Arklow Bank Wind Park
Marine Site Investigations
Natura Impact Statement Comprising a Stage One screening appraisal for appropriate assessment, and a Stage Two appraisal for appropriate assessment
Arklow Bank Wind Park (ABWP) ABWP Marine Site Investigations
Natura Impact Statement
Final F01 11 March 2020
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Approval for issue
James McCrory 11.03.2020 CEcol CEnv MCIEEM CBiol MRSB
Prepared by: Prepared for:
RPS Ireland Ltd (NI) Sure Partners Limited
James McCrory Eimear Lenehan Senior Associate Lead Consent Manager
Elmwood House, 74 Boucher Road Red Oak South, South County Business Park Belfast, Co. Antrim BT12 6RZ Leopardstown, Dublin 18, D18 W688
T +44 28 9066 7914 T +44 28 9033 9119 E [email protected] E [email protected]
Copyright
© Copyright RPS Ireland Limited. All rights reserved. The report has been prepared for the exclusive use of our client and unless otherwise agreed in writing by RPS Ireland Limited no other party may use, make use of or rely on the contents of this report. The report has been compiled using the resources agreed with the client and in accordance with the scope of work agreed with the client. No liability is accepted by RPS Ireland Limited for any use of this report, other than the purpose for which it was prepared. RPS Group Limited accepts no responsibility for any documents or information supplied to RPS Ireland Limited by others and no legal liability arising from the use by others of opinions or data contained in this report. It is expressly stated that no independent verification of any documents or information supplied by others has been made. RPS Ireland Limited has used reasonable skill, care and diligence in compiling this report and no warranty is provided as to the report’s accuracy. No part of this report may be copied or reproduced, by any means, without the written permission of RPS Ireland Limited.
MHC-22113574-1
TABLE OF CONTENTS
1 Introduction ...... 1 1.1 Appropriate Assessment ...... 2 1.1.1 The Habitats Directive ...... 2 1.1.2 Irish Legislation ...... 2 1.1.3 The Appropriate Assessment Process ...... 3 1.2 Objective of the Document ...... 3 1.3 Document Structure ...... 5 1.3.1 Methodology and Guidance ...... 5 1.3.2 Proposed Development ...... 5 1.3.3 Stage One Screening Appraisal ...... 5 1.3.4 Stage Two Appraisal for Appropriate Assessment ...... 5 1.4 Directly connected with or necessary to the management of the site ...... 5 2 Methodology ...... 6 2.1.1 Published guidance on Appropriate Assessment ...... 6 2.1.2 Likely Significant Effect ...... 7 2.1.3 Mitigation Measures ...... 7 2.1.4 Consideration of Ex-situ Effects ...... 8 2.1.5 Conservation Objectives ...... 8 2.1.6 In-combination Effects ...... 9 3 The Proposed Development ...... 10 3.1 Location of the Project ...... 10 3.1.1 Site Location ...... 10 3.1.2 Foreshore Application Area...... 10 3.2 Marine Surveys Proposed ...... 11 3.3 Description of the Proposed Survey Works ...... 14 3.3.1 Survey Schedule ...... 14 3.3.2 Survey Vessels ...... 15 3.3.3 Geotechnical Survey ...... 19 3.3.4 Wind Resource Survey (Floating LiDAR) ...... 23 3.3.5 Sediment dynamics measurement ...... 23 4 Stage One Screening Appraisal for Appropriate Assessment ...... 25 4.1 European sites...... 25 4.2 Ascertaining Whether Impact Pathways Exist ...... 33 4.3 Possible Effects ...... 33 4.3.1 Habitat Loss ...... 33 4.3.2 Water Quality ...... 37 4.3.3 Underwater Disturbance ...... 42 4.3.4 Aerial Disturbance ...... 55 4.4 In-Combination Effects ...... 59 4.4.1 Arklow Bank Wind Park...... 61 4.4.2 Arklow WwTP ...... 62 4.4.3 Energia Wind Farm ...... 63 4.4.4 Codling Bank Wind Park ...... 64 4.4.5 Kilmichael Point ...... 64 4.5 Conclusion of the Screening Appraisal ...... 65 5 Stage Two Appraisal for Appropriate Assessment ...... 71 5.1 Underwater Disturbance ...... 71 5.2 Water Quality ...... 71 5.3 Mitigation Measures ...... 72 6 Conclusion of the Habitats Directive Appraisals ...... 77 Appendix 1: Foreshore Licence Map ...... 79 Appendix 2: Conservation Objectives ...... 81 Appendix 3: Physical Processes Baseline Report ...... 118
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LIST OF FIGURES
Figure 1.1 Step-wise procedure of Article 6 of the Habitats Directive (from EC, 2019) ...... 4 Figure 3.1: Location of the Proposed Development ...... 11 Figure 3.2: Plan of Arklow Harbour area for site investigation survey ...... 12 Figure 3.3: MV Geoquip Saentis; an example of a DP2 geotechnical drillship ...... 17 Figure 3.4: Fugro nearshore jack-up barge with jack-up deployed drilling assembly ...... 18 Figure 3.5: Alphamarines AMS Retriever ...... 19 Figure 3.6: Fugro Seacalf block-push seabed CPT system ...... 21 Figure 3.7: Jack-up barge deployed CPT system ...... 21 Figure 3.8: Example of a crane deployed vibrocore system ...... 22 Figure 3.9: Van Veen Sampler ...... 22 Figure 3.10: Example of a benthic flume ...... 24 Figure 4.1: SACs and SPAs within 50km of the proposed development (and SACs designated for marine mammals within 100km) ...... 26 Figure 4.2: AIS data (Ref: DTTS 2019, ICG AIS Data, July-Dec 2018) ...... 44 Figure 4.3: AIS data surrounding Arklow Bank for a five month period in 2018 ...... 45 Figure 4.4: Other Projects in the wider area...... 60
LIST OF TABLES
Table 3.1: Coordinates of the Proposed Development ...... 12 Table 3.2: Approximate Duration of Works ...... 14 Table 3.3: Proposed Coordinates of Floating LiDAR ...... 23 Table 4.1: SACs within the zone of influence of the proposed development ...... 27 Table 4.2: SPAs within the zone of influence of the proposed development ...... 31 Table 4.3: Injury criteria proposed by Southall et al. (2007), for individual marine mammals exposed to discrete noise events ...... 43 Table 4.4: Marine mammal Auditory Band Width (from NPWS, 2014) ...... 43 Table 4.5: Details of other projects considered in-combination with the proposed development ...... 61 Table 4.6: Summary of the Habitats Directive Stage One Screening Appraisal ...... 66 Table 5.1: Mitigation Measures applied at a Stage Two appraisal for appropriate assessment ...... 73
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1 INTRODUCTION
With the introduction of the Habitats Directive (Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) came the obligation to establish the Natura 2000 network of Sites of Community Interest (SCIs), comprising a network of areas of highest biodiversity importance for rare and threatened habitats and species across the European Union (EU).
In Ireland, the Natura 2000 network of sites comprises Special Areas of Conservation (SACs, including candidate SACs) designated under legislation transposing the obligations under Directive 92/43/EEC, and Special Protection Areas (SPAs, including proposed SPAs) classified under the Birds Directive (Directive 2009/147/EC on the conservation of wild birds) and designated under Irish legislation.
SACs are designated for the conservation of Annex I habitats (including priority types which are in danger of disappearance) and Annex II species (other than birds). SPAs are designated for the conservation of Annex I birds and other regularly occurring migratory birds and their habitats. The annexed habitats and species for which each site is designated correspond to the qualifying interests of the sites; from these the conservation objectives of the site are derived.
SACs and SPAs make up the pan-European network of Natura 2000 sites. In Ireland they are referred to as European sites.
This report has been prepared by RPS on behalf of Sure Partners Limited (“SPL”). The purpose of the report is to document a Habitats Directive stage one screening appraisal and stage two appraisal for appropriate assessment that RPS has conducted on behalf of SPL in relation to marine site investigations comprising geotechnical and wind resource surveys (”the proposed development”). The objective of these site investigations is to build upon information gathered in previous surveys by:
• Confirming the geological model of the site;
• Updating the geological desk study; and
• Providing a detailed ground model of the site.
SPL is seeking a foreshore licence to carry out site investigation and assessment works at the site of their consented offshore windfarm development (“Arklow Bank Wind Park” or “ABWP”) located in the Irish Sea approximately 12km off the Wicklow coast. This work will allow finalisation of the construction design by confirming the conditions predicted in previous surveys so as to allow detailed engagement with the supply chain and enable participation in a Renewable Electricity Support Scheme (“RESS”) auction in line with the timelines laid out in the Government’s Climate Action Plan.
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1.1 APPROPRIATE ASSESSMENT
1.1.1 The Habitats Directive Article 6(3) of the Habitats Directive requires that–
Any plan or project not directly connected with or necessary to the management of the site but likely to have a significant effect thereon either individually or in combination with other plans or projects, shall be subject to appropriate assessment of its implications for the site in view of the site’s conservation objectives. In the light of the conclusions of the assessment of the implications for the site and subject to the provisions of paragraph 4, the competent national authorities shall agree to the plan or project only after having ascertained that it will not adversely affect the integrity of the site concerned and if appropriate, after having obtained the opinion of the general public.
Thus, Article 6(3) provides a two-stage process:
a) The first stage involves a screening for appropriate assessment; and
b) The second stage arises where, having screened the proposed development, the competent authority determines that an appropriate assessment is required, in which case it must then carry out that appropriate assessment.
1.1.2 Irish Legislation For the purposes of applications for planning permission, Part XAB of the 2000 Act implemented the obligations under Article 6(3) into Irish law. In relation to other consent regimes, the provisions of the European Communities (Birds and Natural Habitats) Regulations 2011, as amended (“the 2011 Regulations”), transpose those obligations.
This report has not been drafted in support of an application for planning permission, and so the provisions of the 2011 Regulations are applicable.
1.1.2.1 Screening Regulation 42 of the 2011 Regulations requires inter alia that screening for appropriate assessment of a project, and which is not directly connected with or necessary to the management of the site as a European Site, shall be carried out by the public authority to assess, in view of best scientific knowledge and in view of the conservation objectives of the site, if that project, individually or in combination with other plans or projects is likely to have a significant effect on the European site.
1.1.2.2 Appropriate Assessment Regulation 42 of the 2011 Regulations requires inter alia that a public authority shall determine that an appropriate assessment of a project is required where the project is not directly connected with or necessary to the management of the site as a European Site and if it cannot be excluded, on the basis
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of objective scientific information following screening that the project, individually or in combination with other plans or projects, will have a significant effect on a European site.
1.1.3 The Appropriate Assessment Process According to European Commission guidance documents ‘Assessment of plans and projects significantly affecting Natura 2000 sites’ (EC, 2001) and the ‘Managing Natura 2000 sites: The Provisions of Article 6 of the ‘Habitats’ Directive 92/43/EEC’ (EC, 2019), the obligations arising under Article 6 establish a step-wise procedure as follows, and as illustrated in Figure 1.1.
• The first part of this procedure consists of a pre-assessment stage (‘screening’) to determine whether, firstly, a plan or project is directly connected with or necessary to the management of the site, and secondly, whether it is likely to have a significant effect on the site; it is governed by Article 6(3), first sentence.
• The second part of the procedure, governed by Article 6(3), second sentence, relates to the appropriate assessment and the decision of the competent national authorities.
• A third part of the procedure (governed by Article 6(4)) comes into play if, despite a negative assessment, it is proposed not to reject a plan or project but to give it further consideration. In this case Article 6(4) allows for derogations from Article 6(3) under certain conditions.
The extent to which the sequential steps of Article 6(3) applies to a given plan or project depends on several factors, and in the sequence of steps, each step is influenced by the previous step. The order in which the steps are followed is therefore essential for the correct application of Article 6(3).
Each step determines whether a further step in the process is required. If, for example, the conclusion at the end of a Habitats Directive stage one screening appraisal is that significant effects on European sites can be excluded, there is no requirement to proceed to the next step.
1.2 OBJECTIVE OF THE DOCUMENT The purpose of this Habitats Directive appraisal is to provide an independently produced evaluation and analysis of the possible implications of the proposed marine site investigations (“the proposed development”) on European sites, in view of their conservation objectives.
This exercise has been conducted on behalf of SPL in order to assess the proposed development in light of the requirements of Article 6 of the Habitats Directive..
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Figure 1.1 Step-wise procedure of Article 6 of the Habitats Directive (from EC, 2019)
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1.3 DOCUMENT STRUCTURE
1.3.1 Methodology and Guidance Section 2 of the report sets out the methodology followed and guidance documents used in conducting a stage one screening appraisal of the implications of the proposed development on European sites.
1.3.2 Proposed Development Section 3 of the report describes the proposed development, and is the basis of the subsequent stage one screening and stage two appraisals that follow.
1.3.3 Stage One Screening Appraisal Section 4 of the report contains a preliminary examination and analysis to understand whether or not the proposed works are likely to have a significant effect on any European site. This is the stage one screening appraisal. It has been undertaken in view of best scientific knowledge, in light of the Conservation Objectives of the sites concerned and considers the proposed development individually and in combination with other plans and projects. Measures intended to avoid or reduce the harmful effects of the proposed development on European sites, (i.e. “mitigation measures”) or best practice measures have not been taken into account in the screening stage appraisal.
1.3.4 Stage Two Appraisal for Appropriate Assessment Section 5 of the report contains an examination and analysis of the implications of the proposed development on the Conservation Objectives of those European sites where the possibility of Likely Significant Effects (LSEs) could not be excluded at the screening stage of appraisal. At a stage two appraisal, it is permissible to take into account mitigation measures proposed to avoid adverse effects of the proposed development.
1.4 DIRECTLY CONNECTED WITH OR NECESSARY TO THE MANAGEMENT OF THE SITE The marine site investigations will allow finalisation of the construction design of the offshore wind farm consented under the 2002 ABWP Foreshore Lease (“the Foreshore Lease”) by confirming the conditions predicted in previous surveys .
The proposed development is therefore not directly connected with or necessary to the management of any European Site and is subject to the provisions of the Article 6(3) procedure laid down by the Habitats Directive and its national implementing legislation.
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2 METHODOLOGY
2.1.1 Published guidance on Appropriate Assessment Appropriate Assessment Guidelines for Planning Authorities have been published by the Department of the Environment Heritage and Local Government (DEHLG, 2010a). In addition to the advice available from the Department, the European Commission has published a number of documents which provide a significant body of guidance on the requirements of Appropriate Assessment, most notably including, ‘Assessment of Plans and Projects Significantly Affecting Natura 2000 sites - Methodological Guidance on the Provisions of Article 6(3) and (4) of the Habitats Directive 92/43/EEC’ (EC, 2001), which sets out the principles of how to approach decision making during the process. These principal national and European guidelines have been followed in the preparation of this report. The following list identifies these and other pertinent guidance documents:
• Communication from the Commission on the Precautionary Principle., Office for Official Publications of the European Communities, Luxembourg (EC, 2000);
• Assessment of plans and projects significantly affecting Natura 2000 sites: Methodological guidance on the provisions of Articles 6(3) and (4) of the Habitats Directive 92/43/EEC. Office for Official Publications of the European Communities, Brussels (EC, 2001);
• Guidance document on Article 6(4) of the 'Habitats Directive' 92/43/EEC – Clarification of the concepts of: alternative solutions, imperative reasons of overriding public interest, compensatory measures, overall coherence, opinion of the commission; (EC, 2007);
• Estuaries and Coastal Zones within the Context of the Birds and Habitats Directives - Technical Supporting Document on their Dual Roles as Natura 2000 Sites and as Waterways and Locations for Ports. European Commission (EC, 2009);
• Appropriate Assessment of Plans and Projects in Ireland. Guidance for Planning Authorities. Department of the Environment, Heritage and Local Government, Dublin (DEHLG, 2010a);
• Department of Environment Heritage and Local Government Circular NPW 1/10 and PSSP 2/10 on Appropriate Assessment under Article 6 of the Habitats Directive – Guidance for Planning Authorities (DEHLG, 2010b);
• Guidance document on the implementation of the birds and habitats directive in estuaries and coastal zones with particular attention to port development and dredging. European Commission (EC, 2011a);
• European Commission Staff Working Document ‘Integrating biodiversity and nature protection into port development’ (EC, 2011b);
• Marine Natura Impact Statements in Irish Special Areas of Conservation: A working document, National Parks and Wildlife Service, Dublin (NPWS, 2012);
• Interpretation Manual of European Union Habitats. Version EUR 28. European Commission (EC, 2013);
• Institute of Air Quality Management ‘A guide to the assessment of air quality impacts on designated nature conservation sites (Version 1.0)’ (IAQM, 2019); and
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• European Commission Notice C(2018) 7621 ‘Managing Natura 2000 Sites: the provisions of Article 6 of the 'Habitats' Directive 92/43/EEC’, Office for Official Publications of the European Communities, Luxembourg (EC, 2019).
