and Unst landfalls (Figure 4.1). The EUSeaMap describes the seabed in the subtidal section of the proposed cable routes as high energy infralittoral rock and biogenic reef habitat (NMPI, 2018). Limited geotechnical surveying was carried out along the routes as the sub-bottom profiling data from the geophysical surveys indicated a lack of sediment along the extent of the surveyed corridor. The extent of geotechnical surveys was therefore restricted to seabed grab sampling at selected intervals. Out of the nine grab sample attempts during the survey works, three failed to recover sufficient material due to a lack of sediment. The recovered grab samples revealed the presence of medium sand to coarse gravel sediments with occasional fine to coarse gravel sized fragment shells (ESG, 2015). High energy infralittoral rock habitats typically occur on extremely wave-exposed to exposed bedrock and boulders subject to tidal streams ranging from strong to very strong. The proposed cable routes are located in an area of strong tidal streams which can reach velocities up to 4 m/s as described in 3.4. This habitat typically supports a community of kelp (Laminaria hyperborea) with foliose seaweeds and animals, the latter tending to become more prominent in areas of strongest water movement. Kelp communities are known to occur along a section of the proposed cable routes within the bay to the west of Loch Snarravoe (NAFC Marine Centre, 2015). Kelp beds are designated as Scottish PMFs (Tyler- Walters et al., 2016) and are on the UKBAP list, however there are not listed as Annex I habitats or OSPAR declining or threatened species/habitats (NAFC Marine Centre, 2015). Tidal-swept algal communities, designated as PMF in Scottish waters, have also been recorded approximately 1.2 km south of the Project area (NAFC Marine Centre, 2015). There are no designated conservation sites that protect kelp and seaweed communities in the immediate vicinity of the proposed cable route, the nearest being the Fetlar to Haroldswick NCMPA, located 1.6 km south of the Project area. Given the distance, any impacts on kelp communities protected within this NCMPA are unlikely, therefore the conservation objectives for kelp within the Fetlar to Haroldswick NCMPA are not compromised by the proposed works. Biogenic reefs are rocky marine habitats that rise from the seabed, created by reef-forming animal species, such as the horse mussel (Modiolus modiolus). Horse mussel beds are known to occur in the Bluemull Sound, however there are no records in the direct vicinity of the proposed cable routes, the nearest being located approximately 1.3 km south (NAFC Marine Centre, 2015; NMPI, 2018). Horse mussel beds are protected within the Fetlar to Haroldswick NCMPA, located 1.6 km south. Given the small, discrete area of impact of the proposed works and the distance to the NCMPA, impacts on horse mussel beds are highly unlikely, therefore the conservation objectives of the Fetlar to Haroldswick NCMPA for horse mussel beds will not be compromised. The other benthic features designated under this NCMPA are maerl beds, circalittoral coarse sand and mixed sediments, and shallow tide-swept coarse sands with burrowing bivalves. However, there are no records of such features within the immediate vicinity of the proposed cable routes, the closest being a record of shallow tide-swept coarse sands with burrowing bivalves 2.4 km south-west (NMPI, 2018; NAFC Marine Centre, 2015). Therefore, the benthic conservation objectives of the Fetlar to Haroldswick NCMPA are not compromised by the proposed works.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 41
Figure 4.1 EUSeaMap broad-scale seabed habitat classification in the vicinity of the Project area (NMPI, 2018)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 42
4.4.2 Intertidal areas 4.4.2.1 Yell The environmental desk study of the Yell landfalls for the North and South cables described low lying sand/shingle beaches (ERM, 2018a, 2018b) (Figure 4.2 and Figure 4.3). This habitat could potentially be the 'vegetated shingle' habitat listed on the Annex I of the EU habitats Directive. Semi-improved grasslands are also present above the shingle beach at the Yell landfall. The study also identified the presence of coastal grassland/heathland and bog, which can be observed on the landfall photographs below.
Figure 4.2 North and South cable landfall at Yell, looking North towards Cullivoe harbour Unst
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 43
Figure 4.3 North and South cable landfall at Yell looking South. Existing South cable in background 4.4.2.2 Unst The coastline on Unst is rocky and there are cliffs present along the coastline which limits suitable cable landing locations for the proposed cables to the South of Ness of Wadbister. Figure 4.4 and Figure 4.5 show the landfall sites at Unst. It consists of low-lying sandy beaches with shingles. The environmental desk study undertaken at the North and South cable landfalls identified the potential presence of the Annex I habitat 'vegetated shingle', and coastal grassland/heathland (ERM, 2018a, 2018b).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 44
Figure 4.4 South cable landfall at Unst looking West
Figure 4.5 North cable landfall within the sheltered bay west of Loch Snarravoe
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 45
4.5 Potential impacts to benthic and intertidal ecology
4.5.1 Potential impacts during cable installation Potential impacts that arise from cable installation activities are presented in Table 4.1 for the North cable route, and in Table 2.5 for the South cable route. Due to the strong tidal currents, the majority of the proposed cable routes will be across rocky seabed with very little overlying sediments, therefore cable burial will not be possible in the subtidal areas of the cable routes. For both routes, cable burial will be undertaken in the Yell and Unst intertidal areas where sediments allow undertaking open-cut trenching. However, this will not be possible along the whole length of the cable within these areas, therefore the cable will be surface laid with additional cast iron protection along up to 100 m at each landfall. At this stage, the actual length of cable which will be buried and surface laid with additional cast iron protection is unknown, therefore the maximum lengths of cable for each installation type have been used to estimate the footprint. To stabilise the cables, SHEPD plan to lay either concrete mattresses or rock filter bags on the cable to pin it on the seabed, which will reduce movements on the seabed and thus its footprint. Each rock filter bag has a footprint of 2 m x 2 m and each concrete mattress has a footprint of 6 m x 3 m. To calculate the total footprint of the Project, the worst-case scenario has been considered, which means that the footprint of concrete mattress has been used. Along most of the cable routes, between the KP0.5 at Yell up to the Unst shoreline, concrete mattresses/rock filter bags will be placed on the cable at roughly 50 m intervals. Up to 330 m of the North cable route and up to 260 m of the South cable route will be completely covered with concrete mattresses/rock filter bags from the Yell shoreline up to KP0.5 to maximise the protection in an area of strong tidal currents. A CLV will be used for the cable installation works. Additional smaller support vessels will be required at each of the shallower shore locations, this is likely to be a multicat/dive-support vessel (DSV). This may require an anchoring system to be laid out prior to and during works in the nearshore region. It has been assumed that the DSV will have a 4-anchor system, with each anchor and chain impact an arc of 45° and 150 m radius. The seabed impact calculations are based on the worst-case scenario where the entire chain length (150 m) would be lying on the seabed. Anchor moves will be minimised as far as possible, particularly where sediments are observed in order to reduce re-suspension. Where the anchor chains are slack, there is potential for using midline buoys, which would keep the anchor chain floating and off the seabed. An anchor handling vessel would be required to lay out the anchors, and a guard vessel is likely to be used for safety purposes, however these will not result in any seabed impacts.
The total footprint of the North cable route between Yell and Unst is 0.14 km2 (Table 4.1) and the total footprint of the South cable route between Yell and Unst is 0.14 km2 (Table 4.2).
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 46
Table 4.1 Seabed disturbance from the North cable installation works
Section of Nature of seabed Habitat type Assumptions made in Area of North cable disturbance calculation of area disturbance disturbed (m2)
Intertidal areas Cable burial in Potential Annex I Trenching within 289 at Yell and open-cut trench 'vegetated shingle' intertidal area at Yell Unst habitat (11.3 m) and at Unst (17.6 m);
1 m wide open cut trench.
Intertidal areas Surface laid cable High energy Maximum of 200 m cast 28.6 at Yell and with cast iron infralittoral rock iron shells (100 m at Unst protection, where each landfall); cable burial cannot be achieved Cable diameter is 127 mm;
Cast iron shells have 8 mm wall thickness.
From Yell Surface laid cable High energy Surface laying along 851.9 shoreline up to with complete infralittoral rock 330 m; KP0.5 concrete mattresses/rock Cable diameter is 127 filter bags coverage mm; and
Maximum of 45 concrete mattresses/rock filter bags, each having a footprint of up to 6 m x 3m.
From KP0.5 to Surface laid cable High energy Surface laying along 1,118 Unst shoreline with partial infralittoral rock 1,720 m; KP2.22 protection Cable diameter is 127 mm; and
Maximum of 50 concrete mattresses/rock filter bags, each having a footprint of up to 6 m x 3 m.
Nearshore DSV anchoring High energy 4-anchor system, each 141,300 areas system infralittoral rock anchor and chain impact an arc of 45° and 150 m radius; and
4 deployments at each nearshore area. Total area of disturbance for the North cable route(m2) 142,587 Total area of disturbance for the North cable route (km2) 0.14
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 47
Table 4.2 Seabed disturbance from the South cable installation works
Section of Nature of seabed Habitat type Assumptions made in Area of South cable disturbance calculation of area disturbance disturbed (m2)
Intertidal areas Cable burial in Low-lying Trenching within 431 at Yell and open-cut trench sand/shingle beach intertidal area at Yell Unst (may potentially (11.1 m) and at Unst support the Annex I (32 m); habitat 'vegetated shingle') 1 m wide open cut trench.
Intertidal areas Surface laid cable High energy Maximum of 200 m cast 28.6 at Yell and with cast iron infralittoral rock iron shells (100 m at Unst protection, where each landfall); and cable burial cannot be achieved Cast iron shells are 800 mm diameter.
From Yell Surface laid cable High energy Surface laying along 1,070 shoreline up to with complete rock infralittoral rock 260 m; KP0.5 filter bags coverage Cable diameter is 127 mm; and
Maximum of 45 rock filter bags, each measuring 2 m x 2m.
From KP0.5 to Surface laid cable High energy Surface laying along 2,870 Unst shoreline with partial infralittoral rock 1,970 m; KP2.47 protection Cable diameter is 127 mm; and
Maximum of 50 rock filter bags, each measuring 2 m x 2m.
Nearshore DSV anchoring High energy 4-anchor system, each 141,257 areas system infralittoral rock anchor and chain impact an arc of 45° and 150 m radius; and
4 deployments at each nearshore area. Total area of disturbance for the South cable route(m2) 145,700 Total area of disturbance for the South cable route (km2) 0.14
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 48
4.5.2 Potential impacts during cable operation The rock bags placed on either side of the cable will hold the cable in position, thereby minimising the potential for the cable to move around on the seabed over its lifetime. Given this reduced likelihood for movement of the cable, potential impacts on benthic habitats during cable operation are highly unlikely. The only source of potential impact would be if the cable fails and needs to be repaired; a repair operation could potentially disturb protected habitats in the area as sections of the cable (or the whole cable) may need to be replaced. However, given that the cable will have a design life of more than 30 years, the likelihood that maintenance / repair works will be required is very low.
Electromagnetic fields (EMF) emitted by submarine cables during operation are likely to affect elasmobranch species (shark and rays) which possess specialised electroreceptors and are able to detect induced voltage gradients associated with water movements and geomagnetic emissions. However, it should be noted that EMF is already present due to the existing cables and therefore the replacement cables will not introduce any new EMF. There are three EMF sensitive species that use the Project area as nursery ground, including common skate (Dipturus batis), spotted ray (Raja montagui) and spurdog (Squalus acanthia), however, the intensity of use is estimated to be low in this area, as described in Section 5.4.4. Additionally, the EMFs decrease with distance from the cable and effects become negligible within a few metres. Therefore, no impacts are expected on EMF sensitive species.
4.5.3 Impact, management and mitigation summary Based on the summary of the benthic and intertidal environments provided above and in Table 4.3 below summarises potential impacts on each receptor as a result of the Project. Table 4.3 Potential impacts on benthic and intertidal ecology
Environmental Management and mitigation and overall Potential impacts receptor impact significance
No potential for significant impacts on intertidal and subtidal ecology from seabed disturbance, due to:
Very small area of impact (0.28 km2 for both routes);
Consideration for use of mid-line buoys to keep the DSV anchor chains off the seabed as much as possible:
Seabed disturbance from Although the main habitat type along the cable Intertidal and subtidal physical interaction with the routes is expected to be rocky and thus ecology seabed, shoreline and their sediment re-suspension is not anticipated, associated habitats anchor moves will be minimised as far as possible;
Cable installation activities will be short-term (approximately 30 days per cable) and any increase in suspended sediments will quickly revert back to background levels; and
All cable landfall works undertaken in line with standard best practice and general environmental management plans provided by SHEPD.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 49
5 MAMMALS, FISH, BIRDS AND OTTERS
5.1 Introduction This section of the report provides detail on marine mammals, fish, birds and otters in the vicinity of the Project, as well as the relevant legislation and policy guidance. It then assesses the potential impacts on these and the management and mitigation measures that will be undertaken in order to ensure impacts are minimised. Impacts on otters and seals are also considered in Section 2 – Ecological Protected Sites as Yell Coast SAC qualifying features.
5.2 Legislation and Policy Context With respect to marine mammals, otters, birds and fish, in order to identify potential constraints to routing a subsea cable and identifying potential landfall locations, it is necessary to identify potential habitats and species of conservation importance that could potentially be present in the Project study area and along potential subsea cable route corridors. There are a number of different statutes and guidance that are relevant in this regard. These include: European Habitats Directive (Directive 92/43/EEC); European Birds Directive (Directive 2009/147/EC) The Habitats (Scotland) Regulations 1994 (as amended) which implements species protection requirements of the Habitats Directive in Scotland, on land and in inshore waters (within 12 nm); Wildlife and Countryside Act 1981 (as amended) The Convention for the Protection of the Marine Environment of the North East Atlantic (known as the OSPAR Convention); Marine (Scotland) Act 2010 and Marine and Coastal Access Act (2009); and UK Post-2010 Biodiversity Framework (July 2012) – this supersedes the UK Biodiversity Action Plan (UKBAP) which was the UK Governments Response to the Convention on Biological Diversity (CBD), which the UK signed up to in 1992 in Rio de Janeiro. Marine Strategy Framework Directive, 2008; Bern Convention 1979, The Convention on the Conservation of European Wildlife and Natural Habitats 1979. ASCOBANS, Convention for Migratory Species of Wild Animals (CMS) Conservation of Small Cetaceans of the Baltic, north-east Atlantic, Irish and North seas, 1994;
5.3 Consultation SHEPD has undertaken consultation with statutory and non-statutory bodies. Correspondence of relevance to mammals, fish birds and otters is summarised in Table 3.5 in Section 2.2 (taken directly from the written correspondence).
5.4 Receptor description
5.4.1 Cetaceans 5.4.1.1 Overview All species of cetacean (whale, dolphin, porpoise) occurring in UK waters are listed in Annex IV (species of community interest in need of strict protection) of the Habitats Directive as European Protected
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 50
Species (EPS) and fully protected in Scottish territorial waters (out to 12 nautical miles) under the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended). Bottlenose dolphin and harbour porpoise are also listed on Annex II of the Habitats Directive and thus require the SAC designation. A total of 19 species of cetacean have been recorded in UK waters (Reid et al., 2003). Cetaceans regularly recorded in the North Sea include the harbour porpoise (Phocoena phocoena), bottlenose dolphin (Tursiops truncatus), minke whale (Balaenoptera acutorostrata), killer whale (Orcinus orca), Atlantic white-sided dolphin (Lagenorhynchus acutus) and white-beaked dolphin (Lagenorhynchus albirostris) (NMPI, 2017; Reid et al., 2003). The most sighted species in the waters around Shetland (North Sea - Block T) during the recent Small Cetaceans in the European Atlantic and North Sea (SCANS III) survey were harbour porpoise, white- beaked dolphin, white-sided dolphin, minke whale and Risso’s dolphin (Hammond et al., 2017). The species present in the vicinity of the Project area in low densities in comparison to other areas of the North Sea are minke whale and white-beaked dolphin. Other species regularly sighted in the area include killer whale, Risso's dolphin, Atlantic white-sided dolphin and long-finned pilot whale (Nature in Shetland, 1994; Seawatch Foundation, undated). The general distribution of the most common species in the UK is as follows; Harbour porpoise Phocoena phocoena Harbour porpoise is the most abundant cetacean in Scottish waters (Reid et al. 2003; Hammond et al. 2017). They typically occur in small groups of 2 to 3 individuals but they may aggregate when feeding resources are good and do not appear to migrate (Seawatch foundation, undated). Harbour porpoise occurs on the IUCN Red List for Threatened Species, is listed on Annex II of the Habitats Directive, is on the OSPAR list and is also listed as a Scottish Priority Marine Feature (PMF). White-beaked dolphin Lagenorhynchus albirostris White-beaked dolphin are present all year round in the Scottish near-shore waters at depths of 50 - 100 m, but are observed more frequently between June and October (Seawatch foundation, undated). The species occurs in the waters around the northern and central east coast of Scotland and in the central and northern North Sea (Reid et al. 2003; Hammond et al., 2017). They are usually found in small groups of 10 or less, but have also been observed in large groups of 50 and more (Seawatch foundation, undated). White beaked dolphin is listed as a Scottish PMF. Bottlenose dolphin Tursiops truncatus In the UK there are two known resident populations of bottlenose dolphins, one of which is in the Moray Firth (north east Scotland) and the other in Cardigan Bay in Wales (north Wales). These populations are typically restricted to the coasts of the regions where these sites are located and individuals from these sites will not be present in the area of the proposed activities. Bottlenose dolphins are usually seen in groups of 2 to 25, and occasionally much larger groups in deeper waters. They occur in near-shore in Scottish waters and the greatest numbers have been observed between July and October, but are present all year long (Seawatch Foundation, undated). Bottlenose dolphin is listed on Annex II of the Habitats directive and is listed as a Scottish PMF. Minke whale Balaenoptera acutorostrata Minke whales are mainly present in Scottish waters in the summer months, both in northern and central east coast of Scotland and in the central and northern North Sea (Reid et al., 2003; Hammond et al., 2017). They prefer water depths of 200 m or less, and are often sighted single or in pairs, and sometimes aggregate into larger groups of up to 15 individuals when feeding. Additionally, they appear to return to the same seasonal feeding grounds (Seawatch Foundation, undated). Minke whale is listed as a Scottish PMF. Killer whale Orcinus orca Killer whales are widely distributed across Scottish waters all year round (Reid et al., 2003). They are seen in both inshore waters (April to October) and the deeper continental shelf (November to
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 51
March) and appear to move inshore to target seals seasonally. Killer whale is listed as a Scottish PMF. Risso’s Dolphin Grampus griseus Risso’s dolphins typically form groups of 6-12 individuals in the continental shelf of Scottish waters. They are observed mainly in northern east coast of Scotland and the northern North Sea with most sightings occurring in July and August (Reid et al., 2003; Seawatch Foundation, undated). Risso’s dolphin is listed as a Scottish PMF. Common dolphin Delphinus delphis / Delphinus capensis5 The common dolphin is the name for two species of dolphin, short-beaked and long beaked dolphin, which are often grouped together. The species often occur in groups of 5-20 individuals and are commonly sighted off south-west Scotland to the Isle of Skye (Seawatch Foundation, undated). Sightings usually peak in May to July and decline August onwards (Reid et al., 2003). Delphinus delphis is listed as Scottish PMF. The following sections provide a summary of the most common species in the Project area: 5.4.1.2 Harbour porpoise Nature in Shetland (1994) reports that harbour porpoise is the most common cetacean in Shetland, which is expected as it is also the most common cetacean in UK waters (NMPI, 2018; Hammond et al., 2017; Reid et al., 2003). The relative abundance of cetaceans between 1979 and 1997 provided by the NMPI (2018) show that harbour porpoise is the only species present in high densities in the Project area, these densities remaining high across the entire south coast and medium to high along the east coast of Shetland. Harbour porpoise has been observed in specific locations along the east coast of Shetland including Yell Sound and Bluemull Sound (Nature in Shetland, 1994). The species has been sighted in the vicinity of the cable routes (NAFC Marine Centre, 2015). The SCANS-III density estimate for harbour porpoise in waters around Shetland is 0.402 animals per km2. This is slightly higher than the average density across the entire survey area (0.351 animals per km2). Reid et al. (2003) found harbour porpoise to be present in Shetland during all months except February, November and December, peaking in distribution in July with an abundance of 1-10 individuals/h in all Shetland waters and peaking in abundance in January with an abundance of 10-100 individuals/h along the mid-east coast of Shetland. 5.4.1.3 White-beaked dolphin White-beaked dolphin is particularly common along the east coast waters of Shetland with sightings occurring most months of the year, peaking between May and September (Nature in Shetland, 1994; Seawatch, undated). The SCANS-III density estimate for white-beaked dolphin (0.037 animals/ km2), is lower than the average density across the entire survey area (0.30 animals/ km2) (Hammond et al., 2017). Reid et al. (2003) found white-beaked dolphin to be present in southern Shetland at an abundance of 0.01-1 individuals/h in February. In July, the west coast was found to have an abundance of 0.01-10 individuals/h and the east coast had an abundance of 0.01-1 individuals/h. The vicinity of the cable routes was found to have an abundance of 0.01-1.0 individuals/h (Reid et al. 2003). 5.4.1.4 Minke whale Minke whale frequently occurs in the waters around Shetland, often on the east coast, with peak sightings occurring April to November (Nature in Shetland, 1994; Seawatch Foundation, undated). The species has been observed in the area of the Outer Skerries and the Papa Stour (NAFC Marine Centre, 2015). The SCANS-III density estimate for Minke whale (0.032 animals per km2) is higher than the average density across the entire survey area (0.011 animals per km2) (Hammond et al., 2017). Reid et al. (2003) found Minke whale to be present in Shetland June to September. In July, the abundance on the west coast was 0.01-1 individuals/h. In August and September the abundance on the east coast was 0.001-0.01 individuals/h (Reid et al., 2003).
5 Common dolphin is treated as either one or two species depending on the reference used. The NMPI (2018) only includes short beaked common dolphin, The Hebridean Whale and Dolphin trust treats it as two individual species while Reid et al. (2003) and Hammond et al. (2017) treat common dolphin as a single species.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 52
5.4.1.5 Killer whale Killer whale is a common Shetland visitor with most sightings occurring between April and July, however there has also been observed during the winter months (Nature in Shetland, 1994; Seawatch, undated). The species has been sighted in the vicinity of the cable routes (NAFC Marine Centre, 2015). Reid et al. (2003) found Killer whales to be present in southern Shetland in May at an abundance of 0.01-1 individuals/h and in September at an abundance of 0.001-0.01 individuals/h. Northern Shetland was also found to have an abundance of 0.01-1 individuals/h in May. 5.4.1.6 Risso’s dolphin Risso’s dolphin is widespread and common in Shetland waters with sightings being most common between April and September. Most frequently recorded on the south and east coast of Shetland including Yell Sound and Bluemull Sound, and off the east coast of Unst (Nature in Shetland, 1994). The species has been sighted in the vicinity of the Yell to Unst cable routes (NAFC Marine Centre, 2015). Reid et al. (2003) found Risso’s dolphin to have an abundance of 1-10 individuals/h in northern Shetland in April and 0.01-1 individuals/h in September. 5.4.1.7 Other species Striped dolphin and humpback whale has been sighted in the vicinity of both cable routes (NAFC Marine Centre, 2015). However, these two species have not been reported in the vicinity of the cable routes by Reid et al. (2003) or the NMPI (2018) and thus their presence is viewed as unlikely. 5.4.1.8 Summary Although there is potential for a number of cetacean species to be present along, and in the vicinity of, the cable routes, based on the available information, the areas in which the activities will take place generally exhibit low cetacean density and are not considered to be significant for feeding, breeding, nursery or migrating cetaceans (Hammond et al., 2004; JNCC, 2016; Reid et al., 2003).