2.1.2 Likely Significant Effect The Commission’s 2018 Notice (EC, 2019) advises that the appropriate assessment procedure under Article 6(3) is triggered not by the certainty but by the likelihood of significant effects, arising from plans or projects regardless of their location inside or outside a protected site. Such likelihood exists if significant effects on the site cannot be excluded. The significance of effects should be determined in relation to the specific features and environmental conditions of the site concerned by the plan or project, taking particular account of the site’s conservation objectives and ecological characteristics.
The requirement that the effect in question be ‘significant’ exists in order to lay down a de minimis threshold – thus, plans or projects that have no appreciable effect on the site are thereby excluded.
A significant effect is triggered when:
• there is a probability or a risk of a plan or project having a significant effect on a European site;
• the plan is likely to undermine the site’s conservation objectives; and
• a significant effect cannot be excluded on the basis of objective information.
2.1.3 Mitigation Measures In determining whether or not likely significant effects will occur or can be excluded in the stage one appraisal, measures intended to avoid or reduce the harmful effects of the proposed development on European sites, (i.e. “mitigation measures”) or best practice measures have not been taken into account in this screening stage appraisal. This approach is entirely consistent with EU guidance and the case law of the Court of Justice of the European Union:
• EC (2001) states that “project and plan proponents are often encouraged to design mitigation measures into their proposals at the outset. However, it is important to recognise that the screening assessment should be carried out in the absence of any consideration of mitigation measures that form part of a project or plan and are designed to avoid or reduce the impact of a project or plan on a Natura 2000 site”. This direction in the European Commission’s guidance document is unambiguous in that it does not permit the inclusion of mitigation at screening stage.
• In April 2018, the Court of Justice of the European Union issued a ruling in case C-323/17 People Over Wind & Peter Sweetman v Coillte Teoranta (“People Over Wind”) that Article 6(3) of Directive 92/43/EEC must be interpreted as meaning that, in order to determine whether it is necessary to carry out, subsequently, an appropriate assessment of the implications, for a site concerned, of a plan or project, it is not appropriate, at the screening stage, to take account of the measures intended to avoid or reduce the harmful effects of the plan or project on that site.
• The judgment in People Over Wind is further reinforced in EC (2019) which refers to CJEU Case C-323/17.
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2.1.4 Consideration of Ex-situ Effects EC (2019) advises that Member States, both in their legislation and in their practice, allow for the Article 6(3) safeguards to be applied to any development pressures - including those which are external to European sites but which are likely to have significant effects on any of them.
The CJEU developed this point when it issued a ruling in case C-461/17 (“Brian Holohan and Others v An Bord Pleanála”) that determined inter alia that Article 6(3) of Directive 92/43/EEC must be interpreted as meaning that an appropriate assessment must on the one hand, catalogue the entirety of habitat types and species for which a site is protected, and, on the other, identify and examine both the implications of the proposed project for the species present on that site, and for which that site has not been listed, and the implications for habitat types and species to be found outside the boundaries of that site, provided that those implications are liable to affect the conservation objectives of the site.
In that regard, consideration has been given in this Habitats Directive appraisal to implications for habitats and species located outside of the European sites considered in the appraisal with reference to those sites’ Conservation Objectives where effects upon those habitats and/or species are liable to affect the conservation objectives of the sites concerned.
2.1.5 Conservation Objectives The conservation objectives for each European site are to maintain or restore the favourable conservation condition of the Annex I habitat(s) and/or the Annex II species for which the site has been selected.
The favourable conservation status of a habitat is achieved when:
• its natural range, and area it covers within that range, are stable or increasing;
• the specific structure and functions which are necessary for its long-term maintenance exist and are likely to continue to exist for the foreseeable future; and
• the conservation status of its typical species is favourable.
The favourable conservation status (or condition, at a site level) of a species is achieved when:
• population dynamics data on the species concerned indicate that it is maintaining itself on a long-term basis as a viable component of its natural habitats;
• the natural range of the species is neither being reduced nor is likely to be reduced for the foreseeable future; and
• there is, and will probably continue to be, a sufficiently large habitat to maintain its populations on a long-term basis.
2.1.5.1 Site-Specific Conservation Objectives NPWS began preparing detailed Site-Specific Conservation Objectives (SSCOs) for European sites in 2011. Of the European sites in closest proximity to the proposed development which are considered in relative detail in this report, the majority have had SSCOs set.
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The published SSCO documents note that an appropriate assessment based on the most up to date conservation objectives will remain valid even if the targets are subsequently updated, providing they were the most recent objectives available when the assessment was carried out.
The most up-to-date Conservation Objectives for the European sites being considered have been used in this appraisal, and they are set out in full at Appendix 2 to the report. Details in relation to the Qualifying Interests and Special Conservation Interests of these European sites is based on publicly available data sourced from the relevant Statutory Nature Conservation Bodies in Ireland and the UK in February 2020.
2.1.6 In-combination Effects Article 6(3) of the Habitats Directive requires that in-combination effects with other plans or projects are also considered. As set out in the Commission’s 2018 Notice (EC, 2019), significance will vary depending on factors such as magnitude of impact, type, extent, duration, intensity, timing, probability, cumulative effects and the vulnerability of the habitats and species concerned.
In that context, plans or projects which are completed, approved but uncompleted, or proposed have been considered. EC (2019) specifically advises that “as regards other proposed plans or projects, on grounds of legal certainty it would seem appropriate to restrict the in-combination provision to those which have been actually proposed, i.e. for which an application for approval or consent has been introduced”.
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3 THE PROPOSED DEVELOPMENT
This section sets out a description of the proposed marine site investigations in order to establish the characteristics of the proposed development for the purposes of a Habitats Directive appraisal.
3.1 LOCATION OF THE PROJECT
3.1.1 Site Location The ABWP is located approximately 12km off the north Wicklow coast, as shown in Figure 3.1. The total area within which marine site investigations are proposed, and for which an application for a foreshore licence has been submitted, including main windfarm, cable route and Arklow Harbour (Figure 3.2), covers 130.4km2 (13,039.3 ha). The co-ordinates of the application area extents are shown (in WG84 and Degrees, seconds, minutes) in Table 3.1.
The part of the Irish Sea where ABWP is located has a relatively complex morphology consisting of banks, sediment waves and channels. Data gathered as part of the INFOMAR programme in the last number of years offers high-resolution bathymetric data, extending into the nearshore areas. The bathymetry in the application area ranges from 0-52m water depths.
ABWP is situated in an area known as the Irish Platform, which occupies a corridor some 20 to 30 km wide off the east coast of Ireland. The Arklow Bank is approximately 25 km long and oriented roughly north south. On the bank the water depth varies between 2 and 25 meters.
West of the Arklow Bank the water depth varies between 22 to 35 meters being deepest in the southern part. East of the Arklow Bank is the Irish Sea and Saint George’s Channel, where the water depth varies between 60 and 100 meters. The sea floor in the area is dominated by sand and gravel deposited by the abating ice front during the last glaciation (pre 12.000 BP).
The Arklow Bank exists south-east of the inferred limit of the Delgany Moraine, based on known seabed exposures although this does not discount the possibility of an inferred morainic core at Arklow Bank. The surface sediment is mobile, formed due to reworking following relative sea-level rise post 10.000 BP. Areas around the bank are also characterised by mobile sand overlaying glacial clays. To the west of the bank, gravels are exposed on the seafloor.
3.1.2 Foreshore Application Area This Foreshore Licence Application area is designated between the high tide mark and the 12-nautical mile (22.24km) limit. As can be seen from Figure 3.1, the proposed survey site area is wholly within the foreshore area limit. This includes the main windfarm site (ca. 65km2) and export cable routes (ca. 65.4km2). All geotechnical and wind resource surveys will be kept within the confines of the cable route and development area boundary.
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3.2 MARINE SURVEYS PROPOSED SPL intends to carry out geotechnical and wind resource surveys within the proposed development area. The objective of these site investigations is to confirm conditions predicted in previous surveys by:
• Confirming the geological model of the site,
• Updating the geological desk study,
• Providing a detailed ground model of the site.
Figure 3.1: Location of the Proposed Development
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Figure 3.2: Plan of Arklow Harbour area for site investigation survey
Table 3.1: Coordinates of the Proposed Development System: WGS 84/ UTM zone 30N ID Eastings Northings Latitude (N) Longitude (W) 1 302737.61 5867179.84 52o 55' 4.8" 5o 56' 3.0" 2 305186.39 5866690.49 52o 54' 52.2" 5o 53' 51.0" 3 299605.25 5840204.55 52o 40' 28.8" 5o 57' 51.0" 4 297369.25 5840705.56 52o 40' 42.0" 5o 59' 51.0" 5 298685.99 5847199.10 52o 44' 13.6" 5o 58' 55.3" 6 298266.86 5850156.22 52o 45' 48.6" 5o 59' 24.1" 7 298412.61 5855055.06 52o 48' 27.2" 5o 59' 27.2" 8 296731.49 5856065.01 52o 48' 57.5" 6o 0' 59.2" 9 292957.10 5854449.08 52o 48' 0.1" 6o 4' 16.8" 10 290421.91 5853939.51 52o 47' 40.2" 6o 6' 30.8" 11 288509.57 5853900.09 52o 47' 36.2" 6o 8' 12.7" 12 288508.58 5853916.30 52o 47' 36.7" 6o 8' 12.6" 13 288315.48 5853835.25 52o 47' 33.8" 6o 8' 22.9"
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System: WGS 84/ UTM zone 30N ID Eastings Northings Latitude (N) Longitude (W) 14 287985.65 5853963.90 52o 47' 37.5" 6o 8' 40.7" 15 287968.66 5853926.86 52o 47' 36.3" 6o 8' 41.5" 16 288069.42 5853890.02 52o 47' 35.2" 6o 8' 36.1" 17 287971.00 5853762.23 52o 47' 31.0" 6o 8' 41.1" 18 287904.85 5853800.72 52o 47' 32.1" 6o 8' 44.7" 19 287930.34 5853844.00 52o 47' 33.6" 6o 8' 43.4" 20 287914.73 5853853.79 52o 47' 33.9" 6o 8' 44.3" 21 287886.95 5853813.57 52o 47' 32.5" 6o 8' 45.6" 22 287873.46 5853820.06 52o 47' 32.7" 6o 8' 46.4" 23 287905.60 5853870.86 52o 47' 34.4" 6o 8' 44.8" 24 287889.86 5853881.04 52o 47' 34.7" 6o 8' 45.6" 25 287942.04 5853953.21 52o 47' 37.1" 6o 8' 43.0" 26 287959.41 5853952.89 52o 47' 37.1" 6o 8' 42.1" 27 287964.65 5853961.15 52o 47' 37.4" 6o 8' 41.8" 28 287963.70 5853972.74 52o 47' 37.8" 6o 8' 41.9" 29 288009.19 5854038.25 52o 47' 39.9" 6o 8' 39.7" 30 288079.74 5853985.27 52o 47' 38.3" 6o 8' 35.8" 31 288336.12 5853889.23 52o 47' 35.6" 6o 8' 21.9" 32 288424.54 5853930.21 52o 47' 37.0" 6o 8' 17.2" 33 288437.00 5853934.18 52o 47' 37.2" 6o 8' 16.6" 34 288432.00 5853945.38 52o 47' 37.5" 6o 8' 16.9" 35 288419.14 5853939.58 52o 47' 37.4" 6o 8' 17.6" 36 288354.64 5853904.06 52o 47' 36.1" 6o 8' 20.9" 37 288243.79 5853957.84 52o 47' 37.6" 6o 8' 27.0" 38 288172.37 5854028.67 52o 47' 39.8" 6o 8' 30.9" 39 288171.58 5854091.38 52o 47' 41.9" 6o 8' 31.2" 40 288137.83 5854414.68 52o 47' 52.3" 6o 8' 33.7" 41 289026.47 5855700.01 52o 48' 35.1" 6o 7' 49.3" 42 289269.16 5855879.84 52o 48' 41.2" 6o 7' 36.8" 43 289709.91 5856293.15 52o 48' 55.2" 6o 7' 14.3" 44 289802.56 5856655.10 52o 49' 7.0" 6o 7' 10.1" 45 290044.61 5857268.03 52o 49' 27.2" 6o 6' 58.6" 46 290135.59 5857638.73 52o 49' 39.3" 6o 6' 54.6" 47 290537.74 5858272.55 52o 50' 0.3" 6o 6' 34.7" 48 293116.99 5858943.05 52o 50' 25.6" 6o 4' 18.5" 49 298372.15 5860895.22 52o 51' 35.9" 5o 59' 42.4" 50 301773.78 5862426.71 52o 52' 29.9" 5o 56' 44.1"
In total, the proposed work across the site includes:
1. Array Area Preliminary Site Investigation:
a) Boreholes x 25 locations
b) Cone Penetration Testing (CPT)’s x 40 locations
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c) Vibrocores (VC)’s or Grab samples x 30 locations
2. Cable Route Site Investigations:
a) CPTs every 500m along each route [Northern=24, Central=20, Southern=36]
b) VCs or Grab samples every 500m along each route [Northern=23, Central=21, Southern=36]
3. Floating LiDAR Deployment x 2 locations
4. Sediment Dynamic Measurements:
a) Benthic Flume x 9 locations
b) Benthic Lander x 4 locations
5. Arklow Harbour Site Investigation for O&M Base:
a) 6 x boreholes locations
6. Nearshore Landfall Site Investigation:
a) Landfalls: Boreholes x 4 locations at each landfall
b) CPT’s x 8 locations at each landfall
c) Trial Pits on the beach x 5 at each landfall
The foreshore licence area and locations of all marine investigations are illustrated in a Foreshore Licence Map at Appendix 1 to this appraisal.
3.3 DESCRIPTION OF THE PROPOSED SURVEY WORKS This section will describe the proposed survey works for the Arklow Bank Wind Park application area.
3.3.1 Survey Schedule To minimise the risk of survey vessel and equipment mobilisation that must subsequently return to port due to adverse weather conditions, SPL would seek to carry out most of the proposed site investigation works outside winter months within the three years following award of a Foreshore Licence. However, it would be possible to carry out some of the nearshore operations such as the Arklow Harbour site investigation (SI) work outside of this time frame.
Mobilisation location will be dependent on the contractor, who may choose to mobilise from their home port, port of previous job or local port. The local port options for mobilisation will be Dublin port, Wicklow Port or Arklow Harbour depending on vessel size and marine traffic restrictions.
Table 3.2: Approximate Duration of Works Survey Time Conditions Array area SI 2 - 3 months Dependant on weather and ground conditions encountered Cable route SI 1 month Dependant on weather and ground conditions encountered Dependant on weather and ground conditions encountered, Arklow Harbour SI 3 weeks tides, limitations of working in Harbour Dependant on weather andground conditions encountered, Nearshore landfall SI 1 month tides, nearshore limitations. Wind Resource Survey 1 – 2 years Dependant on findings and extent of existing data
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Survey Time Conditions Landfall trial pits 3 days Access and tide dependant
3.3.2 Survey Vessels The variation in water depth and anticipated marine conditions of the survey area will require a range of marine equipment. The exact equipment to be used will be confirmed following a tender process to procure the site investigation contractor.
Due to the varied nature of the survey area, two types of survey vessels will be required for the geotechnical survey works.
• Larger vessel suitable for main offshore windfarm and cable route survey area, likely with dynamic positioning capabilities.
• Smaller jack-up suitable for shallow water depths of the main wind farm site, nearshore site investigation at shallower landfall, and harbour sites.
These vessels will be comparable to those typically used in the industry for carrying out similar technical work and will possess all relevant classification certificates, complying with international and national statutes as appropriate. The appointed contractor will be responsible for all shipboard systems and equipment calibration and re-calibration, including spares. The vessels will conform to the following minimum requirements as appropriate:
• Station-keeping and sea keeping capabilities required by the specified work at the proposed time of year; the appointed contractor may provide supplemental tug assistance if such assistance benefits the operation;
• Endurance (e.g. fuel, water, stores, etc.) to undertake the required survey works;
• Staffing to allow all planned work to be carried out as a continuous operation. i.e. on a 24 or 12 hour per day basis for all offshore and nearshore activities, limitations in Arklow harbour may apply.