5.4.2 Pinnipeds Although not afforded the strict protection of EPS through the Habitats Directive, pinniped species (seals) occurring in UK waters are listed in Annex V (and hence Schedule 3 of the Habitats Regulations) such that they are defined as species of community interest and taking in the wild may thus be subject to management measures. Grey and harbour seals are also listed in Annex II of the Habitats Directive (and therefore Schedule 2 of the Habitats Regulations) as requiring protection through the designation of SACs and are protected while at 194 haul sites around Scotland under Part 6 of the Marine (Scotland) Act 2010. In addition to that they are also listed as Scottish PMFs. The Act also includes provisions for Scottish Ministers to designate “seal conservation areas”. These include areas previously covered by the Conservation of Seals (Scotland) Orders which include Orkney and the East Coast of Scotland. In these areas Marine Scotland must not grant a seal licence authorising the killing or taking of seals in a seal conservation area unless they are satisfied that there is no satisfactory alternative way of achieving the purpose for which the licence is granted, and that the killing or taking authorised by the licence will not be detrimental to the maintenance of the population of any species of seal at a favourable conservation status in their natural range (within the meaning of Article 1(e) of the Habitats Directive) (SNH, 2015). Grey and harbour seals will feed both in inshore and offshore waters depending on the distribution of their prey, which changes both seasonally and annually. Both species tend to be concentrated close to shore, particularly during the pupping and moulting season. Harbour seals haul-out every few days on tidally exposed areas of rock, sandbanks or mud. Pupping and moulting seasons occur between June to July (harbour seals) and October to December (grey seals), during which time seals will be ashore more often than at other times of the year (Hammond et al., 2004). While grey seals tend to breed on sand or shingle beaches at the foot of cliffs on wave-exposed rocky coasts, often on relatively remote islands, harbour seals prefer more sheltered locations. Grey seals have much larger foraging ranges than harbour seals, often travelling a distance of a few 100 km from
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 53
haul-out sites, compared to harbour seals which generally forage close to their selected haul-out sites (within 50 km). In order to understand the abundance and distribution of harbour and grey seal throughout Scotland, the Scottish Government commissioned the Sea Mammal Research Unit (SMRU) to carry out a study to produce estimates of mean density for grey and harbour seals based on the number of seals per 5 x 5 km grid cells. Results from this study, which involved using data collected in aerial survey counts at haul-out sites to scale up movement patterns from electronically tagged seals to populations levels, have been plotted in a series of seal usage maps. Grey and harbour seal density in the vicinity of the Yell to Unst cable routes was reported to be between 1 - 5 animals per 25 km2 and 0 and 1 animals per 25 km2 respectively (Jones et al., 2015; NMPI, 2018). Recent figures (Duck & Morris, 2014) confirm that harbour seal populations in the Northern Isles (Orkney and Shetland) have been, and are continuing to decline. Reasons for the decline are not known but studies indicate that there could be a number of contributing factors including climate change (affecting distribution and abundance of prey), increased predation from other species e.g. killer whale, increased competition for food and shooting. Under Section 117 of the Marine (Scotland) Act 2010, Scottish Ministers, in consultation with NERC, are permitted to designate specific seal haul-out sites6 to provide additional protection for seals from intentional or reckless harassment. Section 2 – Ecological Protected Sites further described the conservation areas for pinnipeds.
5.4.3 Otters Otters favour low peat-covered coastlines with a good freshwater supply and shallow, seaweed rich waters offshore. Scotland is recognised as a stronghold for the otter in Europe, and is the most significant terrestrial mammal in Shetland. Otter is a Scottish PMF and listed on Annex II of the Habitats Directive. The site supports approximately 80 otters with the highest densities in Britain, representing 2.5% of the UK population. Shetlands Marine National Plan (NAFC Marine Centre, 2015) report that the otter activity at the Yell to Unst cable routes to be medium to medium high. Three sightings of otter (L. lutra) have been recorded from a recorded position approximately 760 m to the north of the proposed Yell landfall in 1979, 1991 and 2015 (NBN Atlas, 2018). One otter holt has been found within 30 m of the proposed South cable route near the Unst landfall (ERM, 2018a, 2018b). Otter conservation, protected sites and mitigation is further discussed in Section 2.
5.4.4 Fish ecology Most fish species are highly mobile and it is therefore highly unlikely that cable installation activities and cable presence would have any impact on the majority of fish species. It is only those species that are either directly dependent upon the seabed environment for important life-stages (e.g. spawning) or are considered to be sensitive to noise generated during cable installation or from electromagnetic fields (EMF) emitted from the installed cable that could potentially be impacted by the Project and are considered further here. 5.4.4.1 Spawning grounds and nursery area Spawning areas for most species are not rigidly fixed and fish may spawn either earlier or later from year to year. In addition, mapped spawning areas represent the widest known distribution given current knowledge and should not be seen as rigid unchanging descriptions of presence and absence (Coull et al., 1998). Whilst most species spawn into the water column of moving water masses over extensive
6 Seal haul-outs can be designated for multiple species or just one species of seal. The breeding seal haul-outs within the Project area are specifically for breeding grey seals, whereas the other seal haul-outs are for both grey and harbour seals.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 54
areas, benthic spawners have very specific habitat requirements, and as a consequence their spawning grounds are relatively limited and potentially vulnerable to seabed disturbance and change. In the UK, Cefas, via Ellis et al. (2012) has published data on the predicted distribution of spawning sites for these species. This data updates the original Coull et al. (1998) data on spawning grounds with additional information obtained from ichthyoplankton surveys (surveys to identify the distribution of the planktonic stages of fish eggs) and from fisheries independent groundfish trawl surveys. There are three key species of commercial and conservation importance that may use the seabed in the Project area, either throughout or during spawning season: sandeel (Ammodytidae), lemon sole (Microstomus kitt) and Norway pout (Trisopterus esmarkii) (Coull et al., 1998; Ellis et al., 2012). Coull et al. (1998) reported the area as a spawning ground for haddock (Melanogrammus aeglefinus), however the haddock spawning grounds described by Ellis et al. (2012) do not extend over the Project area. Whiting (Merlangius merlangus) has also been reported by Ellis et al. (2012) to spawn in the Project area between February and July, however these appear to be low in intensity. There are five species of sandeels known to occur in the North Sea, with the majority (90%) of the commercial catch made up of the lesser sandeel. Sandeels are shoaling fish which lie buried in the sand during the night, and hunt for prey in mid-water during daylight hours (DECC, 2016). They are restricted to sandy sediments (Holland et al., 2005; DECC, 2016). They feed mainly on planktonic prey such as copepods and crustacean larvae, but they can also consume polychaete worms, amphipods, and small fish including other sandeels. When active, sandeels swim continually in order to remain clear of the bottom (DTI, 2001). Sandeels usually spawn between November and February and lay eggs in clumps on sandy substrates (DECC, 2016). The larvae are pelagic up to approximately two to five months after hatching and are believed to over-winter buried in the sand (DECC, 2016). Sandeel are important not only to commercial fisheries but also are also of ecological significance as they are a vital food source for marine birds and predatory fish (DECC, 2016). According to Mazik, et al. (2015), sandeels are likely to avoid areas with greater than 10% of silt/clay or very fine sand. Although data from both Coull et al. (1998) and Ellis et al. (2012) indicates that sandeel spawning grounds are present throughout the entire Project area, the intensity of sandeel spawning, which occur between November and February, is considered to be low. The seabed within the working corridor is predominantly rocky and thus sandeels are unlikely to spawn within the Project area. Ellis et al. (2012) has reported the Project area as a high intensity nursery ground for blue whiting (Micromesistius poutassou), anglerfish (Lophius piscatorius), cod (Gadus morhua) and mackerel (Scomber scombrus). Additionally, the seabed in the Project area appears to be a low intensity nursery grounds for, common skate (Dipturus batis), hake (Merluccius merluccius), herring (Clupea harengus), ling (Molva molva), spotted ray (Raja montagui), spurdog (Squalus acanthias), sandeels and whiting. The following species found in the Project area are Scottish PMFs; anglerfish, blue whiting, cod, skate, herring, ling, mackerel, sandeels, whiting, Norway pout and saithe. The following species are also on the OSPAR list; skate, spotted ray and cod.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 55
Table 5.1 Fisheries sensitivities within the Project area (Coull et al., 1998 and Ellis et al., 2012) Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Anglerfish N N N N N N N N N N N N Blue whiting N N N N N N N N N N N N Cod SN S*N S*N SN N N N N N N N N Skate N N N N N N N N N N N N Hake N N N N N N N N N N N N Herring N N N N N N N N N N N N Ling N N N N N N N N N N N N Mackerel N N N N N N N N N N N N Sandeels SN SN N N N N N N N N SN SN Spotted ray N N N N N N N N N N N N Spurdog N N N N N N N N N N N N Whiting N SN SN SN SN SN SN N N N N N Haddock N S*N S*N S*N SN N N N N N N N Lemon sole N N N SN SN SN SN SN SN N N N Norway pout SN S*N S*N SN N N N N N N N N Saithe N N N N N N N N N N N N S = Spawning, N = Nursery, SN = Spawning and Nursery; * = peak spawning ; Shaded = Period of proposed operations, Species = High spawning intensity as per Ellis et al, 2012, Species = High nursery intensity as per Ellis et al, 2012; Species = High concentration spawning as per Coull et al., 1998;
5.4.4.2 Noise-sensitive species The ability of fish to detect sound depends on whether or not they have a swim bladder and whether the swim bladder is located near to the fish’s ear. Hawkins and Popper (2014) have divided fishes into several different categories based on the structures associated with hearing. The functional groups include: Low sensitivity to noise - fish without a swim bladder (these can only detect kinetic energy – e.g., sharks, common skate complex, mackerel, whiting); Medium sensitivity to noise - fish with a swim bladder that is far from the ear and thus not likely to contribute to pressure reception, so the fish are primarily kinetic detectors (e.g., salmon, sea trout) and eggs and larvae that are less mobile than adult fish and therefore not able to readily move away from the noise source; and High sensitivity to noise - fish where the swim bladder or other air bubble is close to the ear and enables sound pressure to be detected, broadening the hearing range and increasing hearing sensitivity (e.g., herring, sprat, cod). 5.4.4.3 Electro-sensitive species Species of fish that are most vulnerable to the effects of electro-magnetic fields (EMF) are elasmobranch species (sharks and rays), which possess specialised electroreceptors; and other electro-sensitive species (usually migratory species), which are able to detect induced voltage gradients associated with water movements and geomagnetic emissions (e.g. Atlantic salmon Salmo salar). Information on the distribution and migration patterns of many of these species is limited and often the patterns are widespread and not limited to specific areas. Data shows that the replacement cable routes pass through areas defined as potential nursery grounds for three elasmobranch species: common skate (Dipturus batis), spotted ray (Raja montagui) and spurdog (Squalus acanthias). However, the nursing intensity of these species is considered to be low in this area (Ellis et al., 2012). The common skate is critically endangered according to the International Union for the Conservation of Nature (IUCN) Red List.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 56
5.4.4.4 Medium and high noise sensitivity species There is some potential for fish species with medium noise sensitivity to be present in the Project area. The most up to date source on Atlantic salmon migration patterns around Scotland is Malcolm et al. (2010), though the exact routes they take to and from feeding and spawning grounds are not known and population estimates also have a degree of uncertainty inherent within them. The Malcolm et al. (2010) study details the likelihood of Atlantic salmon from rivers on the east coast of Scotland migrating initially north and east, ultimately towards the Faroe Islands and west Greenland. Fish returning to Scotland are most likely to come from a north westerly direction and the lack of historic Atlantic salmon fisheries in Orkney and Shetland suggest the Pentland Firth as the most likely migration route. The use of the Pentland Firth as a key migratory route is supported by a recent Atlantic salmon tagging study undertaken by Godfrey et al. (2014). However, it is uncertain whether Atlantic salmon migrate through the Orkney and Shetland waters or if they prefer the Pentland Firth route or use it exclusively (Malcolm et al., 2010). There are two known salmon rivers in the direct vicinity of the Project area (NMPI, 2018). Atlantic salmon is listed as an OSPAR species, an Annex II species in the Habitats Directive and a PMF, Annex II species and is a Scottish PMF. There is potential for noise sensitive such as herring and cod to be present in the Project area (Coull et al., 1998; Ellis et al., 2012). 5.4.4.5 Basking sharks Basking sharks (Cetorhinus maximus) are the second largest fish in the world, reaching up to 12 m in length (average length is usually 6 - 8 m). They are widely distributed in cold and temperate waters and feed predominately on plankton and zooplankton e.g. barnacles, copepods, fish eggs and deep- water oceanic shrimps by filtering large volumes of water through their wide-open mouth. They typically move very slowly (around 4 miles per hour). In the winter, they dive to great depths to get plankton while in the summer they are mostly near the surface, where they the water is warmer. Basking sharks were hunted in Scotland up to 1995. However, they are now protected in UK waters principally under Schedule 5 of the Wildlife and Countryside Act 1981 and under the Nature Conservation (Scotland) Act 2004 and are classed as Scottish PMF as well as a species on the OSPAR list. Due to their size, slow swimming speeds and preference for swimming in coastal waters during summer months, basking sharks are considered to be at potential risk of collision with installation vessels during cable installation. Given that basking sharks are slow to mature and have a long gestation period, the species can be slow to recover if populations are rapidly depleted. Basking sharks seasonally arrive on Scottish shores during spring and leave in autumn. They appear to aggregate in summer to breed, with peak numbers in July and August. They are mainly found around the western isles of Scotland, but at certain times can be found in the northern isles or even on the east coast. The NMPI (2018) reports two sightings of basking shark in the vicinity of the Yell to Unst cable routes.