• Equipment and spares with necessary tools for all specified works;
• Appropriate accommodation and messing facilities on board;
• Adequate soil laboratory testing facility (Larger vessel)
A non-exhaustive list of examples includes:
• S.I. No. 507/2012 - Merchant Shipping (Collision Regulations) (Ships and Water Craft on the Water) Order 2012.
• Sea Pollution Act 1991 which transposes into Irish statute the requirements of the International Convention for the Prevention of Marine Pollution from Ships (MARPOL 73/78)
• Sea Pollution (Amendment) Act, 1999 - which gives effect to the International Convention on Oil
• Pollution Preparedness, Response and Co-operation, 1990 (OPRC).
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• S.I. No. 372/2012 - Sea Pollution (Prevention of Pollution by Garbage from Ships) Regulations 2012.
• S.I. No. 492/2012 - Sea Pollution (Prevention of Pollution by Sewage from Ships) (Amendment) Regulations 2012
• Sea Pollution (Miscellaneous Provisions) Act 2006 – which gives effect to the International Convention on Ballast Water Management 2004 (amongst others)
3.3.2.1 Offshore Survey Vessel (for deeper water locations) The survey vessel suitable for geotechnical testing in deeper water locations on the main windfarm and cable route site will be a dynamic position (“DP”) vessel.
Dynamic position is a computer-controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters without the use of seabed anchoring. Using Differential GPS (“DGPS”) signals the vessel can transit to, and be positioned over, any point on the seabed and maintain this position for the full duration of drilling. This allows for a seabed equipment footprint of only the drilling seabed frame, estimated at approx. 8m2. If used, DP will have to meet the following requirements:
• The vessel must be fully equipped with a Class II DP system as a minimum
• Two DP certified operators with the necessary experience must be members of the crew
Typical offshore DP vessels used in similar geotechnical works require a minimum draft of 15 – 20m and therefore some areas of the Arklow Bank Wind Park site may not be feasible, requiring jack-ups.
Alternatively, jack-up barges utilise a fixed seabed anchoring system in order to maintain the required position. The vessel consists of a self-elevating work platform and several ‘legs’, typically 4 to 8, that are deployed to the ocean floor mooring the vessel in place. The total seabed footprint of a large sized jack-up barge, including mooring points and seabed frame can be estimated in the region of 15 – 20m2.
In addition to AIS-A and Active Radar Enhancing Systems, the vessel will at a minimum have the following communications equipment:
• Multi-channel VHF and HF radio capable of working at all marine frequencies and with a dual watch facility;
• SATCOM facilities (phone/fax and e-mail);
• Gyrocompass
• 2 independent DGPS systems.
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Figure 3.3: MV Geoquip Saentis; an example of a DP2 geotechnical drillship
3.3.2.2 Jack-up (for shallower water locations) For geotechnical testing in shallower waters at cable landfall locations and Arklow Harbour, jack-up barge will be required. The vessel should have the appropriate draft and manoeuvrability to be able to access the anticipated water depths and space constraints at the Arklow Harbour site. The vessel specifics will be confirmed following a tender process to procure the site investigation contractor.
However, a jack-up barge with a draft of no more than 1.5m with associated safety boat and tug boat for transiting between locations would be typical for these operations. The jack-up barge will at a minimum meet the following requirements:
• Vessel will have at least 4 mooring points;
• Vessel will be provided with a class certificate verifying the provision of adequate safety equipment for the type of vessel and the number of on-board personnel;
• The platform should be certified in compliance with the MODU Code and the BWEA guideline;
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Figure 3.4: Fugro nearshore jack-up barge with jack-up deployed drilling assembly
3.3.2.3 Survey Navigation All navigation equipment and instrumentation will be calibrated and used correctly. Calibration and/or verification shall be repeated in the event of any equipment malfunction, which may nullify earlier calibrations and/or verifications.
Qualified surveyors will be used to operate the navigation and positioning equipment continuously throughout the survey while maintaining a continuous log of all navigation activities throughout the survey.
3.3.2.4 LiDAR Deployment Separate marine craft will be required for the deployment and recovery of the floating LiDAR systems. The vessels will not require DP or jack-up style station keeping technologies and could be adequately kept on station using a manual trusted system in order to transit to and from and maintain station for the duration of works. Vessels must be capable of working on a 12 – 14 hour basis in the conditions to be expected for the time of year in the Irish Sea.
Vessels will be required to have a shallow draft (max. 15m), have suitable crane systems for safe deployment and recovery of the LiDAR systems and have suitable storage space for the safe transit of the devices. Vessels must be suitable coded and entitled to work in the Irish Sea. Two suitable local vessels have been identified as examples:
• Irish Commissioners of Lights – ILV Granuaile
• Alphamarines AMS Retriever
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Figure 3.5: Alphamarines AMS Retriever
3.3.3 Geotechnical Survey The purpose of the geotechnical survey is to confirm the nature and mechanical properties of the sub- surface sediments and/or bedrock formations to a depth below which possible existence of weak formations will not influence the safety or performance of the wind turbine and its support structure.
The proposed geotechnical survey can be divided into the following three separate locations:
• Offshore – the area on and adjacent to Arklow bank, planned for the turbine locations, offshore substation platform locations and inter-turbine and windfarm to shore cable locations;
• Near-shore cable landfall locations;
• Arklow Harbour site investigation.
Each location differs in water depth, exposure and environmental conditions, requiring different marine vessels and equipment. The techniques proposed for this survey include:
• Boreholes (various techniques);
• CPTs (Seabed and deck-push);
• Vibrocore sampling;
• Grab/ gravity sampling;
• Trial pitting.
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3.3.3.1 Location of sampling The exact locations of the geotechnical testing/ sampling locations will be based on a combination of the results of on-going ground-modelling work and the existing survey data from the area. Typically, these locations are selected to confirm the geophysical interpretation and sample each change in geological unit. However, the positioning of locations also needs to take into consideration environmental constraints such as the position of sensitive habitats or archaeological features.
3.3.3.2 Boreholes A borehole is a method of drilling into the seabed to recover samples and enable downhole geotechnical testing to be completed. A drilling head is lowered to the seabed via a drill string and stabilised using a seabed frame. The drill string is then rotated to commence boring. Tools are lowered into the drill string to recover samples or conduct in-situ soil testing. The drilling flush and drill cuttings are largely returned to the vessel and re-used and returned to shore for disposal, however some loss of flush and cutting should be expected.
Boreholes at the landfall will be drilled from a jack up barge using a percussion and a rotary corer. The number of legs used for the operations is dependent on seabed conditions, current strength and wave action. The borehole will be left to collapse naturally following completion of drilling where the cuttings are likely to fall back down the hole.
3.3.3.3 Cone Penetration Testing (CPT) The Cone Penetration Test (CPT) provides information on soil type and stratification as well as on undrained shear strength in clays, and relative density and angles of shearing resistance in sand. Up to 40 seabed CPT’s are scheduled at the array site and an additional seabed CPT is required every 500m along the proposed cable route. Eight jack-up deployed CPT’s are required at the nearshore landfall survey sites.
The CPT is a rod-shaped tool whose end has the shape of a cone with a known apex angle (e.g. 60 degrees). As it is pushed at a constant speed into the soil, the resistance to penetration is measured, thereby providing an indication of soil strength (See Figure 3.6). A sleeve behind the cone allows the independent determination of the frictional resistance. Most cones are also able to measure pore water pressure. The resulting combination of these three parameters provides a signature for the soil, allowing the type of material to be identified as well as providing direct strength parameters for engineering design.
For nearshore and shallow water operations a jack-up deployed CPT system will be required. There are a number of different systems commonly used on nearshore operations, most commonly an existing CPT unit similar to those seen on land will be mobilised on the working platform of the jack-up. The test is carried out down a larger casing through the moonpool (Figure 3.7). The equipment used to carry out the testing will often be anchored to the deck at a number of points allowing for greater pushing capacities. The test can be carried out from surface or at depth, carrying out testing down the existing drill string.
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No sampling is carried out during CPT testing and the resulting hole in the seabed from the rod penetration will fall in on itself almost instantly upon retrieval of the cone and rods. The exact equipment to be used will be confirmed following a tender process to procure the site investigation contractor.
Figure 3.6: Fugro Seacalf block-push Figure 3.7: Jack-up barge deployed CPT seabed CPT system system
3.3.3.4 Vibrocore/ Gravity Sampling Either vibrocores or grab sampling will be conducted, both are not required. 30 vibrocores are scheduled at the main array site and an additional vibrocore is required every 500m along the proposed cable route.
The rig will be fitted with a PVC liner, core catcher and cutting shoe. The vibrocorer such as the one shown in Figure 3.8, is lowered onto the seabed, position and depth are noted, after which the vibrocoring process is started. Upon refusal or at target depth, the stop condition is recorded and the vibrocorer is recovered on deck where the recovery rate is measured. If required, a core catcher can be used to prevent the sample dropping out of the PVC liner.
Cores will be examined offshore, testing will be carried out in the offshore laboratory while other samples will be adequately sealed for onshore testing. Recovered disturbed material and soil found in the vibrocoring shoe will be stored in a bag. The maximum expected depth of a core sample is 6-8m. The nominal diameter is typically 50-150mm.
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Figure 3.8: Example of a crane deployed vibrocore system
3.3.3.5 Grab sampling As mentioned above, either vibrocores or grab sampling will be conducted, both are not required. 30 grab sampling locations are scheduled for the main array survey area and an additional grab sample is required every 500m along the proposed cable route.
Grab sampling will be carried out by lowering a lightweight sampling device from the vessel, either by crane or handheld device depending on requirements. The exact equipment to be used confirmed by the contractor at the tendering stage, however a Van Veen (Figure 3.9), box corer or similar device would most commonly be used. Upon returning grab samples to the deck, material will be logged and then stored in a sealed bag.
Figure 3.9: Van Veen Sampler
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3.3.3.6 Trial Pits A number of trial pits will be carried out at each of the proposed landfall sites. This will be dependent on the ground conditions present, site access and tides. Digging of trial pits will involve the excavation of material at the landfall area of the proposed cable route. The target trial pit depth would be 4m deep and would result in approximately 30m3 of excavated material.
3.3.4 Wind Resource Survey (Floating LiDAR) A survey is required to evaluate the wind conditions across the survey site. As part of the wind resource survey, 2 no. floating LiDAR locations are proposed for the main array survey area. Table 3.3 outlines proposed coordinates. The proposed coordinates are subject to a statutory sanction from CIL and therefore may change. The exact location and installation of the equipment will be dependent on a review of the existing data and the contractor’s equipment specification. An installation vessel will be required for the deployment and recovery of this equipment, the details of which will become available on award of the tender contract.
Table 3.3: Proposed Coordinates of Floating LiDAR Location Easting Northing Latitude Longitude FLS1 – South 297978 5840866 52.680 -5.989 FLS2 – North 303190 5863530 52.885 -5.925
The LiDAR will be mounted on a buoy and will be moored using 150m long mooring chain and a 3 tonne concrete anchor. The buoy will be moored to the seabed for a duration of 12 to 36 months and will be powered by solar panels and micro wind turbine generators. The buoy will be yellow in colour and will be clearly marked with navigation lights to satisfy all CIL requirements.
3.3.5 Sediment dynamics measurement As part of the detailed design of the windfarm, sediment dynamics measurements need to be carried out across the Arklow Bank Wind Park and surrounding area, including the export cable route(s) and up to the adjacent coastline to confirm conditions predicted in previous surveys. The method to obtain the additional information is discussed in the following section.
3.3.5.1 Benthic Flumes and Landers Benthic flumes and benthic landers are marine instruments which collect measurements on sediment transport processes and parameters directly in the sea.
Benthic flumes directly collect information on entrainment-deposition parameters and the sediment transport rate coefficients which can be fed into the sediment transport model to improve the parameterisation of these variables within the model. The advantage of this lies in having a model which contains values for these parameters which are specific to Arklow Bank and which is, therefore, inherently more accurate in its predictions of sediment transport.
Benthic landers are intermediate scale seabed frames equipped with sensors such as ADCP’s, single point current meters, turbidity sensors and marine altimeters to measure seabed sediment transport.
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They provide an open area beneath an upper frame in which sensors are suspended and provide improved measures specifically of very nearbed hydrodynamic and sedimentary processes. In addition, landers are more heavily ballasted and so highly stable when deployed. Observational evidence from lander deployment(s) would form a key, additional element in developing the conceptual site model, and a numerical predictive capacity for future morphological change, within the study.
Figure 3.10: Example of a benthic flume
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4 STAGE ONE SCREENING APPRAISAL FOR APPROPRIATE ASSESSMENT
4.1 EUROPEAN SITES A screening exercise must be undertaken by the competent authority to determine whether, firstly, the proposed development is directly connected with or necessary to the management of the site, and secondly, whether it is likely to have a significant effect on the site.
In addition, the provisions of national legislation make clear that screening for appropriate assessment shall be carried out to assess, in view of best scientific knowledge, if that proposed development, individually or in combination with another plan or project is likely to have a significant effect on the European site.
Given the location of the site of the proposed development, within the marine environment, and the wide range of European sites that are hydrologically connected to the ABWP site by open water across the Irish Sea, a distance of 50km radius has been selected to ensure that features of European sites that can potentially be affected at great distances are not automatically excluded by selecting a narrower range of sites to scope (illustrated on Figure 4.1). Additionally, European sites which lie within 100km and are designated on account of the supported populations of grey seal, harbour porpoise or bottlenose dolphin have also been included for consideration. In total, 40 European sites were considered within this appraisal.
Having firstly determined that the project is not directly connected with or necessary to the management of any European sites (refer Section 1.4 above), the identified European sites will be screened against the activities comprising the proposed development in order to appraise whether or not it is likely to have a significant effect on any of those European sites.
Details in relation to the Qualifying Interests and Special Conservation Interests of these European sites are provided in Table 4.1 in the case of SACs and Table 4.2 in the case of SPAs. The information contained in these tables is based on publicly available data on these European Sites, which along with the most up-to-date Conservation Objectives for the European sites under consideration (listed at Appendix 2), have been sourced from the relevant Statutory Nature Conservation Bodies in Ireland and the UK in February 2020.
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Figure 4.1: SACs and SPAs within 50km of the proposed development (and SACs designated for marine mammals within 100km)
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Table 4 . 1 : SACs within the zone of influence of the proposed development
Site Code Site Na m e Q ualifying Feature(s) Feature Type Distance and direction of site from proposed development
UK SACs UK0030397 W est W ales Marine / Harbour porpoise Phocoena phocoena [1351] Marine 50 km E Gorllewin Cymru Forol SAC UK0030398 North Anglesey Marine / Harbour porpoise Phocoena phocoena [1351] Marine 63 km NE Gogledd Môn Forol SAC UK0012712 Cardigan Bay/ Bae Bottlenose dolphin Tursiops truncatus [1349] Marine 83 km E C eredigion SA C UK0013116 Pembrokeshire Marine/ Sir Estuaries [1130] Marine 87 km SE Benfro Forol SA C Large shallow inlets and bays [1160] Marine R eefs [1170] Marine Grey seal Halichoerus grypus [1364] Marine Shore dock Rumex rupestris [1441] C oastal IRISH SACs IE000729 Buckroney- Brittas Dunes and Annual vegetation of drift lines [1210] C oastal 190 m W Fen SAC Perennial vegetation of stony banks [1220] C oastal Mediterranean salt meadows (Juncetalia maritimi) [1410] C oastal Embryonic shifting dunes [2110] Shifting dunes along the shoreline with Ammophila arenaria C oastal (white dunes) [2120]
Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] C oastal Atlantic decalcified fixed dunes (Calluno- Ulicetea) [2150] C oastal Dunes with Salix repens ssp. argentea (Salicion arenariae) [2170] C oastal Humid dune slacks [2190] C oastal Alkaline fens [7230] C oastal Terrestrial IE002274 Wicklow Reef SAC Reefs [1170] Marine 4.5 km N
IE001766 Magherabeg Dunes SAC Annual vegetation of drift lines [1210] C oastal 5.8 km W Embryonic shifting dunes [2110] C oastal Shifting dunes along the shoreline with Ammophila arenaria (white dunes) C oastal [2120] C oastal Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] C oastal Atlantic decalcified fixed dunes (Calluno- Ulicetea) [2150] Terrestrial Petrifying springs with tufa formation (Cratoneurion) [7220] IE001742 Kilpatrick San dhills SA C Annual vegetation of drift lines [1210] C oastal 6.2 km W
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Site Code Site Na m e Q ualifying Feature(s) Feature Type Distance and direction of site from proposed development
Embryonic shifting dunes [2110] Coastal Shifting dunes along the shoreline with Ammophila arenaria (white dunes) C oastal [2120] C oastal Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] C oastal Atlantic decalcified fixed dunes (Calluno- Ulicetea) [2150 IE002249 The Murrough Wetlands SAC Annual vegetation of drift lines [1210] C oastal 10.1 km NW Perennial vegetation of stony banks [1220] C oastal Atlantic salt meadows (Glauco- Puccinellietalia maritimae) [1330] C oastal Mediterranean salt meadows (Juncetalia maritimi) [1410] C oastal Calcareous fens with Cladium mariscus and species of the Caricion Terrestrial davallianae [7210] Alkaline fens [7230] Terrestrial IE000717 Deputy's Pass Nature Old sessile oak woods with Ilex and Blechnum in the British Isles [91A0] Terrestrial 16.8 km NW R eserve SA C IE000733 Vale of Clara (Rathdrum Old sessile oak woods with Ilex and Blechnum in the British Isles [91A0] Terrestrial 19.4 km NW W ood) SAC IE000700 C ahore Polders and Dunes Annual vegetation of drift lines [1210] C oastal 19.8 km SW SAC Embryonic shifting dunes [2110] C oastal Shifting dunes along the shoreline with Ammophila arenaria (white dunes) C oastal [2120] C oastal Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] C oastal Hu mid dune slacks [2190] IE002953 Blackwater Bank SAC Sandbanks which are slightly covered by sea water all the time [1110] Marine 21.1 km S
IE000781 Slaney River Valley SA C Estuaries [1130] Marine 22.7 km SW M udflats and sandflats not covered by seawater at low tide [1140] Marine Atlantic salt meadows (Glauco- Puccinellietalia maritimae) [1330] C oastal Mediterranean salt meadows (Juncetalia maritimi) [1410] C oastal W ater courses of plain to montane levels with the Ranunculion fluitantis andFreshwater C allitricho- Batrachion vegetation [3260] Old sessile oak woods with Ilex and Blechnum in the British Isles [91A0] Terrestrial Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno- Padion,Terrestrial Alnion incanae, Salicion albae) [91E0] Margaritifera margaritifera (Freshwater Pearl Mussel) [1029] Freshwater Petromyzon marinus (Sea Lamprey) [1095] Marine/Freshwater Lampetra planeri (Brook Lamprey) [1096] Freshwater Lampetra fluviatilis (River Lamprey) [1099] Marine/Freshwater Alosa fallax fallax (Twaite Shad) [1103] Marine/Freshwater
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Site Code Site Na m e Q ualifying Feature(s) Feature Type Distance and direction of site from proposed development
Salmo salar (Salmon) [1106] Marine/Freshwater Lutra lutra (Otter) [1355] Freshwater/Coastal Phoca vitulina (Harbour Seal) [1365] Marine IE002122 Wicklow Mountains SAC Oligotrophic waters containing very few minerals of sandy plains Freshwater 26.5 km NW (Littorelletalia uniflorae) [3110] Natural dystrophic lakes and ponds [3160] Freshwater Northern Atlantic wet heaths with Erica tetralix [4010] Terrestrial European dry heaths [4030] Terrestrial Alpine and Boreal heaths [4060] Terrestrial C alaminarian grasslands of the Violetalia calaminariae [6130] Terrestrial Species- rich Nardus grasslands, on siliceous substrates in mountain areasTerrestrial (and submountain areas, in Continental Europe) [6230] Blanket bogs (* if active bog) [7130] Terrestrial Siliceous scree of the montane to snow levels (Androsacetalia alpinae and Terrestrial Galeopsietalia ladani) [8110] Calcareous rocky slopes with chasmophytic vegetation [8210] Terrestrial Siliceous rocky slopes with chasmophytic vegetation [8220] Terrestrial Old sessile oak woods with Ilex and Blechnum in the British Isles [91A0] Terrestrial Lutra lutra (Otter) [1355] Freshwater IE001741 Kilmuckridge- Tinnaberna Embryonic shifting dunes [2110] C oastal 27.0 km SW San dhills SA C Shifting dunes along the shoreline with Ammophila arenaria (white dunes) C oastal [2120] C oastal Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] IE000716 Carriggower Bog SAC Transition mires and quaking bogs [7140] Terrestrial 27.1 km NW
IE000719 Glen of the Downs SAC Old sessile oak woods with Ilex and Blechnum in the British Isles [91A0] Terrestrial 27.5 km NW
IE000714 Bray Head SAC Vegetated sea cliffs of the Atlantic and Baltic coasts [1230] C oastal 29.9 km N European dry heaths [4030] Terrestrial IE000713 Ballyman Glen SAC Petrifying springs with tufa formation (Cratoneurion) [7220] Terrestrial 35.9 km NW Alkaline fens [7230] Terrestrial IE000725 Knocksink W ood SAC Petrifying springs with tufa formation (Cratoneurion) [7220] Terrestrial 36.2 km NW Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno- Padion,Terrestrial Alnion incanae, Salicion albae) [91E0] IE003000 R ockabill to Dalkey Island Reefs [1170] Marine 38.0 km N SAC Phocoena phocoena (Harbour Porpoise) [1351] Marine IE000708 Screen Hills SAC Oligotrophic waters containing very few minerals of sandy plains 40.6 km SW (Littorelletalia uniflorae) [3110] Freshwater European dry heaths [4030] Terrestrial
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Site Code Site Na m e Q ualifying Feature(s) Feature Type Distance and direction of site from proposed development
IE002161 Long Bank SAC Sandbanks which are slightly covered by sea water all the time [1110] Marine 41.6 km S
IE000710 Raven Point Nature Reserve M udflats and sandflats not covered by seawater at low tide [1140] Marine 43.0 km S SAC Annual vegetation of drift lines [1210] C oastal Atlantic salt meadows (Glauco- Puccinellietalia maritimae) [1330] C oastal Embryonic shifting dunes [2110] C oastal Shifting dunes along the shoreline with Ammophila arenaria (white dunes) C oastal [2120] C oastal Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] C oastal Dunes with Salix repens ssp. argentea (Salicion arenariae) [2170] C oastal Humid dune slacks [2190] IE001209 Glenasmole Valley SAC Semi- natural dry grasslands and scrubland facies on calcareous substrates Terrestrial 45.8 km NW (Festuco- Brometalia) (* important orchid sites) [6210] Molinia meadows on calcareous, peaty or clayey- silt-laden soils (MolinionTerrestrial caeruleae) [6410] Petrifying springs with tufa formation (Cratoneurion) [7220] Terrestrial IE003015 Codling Fault Zone SAC Submarine structures made by leaking gases [1180] Marine 45.8 km N
IE000210 South Dublin Bay SA C M udflats and sandflats not covered by seawater at low tide [1140] Marine 46.0 km N (also Sandymount Annual vegetation of drift lines [1210] C oastal Strand/Tolka Estuary Ramsar Salicornia and other annuals colonizing mud and sand [1310] C oastal site) Embryonic shifting dunes [2110] C oastal IE000770 Blackstairs Mountains SAC Northern Atlantic wet heaths with Erica tetralix [4010] Terrestrial 48.7 km SW European dry heaths [4030] Terrestrial IE000204 Lambay Island SAC Reefs [1170] Marine 63.8 km N Vegetated sea cliffs of the Atlantic and Baltic coasts [1230] C oastal Halichoerus grypus (Grey Seal) [1364] Marine Phoca vitulina (Harbour Seal) [1365] Marine IE000707 Saltee Islands SAC M udflats and sandflats not covered by seawater at low tide [1140] Marine 66.0 km S Large shallow inlets and bays [1160] Marine R eefs [1170] Marine Vegetated sea cliffs of the Atlantic and Baltic coasts [1230] C oastal Submerged or partially submerged sea caves [8330] Marine Halichoerus grypus (Grey Seal) [1364] Marine
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Table 4 . 2 : SPAs within the zone of influence of the proposed development
Site Code Site Na m e Q ualifying Feature(s) Distance and direction of site fro m proposeddevelopment
IE004127 Wicklow Head SPA Kittiwake (Rissa tridactyla) [A188] 6.0 km NW
IE004186 The Murrough SPA Red- throated Diver (Gavia stellata) [A001] 1 0.1 km NW Greylag Goose (Anser anser) [A043] Light- bellied Brent Goose (Branta bernicla hrota) [A046] Wigeon (Anas penelope) [A050] Teal (Anas crecca) [A052] Black- headed Gull (Chroicocephalus ridibundus) [A179] H erring Gull (Larus argentatus) [A184] Little Tern (Sterna albifrons) [A195] W etland and W aterbirds [A999] IE004040 Wicklow Mountains SPA M erlin (Falco columbarius) [A098] 27. 2 km NW Peregrine (Falco peregrinus) [A103] IE004143 Cahore Marshes SPA Wigeon (Anas penelope) [A050] 20. 5 km S Golden Plover (Pluvialis apricaria) [A140] Lapwing (Vanellus vanellus) [A142] Greenland White- fronted Goose (Anser albifrons flavirostris) [A395] Wetland and Waterbirds [A999 IE004019 The Raven SPA Red- throated Diver (Gavia stellata) [A001] 35.5 km SW Cormorant (Phalacrocorax carbo) [A017] C om m on Scoter (Melanitta nigra) [A065] Grey Plover (Pluvialis squatarola) [A141] Sanderling (Calidris alba) [A144] Greenland White- fronted Goose (Anser albifrons flavirostris) [A395] W etland and W aterbirds [A999] IE004172 Dalkey Islands SPA Roseate Tern (Sterna dougallii) [A192] 4 1 . 6 km N Common Tern (Sterna hirundo) [A193] Arctic Tern (Sterna paradisaea) [A194] IE004076 W exford Harbour and Slobs SPA Little Grebe (Tachybaptus ruficollis) [A004] 42.9 km SW Great Crested Grebe (Podiceps cristatus) [A005] Cormorant (Phalacrocorax carbo) [A017] Grey Heron (Ardea cinerea) [A028] Bewick's Swan (Cygnus columbianus bewickii) [A037] Whooper Swan (Cygnus cygnus) [A038] Light- bellied Brent Goose (Branta bernicla hrota) [A046] Shelduck (Tadorna tadorna) [A048] Wigeon (Anas penelope) [A050] Teal (Anas crecca) [A052]
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Site Code Site Na m e Q ualifying Feature(s) Distance and direction of site fro m proposeddevelopment
Mallard (Anas platyrhynchos) [A053] Pintail (Anas acuta) [A054] Scaup (Aythya marila) [A062] G oldeneye (Bucephala clangula) [A067] Red- breasted Merganser (Mergus serrator) [A069] Hen Harrier (Circus cyaneus) [A082] C oot (Fulica atra) [A125] Oystercatcher (Haematopus ostralegus) [A130] Golden Plover (Pluvialis apricaria) [A140] Grey Plover (Pluvialis squatarola) [A141] Lapwing (Vanellus vanellus) [A142] Knot (Calidris canutus) [A143] Sanderling (Calidris alba) [A144] Dunlin (Calidris alpina) [A149] Black- tailed Godwit (Limosa limosa) [A156] Bar- tailed Godwit (Limosa lapponica) [A157] Curlew (Numenius arquata) [A160] Redshank (Tringa totanus) [A162] Black- headed Gull (Chroicocephalus ridibundus) [A179] Lesser Black- backed Gull (Larus fuscus) [A183] Little Tern (Sterna albifrons) [A195] Greenland White- fronted Goose (Anser albifrons flavirostris) [A395] W etland and W aterbirds [A999] IE004063 Poulaphouca Reservoir SPA Greylag Goose (Anser anser) [A043] 4 4 . 6 km NW Lesser Black- backed Gull (Larus fuscus) [A183] IE004024 South Dublin Bay and River Tolka Light- bellied Brent Goose (Branta bernicla hrota) [A046] 4 5 . 9 km N Estuary SPA Oystercatcher (Haematopus ostralegus) [A130] Ringed Plover (Charadrius hiaticula) [A137] Grey Plover (Pluvialis squatarola) [A141] Knot (Calidris canutus) [A143] Sanderling (Calidris alba) [A144] Dunlin (Calidris alpina) [A149] Bar- tailed Godwit (Limosa lapponica) [A157] Redshank (Tringa totanus) [A162] Black- headed Gull (Chroicocephalus ridibundus) [A179] Roseate Tern (Sterna dougallii) [A192] Common Tern (Sterna hirundo) [A193] Arctic Tern (Sterna paradisaea) [A194] W etland and Waterbirds [A999]
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4.2 ASCERTAINING WHETHER IMPACT PATHWAYS EXIST The possibility of significant effects is considered using a source-pathway-receptor model. ‘Source’ is defined as the individual elements of the proposed works that have the potential to affect the identified ecological receptors both within the European site and outside of it in accordance with the ‘Holohan’ judgment (refer Section 2.1.4 above). ‘Pathway’ is defined as the means or route by which a source can affect the ecological receptor. ‘Ecological receptor’ is defined as the Special Conservation Interests (for SPAs) or Qualifying Interests (of SACs) for which conservation objectives have been set for the European sites under consideration. Each element can exist independently however an effect is created when there is a linkage between the source, pathway and receptor.
Possible direct and indirect effects arising as a result of activities undertaken as part of the proposed development are discussed under the following themes:
• Direct Effects
o Habitat loss and alteration (“Habitat Loss”) • Indirect Effects
o Water quality and habitat deterioration (“Water Quality”)
o Underwater noise and acoustic disturbance or displacement (“Underwater Disturbance”)
o Aerial noise and visual disturbance or displacement (“Aerial Disturbance”)
4.3 POSSIBLE EFFECTS
4.3.1 Habitat Loss The site of the proposed development is located outside of any European site, and as such no direct habitat loss or alteration from any European site is anticipated as a result of any aspect of the proposed development. However, the site is hydrologically connected to a number of European sites supporting marine selection features and in particular is located within 200m of one European site. Consideration is given in the next section as to whether or not the proposed development could indirectly affect the habitats of those sites.
Of the 28 SAC sites within 50km of the proposed development, not including those which lie at greater distances and are considered on account of the supported marine mammal populations only, ten are designated on account of the supported terrestrial and freshwater features only. These features are tabulated in Table 4.1, for the relevant sites.
Given the nature of the proposed marine site investigations which relate only to works within the marine environment with no potential to impact upon terrestrial habitats, or freshwater habitats lying upstream (along a hydrological gradient) of the proposed works, all potential likely significant water quality and habitat deterioration effects upon terrestrial and freshwater European sites which do not directly interact with the marine environment can be excluded.
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Likely significant effects upon the conservation objectives of the following sites containing Annex I terrestrial and freshwater habitats can be excluded at this stage as no impact pathway exists:
• Deputy’s Pass Nature Reserve SAC
• Vale of Clara (Rathdrum Wood) SAC
• Carriggower Bog SAC
• Wicklow Mountains SAC
• Glen of the Downs SAC
• Ballyman Glen SAC
• Knocksink Wood SAC
• Screen Hills SAC
• Glensamole Valley SAC
• Blackstairs Mountains SAC
Of the 28 SAC sites within 50km of the proposed development, not including those which lie at greater distances and are considered on account of the supported marine mammal populations only, ten are designated on account of their coastal features which occur in the intertidal or supralittoral zones. Perennial vegetation of stony banks is vegetation that is found at or above the mean high water spring tide mark on shingle beaches. Sand dune communities are also found above the high tide line. Saltmarsh communities are flooded periodically by the sea and are restricted to the area between mid- neap tide level and high water spring tide level.
The nearest SAC containing these features to the proposed development is Buckroney-Brittas Dunes and Fen SAC, which is located 190m from a cable route landfall location at its closest point. All other SACs supporting coastal features are located at distances greater than 5km from the site of the proposed development.
4.3.1.1 Buckroney-Brittas Dunes and Fen SAC As outlined in Table 4.1, this SAC is designated for 10 nr Annex 1 habitats:
• Annual vegetation of drift lines [1210]
• Perennial vegetation of stony banks [1220]
• Mediterranean salt meadows (Juncetalia maritimi) [1410]
• Embryonic shifting dunes [2110]
• Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]
• Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130]
• Atlantic decalcified fixed dunes (Calluno-Ulicetea) [2150]
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• Dunes with Salix repens ssp. argentea (Salicion arenariae) [2170]
• Humid dune slacks [2190]
• Alkaline fens [7230]
Within the sediment budget of nearshore coastal cells, sediments (clay, silt, sand and shingle) are entrained by longshore drift within littoral cells until they are accreted upon the intertidal or supralittoral habitats. Different sizes of sediments are moved in different ways and to different extents by longshore drift depending on the wave, wind and tidal conditions at any location.