5.4.5 Ornithology With regards to birds on the shore at the cable landfalls, all wild birds in the UK are protected under the Wildlife and Countryside Act 1981 (as amended) and under this Act it is an offence to intentionally or recklessly: kill, injure, take, damage, interfere, disturb or harass wild birds listed on Schedule 1 and 1A. This applies to their nests, eggs and young. Cable installation activities will most likely be undertaken between October 2018 and March 2019, which is outwith the main breeding season (Table 5.2). There is one conservation site for seabirds located within the Project area, the Blue Mull and Colgrave Sounds pSPA. This site is proposed for the presence of breeding red-throated diver. The cable installation activities are planned to occur between October 2018 and March 2019, which is mostly outwith the breeding season for red-throated diver, mid-September being the end of the breeding season (Table 5.2). Therefore, any impacts on red-throated divers are unlikely. The full description of potential impacts on the Blue Mull and Colgrave Sounds pSPA and mitigation measures are described in Section 2.3.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 57
A small colony of Arctic tern (Sterna paradisaea) is known to breed at Loch Snarravoe, approximately 200 m south-west of the cable landfall at Unst (ERM, 2018b). However, the works are planned to occur between October 2018 and March 2019, which is outwith the breeding season for Arctic tern (Table 5.2). Table 5.2 Seabirds breeding seasons and nest occupancy periods in the Scottish marine environment (SNH, 2009)
Protected seabird Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec species
Arctic tern Common guillemot M M M M Kittiwake Arctic Skua Fulmar Great skua Red-throated diver M M M M Razorbill M M M M European shag Slavonian grebe Common eider M M M Long-tailed duck Velvet scoter Red-breasted merganser M M M
Black-headed gull Great black-backed gull Black guillemot M M M M Common gull Lesser black-backed gull
Cormorant Puffin M M Black-headed gull Northern gannet Common tern Lech’s storm petrel
Key: Black = breeding season White = not present in significant numbers Dark blue = breeding site attendance M = flightless moult period Light blue = non-breeding period
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 58
5.5 Summary of potential impacts Table 5.3 summarises the potential impacts on each receptor as a result of the Project. Table 5.3 Potential impacts on marine mammals, fish, birds and otters
Environmental Management and mitigation and overall Potential impacts receptor impact significance
No potential for significant impacts on cetaceans (and pinnipeds), due to
Marine (vessel) activities will only last approximately will only last approximately 30 days; Operations to occur outside of the Cetaceans and pinnipeds could harbour seal pupping season (June- potentially be present in the July); Project area and experience Operations will not occur within Cetaceans and short term physical disturbance recognised seal haul outs (grey seal and pinnipeds / displacement due to vessel harbour seal); presence (offshore) and noise. Implementation of a Marine Mammal Protection Plan (MMPP), incorporating the EPS management plan (to support the EPS Licence); Although no significant impacts are predicted, as there is the potential for disturbance to protected cetacean species an EPS Licence will be applied for.
Disturbance to sensitive fish habitats such as spawning and No potential for significant impacts on fish and nursery grounds. Project area is shellfish, due to high intensity nursery area for; anglerfish, blue whiting, cod and Marine (vessel) activities will only last mackerel. approximately will only last approximately 30 days; Any seabed disturbance and suspended Fish and shellfish Electro sensitive species (and sediments limited to immediate vicinity of (including pinnipeds) could potentially be cable retrieval activities; elasmobranchs and present in the Project area and electro sensitive experience short term physical Project area is extremely small compared species) disturbance / displacement due to spawning and nursery areas available; to electromagnetic field (iE) No particularly sensitive fish habitats are created by subsea cables. located in the vicinity of the Project area and no high spawning intensity in the vicinity of the Project area; With distance from the cable the field is attenuated and drops off significantly (Gill et al., 2005; DECC, 2011);
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 59
Environmental Management and mitigation and overall Potential impacts receptor impact significance
Low nursing intensity of common skate, spotted ray and spurdog in the Project area;
The mobile nature of basking shark and Collision risk (Basking shark) short duration of cable installation; Operations will be avoided during summer months basking sharks may be swimming in coastal waters.
No potential for significant impacts on shore birds, due to: Breeding and wintering birds could be present in the area of Avoidance of red-throated diver breeding the landfall works and be season (April to mid-September), Shore birds disturbed by landfall excavation protected within the Bluemull Sound and works when foraging within the Colgrave pSPA that is in the immediate working corridor vicinity of the proposed works; and Limited duration of cable installation activities and small area of impact.
No potential for significant impacts on otters, due to:
Pre-construction surveys undertaken to confirm presence or absence of otters in the vicinity of the landfall works; Otters could be present in the In the event that potential impacts on otters at area of the landfall works and be the cable landfall cannot be avoided, any disturbed during excavation disturbance will require a European Protected Otters works at the intertidal areas, or Species (EPS) licence and specific mitigation when swimming within the implemented in order to minimise impacts; vicinity of the vessels deployed An EcoW may be present to ensure distance for cable installation works. to otter holts is at least 30 m from the proposed works, and to look for new otter activity; Limited duration of cable installation activities; and Although otters apparently have no specific breeding season, Kruuk et al. (1987) found that in Shetland a birth peak occurs in June.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 60
6 MARINE ARCHAEOLOGY
6.1 Introduction This chapter describes the key characteristics of the marine historic environment along the replacement cable routes across Blue Mull Sound between the east coast of Yell south of Culli Voe, and Snarra Voe on the west coast of Unst, Shetland (Section 6.5), and presents results from an assessment of potential impacts of the Project on these characteristics (Section 6.6). The chapter is a desk study only. Seabed survey data is due to be acquired during 2018 and a review of these data will be undertaken in order to confirm any other potential marine archaeological interests once the data is available. This chapter also provides a summary of relevant historic environment legislation (Section 6.2) and describes the criteria used to determine the importance or sensitivity of the identified historic environment assets (Section 6.4). Where potential direct or indirect impacts are identified, recommendations have been made for mitigating and managing those impacts (Section 6.7). Marine cultural heritage in general is considered to encompass submerged landscapes, along with all evidence of human exploitation of maritime resources such as shipwrecks, aircraft wrecks, shipyards, piers, fish traps, anchor sites etc.
6.2 Legislation and policy context The Project is located within Scottish and UK Territorial Waters (within 12 nautical miles of land). There are a number of international legally binding conventions, EU Directives, UK and Scottish legislation, policy frameworks and guidance to consider in relation to the historic environment. Various EU EIA Directives have been incorporated in UK and Scottish legislation, all of which include the requirement to address potential impacts on the historic environment. Relevant guidance and legislation relating to the assessment of impacts on the marine historic environment are discussed below.
6.2.1 International/ EU legislation and policy The following conventions promote the protection of underwater heritage, with provisions for appropriate recording and recovery if disturbance is unavoidable. The United Nations Convention of the Law of the Sea (UNCLOS); Annex to the UNESCO Convention on the Protection of the Underwater Cultural Heritage 2001; and The European Convention on the Protection of the Archaeological Heritage (revised), known as the Valletta Convention.
6.2.2 UK legislation and policy Key UK legislation and policy includes: The Merchant Shipping Act 1995; The Protection of Wrecks Act 1973 (Section 1 of the Protection of Wrecks Act was repealed in Scotland on the 1st November 2013 and the 8 wrecks around the coast of Scotland designated under this section of the Act are now protected by Historic Marine Protected Areas (HMPAs) as defined in the Marine (Scotland) Act 2010); The Protection of Military Remains Act 1986 has the principal concern to protect the sanctity of vessels and aircraft that are military maritime graves. Any aircraft lost while in military service is automatically protected under this Act; and The UK Marine Policy Statement (2011) states heritage assets should be conserved through marine planning in a manner appropriate and proportionate to their significance. Many heritage
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 61
assets with archaeological interest are not currently designated as scheduled monuments or protected wreck sites but are demonstrably of equivalent significance.
6.2.3 Scottish legislation and policy Relevant Scottish legislation and policy includes: The Marine (Scotland) Act 2010. This requires licensing activities in the marine environment to consider potential impacts on the marine environment including features of archaeological or historic interest and defines marine historic assets (Section 73); The Historic Environment Scotland (HES) Policy Statement 2016; Scottish Planning Policy (SPP) 2014; The Scottish Government’s Planning Advice Note (PAN 2/2011) Planning and Archaeology 2011; and The Scottish Government’s Planning Scotland’s Seas: Scotland’s National Marine Plan (March 2015). HES Policy Statement 2016, SPP 2014. PAN 2/2011 and Scotland’s National Marine Plan all contain the principle that licensing authorities should seek to identify significant underwater historic environment resources in the early stages of the planning process and preserve them in situ wherever feasible. Where this is not possible, licensing authorities should require developers to undertake appropriate recording of the assets before they are lost.