The substratum on the Arklow Bank ranges from sandy shell and gravel to the west, north and south of the bank to coarse shell and gravel with some rock to the east of the bank. The bank consisted mainly of sand, with areas of mixed sediment (cobbles, shells and pebbles) at the northern end and fine sand at the southern end. Closer to Arklow Port the substratum was muddy sand. The area is subject to very strong currents with evidence of sand transport northwards on the landward side of the bank and southwards on the seaside of the Bank.
Computational modelling was used to aid an understanding of these conditions and sediment transport regimes on and around the Arklow Bank for SPL. This is described in a Physical Processes report at Appendix 3 to this appraisal. Tidal and littoral currents of the Arklow Bank are characterised by a clockwise current around the bank. The western side of the bank is eroded on the ebb tide and accretes on the flood; with the reverse occurring on the eastern side of the bank. The resultant sediment transport pattern follows this cycle - sediment transport goes around the bank clockwise, with the seabed sediments being mobilised in the ebb and flood currents but the net result is that the bank itself is relatively stable. This correlates with previous studies undertaken at Arklow Bank, e.g. Panigrahi et al. (2009).
Conservation objectives set for the Annex 1 coastal habitats (refer to Table A1 of Appendix 2) aim to define the favourable conservation condition of the habitats by setting targets for area; distribution; and structure and function, with this latter group broken down into a number of attributes, including physical structure, vegetation structure and vegetation composition at a particular site.
Completing the vibrocore/grab sampling and CPTs (as illustrated in Appendix 1) as part of marine investigations 190m from this SAC will not offend the conservation targets for area or distribution of its habitats as no habitats will be lost.
The targets for Annex I sand dune and saltmarsh habitats listed under ‘Physical structure: functionality and sediment supply’ are to maintain, or where necessary restore, the natural circulation of sediment and organic matter, without any physical obstructions. Small scale and temporary site investigations are required in the seabed sandbank habitats no closer than 190m from these habitats. Such interventions are temporary and will not result in permanent physical obstructions to the natural circulation of sediment and organic matter.
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The benthic survey will involve the extraction of 0.5m3 of material directly from the seabed using a grab sampler. As Grab sampling by its nature can only be carried out in soft sediments (muds, sands, gravels) once the sampling device is retrieved any disturbance to the sediment will be filled in naturally.
As discussed in Section 3, Borehole locations will involve the penetration of a drill pipe to a scheduled depth, up to 80m below the seafloor. This will cause disturbance to the area of the drill pipe penetration itself and the area directly surrounding this by the mound created by drill risings. An estimated 2m2 area of the seafloor will be affected by the footprint of the mound created by drill cuttings. Immediately following the removal of the cores, the void in the seabed will fill naturally leaving only a minor impression on the seafloor.
Core penetration testing (CPT) does not involve the removal of any material and the hole created by the penetration of the core (approx. 5cm diameter), will infill almost instantly upon extraction of the rods. The CPT unit has a footprint of approx. 8m2 which will sit on the sea floor for the duration of the test, commonly 2-3 hours.
Benthic communities in the footprint of sampling equipment will be impacted through minor disturbance around the drill site and a very small volume of substratum loss, direct displacement or smothering during sampling. Any smothering will be a thin layer due to small volumes of sediment displaced during the sampling. The coarse sands and gravel of the area are highly mobile and have sparse fauna and so will be unaffected by any disturbance. Softer sediments (such as sand and mud) are highly recoverable to disturbance and typical species can quickly recolonise the area. Most fauna in the area is infaunal therefore species will be able to burrow away from areas of disturbance. Epifaunal species recorded from the rocky/mixed substrate area are predominantly silt-and scour-tolerant species and therefore will not be impacted by survey activity. The geotechnical sampling methods proposed are likely to cause a small amount of sediment to become suspended. The resulting sediment suspension will be dispersed and deposited on the sea floor at a location subject to wave action and tidal stream. As a result, the deposition levels of this material will be very insignificant, given the fact the site is extremely exposed and prone to strong sea currents.
As noted in Figure 2-24 of Appendix 3, the average annual net transport (based on spring tide) is 2,500m3/y/m. With 700 tides a year this sediment transport rate results in 3,500m3 travelling south along the bank each spring tide. The small amount of native seabed sediment comprising sands and gravel material released into the water column at each vibrocore/grab sampling or CPT location will constitute a very small fraction of the quantum of native sediment being transported along the Arklow Bank each spring tide. This increased amount of native sands and gravel being released as a result of the proposed development remains well within the range of natural variability and is certainly de minimis (refer to Section 2.1.2 above).
Any localised sediment plumes associated with site investigation activities at the site would have no appreciative effect upon the sediment supply of Buckroney-Brittas Dunes and Fen SAC, nor any coastal
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site located at a distance exceeding 5km, given the circulatory characteristics of the currents and sedimentation around the bank.
The natural circulation of sediment and organic matter, without any physical obstructions, will not be impeded at any coastal SAC. The conservation objectives for ‘Physical structure: functionality and sediment supply’ (in the case of sand dune habitats); ‘Physical structure: sediment supply’ (in the case of saltmarsh habitats); or ‘Ecosystem function: Soil nutrients / peat formation’ (in the case of alkaline fen habitat), will not be offended.
In the absence of any physical changes to the Annex 1 habitats as a result of the temporary marine site investigations, the conservation targets set for the attributes of vegetation structure and vegetation composition as set out in Table A1 of Appendix 2 would not be affected in any way either.
The only element of the marine site investigations that will last longer than a number of weeks is the floating LiDAR devices, and as can be seen from the Foreshore Map at Appendix 1, these devices are to be located in deeper water many kilometres from the coastal habitats of any European site. They will have no effect whatsoever on the conservation objectives set for any site with Annex 1 coastal habitats.
The proposed development does not have potential to give rise to any likely significant effects impeding the natural circulation of sediment and organic matter, without any physical obstructions. As such it is not envisaged that the proposed development will give rise to any changes to the extant sediment transport processes of any European site. On this basis, no likely significant effects associated with habitat loss or alteration are anticipated and such effects can be excluded at the screening stage in the absence of mitigation measures.
4.3.2 Water Quality As outlined above, Annex I coastal habitats within a number of SACs are hydrologically linked to the proposed development. Any engineering activity in the marine environment has potential to give rise to water quality impacts and associated habitat deterioration through the release of pollutants or contaminants, such as concrete and petrochemical fuels.
If pollutants accidentally escaped to surrounding marine waters as a result of the proposed marine site investigations, the water quality of certain Annex 1 habitats of SACs could deteriorate.
The proximity of Buckroney-Brittas Dunes and Fen SAC to the proposed development has already been noted above. Wicklow Reef SAC is located 4.5km from the proposed development.
4.3.2.1 Wicklow Reef SAC A current-swept subtidal reef community complex is recorded throughout this site in depths ranging from 6m on the western margin of the site to up to 40m at its eastern extreme. The shallower and more level areas of the sea bed are composed of cobble and boulder with pockets of gravelly sand and shell.
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An area of sloping bedrock runs in a northwest-southeast direction in the centre of the site, where the sea floor drops sharply to deeper water. NPWS literature reports that currents of up to 6 knots were recorded within this site, with no significant period of slack water.
Conservation targets (as set out at Appendix 2) for area and distribution of reef habitat are met when the permanent area (or distribution as the case may be) is stable or increasing, subject to natural processes. The SAC Conservation objectives supporting document (NPWS, 2013) notes that these targets refers to activities or operations that propose to permanently remove reef habitat, thus reducing the permanent amount of reef habitat (or range over which this habitat occurs as the case may be). Importantly, the targets do not refer to long or short term disturbance of the biology of reef habitats. On this basis, these conservation targets will not be undermined by the proposed development.
On the basis of the evaluation and analysis set out in Section 4.3.1.1 above in relation to Buckroney- Brittas Dunes and Fen SAC, the community structure target to conserve the reef community complex of Wicklow Reef SAC in a natural condition will not be undermined by sediment plumes or changes in the sediment transport regime as a result of the marine site investigations.
4.3.2.2 Potential for Pollution There is however the potential for accidental pollution to undermine the conservation targets for the Annex 1 habitats of Buckroney-Brittas Dunes and Fen SAC or Wicklow Reef SAC if they cause habitat deterioration. It has already been stated that activities will occur within 200m of Buckroney-Brittas Dunes and Fen SAC, and the reef habitat of Wicklow Reef SAC is located 4.5km from the proposed site investigations.
There is a possibility that accidental pollution events could undermine the conservation targets for vegetation structure or vegetation composition of sand dune or saltmarsh habitats, or ecosystem function targets for fen habitat in Buckroney-Brittas Dunes and Fen SAC.
While the Wicklow Reef SAC lies 4.5km the proposed site investigations, when compared with further marine sites within the projects zone of influence, it is considered that given the scale and temporary nature of the proposed activities, there is potential for only a minor pollution or contamination incident in the absence of control measures. Also, as discussed previously and as detailed in Appendix 3, the currents and sedimentation around the Arklow Bank are circulatory. There is no net migration of water northwards.
Notwithstanding these observations, in applying the precautionary principle, there is a possibility that accidental pollution events could undermine the conservation targets to conserve the reef community complex of Wicklow Reef SAC in a natural condition.
The possibility of likely significant water quality effects on Annex 1 habitats of Buckroney-Brittas Dunes and Fen SAC or Wicklow Reef SAC cannot be excluded at the screening stage in the absence of mitigation measures.
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All other SACs are located at least 5km away from the proposed marine site investigations. At such distances, the mixing of any polluting materials that escape is aided by the tidal currents, wind and wave climate which help mixing and dilution throughout the distance that any polluting substance must travel before it reaches the Annex habitats of any other SACs under consideration, such as Magherabeg Dunes ASAC (at a distance of 5.8km from the site investigations) or Kilpatrick Sandhills SAC (at a distance of 6.2km from the site investigations).
It is not considered that the proposed site investigations would give rise to a likely significant effect on any of these sites given the significant distance over which pollutants must migrate in the water column, and capacity of the marine environment to dilute any elevated concentrations of released pollutants over distances exceeding 5km of open marine water. Recall also that these coastal habitat qualifying interests are primarily supported above the high tide line; and in light of the conservation objectives for these SAC selection features, likely significant effects can be excluded at the screening stage. This is the case in the absence of mitigation measures.
On the basis of the above, likely significant effects upon the conservation objectives of the following sites supporting Annex I coastal habitats can be discounted at the screening stage:
• Magherabeg Dunes SAC
• The Murrough Wetlands SAC
• Kilpatrick Sandhills SAC
• Bray Head SAC
• Cahore Polders and Dunes SAC
• Kilmuckridge-Tinnaberna Sandhills SAC
4.3.2.3 Marine Species Of the 34 SAC sites within the zone of influence of the proposed development, including those considered on account of the supported marine mammal populations only which lie at distances up to 100km from the site, eight are designated on account of their mobile marine species features.
The SACs for which mobile features (as listed in Table 4.1), including marine mammals and fish species, may be potentially affected by water quality and habitat deterioration effects resulting from the proposed works, leading to a reduction in their prey. However, SACs containing these features are all located at least 20km away from the proposed development.
Given that any elevated concentrations of suspended sediments or localised polluting events arising at construction/maintenance phase would be subject to extremely high levels of dilution in the water column around the site over time and across the normal tidal cycle as sediments and concentrations of pollutants disperse and dilute to background levels, it is very unlikely that a decrease in prey availability in any SAC at a distance of >20km in the Irish Sea would occur as a result of any temporary construction phase plumes or pollution events to such an extent as to reduce the prey items of these mobile species
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and conflict with the sites conservation targets for disturbance at a community or population level within the respective SACs.
It is noted that marine mammals including harbour seal Phoca vitulina, grey seal Halichoerus grypus, harbour porpoise Phocoena phocoena and bottlenose dolphin Tursiops truncatus, in addition to marine fish species including Atlantic salmon Salmo salar, Twaite shad Alosa fallax, sea lamprey Petromyzon marinus and river lamprey Lampetra fluviatilis are known to range at long distances for the purposes of foraging or migration. As such while potential pollution effects are not envisaged to give rise to a likely effect upon the marine waters of the SACs themselves, individuals of the species of Annex II marine mammals or fish may occasionally be present in close proximity to the site of proposed works.
While these mobile marine species may be periodically present within the foreshore licence application site and thus have potential to be affected by the proposed development, any area of marine habitat to be potentially affected by a pollution event will be (a) outside of the SAC and (b) so infinitesimally small and affected for a short period of time over a tidal cycle that the proposed development does not have any potential to give rise to a likely significant effect upon the prey species of, or the relevant populations of qualifying interests. On this basis the following SACs have been excluded from further assessment, on the basis of the potential water quality and habitat deterioration effects upon the supported marine mammal and fish populations:
• Slaney River Valley SAC
• Rockabill to Dalkey Island SAC
• Lambay Island SAC
• Saltee Islands SAC
• West Wales Marine / Gorllewin Cymru Forol SAC
• North Anglesey Marine / Gogledd Mon Forol SAC
• Cardigan Bay / Bae Ceredigion SAC
• Pembrokeshire Marine / Sir Benfro Forol SAC
Of the 28 SAC sites considered within 50km of the project and excluding those considered in respect of marine mammals only, eight are designated on account of their supported marine Annex I habitats. These features include:
• Estuaries [1130]
• Mudflats and sandflats not covered by seawater at low tide [1140]
• Reefs [1170]
• Sandbanks which are slightly covered by sea water all the time [1110]
• Submarine structures made by leaking gases [1180]
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These features are tabulated in Table 4.1 which lists the features and the sites within which they occur. Apart from Reefs [1170] in Wicklow Reef SAC, all these features occur at least 20km from the site of the proposed development. Wicklow Reef SAC has already been discussed in Section 4.3.2.1.
4.3.2.4 Wetlands of SPA Sites Wetland and Waterbirds [A999] is a feature of five of the SPAs scoped within 50km of the consented development. These SPAs are tabulated in Table 4.2 which lists the sites and the distances from the proposed development at which they occur.
In relation to the conservation objective for wetland habitat, NPWS conservation objective supporting documents for SPAs (as set out in Table A2 of Appendix 2) note that for the wetland to be in favourable condition, the permanent area occupied by the wetland habitat should be stable and not significantly less than the target area cited for each SPA, other than that occurring from natural patterns of variation. The wetland habitats can be categorised into three broad types: subtidal; intertidal and supratidal, and that over time and though natural variation these sub-components of the overall wetland complex may vary due to factors such as changing rates of sedimentation, erosion etc. Many waterbird species will use more than one of the habitat types for different reasons throughout the tidal cycle.
Whilst the maintenance of the ‘quality’ of wetland habitat lies outside the scope of the wetland habitat objective, for the species of Special Conservation Interest the scope of the trend and distribution objective covers the need to maintain, or improve where appropriate, the different properties of the wetland habitats contained within the SPA.
On this basis, wetlands of SPA sites should be considered under the theme of water quality and habitat deterioration effects. As stated within Table 4.2, all SPAs designated for their wetlands are located at least 10km away from the proposed marine site investigations. The closest site is The Murrough SPA, 10.1km to the south.
At such distances, the mixing of any polluting materials that escape is aided by the tidal currents, wind and wave climate which help mixing and dilution throughout the distance that any polluting substance must travel before it reaches the wetland habitats of any SPA under consideration, such as The Murrough SPA. It is not considered that the proposed site investigations would give rise to a likely significant effect on any of these sites given the significant distance over which pollutants must migrate in the water column, and capacity of the marine environment to dilute any elevated concentrations of released pollutants over distances exceeding 10km of open marine water.
In light of the conservation objectives for these SPA selection features, likely significant effects can be excluded at the screening stage. This is the case in the absence of mitigation measures.
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4.3.3 Underwater Disturbance Marine site investigations have the potential to create underwater noise causing disturbance to or displacement of, or injure individuals of marine mammal species. Potential effects could occur from:
• Disturbance from vibration and underwater noise associated with surveys
• Injury due to collision (survey vessels/Sampling equipment)
Twenty-five species of cetacean and two species of pinniped have been recorded in Irish waters, evidenced from sightings or stranding records (Berrow et al., 20181). This high species richness is attributed to the suitability of the physical marine environment (bathymetry, seabed topography, salinity, temperature etc.) and the availability and distribution of prey species in Irish waters. The waters off the west and southwest of Ireland support the greatest diversity and abundance of marine mammals in Irish Waters. Off the east coast of Ireland, in the western Irish Sea, the more commonly recorded cetaceans include harbour porpoise Phocoena phocoena, common dolphin Delphinus delphis, bottlenose dolphin Tursiops truncatus, killer whale Orcinus orca, minke whale Balaenoptera acutorostrata, humpback whale Megaptera novaeangliae, and fin whale Balaenoptera physalus. Both species of pinniped, harbour seal Phoca vitulina and grey seal Halichoerus grypus, are also recorded in the western Irish Sea.
Both cetaceans and pinnipeds have evolved to use sound as an important aid in navigation, communication and hunting (Richardson et al, 1995). It is widely accepted that the main environmental concern relating to marine mammals is the potential effects of anthropogenic underwater noise/sound. Such exposure can induce a range of effects on marine mammals. Effects may produce a temporary reduction in hearing sensitivity (termed Temporary Threshold Shift (TTS) which is reversible. Activities that generate very high sound pressure levels can cause permanent auditory injuries and other types of physical injury and, in some circumstances, lead to the death of the receiver (Richardson et al, 1995; Southall et al, 2007). These impacts are considered to be permanent threshold shift (PTS) and are of particular concern (Southall et al, 2007).
Acoustic instruments and equipment used in targeted marine geophysical/geotechnical investigations have been reported to produce sound at frequencies within the range of marine mammals. In order to evaluate the potential of the proposed survey equipment to cause harm to marine mammals, an assessment has been conducted using the Southall et al, (2007) approach. They separated marine mammals into 5 groups based on their functional hearing, namely low-frequency cetaceans, mid frequency cetaceans, high frequency cetaceans, pinnipeds in water and pinnipeds in air. For each of these groups they proposed noise levels that would result in injury (PTS or TTS of hearing ability) for individuals exposed to single, multiple and non-pulsed sources (Table 4.3).
1 Berrow, S.D., O’Brien, J., Meade, R., Delarue, J., Kowarski, K., Martin, B., Moloney, J., Wall, D., Gillespie, D., Leaper, R., Gordon, J., Lee, A. and Porter, L. (2018). Acoustic Surveys of Cetaceans in the Irish Atlantic Margin in 2015–2016: Occurrence, distribution and abundance. Department of Communications, Climate Action & Environment and the National Parks and Wildlife Service (NPWS), Department of Culture, Heritage and the Gaeltacht, Dublin, Ireland, 348pp. Available at: https://secure.dccae.gov.ie/downloads/SDCU_DOWNLOAD/ObSERVE_Acoustic_Report.pdf ABWP Marine Site Investigations | Natura Impact Statement | 11 March 2020 www.rpsgroup.com 42
Table 4.3: Injury criteria proposed by Southall et al. (2007), for individual marine mammals exposed to discrete noise events Injury Criteria Marine Mammal group TTS PTS Low-Frequency Cetaceans 224dB re: 1µPa (peak) 230dB re: 1µPa (peak) (Baleen whales)
Mid-Frequency Cetaceans 224dB re: 1µPa (peak) 230dB re: 1µPa (peak) (including Bottlenose dolphins)
High Frequency Cetaceans 224dB re: 1µPa (peak) 230dB re: 1µPa (peak) (including harbour porpoise)
Pinnipeds (in water) 212dB re: 1µPa (peak) 218 dB re: 1µPa (peak)
The NPWS (2014) report ‘Guidance to Manage the Risk to Marine Mammals from Man-made Sound Sources in Irish Waters’ addresses several key potential sources of anthropogenic sound that may impact detrimentally upon marine mammals in Irish waters. The following auditory band widths for marine mammals which may be present in the vicinity of the proposed survey area are extracted from the NPWS (2014) guidelines and are shown in Table 4.4.
Table 4.4: Marine mammal Auditory Band Width (from NPWS, 2014) Frequency Species Estimated Auditory Band Width (Hz)
Low-Frequency Cetaceans Baleen whales 7-22,000
Mid-Frequency Cetaceans Most toothed whales and dolphins 150-160,000
High Frequency Cetaceans Certain toothed whales, porpoises 200-180,000
Pinnipeds (in water) Grey Seal, Harbour Seal 75-75,000
On this basis, vessel noise and rotary drilling activities carry an inherent risk of noise induced effects upon some marine mammal species as a result of underwater acoustic energy being released into the marine environment. The purpose of the screening stage appraisal is to determine whether or not the possibility of likely significant effects arising from such noise sources can be excluded.
Underwater noise is not a persistent effect, and once the noise source ceases noise levels drop very quickly to pre-existing levels. The natural underwater soundscape of the marine waters surrounding the site is not silent - biological sounds from fish and marine mammals are mixed with sounds from waves and surface noise; current flow and turbulence; rain and wind/storm noise; and noise from shipping and leisure craft activities.
Figure 4.2 illustrates data from the Irish Coast Guard department of the Department of Transport, Tourism and Sport (DTTS) representing the number of vessels per 250m2 over the 6 month period ABWP Marine Site Investigations | Natura Impact Statement | 11 March 2020 www.rpsgroup.com 43
(July-Dec 2018) near the site. Shipping channels are shown either side of the bank running North/South up the Irish sea with more concentrated marine traffic to the east of the proposed application area.
It can be clearly seen that there is a lot of existing shipping traffic around the Arklow Bank. Figure 4.3 illustrates vessel tracking automatic identification system (AIS) data surrounding the Arklow Bank, colour-coded by vessel type for a period of time in 2018. This data reveals that marine traffic around the Arklow Bank is dominated by recreational and fishing vessels inshore of the bank, and commercial cargo shipping vessels offshore of the bank.
Figure 4.2: AIS data (Ref: DTTS 2019, ICG AIS Data, July-Dec 2018)
The ambient noise levels in coastal waters are subject to huge variation. The following sites are at least in part designated on account of the supported marine mammals and lie at least 20km from the proposed development, as listed at Table 4.1:
• Slaney River Valley SAC;
• Rockabill to Dalkey Island SAC;
• Lambay Island SAC;
• Saltee Islands SAC;
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• West Wales Marine / Gorllewin Cymru Forol SAC;
• North Anglesey Marine / Gogledd Mon Forol SAC;
• Cardigan Bay / Bae Ceredigion SAC; and
• Pembrokeshire Marine / Sir Benfro Forol SAC.
Figure 4.3: AIS data surrounding Arklow Bank for a five month period in 2018
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Slaney River Valley SAC is in part designated for its populations of harbour seal; Rockabill to Dalkey Island SAC is designated for its harbour porpoise community; Lambay Island SAC is designated in part for its supported harbour seal and grey seal populations; Saltee Islands SAC is designated in part on account of its supported grey seal population; West Wales Marine / Gorllewin Cymru Forol SAC is designated on account of the supported harbour porpoise population; North Anglesey Marine / Gogledd Mon Forol SAC is designated on account of the supported populations of harbour porpoise; Cardigan Bay / Bae Ceredigion SAC is designated on account of the supported bottlenose dolphin populations; and Pembrokeshire Marine / Sir Benfro Forol SAC is in part designated on account of the supported population of grey seal.
The distance separating the site of proposed marine investigations and all SACs within 100km designated on account of the supported marine mammal populations, greater than 20km in all cases, requires that in order for the proposed works to give rise to a likely significant effect upon these species within the respective SACs any underwater noise or vibration would have to act in a manner likely to give rise to significant disturbance or displacement of populations of these species over such a distance. The works proposed will not give rise to any measurable increase in underwater noise levels or vibrational disturbance to marine waters within any of these SACs. On this basis, disturbance or displacement of the feature species will not occur within the sites themselves as a result of the proposed development.
As discussed above in respect of water quality and habitat deterioration effects, marine mammals are known to range widely from their core areas for the purposes of foraging or migration. As such while no potential likely significant effects will occur in the marine waters of the SACs or the populations of marine mammals for which they are designated, there is the potential for individuals of the populations of marine mammals to enter the marine area surrounding the proposed development and be subject to elevated levels of underwater noise. This may trigger behavioural changes in individual marine mammals associated with SAC sites.
A review of the conservation objectives set for these sites is required to determine whether or not disturbance to individuals of the qualifying species outside of the SAC has any bearing.
4.3.3.1 West Wales Marine / Gorllewin Cymru Forol SAC Conservation objectives for the harbour porpoise population in this SAC are set out in Table A1 of Appendix 2, and are to avoid deterioration of the habitats of the species or significant disturbance to the species, thus ensuring that the integrity of the site is maintained and the site makes an appropriate contribution to maintaining Favourable Conservation Status (FCS) for the UK harbour porpoise population. To ensure for the species that, subject to natural change, the following attributes are maintained or restored in the long term:
1. The species is a viable component of the site. 2. There is no significant disturbance of the species.
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3. The supporting habitats and processes relevant to harbour porpoises and their prey are maintained
Harbour porpoises are considered to be a ‘viable component’ of the site if they are able to survive and live successfully within it. The West Wales Marine / Gorllewin Cymru Forol site has been selected primarily on the basis of its long-term, preferential use by harbour porpoise in contrast to other areas of the UK portion of the Irish Sea. The implication is that this site provides good foraging habitat and it may also be used for breeding and calving. However, because the number of harbour porpoise using the site naturally varies, there is not an exact number of animals within the site above which the species is viable or below which it will become unviable. For that reason, the intent of this objective is to minimise the risk posed by activities within the site to the species viability. Activities that kill, injure or significantly disturb harbour porpoise have the potential to affect species viability within the site.
Disturbance of harbour porpoise generally, but not exclusively, originates from activities that cause underwater noise. Responses to noise can be physiological and/or behavioural however, disturbance is a behavioural (non-injurious) response to noise and may lead to harbour porpoises being displaced from the area affected. Within sites, the immediate effects of disturbance are in the loss (usually temporary) of habitat available to harbour porpoise. The West Wales Marine / Gorllewin Cymru Forol site has been identified on the basis of having persistent higher densities of harbour porpoises when compared to other areas of the UK’s Irish Sea and Celtic Sea continental shelf, which is linked to the habitats within the site that likely promote good feeding opportunities. Therefore, activities within the site should be managed to ensure access to the site. Any disturbance should not lead to the exclusion of harbour porpoise from a significant portion of it for a significant period of time. This Conservation Objective aims to ensure that the site contributes as best it can to maintaining the Favourable Conservation Status of the wider harbour porpoise population. As such, how any impacts within the site translate into effects on the Management Unit population are of greatest concern.
The construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species within the site, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the harbour porpoise population within West Wales Marine / Gorllewin Cymru Forol SAC can be excluded. That is the case in the absence of mitigation measures.
4.3.3.2 North Anglesey Marine / Gogledd Môn Forol SAC As above, conservation objectives for this Annex II species are set out in Table A1 of Appendix 2, and are to avoid deterioration of the habitats of the species or significant disturbance to the species, thus ensuring that the integrity of the site is maintained and the site makes an appropriate contribution to
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maintaining Favourable Conservation Status (FCS) for the UK harbour porpoise. To ensure for the species that, subject to natural change, the following attributes are maintained or restored in the long term:
1. The species is a viable component of the site. 2. There is no significant disturbance of the species. 3. The supporting habitats and processes relevant to harbour porpoises and their prey are maintained Harbour porpoises are considered to be a ‘viable component’ of the site if they are able to survive and live successfully within it. The North Anglesey Marine / Gogledd Môn Forol SAC site has been selected primarily on the basis of its long-term, preferential use by harbour porpoise in contrast to other areas of the UK portion of the Irish Sea. The implication is that this site provides good foraging habitat and it may also be used for breeding and calving. However, because the number of harbour porpoise using the site naturally varies, there is not an exact number of animals within the site above which the species is viable or below which it will become unviable. For that reason, the intent of this objective is to minimise the risk posed by activities within the site to the species viability. Activities that kill, injure or significantly disturb harbour porpoise have the potential to affect species viability within the site. Activities within the site should be managed to ensure access to the site.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species within the site, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the harbour porpoise population within North Anglesey Marine / Gogledd Môn Forol SAC can be excluded. That is the case in the absence of mitigation measures.
4.3.3.3 Cardigan Bay / Bae Ceredigion SAC For Bottlenose dolphin conservation objectives for Cardigan Bay SAC are set out in Table A1 of Appendix 2, and are stated in respect of population, range, supporting habitats and species and restoration and recovery. The population is maintaining itself on a long-term basis as a viable component of its natural habitat with important elements including:
• population size;
• structure;
• production; and
• condition of the species within the site.
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As part of this objective it should be noted that for bottlenose dolphin, contaminant burdens derived from human activity should be below levels that may cause physiological damage, or immune or reproductive suppression.
The species population within the site should be such that the natural range of the population is not being reduced or likely to be reduced for the foreseeable future.
As part of this objective it should be noted that for bottlenose dolphin
• Their range within the SAC and adjacent inter-connected areas is not constrained or hindered;
• There are appropriate and sufficient food resources within the SAC and beyond; and
• The sites and amount of supporting habitat used by these species are accessible and their extent and quality is stable or increasing.
The presence, abundance, condition and diversity of habitats and species required to support this species is such that the distribution, abundance and populations dynamics of the species within the site and population beyond the site is stable or increasing. Important considerations include;
• Distribution;
• Extent;
• Structure;
• function and quality of habitat; and
• prey availability and quality.
As part of this objective it should be noted that;
• The abundance of prey species subject to existing commercial fisheries needs to be equal to or greater than that required to achieve maximum sustainable yield and secure in the long term.
• The management and control of activities or operations likely to adversely affect the species feature is appropriate for maintaining it in favourable condition and is secure in the long term.
• Contamination of potential prey species should be below concentrations potentially harmful to their physiological health.
• Disturbance by human activity is below levels that suppress reproductive success, physiological health or long-term behaviour
As part of this objective it should be noted that for the bottlenose dolphin populations should be increasing.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical
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investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species within the site, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the Bottlenose dolphin population within Cardigan Bay / Bae Ceredigion SAC can be excluded. That is the case in the absence of mitigation measures.
4.3.3.4 Pembrokeshire Marine / Sir Benfro Forol SAC For grey seal, conservation objectives for Pembrokeshire Marine SAC are set out in Table A1 of Appendix 2, and are stated in respect of population, range, supporting habitats and species.
The population is maintaining itself on a long-term basis as a viable component of its natural habitat with important elements including:
• population size;
• structure;
• production; and
• condition of the species within the site.
As part of this objective it should be noted that for grey seal contaminant burdens derived from human activity are below levels that may cause physiological damage, or immune or reproductive suppression. Populations should not be reduced as a consequence of human activity.
The species population within the site is such that the natural range of the population is not being reduced or likely to be reduced for the foreseeable future. As part of this objective it should be noted that for grey seal:
• Their range within the SAC and adjacent inter-connected areas is not constrained or hindered;
• There are appropriate and sufficient food resources within the SAC and beyond;
• The sites and amount of supporting habitat used by these species are accessible and their extent and quality is stable or increasing.
The presence, abundance, condition and diversity of habitats and species required to support this species is such that the distribution, abundance and populations dynamics of the species within the site and population beyond the site is stable or increasing. Important considerations include:
• Distribution;
• Extent;
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• Structure;
• function and quality of habitat; and
• prey availability and quality.
As part of this objective it should be noted that:
• The abundance of prey species subject to existing commercial fisheries needs to be equal to or greater than that required to achieve maximum sustainable yield and secure in the long term;
• The management and control of activities or operations likely to adversely affect the species feature is appropriate for maintaining it in favourable condition and is secure in the long term;
• Contamination of potential prey species should be below concentrations potentially harmful to their physiological health. Disturbance by human activity is below levels that suppress reproductive success, physiological health or long-term behaviour.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species within the site and adjacent inter-connected areas, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the grey seal population within Pembrokeshire Marine / Sir Benfro Forol SACcan be excluded. That is the case in the absence of mitigation measures.
4.3.3.5 Slaney River Valley SAC Conservation objectives for harbour seal are set out in Table A1 of Appendix 2, and are to maintain the conservation condition of harbour seal in the Slaney River Valley SAC, as defined by 5 no. SSCO attributes and targets:
Access to suitable habitat: Species range within the site should not be restricted by artificial barriers to site use.
Breeding behaviour: Breeding sites should be maintained in a natural condition.
Moulting behaviour: The moult haul-out sites should be maintained in a natural condition.
Resting behaviour: The resting haul-out sites should be maintained in a natural condition.