6.2.4 Local planning policy The Shetland Local Development Plan 2014 (LDP) contains various policies covering the safeguarding and sustainable management of the historic environment, which includes marine heritage as well as onshore assets. For example, General Policy GP2g that states ‘Development should not adversely affect areas, buildings or structures of archaeological, architectural or historic interest’. Historic Environment Policy HE1 states that there should be a presumption ‘in favour of the protection, conservation and enhancement of all elements of Shetland’s historic environment, which includes buildings, monuments, landscapes and areas’. Historic Environment Policy HE4 includes, as well as the in situ preservation of nationally important cultural heritage resources in an appropriate setting, the policy that ‘All other significant archaeological resources should be preserved in situ wherever feasible. Where preservation in situ is not possible the planning authority should ensure that developers undertake appropriate archaeological excavation, recording, analysis, publication and archiving in advance of and/ or during development.' The Shetland Islands Marine Spatial Plan 2015 (SIMSP) has been adopted as non-statutory supplementary planning guidance and policy framework by Shetland Islands Council and is a material consideration in the determination of relevant planning applications. This contains similar policies and principles as the LDP, specifically for marine and coastal heritage. The SIMSP recognises that there is potential for the discovery of new sites on the seabed, which itself is of possible paleoenvironmental interest, especially areas that were once dry land, where there is potential for buried deposits of archaeological interest.
6.2.5 Codes of practice, professional guidance and standards documents The following codes of practice, professional guidance and standards documents informed this assessment: The Chartered Institute for Archaeologists (CIfA) Codes, Standards and Guidance (various) http://www.archaeologists.net/codes/cifa ;
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 62
The Crown Estate. (2010.) Model clauses for Archaeological Written Schemes of Investigation: Offshore Renewables Projects. Wessex Archaeology Ltd (Ref 73340.05) for The Crown Estate; English Heritage. (2012). Ships and Boats: Prehistory to Present. Designation Selection Guide. Swindon: English Heritage. The Joint Nautical Archaeology Policy Committee and Crown Estate. (2006). Maritime Cultural Heritage & Seabed Development: JNAPC Code of Practice for Seabed Development. York: CBA; Wessex Archaeology. (2014). Protocols for Archaeological Discoveries http://www.wessexarch.co.uk/protocols-archaeological-discoveries-pad . Salisbury: Wessex Archaeology; Wessex Archaeology. (2006). On the Importance of Shipwrecks: Final Report Volume 1. Salisbury: Wessex Archaeology; Wessex Archaeology. (2011a). Assessing Boats and Ships 1860-1913 Archaeological Desk- Based Assessment. Salisbury: Wessex Archaeology; and Wessex Archaeology. (2011b). Assessing Boats and Ships 1914-1938 Archaeological Desk- Based Assessment. Salisbury: Wessex Archaeology.
6.3 Consultation SHEPD has undertaken consultation with statutory and non-statutory bodies. Correspondence of relevance to marine archaeology is summarised below in Table 6.1. Table 6.1 Consultation
Date and type of Consultee Issues raised consultation
With regard to the way that marine archaeological features are Shetland 25th April 2017, Open detailed within marine GIS systems, they are often at the nearest Amenity Door at Shetland latitude/longitude intersection on the map where an exact location is Trust Museum not known. However, Shetland Amenity Trust often have detailed knowledge of these locations.
Shetland 25th April 2017, Open Noted that no scheduled archaeological sites are shown on GIS Amenity Door at Shetland systems, but Shetland Amenity Trust will do a local site search to Trust Museum confirm that there are no points of interest along proposed routes.
Shetland 25th April 2017, Open In terms of marine archaeology, the locations and our micro-siting Amenity Door at Shetland should be held in a confidential appendix to the marine licence, to Trust Museum prevent looting.
16-18 August 2016, To the north of the cable is a significant archaeological site (Dragger Stakeholder Yell-Unst Open Door [sic], a historical wreck) which is used by recreational divers.
6.4 Sources of information A review was undertaken of existing literature, data sources and databases to identify known sites in the area, and the potential for unidentified marine cultural heritage sites and areas. It should be noted that the Shetland Sites and Monuments Record (SMR) has not been consulted by ORCA, due to the indication that Shetland Amenity Trust (SAT) will be conducting this local site search and feeding back to SHEPD. As indicated earlier, marine survey data (geophysical data) for the Project area will be reviewed at a later date (once available) to identify the potential presence of marine historic assets in the survey area.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 63
6.4.1 Desk-based assessment The results of a desk-based assessment (DBA) of potential submerged cultural heritage in the study area prepared by Scientific Underwater Logistics And Diving (SULA Diving) on behalf of ORCA Marine is incorporated into this report. The appraisal was confined to a review of key existing data sources of known submerged sites in the Project area. Historic environment assets that could be sensitive to the Project, if present, may include shipwrecks, aircraft wrecks, submerged landscapes and other marine cultural features such as marine dumping and mine areas. The principal reference sources examined for this appraisal were: The National Record of the Historic Environment (NRHE) of Scotland, using the Canmore and Pastmap database websites (https://canmore.org.uk/ ; http://pastmap.org.uk/ ); The Shetland Sites and Monuments Record (SMR) has not been consulted by ORCA, due to the indication that Shetland Amenity Trust (SAT) will be conducting this local site search and feeding back to SHEPD as per Consultation (see Table 6.1). This feedback will be incorporated in time for the marine survey data review; Statutory lists, registers and designated areas, including List of Scheduled Ancient Monuments, Designated Wrecks and Historic Marine Protected Areas; UK Hydrographic Office (UKHO) wreck register and relevant nautical charts; The Shetland Islands Marine Spatial Plan 2015; Marine Scotland National Marine Plan interactive https://marinescotland.atkinsgeospatial.com/nmpi/ ; Aviation Research Group Orkney and Shetland http://www.crashsiteorkney.com/orkney- projects; https://wrecksite.eu/ database; Flemming, N.C., (2003). Strategic Environmental Assessment of Continental Shelf Area SEA4 in regard to prehistoric archaeological remains. Prepared for the Dept of Trade & Industry; Larn, R., & Larn, B., (1998). The Ship Wreck Index of Great Britain & Ireland Vol.4 Scotland. London: Lloyds Register of Shipping; Whittaker, I.G., (1998). Off Scotland: a comprehensive record of maritime and aviation losses in Scottish waters. Edinburgh: C-Anne Publishing; Fergusson, R.M., (1988) Shipwrecks of Orkney, Shetland and the Pentland Firth. Newton Abbot: David & Charles; Heath/Ferguson private wreck database, which contains material not published by Ferguson (see Ferguson 1988) and has been added to by Heath and Ferguson as new discoveries of wreck sites have been made; Further information on wrecks and on minesweeping and mine-laying activities was followed up in the National Archives Admiralty files, based at Kew in Surrey, which holds ship log books and casualty reports from wrecks (http://www.nationalarchives.gov.uk/); Other readily available archaeological and historical reports, databases, websites and publications were consulted for information about the study area and, where used, are cited in the report. They are listed in the reference section.
6.5 Assessment Methodology This assessment identifies, where possible, any marine sites of archaeological or cultural heritage significance in the Project area, and assesses whether there is potential for these sites to be affected
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 64
by the Project. Where potential impacts are identified, recommendations for mitigating and managing these potential impacts are provided. It is assumed that standard mitigation by avoidance will be incorporated into the Project design where appropriate and possible.
6.5.1 Desk Based Assessment The DBA reviewed key existing data sources of known submerged sites within a corridor from 250m to the north of the proposed northern cable replacement route to 250m south of the proposed southern replacement cable route (the study area) to MHWS at landfall. This was in order to capture information on the approximate Position Approximate7 cultural heritage and other sites with unknown locations that have the potential to be in the area8 (Figure 6.1). The DBA has been completed in accordance with the Chartered Institute for Archaeologists (CIfA) Standard and Guidance for historic environment desk-based assessment (revised January 2017).
7 United Kingdom Hydrographic Office (UKHO) term, used on UKHO charts, to indicate an approximate position of a wreck, where precise location is not known. 8 Sites with unknown locations are often placed at the SW corner of the 1 or 5 km grid square in which they may be located, as in the Canmore database.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 65
Figure 6.1 Distribution of all sites identified
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 66
6.5.2 Receptor evaluation The importance of the marine historic environment asset is determined by the criteria as described in Table 6.2 based on the professional guidance and standards documents listed in Section 6.2.5 above. It should be noted that a site that has not been statutorily designated can still be of high importance / significance. Features that would require considerable further work to interpret them are recorded as of uncertain significance / importance. Table 6.2 Definitions for importance / significance of the marine historic environment asset
Importance Criteria
Archaeological and historical sites, submerged prehistoric landscapes and deposits, wrecks, wreck cargos, or areas of relative international or national importance, including world heritage sites, designated wrecks (designated under UK or Scottish legislation) or HMPAs. Shipwrecks dating to the prehistoric, Norse and Medieval periods, which are very rare; wreck cargos that contain rare artefacts or artefacts representative of a particular area or time period; and vessels, including High aircraft lost in international conflicts which may have involved large losses of life. Shipwrecks involved in national or international trade, which were lost before 1913, a period during which the shipping industry was a major element in Britain’s world influence, particularly if their cargo survives, or the remains provide evidence of changes in construction technology or vessel design would also be considered of high importance.
Archaeological and historical sites, wrecks, wreck cargos and areas of relative regional importance. This would involve shipwrecks, shipwreck cargos, anchorages and fishing areas from before 1913 that would have been involved in Medium regional industry and trade. Wrecks and cargos considered representative of the changes in naval engineering or support the identification and preservation of the diversity of vessels from this period are considered of medium importance.
Archaeological and historical sites, wrecks, wreck cargos and areas of relative local importance. Shipwrecks dating from after 1913 relating to fishing, ferrying or other Low coastwise trade. Wreck cargos of limited intrinsic, contextual or associative characteristics, or that are commonly recovered are considered of low importance / significance.
Features that have been recorded but assessed as having little or no archaeological Negligible or historical interest, such as recent wrecks, or those wrecks whose structure or cargos have been so damaged that they no longer have any historical merit.
Features that cannot be identified without detailed work, but potentially of some interest. Also, for example, if the date of construction or rarity of a vessel is not known, but is potentially of some interest. Find spots, which may represent an Uncertain isolated find, or could represent the location of a hitherto unknown site. Unidentified geophysical anomalies are also of uncertain importance and are evaluated further in Table 5.2
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 67
6.6 Site characterisation
6.6.1 Potential for submerged landscapes and prehistoric sites Submerged landscapes are where human beings and early hominids previously lived or hunted on terrain which was at that time dry land, or where they exploited fish and shellfish on the coast which is now submerged. The study area is within Zone 4 of the Strategic Environmental Assessment (SEA) of the Continental Shelf (Flemming, 2003). In the SEA, Flemming notes the potential for the survival of submerged landscapes and prehistoric sites in the study area is influenced by various physical factors, processes and topography with sheltered areas with lower seabed water movements, deep sediment deposits in rocky gullies and depressions and sea caves often providing conditions suitable for good site preservation (Flemming, 2003: 15 – 21). The SIMSP indicates that the study area has potential for submerged archaeology (Map 5b(xxii)). The survival of submerged landscapes and in particular submerged peat deposits and woodland remains that contain organic microfossils (e.g. pollen, diatoms, foraminifera) and macrofossils (e.g. seeds, wood, buds, insects) are important resources in reconstructing former landscapes, the activities of past human communities and sea level change. The likelihood of such material surviving rises in shallow more sheltered waters close to land, potentially in Snarra Voe for example. Analysis of the geophysical and DDV surveys will help to assess the nature of the seabed along the routes and whether any submerged prehistoric sites or landscapes exist that may be impacted by the cable. At this stage it is assumed that the strong tidal current of Bluemull Sound will have removed any seabed sediments of potential interest except near landfall.