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Disturbance: Human activities should occur at levels that do not adversely affect the harbour seal populations at the site.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species at the site, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the harbour seal population within Slaney River Valley SAC can be excluded. That is the case in the absence of mitigation measures.
4.3.3.6 Rockabill to Dalkey Island SAC Conservation objectives for harbour porpoise are set out in Table A1 of Appendix 2, and are to maintain the favourable conservation condition of the species in Rockabill to Dalkey Island SAC, as defined by 2 no SSCO attributes and targets:
Access to suitable habitat: Species range within the site should not be restricted by artificial barriers to site use
Disturbance: Human activities should occur at levels that do not adversely affect the harbour porpoise community at the site
The ‘Conservation objectives supporting document – Marine habitats and species’ for Rockabill to Dalkey Island SAC (NPWS, 2013) notes that the targets for the SSCO attribute ‘Access to suitable habitat’ is measured in ‘number of artificial barriers’. The target for ‘Disturbance’ is measured in ‘Level of impact’.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species at the site, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the harbour porpoise population within Rockabill to Dalkey Island SAC can be excluded. That is the case in the absence of mitigation measures.
4.3.3.7 Lambay Island SAC Conservation objectives for harbour seal are set out in Table A1 of Appendix 2, and are to maintain the favourable conservation condition of Harbour seal (or Grey seal as the case may be) population in Lambay Island SAC, as defined by 5 no SSCO attributes and targets:
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Access to suitable habitat: Species range within the site should not be restricted by artificial barriers to site use
Breeding behaviour: The breeding sites should be maintained in a natural condition.
Moulting behaviour: The moult haul-out sites should be maintained in a natural condition
Resting behaviour: The resting haul-out sites should be maintained in a natural condition
Disturbance: Human activities should occur at levels that do not adversely affect the Harbour seal (or Grey seal) population at the site
The targets for the SSCO attribute ‘Access to suitable habitat’ is measured in ‘number of artificial barriers’. The target for ‘Breeding behaviour’ is measured in ‘Breeding sites’. The target for ‘Moulting behaviour’ is measured in ‘Moult haul-out sites’. The target for ‘Resting behaviour’ is measured in ‘Resting haul-out sites’. The target for ‘Disturbance’ is measured in ‘Level of impact’.
Conservation objectives for grey seal are to maintain the favourable conservation condition of Grey seal population in Lambay Island SAC, as defined by 5 no SSCO attributes and targets:
Access to suitable habitat: Species range within the site should not be restricted by artificial barriers to site use.
Breeding behaviour: Breeding sites should be maintained in a natural condition.
Moulting behaviour: The moult haul-out sites should be maintained in a natural condition.
Resting behaviour: The resting haul-out sites should be maintained in a natural condition.
Disturbance: Human activities should occur at levels that do not adversely affect the Grey seal population at the site.
The targets for the SSCO attribute ‘Access to suitable habitat’ is measured in ‘number of artificial barriers’. The target for ‘Breeding behaviour’ is measured in ‘Breeding sites’. The target for ‘Moulting behaviour’ is measured in ‘Moult haul-out sites’. The target for ‘Resting behaviour’ is measured in ‘Resting haul-out sites’. The target for ‘Disturbance’ is measured in ‘Level of impact’.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species at the site, given the distance between the ABWP site and the SAC over
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which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the harbour seal and grey seal populations within Lambay Island SAC can be excluded. That is the case in the absence of mitigation measures.
4.3.3.8 Saltee Islands SAC Conservation objectives for grey seal are set out in Table A1 of Appendix 2, and are to maintain the favourable conservation condition of Grey seal population in Saltee Islands SAC, as defined by 6 no SSCO attributes and targets:
Access to suitable habitat: Species range within the site should not be restricted by artificial barriers to site use.
Breeding behaviour: Breeding sites should be maintained in a natural condition.
Moulting behaviour: The moult haul-out sites should be maintained in a natural condition.
Resting behaviour: The resting haul-out sites should be maintained in a natural condition.
Population composition: The grey seal population occurring within this site should contain adult, juvenile and pup cohorts annually.
Disturbance: Human activities should occur at levels that do not adversely affect the grey seal population.
The targets for the SSCO attribute ‘Access to suitable habitat’ is measured in ‘number of artificial barriers’. The target for ‘Breeding behaviour’ is measured in ‘Breeding sites’. The target for ‘Moulting behaviour’ is measured in ‘Moult haul-out sites’. The target for ‘Resting behaviour’ is measured in ‘Resting haul-out sites’. The target for ‘Disturbance’ is measured in ‘Level of impact’.
As above, the construction activities proposed do not comprise underwater dredging, piling, blasting or high frequency energy release as part of seismic or geophysical survey. The modest geotechnical investigation activities will not generate significant underwater noise levels so as to imperil the individuals of the species at the site, given the distance between the ABWP site and the SAC over which underwater acoustic energy will travel. Noise generated at the site of proposed development will attenuate rapidly to background levels with ambient environmental noise and shipping noise.
Likely significant effects on the grey seal populations within Saltee Islands SAC can be excluded. That is the case in the absence of mitigation measures.
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4.3.3.9 Individuals of populations of Marine Mammals outside of their sites There is no doubt that individuals of the Annex II populations of cetaceans or pinnipeds discussed above in relation to Irish and Welsh SACs forage far and wide in their range and may from time to time journey through the foreshore licence application area. In such cases, individuals of the harbour porpoise or bottlenose dolphin communities or seal populations of the SACs discussed above could suffer physical injury, hearing damage, disturbance or displacement by underwater noise levels generated by the marine site investigations.
In applying the precautionary principle, there is a possibility that individuals of a species could be significantly affected, even if only temporarily, by the proposed site investigations. As such, mitigation measures must be applied to prevent such effects occurring.
4.3.4 Aerial Disturbance The proposed development will potentially give rise to aerial noise and visual triggers of disturbance to seabirds and inshore waterbirds due to construction operatives and plant being present for the site investigations, in addition to vessel movements and general on-deck construction activities. In addition the deployment of the LiDAR devices will require additional vessel movements to the proposed deployment locations. Both noise and visual triggers could result in disturbance to seabirds or waterbirds.
Disturbance is any situation in which human activities cause a bird to behave differently from the behaviour it would be reasonably expected to exhibit without the presence of that activity. In the marine environment, disturbance can manifest in a number of forms of varying severity depending on the nature, duration and intensity of the disturbance source:
• Birds looking up or heads raised, temporarily stopping feeding or loafing
• Birds moving away from the cause of the disturbance by swimming before resuming previous activity
• Birds taking flight and landing somewhere else in the same target area more distant to the disturbance stimulus
• Birds taking flight and leaving the target area completely.
Disturbance events result in a greater reduction in feeding time, and greater energy expenditure. Disturbance results in an energetically expensive response by birds that increases their energy expenditure and can result in decreases in the overall fitness of a population, which in turn can lead to reduced breeding success and increased mortality. Birds that are more tolerant than other individuals and remain in an area affected by disturbance may not forage as efficiently.
If there are additional pressures on the birds (for example cold weather in overwintering populations), then this may impact upon the survival of individual birds or their ability to breed later in the year.
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Table 4.2 contains details of nine SPA sites. The key potential effects upon populations of SPA feature species arising from the marine site investigations is bird disturbance during the investigations.
A number of these sites are entirely comprised areas of terrestrial and freshwater habitats which are separated from the proposals by more than 20km of terrestrial habitat in addition to 5km of marine habitat, namely Wicklow Mountains SPA and Poulaphouca Reservoir SPA. Given this vast spatial separation, it is not considered that the proposals have potential to give rise to a likely significant effect upon these sites through aerial noise or visual disturbance.
Many of the coastal SPAs considered in this assessment include intertidal and shallow wetlands that have significant overwintering populations of waders and waterfowl. These types of birds do not use the marine waters or offshore sandbanks found at the site of proposed development. They may however fly through the area during passage seasons between staging posts and the arctic and subarctic regions of higher latitudes on their annual migration. As the marine site investigations will not introduce permanent structures into the marine environment which sit above the water line and are of sufficient height so as to displace birds from their natural flight lines or to cause a collision risk, it is considered that the proposed development will not give rise to a likely disturbance, displacement or collision risk effect upon feature species associated with these SPAs.
The other SPAs considered in this assessment are also designated for their overwintering waterbird or breeding seabird colonies which do use marine waters, or marine sites designated for the use of their waters by water birds or seabirds for rafting or foraging.
The closest of these SPA sites is Wicklow Head SPA, 6.0km to the north, and designated for Kittiwake. Key prey items of this species include small pelagic shoaling fish and marine invertebrates. Key habitats include fronts, tidal upwellings and eddies, offshore sandbanks and areas over rocky seabed. The maximum foraging range for the species is listed in the BirdLife International Seabird Database (Birdlife International, 2011) as 200km (mean max: 65.81km; mean: 25.45km).
The Murrough SPA is located 10.1km north of the consented development. It is designated for inter alia Red-throated diver, Black-headed gull, Herring gull and Little tern.
South Dublin Bay and River Tolka Estuary, located 45.9km to the north and south is designated for inter alia Black-headed gull.
SPAs designated for their breeding colonies of Roseate tern, Common tern, Arctic tern and Sandwich tern include Dalkey Islands SPA; and South Dublin Bay and River Tolka Estuary SPA.
Wexford Harbour and Slobs SPA is designated in part on account of the supported populations of Great Crested Grebe, Cormorant, Scaup, Black-headed gull and little tern. While the Raven SPA is in part designated on account of the supported populations of red-throated diver, cormorant and common scoter.
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As set out in Table A2 of Appendix 2, overwintering populations of waterbirds in Irish SPAs have conservation targets set for their long term population trend and range, timing or intensity of use of areas of the SPAs by its waterbird populations.
Breeding SPAs additionally have conservation targets set for their breeding population levels, distribution, barriers to connectivity and disturbance at the breeding sites.
The most common seabird species recorded in the wider area surrounding the Arklow Bank are recorded by Jessopp et al. (20182) as including: Red-throated Diver, Fulmar, Manx Shearwater, Gannet, Shag, Little Gull, Common Gull, Kittiwake, Common Tern, Arctic Tern, Guillemot, Razorbill, and Auk species.
A wealth of data (now historic data) exists in association with annual monitoring in the early operational years after Phase 1 of the ABWP was constructed. Annual monitoring surveys for Phase 1 of the ABWP has recorded many SPA feature species in the survey area, including Kittiwake, Razorbill, Guillemots, Red-throated Diver, Storm Petrel, Mediterranean Gull and four species of tern (Sandwich Tern, Roseate Tern, Arctic Tern and Common Tern) among others. Year on year data has revealed that Red-throated Diver, Little Gull, Kittiwake, Guillemot, Razorbill, Manx Shearwater and Common Gull can occur in large numbers.
Individuals of species of Auks (guillemot, razorbill and puffin) could potentially be subject to low levels of disturbance or displacement as a result of vessel activities, at construction phase, if they continue to use marine waters in proximity to the site in significant numbers during the planned activities. Behavioural studies of the three species of Auk that were present within the monitoring area recorded no behavioural responses beyond 100 m from a boat (Heintz, 2006). Furness and Wade (2012) however reported displacement effects within a few hundred metres of vessel disturbance.
Other qualifying species such as terns are less frequently recorded on the sea surface and their predominantly aerial behaviours means that they will be unlikely to be displaced by vessels. Gulls (herring gull and kittiwake), fulmars and to a lesser extent gannets are known to be attracted to vessels in search for food and therefore unlikely to be displaced (Skov and Durink, 2001); (Camphuysen et al., 1995).
While there is potential for individuals of a wide range of species to be disturbed or displaced over the duration of the marine investigations, the works will take place over a relatively short duration, and will be highly localised in nature.
As noted above and illustrated in Figure 4.2, the marine area surrounding the Arklow Bank contains significant levels of boating and shipping activity. The proposed site investigations will not disturb or
2 Jessopp, M., Mackey, M., Luck, C., Critchley, E., Bennison, A, and Rogan, E. (2018) The seasonal distribution and abundance of seabirds in the western Irish Sea. Department of Communications, Climate Action and Environment, and National Parks & Wildlife Service, Department of Culture, Heritage & the Gaeltacht, Ireland. 90pp. Available at: https://secure.dccae.gov.ie/downloads/SDCU_DOWNLOAD/ObSERVE_Seabirds_2016.pdf ABWP Marine Site Investigations | Natura Impact Statement | 11 March 2020 www.rpsgroup.com 57
displace seabirds or inshore waterbirds any more than the existing and ever present recreational boating, fishing and shipping traffic does. The conservation targets in breeding seabird SPAs for population levels, distribution, barriers to connectivity and disturbance at the breeding sites will not be offended by the works.
The physical presence of the survey vessels may result in temporary disturbance to birds present in the vicinity of the survey area. However, it is deemed that the proposed surveys will not impact significantly on populations of bird species, directly or indirectly, due to the nature of the surveys and the very short duration of activities.
Any disturbance effects are considered likely to give rise to inconsequential and temporary displacement of individuals of a species only, below a de minimis threshold, which would not lead to a likely significant effect on the conservation objectives set for the overwintering waterbird species (being long term ‘population trend’ and ‘range, timing and intensity of use of areas’); or breeding seabird species (being ‘population abundance’, ‘productivity rate’, ‘distribution of breeding colonies’, ‘barriers to connectivity’, and ‘disturbance’) (refer to Table A2 of Appendix 2). Likely significant effects on these conservation objectives of the following SPA sites can be excluded at the screening stage in the absence of mitigation measures:
• Wicklow Head SPA
• The Murrough SPA
• Dalkey Islands SPA
• South Dublin Bay and River Tolka Estuary SPA
• Wexford Harbour and Slobs SPA
• The Raven SPA
Only the ‘prey biomass available’ conservation attribute of the Wicklow Head SPA breeding seabird colony could likely be significantly affected due to pollution and water quality deterioration (as discussed in Section 4.3.2.2 above for Wicklow Reef SAC). There is a possibility that accidental pollution events could undermine the conservation target of no significant decline in prey biomass available for the foraging Kittiwake population of Wicklow Head SPA.
The possibility of likely significant water quality effects on the prey biomass available for the Kittiwake colony of Wicklow Head SPA cannot be excluded at the screening stage in the absence of mitigation measures.
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4.4 IN-COMBINATION EFFECTS Article 6(3) of the Habitats Directive requires that in-combination effects with other plans or projects are also considered. As set out in the Commission’s 2018 Notice (EC, 2019), significance will vary depending on factors such as magnitude of impact, type, extent, duration, intensity, timing, probability, cumulative effects and the vulnerability of the habitats and species concerned. The significance of any identified combined effects of the proposed development and other past, present or reasonably foreseeable future plans or projects must be evaluated.
In that context, plans or projects which are completed, approved but uncompleted, or proposed have been considered. EC (2019) specifically advises that “as regards other proposed plans or projects, on grounds of legal certainty it would seem appropriate to restrict the in-combination provision to those which have been actually proposed, i.e. for which an application for approval or consent has been introduced”.
Given the location of the site, which lies approximately 5km off the coast of County Wicklow, in addition to the nature of predicted likely significant effects which relate to the marine environment only, it is considered that there is limited potential for the proposals to act in combination with terrestrial plans or projects in County Wicklow or elsewhere.
Shipping noise is a key characteristic of the ambient underwater noise in the area, and the noise produced by survey vessels described in Section 3.3.2 during the implementation of the works, when considered cumulatively with existing shipping, shall not increase background underwater noise to levels that could disrupt communication due to masking or alter behaviour patterns in combination with the proposed development.
On this basis projects considered were limited to those with potential to have in-combination effects with the proposed development, namely marine developments or activities in the vicinity of the proposed development which were limited to the existing partly constructed and operational ABWP Project. A range of other development projects as listed in Table 4.5 were considered in terms of their potential to give rise to in-combination effects with the Proposed Development. The locations of these projects are shown in Figure 4.4.