6.6.2 Shipwrecks and aircraft wrecks This section discusses the shipwrecks and aircraft recorded in national and local inventories along the replacement cable routes, and the potential for as yet undiscovered remains to be present. Shipwreck inventories and documentary sources are usually biased towards the 18th century and later when more systematic reporting began (Pollard et al., 2014, 44). Therefore, there are few known historical records of medieval and earlier wrecks. The coastal archaeological evidence suggests exploitation of the marine environment within the Project area for fishing and transport purposes from prehistoric times. As a maritime nation with a reliance on marine based trade and exchange, there have been countless shipwrecks around UK waters from all periods – many of which remain unreported. As such, there is a high probability for unknown, unrecorded vessels to have sunk in the Project area over the centuries, although most will have been destroyed by the marine environment. Depending on the results from the geophysical surveys conducted, the nature of the seabed and the narrow width of potential disturbance (up to 8 m), the risk of impacting unknown remains is likely to be low. No marine cultural heritage statutory designations have been identified in the Project area. There are five wreck sites listed on the Canmore database and Whittaker (1998) that may be in or close to the study area (Table 6.3). The precise locations of their sinking are unknown and therefore are not shown on Figure 6.1. However, descriptions included within details of their circumstance of loss indicate the possibility of being located along the cable routes. There are five wrecks potentially lost within the study area. Two are potentially of high importance – one a Norse vessel, the other a Dutch East Indiaman – and the others are of low importance, due to being smashed up or salvaged. These wrecks are: Unknown. Canmore reproduces a Whittaker (1998) entry that states wreckage was washed ashore at Stonganess, Yell in 900 AD. Whittaker does not reference the source of this information (possibly one of the sagas). Note that this entry is for wreckage not a wreck. It is highly unlikely that anything survives, although it would be of high importance if it did;
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 68
Equestrian. “Ketch 63 tons. Capt. Edmiston. EQUESTRIAN. Cullivoe, Lerwick, May 17. The ketch EQUESTRIAN, of Peterhead, Edmiston, after discharging cargo here: was proceeding to Peterhead, and came to anchor off the Unst shore, but the anchor dragged, and the vessel came on the rock yesterday and is likely to be a wreck: crew saved.” (Source: Casualties &c., Lloyds of London, No. 21,862, London, Tuesday May 27 1884.); Fanny M Carvill. “The crew of the barque Fanny Carvill, wrecked at Unst, Shetland, during the recent gale, were brought to Lerwick by the SS Earl of Zetland, and sent south by the mail steamer which left last night. It appears that the barque had anchored, but by the force of the gale she was driven ashore. Communication was established with the shore means of hawser, and the crew thus landed. They saved nothing, the ship was almost immediately smashed to pieces.” (Aberdeen Evening Express - Tuesday 18 October 1881); Harmonia. “The HARMONIA, from New York to the Clyde, was warped into Cullavoe [Cullivoe] on the 17th Dec., where she grounded, and drove on the East side, and there remains aground: on the 19th she was surveyed and ordered to be sold: part of the cargo has been already put on board a vessel for this place.” (Source: The Marine List, Lloyds of London, No. 13,652, London, Monday January 4 1858.); Lastrager or Lastdrager. VOC (Dutch East Indies Company) ship, lost on Ness of Cullivoe in 1653. The incomplete remains of the wreck were discovered in an exposed situation off the tip of Crussa Ness, east of the beach of Crooks Ayre and north of Cullivoe. Only the forward portion was identified, lying in kelp at a depth of up to 10m on a heavily gullied seabed. The stern had apparently broken away, and was not found during magnetometer or diver survey over much of the deeper water of Blue Mull Sound the following year (Stenuit 1974). There are no recorded losses of aircraft in the study area, although a number of aircraft did go missing without trace over Shetland. The risk of finding one along the cable routes is likely to be negligible-low. Aircraft are automatically protected under the Protection of Military Remains Act 1986 if lost on active service. These would be considered to be of high importance.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 69
Table 6.3 List of possible wreck sites within 1 km of the Project area
Proximity to Name UKHO Canmore Ship Type Circumstance of loss Date Lost Significance Source development Unknown; more Unknown 290396 vessel Wreckage found near Stonganess 900 AD 1,5 High than 400m north
Equestrian 239663 Wooden ketch Drifted ashore and wrecked at Snarravoe 16/05/1884 Unknown 1,3, 5 Low
Fanny M Carvill 239662 Wooden Barque Drifted ashore at Snaravoe in a W 10 gale. 12/10/1881 Unknown 1,3,5,6 Low
329264 & Harmonia vessel Stranded at Ness of Cullivoe 9/12/1857 Unknown 1, 5 Low 284010 213917 & Dutch East India Wrecked at Crook's Ayre, Crussa Ness Cullivoe Ness. Unknown; more Lastrager 02/03/1653 1,2,5,8 High 324832 VOC ship Stern broke away. than 1000m north Sources: 1 = Whittaker (1998); 2 = Larn & Larn (1998); 3 = Lloyds Register; 4 = UKHO 5 = Canmore; 6 = Aberdeen Evening Express (various); 7 = National Archive Kew; 8 = Wrecksite.eu; 9= Ferguson (1988)
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 70
6.6.3 Unexploded ordinance (UXO) During both World Wars a large amount of ordnance, both offensive and defensive, was used in the seas around Orkney and Shetland. However, no reports of any mine laying in the study area have been found in the Bi-Monthly Minesweeping Reports or in the reports from U Boats operating in the area in both World Wars. There have been no modern reports of discovering wartime UXO in the study area. This study for the potential of UXO in the study area was carried out for the purposes of this historical and cultural assessment only and does not replace the UXO identification study that SHEPD will undertake prior to cable installation to ensure there is no risk of encountering any UXO during the installation activities.
6.7 Potential Impacts The Project will be designed to avoid existing cultural heritage assets and charted wrecks where possible. The potential impacts to marine cultural heritage are identified below, and summarised in Table 6.4. There is no difference between either routes in terms of potential impact on the marine historic environment.
6.7.1 Direct damage to or destruction of known marine historic environment assets and unexploded ordnance During construction and installation of the replacement cable, direct impacts to known cultural material on the seabed could be caused by vessel activities, seabed preparation and boulder clearance resulting in the removal of marine cultural heritage or removal of material that forms the context of the site. However, there are no shipwrecks or aircraft with known locations in close proximity to the cable routes. Therefore, no impacts are predicted on known marine heritage assets.
6.7.2 Direct damage to or destruction of unknown marine historic environment assets including unexploded ordnance During construction and installation, direct impacts to unknown cultural material on the seabed could be caused by vessel activities, seabed preparation and boulder clearance resulting in the removal of marine cultural heritage or removal of material that forms the context of the site. The potential for such an impact will be reduced during Project development by analysis of the geophysical and DDV surveys, and is further reduced by the dynamic nature of much of the seabed (meaning the likelihood of survival of cultural remains near the surface is low). Therefore, the likelihood of impact is considered low. The cables will be surface laid over the routes (except at landfall), and will be held in place by rock filter bags/concrete mattresses in regularly spaced spot locations to pin the cable to the seabed. This has the potential to cause direct damage to unknown marine cultural heritage through compression. The potential for such an impact will be reduced during Project development by analysis of the geophysical and DDV surveys, and is further reduced by the dynamic nature of much of the seabed (meaning the likelihood of survival of cultural remains near the surface is low). Therefore, the likelihood of impact is considered low. At landfall, the cable will be laid in an open cut trench from MLWS. This has the potential to remove unknown cultural heritage material, should any objects or deposits survive below the surface sediment at the shore, especially in Snarra Voe. The possible shipwreck sites identified in Section 6.6.2 have unknown locations. Two of these sites are of high significance and three of low significance. The potential for impacts on these will be reduced during Project development by analysis of the geophysical and drop-down camera surveys, and is
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 71
further reduced by the dynamic nature of much of the seabed. Therefore, the likelihood of impacting them accidentally is considered low.
6.7.3 Direct damage to or destruction of known and unknown marine historic environment assets and unexploded ordnance During operation and maintenance, it is possible that accidental direct impacts to unknown cultural material on the seabed could be caused by maintenance vessels dropping anchors on the seabed during routine inspections or preventative maintenance. The likelihood of such impacts is considered negligible-low. No known heritage assets were identified, therefore no impacts are predicted on known marine heritage assets. There is potential that movement of the cable could expose areas of seabed which could affect unknown sites of cultural heritage interest (if present). However, such movement will be prevented by the use of rock filter bags at regular intervals to pin the cable in place. Therefore no impact is predicted.
6.7.4 Potential indirect damage to or destruction of known and unknown marine historic environment assets including unexploded ordnance There is the possibility of indirect impacts on marine cultural heritage assets and their associated environment if the Project causes scour on the seabed. Scour occurs on the seafloor when sediment is eroded from an area in response to forcing by waves and currents (Quinn, 2006: 1419). It can be initiated by the introduction of an object to the seafloor such as a shipwreck or cable. Marine features such as shipwrecks and submerged landscape deposits are therefore made vulnerable to erosion due to scouring by currents or waves, and scour processes can ultimately lead to the complete failure and collapse of structures on the seafloor. However, the potential for indirect impacts to cultural material on the seabed as a result of scouring or sediment deposition during operations and maintenance is considered to be negligible, due to the lack of identified sites, the low likelihood of the cable being accidentally laid over unknown sites, and the use of regularly spaced rock filter bags, which prevent scour.
6.8 Mitigation In general terms, it is preferable to manage the presence of cultural heritage sites by locating construction footprints and routing the cable to avoid them. However, where this is not possible various strategies can be put in place, although few are required for this development due to the lack of identified maritime heritage. The mitigation and management measures outlined below will result in the avoidance, reduction or offsetting of any potential impacts on cultural heritage by the Project. These are appropriate for either of the cable routes.
6.8.1 Mitigation by design The potential for significant impacts on marine cultural heritage has been reduced to negligible-low during the development and design of the Project by conducting a DBA to identify any marine historic environment assets. Analysis of geophysical survey data will be undertaken once available to identify any geophysical anomalies that could be of marine archaeological interest. As no maritime heritage was identified within the Project area it is unlikely there will be any impacts on cultural heritage, however, the proposed geophysical survey will be used to inform the final cable routing which will seek to avoid any anthropogenic seabed features. Furthermore, the use of rock filter bags/concrete mattresses to pin the cable in place will significantly reduce any cable movement and potential scour over the lifetime of the cable.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 72
6.8.2 Mitigation during installation In order to manage the potential for impacting unknown heritage, a reporting protocol will be instigated for the discovery of previously unknown marine cultural material during development. The reporting protocol produced by Wessex Archaeology (2014) for the Crown Estate will be sufficient (http://www.wessexarch.co.uk/protocols-archaeological-discoveries-pad). Unknown cultural material could come from the presence of wrecks of uncertain location and the potential for submerged landscape material, although as outlined in Section 6.6, this a low risk. However, should any cultural heritage sites be reported during the course of the Project, it is recommended that they are investigated by a qualified marine archaeologist as their potential for retaining cultural heritage information could be high. At landfall the cable will be laid in an open-cut trench. The potential impact can be mitigated by conducting a watching brief when trenching and taking and analysing samples if any buried or submerged archaeological deposits are observed. The shallow sediments and bog at Snarra Voe indicate that this mitigation may be required.
6.8.3 Mitigation during operation Because the likelihood of impacts during this phase is considered negligible-low, it is suggested that a reporting protocol is kept in place in case anything of interest is observed during maintenance operations. If any cultural heritage sites are reported, it is recommended that they are investigated by a qualified marine archaeologist as their potential for retaining cultural heritage information could be high.
6.9 Residual Impacts The reduction of potential impacts by the work conducted during the design and development of the Project, after the geophysical survey review has been conducted, combined with instigating a reporting protocol for the accidental discovery of cultural remains are likely to result in impacts of negligible significance on the marine historic environment, depending on the results of the survey review.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 73
Table 6.4 Residual impacts on archaeological receptors Likelihood of Receptor Sensitivity Potential Impact Significant Management / Mitigation Residual Impact Impact Direct: vessel activities, seabed DBA has identified none present in cable Known marine heritage assets Negligible preparation, post-lay jetting, rock None None corridor filter bag placement Geophysical and DDV surveys to be reviewed Direct: vessel activities, seabed and results used to inform project design and preparation, post-lay jetting, rock management / mitigation strategy. Reporting Shipwrecks with unknown locations Low-High Low Low filter bag placement. protocol for accidental discoveries. Indirect: cable movement, scour. Use of rock filter bags to prevent cable movement and scour. Geophysical and DDV surveys – none Direct: vessel activities, seabed Aircraft with unknown locations. identified. Reporting protocol for accidental preparation, post-lay jetting, rock Aircraft legally protected and must High Negligible discoveries. Avoidance. Low filter bag placement. not be disturbed, even accidentally. Use of rock filter bags to prevent cable Indirect: cable movement, scour. movement and scour. None identified by DBA. Geophysical surveys to be reviewed and results used to inform Direct: vessel activities, seabed project design and management / mitigation preparation, post-lay jetting, rock UXO High Negligible strategy. Reporting protocol for accidental Negligible filter bag placement. discoveries. Indirect: cable movement, scour. Use of rock filter bags to prevent cable movement and scour. Geophysical surveys to be reviewed and results used to inform project design and Direct: vessel activities, seabed management / mitigation strategy. Reporting preparation, post-lay jetting, rock protocol for accidental discoveries. Sampling Unknown submerged deposits Low-High Low Negligible filter bag placement. and analysis of intertidal deposits observed Indirect: cable movement, scour. during trench cutting. Use of rock filter bags to prevent cable movement and scour. Geophysical surveys to be reviewed and Direct: vessel activities, seabed results used to inform project design and preparation, post-lay jetting, rock management / mitigation strategy. Reporting Unknown cultural material Low-High Low Negligible filter bag placement. protocol for accidental discoveries. Indirect: cable movement, scour. Use of rock filter bags to prevent cable movement and scour.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001 74
7 CONCLUSIONS Environmental management and mitigation measures have been identified for the Project to ensure that impacts are avoided, or where they cannot be avoided are minimised as far as possible. Some of this is embedded into the Project design and operational procedures, where as other is specific to the environmental sensitivities in and around the proposed activities.
7.1 Key receptors The environmental overview identified a number receptors of concern present in the area, and further assessment has been undertaken in order to identify potential impacts. The results of the assessment on commercial fisheries and other sea users are reported in the FLMAP. Protected sites, benthic and intertidal ecology, species of conservation importance and marine archaeological features within the vicinity of the Project area were reported in this document
7.1.1 Ecological protected sites The nearest conservation sites to the Project area are the Bluemull and Colgrave Sound pSPA, which encompasses the North and South cable routes, the Fetlar to Haroldswick NCMPA (1.6 km south), the Westing Seal haul-out (2 km north), the North Fetlar SSSI (6 km south-east) and the Yell Sound Coast SAC (24 km south-east). The features protected within these sites that are likely to be present within the Project area include the breeding red-throated diver, breeding black guillemot, and the harbour and grey seals. Potential impacts on these designated features will be mitigated by: Undertaking the works between October 2018 – March 2019, which is outwith the breeding season for red-throated diver (April and mid-September) and black guillemot (May to July); Limiting the duration of cable installation works (30 days per cable); and Limiting the speed of the cable installation vessel to reduce physical disturbance to seabirds. Given the distance to the Fetlar to Haroldswick NCMPA and the small area of impact (0.28 km2), impacts on the benthic features of the NCMPA are not anticipated.
7.1.2 Benthic and intertidal ecology The main habitat identified in this desk-based assessment within the Project area was infralittoral rock, with the intertidal areas at Yell and Unst landfalls potentially supporting the Annex I 'vegetated shingle' habitat. No other sensitive habitats or species of conservation importance were identified in the desk-based assessment, and the potential impacts on benthic and intertidal ecology have been minimised in the following ways: Very small area of impact (0.28 km2); Cable installation activities will be short-term (approximately 30 days per cable) and any increase in suspended sediments will quickly revert back to background levels; All cable landfall works undertaken in line with standard best practice and general environmental management plans provided by SHEPD; and A corridor 500 m wide (250 m either side of the cable) has been applied for within the Marine Licence application; this will enable micro-routing during installation to avoid any key features of conservation interest. Seabed surveys are still on-going, and the data gathered during these surveys will allow to better quantify existing and/or identify further impacts and mitigation measures.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
7.1.3 Marine mammals, fish, birds and otters There are no conservation sites with cetacean features in the vicinity of the Project area, and the area is not considered to be significant for feeding, breeding, nursery or migrating cetaceans. Grey seal and harbour seal densities are low in the Project area, and the nearest haul-out for seals is located the Westing Seal haul-out (2 km north). Therefore, no Likely Significant Effects (LSE) on cetaceans and pinnipeds are anticipated. However, it is possible to find cetaceans and pinnipeds on passage within the Project area, therefore, a Marine Mammal Protection Plan (MMPP) will be implemented to mitigate any potential impacts. As there is the potential for disturbance to protected cetacean species an EPS Licence will be applied for. Otter holts have been sighted within 30 m of the proposed South cable landfall on Unst during a site survey in January 2018. The potential impacts on otters that occur in the vicinity of the Project area have been minimised the following ways: Pre-construction surveys undertaken to confirm presence or absence of otters in the vicinity of the landfall works; An ECoW will ensure distance to otter holts is at least 30 m from the proposed works, and will look for any evidence of new otter activity; In the event that potential impacts on otters and seals at the cable landfall cannot be avoided, any disturbance will require a European Protected Species (EPS) licence and will be accompanied by an otter species protection plan; and Limited duration of cable installation activities (approximately 30 days per cable). The Project area is used as nursery area by anglerfish, blue whiting, cod, common skate, mackerel, spotted ray and spurdog. Electro sensitive species could also potentially be present and experience short-term physical disturbance. However, no significant impacts on fish and shellfish species are expected since there are no particular sensitive fish habitats, the works will be temporary (approximately 30 days per cable) and the Project area is small compared to the nursery areas available. The proposed works are planned outwith the summer months, therefore the collision risk with basking sharks will be minimised.
7.1.4 Marine archaeology Finally, they were no archaeological features identified within the Project area. A reporting protocol will be implemented in case of accidental discovery of cultural remains during maintenance operations.
7.2 Residual impacts Taking into account the proposed activities, and associated management and mitigation measures, the cable installation activities for the two cable routes between Yell and Unst will not result in any significant residual impacts, including no potential for Likely Significant Impacts (LSE) on any Natura sites.
7.3 Compliance with the NMP SHEPD has considered all the relevant policies within the NMP when developing the replacement cable between Yell and Unst. The need to replace the cable is of over-riding public concern as without the new cable there is high potential that the existing cable may fail resulting in loss of power supply to the island of Unst and the consequences this would have on the local communities on the island and further afield. However, the design of the replacement cable routes has been carried out in a manner of sustainable development and co-existence with other users of the sea as far as practically possible. The nearest NCMPA to the Project area is the Fetlar to Haroldswick NCMPA, located 1.6 km south of the Project area. It protects Given the distance to this NCMPA, the temporary nature of the proposed works (approximately 30 days per cable) and the small discrete area of seabed impacted (0.28 km2 for both routes), no impacts on the features of the NCMPA are expected and no further assessment was undertaken. The distribution submarine electricity cable installation has been designed to be as short as possible (approximately 30 days per cable), thereby limiting the duration of potential impact and disturbance to sensitive species from man-made noise and physical presence as much as possible. The installation activities are
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
currently scheduled to take place from October 2018 to March 2019, which is outwith the breeding seasons of red-throated diver (April to mid-September), and therefore, any impacts on the Bluemull and Colgrave pSPA, which is located in the immediate vicinity of the Yell-Unst proposed cable routes are unlikely. Fisheries policies (specifically policies 1, 2 and 3 in Section 1.4.2) have been taken into account throughout the cable design process. Engagement with fishermen has been extensive with an aim to understand the extent of commercial fishing within the area and the potential impacts of the cable installation on their livelihoods. Fish spawning and nursery grounds in the area have been assessed and the impact of the cable installation activities on fish stocks and sustain healthy fisheries is considered to be low. The duration of the works, and so exclusion from fishing areas, will be very temporary (approximately 30 days per cable) and the works will take place on a linear dimension so the whole cable routes will not be excluded at the same time. Further assessment is provided in the FLMAP which includes measures to manage any potential conflicts with fishermen and methods of informing them (and other users of the sea) of the installation works and progress throughout the installation campaign. In terms of the Submarine Cables policies of the NMP, SHEPD has carried out a series of consultation and public engagement exercises with regulators, stakeholders and the general public; these are presented in the Pre-Application Consultation report. As a result, this report documenting and assessing the potential impacts on sensitive receptors and the FLMAP form part of the Marine Licence application that is required for cable replacement activities as part of Cables policy 1 (Section 1.4.2). The cable has been designed using best industry practice to ensure it achieves high quality and safety standards and ensures the continued safe distribution of electricity to the inhabitants of Yell. Whilst it is not possible to bury the cable across the whole routes due to the rocky nature of the seabed, SHEPD plan to bury the cable where they can in the intertidal areas of sufficient sediment using jetting methods. Use of rock bags in spot locations in the subtidal area will pin the cable to the seabed thereby ensuring it does not move. Not only does this limit the footprint it also ensures that the location of the cable is fully understood and documented accurately on navigational charts. These factors ensure that Cables policy 2 (Section 1.4.2) has been complied with as far as practically possible. At each shore end landfall, the existing land-based network of OHL connects the submarine cable to the SHEPD network. As it is proposed to re-use the existing shore end landfall position on Yell, the existing Aid to Navigation (AtoN) warning beacon location will be retained. Similarly, on Unst there is a suitably positioned AtoN that will be reused. Alternative landfall positions were reviewed but discounted due the rocky coastline, harbour authority area to the North and locations of consented offshore developments. As such, the cable replacement programme has considered the requirements of Cables policy 4.
The above demonstrates SHEPD has complied with all relevant policies within the NMP, as far as practically possible and relevant to cable installation activities. As the policy requirements of the Shetland Islands Marine Spatial Plan, relating to the development of subsea cables reflect those of the NMP, it can be concluded that these have been considered in conjunction with the NMP as part of the Project.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
8 REFERENCES ARGOS (Aviation Research Group Orkney and Shetland). Available at: http://www.crashsiteorkney.com/shetland-projects [Accessed 04/04/2018].http://www.crashsiteorkney.com/ Baird, RN (2003) Shipwrecks of the North of Scotland, Edinburgh: Birlinn. Barne, J.H., Robson, C.F., Kaznowska, S.S., Doody, J.P., Davidson, N.C. and Buck, A.L. (1997). Region 1. Shetland, 207 pages A4 hardback, ISBN ISBN 1 873701 75 6. Coull, K., Johnstone, R. & Rogers, S. (1998). Fisheries Sensitivity Maps in British Waters, Published and distributed by UKOOA Ltd. Available online at https://www.cefas.co.uk/media/52612/sensi_maps.pdf DECC (2016). UK Offshore Energy Strategic Environmental Assessment 3 (OESEA3). Available online at: https://www.gov.uk/government/consultations/uk-offshore-energy-strategic-environmental-assessment-3- oesea3 DEFRA (2012). Marine Strategy Part One: UK Initial Assessment and Good Environmental Status. Available from https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/69632/pb13860-marine- strategy-part1-20121220.pdf [Accessed on 20/03/2018]. DEFRA (2014). Marine Strategy Part Two: UK Marine Monitoring Programmes. Available from https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/341146/msfd-part-2-final.pdf [Accessed 20/03/2018]. DEFRA (2015). Marine Strategy Part Three: UK programme of measures. Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/486623/marine-strategy-part3- programme-of-measures.pdf [Accessed 20/03/2018]. DTI (Department of Trade and Industry) (2001). Report to the Department of Trade and Industry. Strategic Environmental Assessment of the Mature Areas of the Offshore North Sea SEA 2. Consultation Document. Ellis, J.R., Milligan, S., Readdy, L., South, A., Taylor, N. & Brown, M. (2012). Mapping the spawning and nursery grounds of selected fish for spatial planning. Report to the Department of Environment, Food and Rural Affairs from Cefas. Defra Contract No. MB5301, Available online at https://www.cefas.co.uk/publications/techrep/TechRep147.pdf ERM (2018a). Scottish Island Cables, Shore Ends. Environmental Appraisal Report. Yell - Unst 1, Shetland. Final version. April 2018. ERM (2018b). Scottish Island Cables, Shore Ends. Environmental Appraisal Report. Yell - Unst 2, Shetland. Final version. April 2018. ESG (2015). SSE Cable Burial Assessment Surveys. Hydrographic, Geophysical and Intrusive Surveys. Report No. L5248-15. Ewins, P. J. (1985). Colony attendance and censusing of Black Guillemots Cepphus grylle in Shetland. Bird Study, 32(3), 176-185. Ferguson, D.M. (1988) Shipwrecks of Orkney, Shetland and the Pentland Firth, David & Charles, Newton Abbot. Flemming, N.C. (2003). The scope of Strategic Environmental Assessment of Continental Shelf Area SEA 4 in regard to prehistoric archaeological remains. Available at: www.offshore- sea.org.uk/site/scripts/sea_archive.php [Accessed 04/04/2018]. Godfrey, J. D., Stewart, D. C., Middlemas, S. J., & Armstrong, J. D. (2014). Depth use and migratory behaviour of homing Atlantic salmon (Salmo salar) in Scottish coastal waters. ICES Journal of Marine Science, 72(2), 568-575. Hammond, P.S., Lacey, C., Gilles, A., Viquerat, S., Börjesson, P., Herr, H., Macleod, K., Ridoux, V., Santos, M.B., Scheidat, M., Teilmann, J., Vingada, J., and Øien, N. (2017). Estimates of cetacean abundance in European Atlantic waters in summer 2016 from the SCANS-III aerial and shipboard surveys. May 2017.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
Hammond, P.S., Northridge, S.P., Thompson, D., Gordon, J.C.D., Hall, A.J., Sharples, R.J., Grellier, K. and Matthiopoulos, J. (2004). Background Information on Marine Mammals Relevant to Strategic Environmental Assessment 5. April 2005. Hawkins, A. D., & Popper, A. N. (2014). Assessing the impacts of underwater sounds on fishes and other forms of marine life. Acoustic Today, 10(2), 30-41. Heath/Ferguson private wreck database, unpublished. Holland, G. J., Greenstreet, S. P. R., Gibb, I. M., Fraser, H. M. & Robertson, M. R. (2005). Identifying sandeel Ammodytes marinus sediment habitat preferences in the marine environment. Marine Ecology Progress Series, 303: 269–282. Howson, C.M., Steel, L., Carruthers, M. & Gilham, K. (2012) Identification of Priority Marine Features in Scottish Territorial waters. Scottish Natural Heritage Commissioned Report No. 388. JNCC (2012). Species accounts – species list. Available at: http://jncc.defra.gov.uk/page-1419 [Accessed 22/03/2018]. Jones, E.L., McConnel, B.J., Sparling, C., & Matthiopoulos, J. (2015). Produce, publish and maintain seal usage maps with confidence intervals. Sea Mammals Research Unit, University of St Andrews, Report to Scottish Government, no. MR 5.1, St Andrews, 6pp. Kruuk, H., Conroy, J.W.H. and Moorhouse, A. (1987). Seasonal reproduction, mortality and food of otters (Lutra lutra L.) in Shetland. Symp. Zool. Soc. Lond. 58, 263-278. Larn, R. & B. Larn (1998) The Ship Wreck Index of Great Britain & Ireland Vol.4 Scotland. London: Lloyds Register of Shipping. Malcolm, I. A., Godfrey, J., & Youngson, A. F. (2010). Review of migratory routes and behaviour of Atlantic salmon, sea trout and European eel in Scotland’s coastal environment: implications for the development of marine renewables. Scottish Marine and Freshwater Science, 1(14), 1-72. Mazik, K., Strong, J., Little, S., Bhatia, N., Mander, L., Barnard, S. & Elliott, M. (2015). A review of the recovery potential and influencing factors of relevance to the management of habitats and species within Marine Protected Areas around Scotland. Scottish Natural Heritage Commissioned Report No. 771. Available at: http://www.snh.org.uk/pdfs/publications/commissioned_reports/771.pdf [Accessed 05/04/2018]. McLeod, C.R., Yeo, M., Brown, A.E., Burn, A.J., Hopkins, J.J., & Way, S.F. (eds.) (2005). The Habitats Directive: selection of Special Areas of Conservation in the UK. Updated August 2009. Joint Nature Conservation Committee, Peterborough. Available at: www.jncc.gov.uk/SACselection [Accessed 02/04/2018]. MSFD (2015). Supporting the Marine Strategy Framework Directive. MSFD. Available from http://www.msfd.eu/index.html [Accessed 20/03/2018]. NAFC Marine Centre (2015). The Shetland Islands' Marine Spatial Plan. Fourth Edition. Strategic Environmental Assessment. Environmental Report. Available at: http://www.nafc.uhi.ac.uk/research/marine- spatial-planning/shetland-islands-marine-spatial-plan-simsp/ [Accessed 3/04/2018]. Nature in Shetland (1994). Nature in Shetland – Shetland Sea Mammal Group. Whales and Dolphins in Shetland Waters. Available at: http://www.nature-shetland.co.uk/seamammal/cetaceans.htm [Accessed 3/04/2018]. NBN Atlas (2018). National Biodiversity Network. Available at https://records.nbnatlas.org/explore/your-area [Accessed 16/03/2018]. NMPI (2018). The Scottish Government National Marine Plan Interactive available at http://www.gov.scot/Topics/marine/seamanagement/nmpihome [Accessed 02/04/2018]. OSPAR (2008). Case Reports for the OSPAR List of threatened and/or declining species and habitats. OSPAR Commission. Available online at http://qsr2010.ospar.org/media/assessments/p00358_case_reports_species_and_habitats_2008.pdf [Accessed on 26/03/2018].
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
Pollard, E., Robertson, P., Littlewood, M., Geddes, G. (2014). Insights from archaeological analysis and interpretation of marine data sets to inform marine cultural heritage management and planning of wave and tidal energy development for Orkney Waters and the Pentland Firth, NE Scotland. Ocean & Coastal Management 99 (2014) 39-51. Quinn, R. (2006). The role of scour in shipwreck site formation processes and the preservation of wreck- associated scour signatures in the sedimentary record - evidence from seabed and sub-surface data. Journal of Archaeological Science 33, 1419-1432. Reid, J.B, Evans, P.G.H and Northridge, S.P. (2003). Atlas of cetacean distribution in north-west European waters. Joint Nature Conservation Committee. SAT (Shetland Amenity Trust) (2018). An otter survey along four stretches of coastline on Unst, Yell and Mainland, Shetland with regard to SSE cable replacement. 7th February 2018. SCOS (2014). Scientific advice on matters related to the management of seal populations: 2014. Special Committee on Seals. Scottish Government (2011). Habitats Regulations Appraisal of Draft Plan for Offshore Wind Energy in Scottish Territorial Waters: Appropriate Assessment Information Review. Seabird Foraging and Migratory Baseline Review for the Draft OWE Plan HRA. Appendix D. March 2011. Scottish Government (2016). Marine Strategy Framework Directive (MSFD). Available at: http://www.gov.scot/Topics/marine/seamanagement/msfd [Accessed 20/03/2018]. Scottish Government (2017). Haul-out sites. Page updated 9th March 2017. Available at http://www.gov.scot/Topics/marine/marine-environment/species/19887/20814/haulouts [Accessed 02/04/2018]. Seawatch Foundation. Undated. Seawatch Foundation. Shetland Biological Records Centre. Cetaceans of Shetland. Available at: http://seawatchfoundation.org.uk/wp-content/uploads/2012/07/Shetland.pdf. [Accessed 3/04/2018]. SHEPD Section ID151,152, Project Description Yell – Unst North (1), Yell -Unst South (2), undated. SNH & JNCC (2012). Advice to the Scottish Government on the selection of Nature Conservation Marine Protected Areas (MPAs) for the development of the Scottish MPA network. Scottish Natural Heritage Commissioned Report No. 547. SNH & JNCC (2014). Priority Marine Features in Scotland’s seas. Available online at http://www.snh.gov.uk/docs/A1327320.pdf [Accessed on 01/05/2017]. SNH (2009). Bird breeding season dates in Scotland. Available at: https://www.nature.scot/bird-breeding- season-dates-scotland [Accessed 30/03/2018]. SNH (2014). SiteLink - Protected Areas Database. Available at: http://gateway.snh.gov.uk/sitelink/index.jsp [Accessed 15/03/2018]. Stenuit, R. (1974) Early relics of the VOC trade from Shetland. The wreck of the flute Lastdrager lost off Yell, 1653', Int J Naut Archaeol Underwater Exploration, vol. 3, 1974: 213-56. Tyler-Walters, H., James, B., Carruthers, M. (eds.), Wilding, C., Durkin, O., Lacey, C., Philpott, E., Adams, L., Chaniotis, P.D., Wilkes, P.T.V., Seeley, R., Neilly, M., Dargie, J. & Crawford-Avis, O.T. (2016). Descriptions of Scottish Priority Marine Features (PMFs). Scottish Natural Heritage Commissioned Report No. 406 Wessex Archaeology (2014) Protocols for Archaeological Discoveries http://www.wessexarch.co.uk/protocols- archaeological-discoveries-pad. Salisbury: Wessex Archaeology Whittaker, I.G. (1998) Off Scotland: a comprehensive record of maritime and aviation losses in Scottish waters. Edinburgh: C-Anne Publishing
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001
Wolf, J., Yates, N., Brereton, A., Buckland, H., De Dominicis, M., Gallego, A. and O'Hara Murray, R. (2015). The Scottish Shelf Model. Part 1: Shelf-Wide Domain. Scottish Marine and Freshwater Science Volume 7 No. 3.
Yell - Unst Marine Licence Application – Environmental Supporting Information Assignment Number: A100487-S01 Document Number: A-100487-S01-REPT-001