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Figure 4.4: Other Projects in the wider area
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Table 4.5: Details of other projects considered in-combination with the proposed development Project Developer Details ABWP (Phase 1) Airtricity and 25.2MW offshore wind farm constructed in 2003/4. This installation GE Energy (Owned has been operational for 16 years. and Operated by GE Energy) ABWP (Phase 2) SPL Project requires an extension of the Foreshore Lease long stop dates before it can be constructed. To be brought forward under Measures to Deliver Targets of Ireland’s 2030 decarbonisation ambition set out in the Government’s 2019 Climate Action Plan. Arklow Waste Water Irish Water Works to construct a new Wastewater Treatment Plant (WwTP), Treatment Plant associated infrastructure including the interceptor sewer network and marine outfalls as well as an upgrade to the existing coastal revetment. Energia Wind Farm Energia Offshore The marine surveys will include: Wind Limited • Bathymetry - seabed levels/water depths Multibeam echo sounder • Seabed type and targets Side Scan Sonar • Seabed geology Sub-Bottom Profiling • Marine archaeology/wrecks/UXO targets, cables and pipelines Magnetometry • Grab / Vibrocore Sampling • Cone Penetration Tests • Boreholes Codling Bank Wind Codling Wind Park • Acoustic monitoring for marine mammals Park Limited • Natural fish surveys • Benthic monitoring • Met Ocean and Coastal processes monitoring Kilmichael Point Hibernian Wind • Geophyscial survey including MBES, Magnetometer, SBP Power (sparker/boomer) and SSS • Geotechnical survey including grab samples, CPTs and Vibrocores • Archaeological surveys • Ecological surveys
4.4.1 Arklow Bank Wind Park
4.4.1.1 Phase 1 The Arklow Bank Wind Park (ABWP) project holds a Foreshore Lease which was signed in 2002. The 99 year Foreshore Lease provides for a wind farm with a minimum total installed capacity of at least 520MW, with consent for 200 turbines with a tower height of up to 100m and a minimum distance between the sea and the blade tips of 20m.
The first phase of the ABWP was constructed by GE Wind Energy in 2003/4 and is owned and operated by GE Energy under a Sublease to the Foreshore Lease. It remains operational, and has been so for at least 16 years. That first phase comprises 7 wind turbines installed on monopile foundations with a combined maximum export capacity of 25.2MW delivered to the onshore electrical grid via cabled connection to the Arklow 110kV Substation. The remainder of ABWP (Phase 2) has yet to be constructed. An extension to the long stop dates in the Foreshore Lease is required before Phase 2 can be constructed.
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In relation to ABWP Phase 1, the potential for disturbance or pollution effects at construction stage have long since passed. As the facility continues to be operated and maintained, service and maintenance vessels will visit the site of Phase 1 from time to time. Any potential for bird strike and collision with the moving turbine blades of ABWP Phase 1 cannot act in combination with any of the identified effects of the proposed development as likely significant effects of disturbance or displacement will not occur as a result of the proposed development alone.
No significant underwater noise producing activities occur as part of ongoing maintenance but as noted above, service and maintenance vessels will visit the site of Phase 1 from time to time, and vessel noise and rotary drilling activities have been identified as resulting in underwater noise that could potentially disturb marine mammals (in Section 4.3.3).
If service or maintenance vessels were visiting the Phase 1 wind farm at the same time as planned site investigations were occurring there is a possibility that individuals of a species of marine mammal could be significantly affected, even if only temporarily, by the proposed site investigations in combination with ABWP Phase 1. Applying the precautionary principle, mitigation measures must be applied to prevent such effects occurring.
4.4.1.2 Phase 2 As noted in Table 4.5, Phase 2 of ABWP requires an extension of the long stop dates in the Foreshore Lease before it can be constructed , and indeed the marine site investigations which are the subject of this appraisal are required to inform the detailed design of Phase 2 of the ABWP by confirming conditions predicted in previous surveys. The proposed marine site investigations will have been completed by the time Phase 2 commences construction. It is intended that Phase 2 will be brought forward under Measures to Deliver Targets of Ireland’s 2030 decarbonisation ambition set out in the Government’s 2019 Climate Action Plan.
Taking into account the time it takes to design an offshore wind project, prepare and submit applications for development consent including any environmental information, for aspects of ABWP not yet consented, and then for determination of those applications and subsequent procurement of goods and services required to construct ABWP Phase 2, it is our firm conclusion that all planned marine site investigations will have long since ended and there will be no enduring likely significant effects on any qualifying interest features of any European site. As such, there is no possibility of likely significant in- combination effects between the proposed development and ABWP Phase 2.
4.4.2 Arklow WwTP A Foreshore licence application was submitted (FS006862) by Irish Water in June 2019 for a proposed Wastewater Treatment Plant Project in Arklow comprising a new Wastewater Treatment Plant, associated infrastructure including sewer network and marine outfalls as well as an upgrade to existing coastal revetment. This project is located within the ABWP foreshore licence application area shown in Figure 4.5 above.
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A screening appraisal for appropriate assessment and a Natura Impact Statement was prepared by the developer. The stage one screening appraisal identified three European sites where likely significant effects could not be excluded:
• Buckroney – Brittas Dunes and Fen SAC (Site Code 000729)
• Kilpatrick Sandhills SAC (Site Code 001742)
• Magharabeg Dunes SAC (Site Code 001766)
A stage two appraisal concluded that to prevent adverse effects on the integrity of Buckroney-Brittas Dunes and Fen SAC in relation to ‘Physical structure: functionality and sediment supply’ of the coastal habitats, mitigation was required in the construction of the long sea outfall element of the project.
The stage two appraisal also concluded that to rule out a risk of injury or a disturbance/behavioural response to protected marine mammals, NPWS (2014) Guidance to Manage the Risk to Marine Mammals from Man-made Sound Sources in Irish Waters was to be applied to construction of the project.
As there are no likely significant effects of the proposed development on conservation targets of ‘Physical structure: functionality and sediment supply’ for coastal habitats in relation to Buckroney- Brittas Dunes and Fen SAC (see Section 4.3.1.1 above), there is no possibility of likely significant in- combination effects between the proposed development and the Arklow WwTP project in that regard.
In circumstances where noise producing activities or survey vessels as a consequence of the proposed development were occurring in close proximity at the same time, potentially significant underwater noise disturbance effects on individuals of species of marine mammals which are qualifying interests of SACs considered in this appraisal could occur outside of the SACs and inside the foreshore licence areas of both ABWP and Arklow WwTP. As such, mitigation measures must be applied to prevent such effects occurring.
4.4.3 Energia Wind Farm A Foreshore licence application was submitted (FS007048) by Energia Offshore Wind Limited in October 2019 for proposed Site Investigations to inform on possible construction of a windfarm off the Wexford coast. This project is located to the south and east of the southern part of the ABWP foreshore licence application area shown in Figure 4.5 above.
No significant effects were identified by the developer on Annex I habitats of SACs or wetland habitats of SPAs in its stage 1 screening and stage 2 appraisal supporting document. Likely significant underwater noise effects could not be excluded at the screening stage for certain Annex II marine mammal and fish species which are qualifying interests of several SACs (twaite shad, grey and harbour seals, harbour porpoise and bottlenose dolphin). Mitigation measures were applied at a stage 2 appraisal to include MMO monitoring, pre-start monitoring and ramp-up procedures, to ensure that the integrity of all European sites would not be adversely affected.
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In circumstances where noise producing activities or survey vessels as a consequence of the proposed development were occurring in close proximity at the same time as surveys associated with the Energia development, potentially significant underwater noise disturbance effects on individuals of species of marine mammals which are qualifying interests of SACs considered in this appraisal could occur outside of the SACs and inside the foreshore licence areas of both ABWP and Energia. As such, mitigation measures must be applied to prevent such effects occurring.
4.4.4 Codling Bank Wind Park A Foreshore licence application was submitted (FS006241) by Codling Wind Park Ltd in November 2013 for site investigation works off the coast of Wicklow. The licence application area for Codling Bank (and Codling Bank extension) is approximately 10km to the NNE of the ABWP licence application area, as illustrated in Figure 4.5. The range of activities anticipated under the licence are set out in Table 4.5 above.
No significant effects on European sites are predicted by the developer in its Environmental supporting document. Submissions made to the Department’s Marine Licence Vetting Committee (“MLVC”) by prescribed bodies were also reviewed. NPWS, through its parent department had no observations to make on the application. The then Department of Environment, Community and Local Government required that NPWS guidelines for the protection of marine mammals be applied to the activities.
Given the distance between the Codling foreshore application area and the ABWP application area, in circumstances where noise producing activities or survey vessels as a consequence of the proposed development were occurring in close proximity at the same time, it is considered that potentially significant underwater noise disturbance effects on individuals of species of marine mammals which are qualifying interests of SACs considered in this appraisal would not occur in combination either inside or outside of the SACs and inside the foreshore licence areas. This is the case in the absence of any mitigation measures.
4.4.5 Kilmichael Point A Foreshore licence was granted (FS006788) to Hibernian Wind Power in December 2018 to undertake surveys and investigations in order to further assess the site and seabed, in order to select an optimum route for submarine electricity cables required for the development of an offshore wind farm; to acquire baseline data to allow cable design and the development of cable installation methodologies; to acquire baseline data to optimise the windfarm layout design and finalise offshore foundation locations; and to acquire baseline data on the wind resource and baseline information for environmental studies of the area. The range of activities anticipated under the licence are set out in Table 4.5 above. The licence area for Kilmichael Point surrounds the lower protrusion of the ABWP licence application area, as illustrated in Figure 4.5.
An appropriate assessment report prepared by the MLVC concluded that the integrity of any Natura 2000 site would not be adversely affected and that compliance with NPWS (2014) guidelines would
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minimise any potential effects on marine mammals. A subsequent condition of the licence granted includes that aII relevant site investigations and marine surveys shall comply with the NPWS (2014) "Guidance to Manage the risk Marine Mammals from Man-made Sound sources in Irish Waters" including the employment of a Marine Mammal Observer as appropriate.
In circumstances where noise producing activities or survey vessels as a consequence of the proposed development were occurring in close proximity at the same time, potentially significant underwater noise disturbance effects on individuals of species of marine mammals which are qualifying interests of SACs considered in this appraisal could occur outside of the SACs and inside the foreshore licence areas of both ABWP and Kilmichael Point. As such, mitigation measures must be applied to prevent such effects occurring.
It is considered that no other plans or projects lie within proximity to the proposed works or have potential to give rise to significant in-combination effects in the context of the likely significant effects predicted as part of the proposed works which are limited to temporary localised effects.
4.5 CONCLUSION OF THE SCREENING APPRAISAL The stage one screening appraisal was completed in compliance with EU and Irish law and the relevant European Commission and national guidelines to determine whether or not Likely Significant Effects on any European site could be excluded as a result of the proposed development.
The proposed development is not directly connected with or necessary to the management of any European site. From the findings of the screening stage appraisal presented, the possibility of Likely Significant Effects upon the European sites considered in the appraisal is set out below and summarised in Table 4.3, which notes the outcome of the screening exercise for each European site considered.
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Table 4 . 6 : Summary of the Habitats Directive Stage One Screening Appraisal
Can the possibility of Likely Significant Effects be excluded at the Stage One Screening Appraisal? Site Code Site Na m e Habitat Loss W ater Qu ality Underwater Disturbance Aerial Disturbance
W est W ales Marine / Gorllewin UK0030397 √ √ X √ Cymru Forol SAC North Anglesey Marine / UK0030398 √ √ X √ Gogledd Môn Forol SAC C ardigan Bay/ Bae Ceredigion UK0012712 √ √ X √ SAC Pembrokeshire Marine/ Sir UK0013116 √ √ X √ Benfro Forol SA C
IE001766 Magherabeg Dunes SAC √ √ √ √
IE002274 Wicklow Reef SAC √ X √ √
Buckroney- Brittas Dunes and IE000729 √ X √ √ Fen SAC
IE002249 The Murrough Wetlands SAC √ √ √ √
Deputy's Pass Nature Reserve IE000717 √ √ √ √ SAC Vale of Clara (Rathdrum IE000733 √ √ √ √ W ood) SAC
IE001742 Kilpatrick San dhills SA C √ √ √ √
IE002122 Wicklow Mountains SAC √ √ √ √
IE000716 Carriggower Bog SAC √ √ √ √
IE000719 Glen of the Downs SAC √ √ √ √
IE000781 Slaney River Valley SA C √ √ √ √
IE000714 Bray Head SAC √ √ √ √
IE000713 Ballyman Glen SAC √ √ √ √
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Can the possibility of Likely Significant Effects be excluded at the Stage One Screening Appraisal? Site Code Site Na m e Habitat Loss W ater Qu ality Underwater Disturbance Aerial Disturbance
IE000725 Knocksink W ood SAC √ √ √ √
Rockabill to Dalkey Island IE003000 √ √ X √ SAC Cahore Polders and Dunes IE000700 √ √ √ √ SAC
IE002953 Blackwater Bank SAC √ √ √ √
IE000708 Screen Hills SAC √ √ √ √
IE002161 Long Bank SAC √ √ √ √
Raven Point Nature Reserve IE000710 √ √ √ √ SAC
IE001209 Glenasmole Valley SAC √ √ √ √
Kilmuckridge- Tinnaberna IE001741 √ √ √ √ San dhills SA C
IE000210 South Dublin Bay SA C √ √ √ √
IE003015 Codling Fault Zone SAC √ √ √ √
IE000770 Blackstairs Mountains SAC √ √ √ √
IE000204 Lambay Island SAC √ √ √ √
IE000707 Saltee Islands SAC √ √ √ √
IE004127 Wicklow Head SPA √ X √ √
IE004186 The Murrough SPA √ √ √ √
IE004040 Wicklow Mountains SPA √ √ √ √
IE004143 Cahore Marshes SPA √ √ √ √
IE004019 The Raven SPA √ √ √ √
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Can the possibility of Likely Significant Effects be excluded at the Stage One Screening Appraisal? Site Code Site Na m e Habitat Loss W ater Qu ality Underwater Disturbance Aerial Disturbance
IE004172 Dalkey Islands SPA √ √ √ √
IE004063 Poulaphouca Reservoir SPA √ √ √ √
South Dublin Bay and River IE004024 √ √ √ √ Tolka Estuary SPA W exford Harbour and Slobs IE004076 √ √ √ √ SPA
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It can be excluded, on the basis of objective information, that the proposed development will have a significant effect on the following European sites. That is the case in the absence of mitigation measures.
SACs
• Ballyman Glen SAC • Knocksink Wood SAC
• Blackstairs Mountains SAC • Lambay Island SAC
• Blackwater Bank SAC • Long Bank SAC
• Bray Head SAC • Magherabeg Dunes SAC
• Cahore Polders and Dunes SAC • Raven Point Nature Reserve SAC
• Carriggower Bog SAC • Saltee Islands SAC
• Codling Fault Zone SAC • Screen Hills SAC
• Deputy's Pass Nature Reserve SAC • Slaney River Valley SAC
• Glen of the Downs SAC • South Dublin Bay SAC
• Glenasmole Valley SAC • The Murrough Wetlands SAC
• Kilmuckridge - Tinnaberna Sandhills • Vale of Clara (Rathdrum Wood) SAC SAC • Wicklow Mountains SAC • Kilpatrick Sandhills SAC
SPAs
• Cahore Marshes SPA
• Dalkey Islands SPA
• Poulaphouca Reservoir SPA
• South Dublin Bay and River Tolka Estuary SPA
• The Murrough SPA
• The Raven SPA
• Wexford Harbour and Slobs SPA
• Wicklow Mountains SPA
Conversely, and in applying the precautionary principle, the proposed development will give rise to potential likely significant water quality and/or underwater disturbance effects on the conservation objectives of a number of European sites as outlined below, either alone or in combination with other projects considered in Section 4.4. it cannot be excluded, on the basis of objective information, that the proposed development will have a significant effect on the following European sites:
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Underwater Disturbance
• Cardigan Bay/ Bae Ceredigion SAC
• North Anglesey Marine / Gogledd Môn Forol SAC
• Pembrokeshire Marine/ Sir Benfro Forol SAC
• Rockabill to Dalkey Island SAC
• West Wales Marine / Gorllewin Cymru Forol SAC
Water Quality
• Buckroney-Brittas Dunes and Fen SAC
• Wicklow Head SPA
• Wicklow Reef SAC
Having regard to the methodology employed and the findings of the stage one screening appraisal, it is concluded that a Stage two appraisal for appropriate assessment of the implications of the proposed development is required and a Natura Impact Statement is required.
The focus of the remainder of this report will therefore be on the identified likely significant effects of the proposed development upon the following:
• marine mammals in Cardigan Bay/ Bae Ceredigion SAC, North Anglesey Marine / Gogledd Môn Forol SAC, Pembrokeshire Marine/ Sir Benfro Forol SAC, Rockabill to Dalkey Island SAC, and West Wales Marine / Gorllewin Cymru Forol SAC; and
• annex 1 habitats of Buckroney-Brittas Dunes and Fen SAC and Wicklow Reef SAC, and upon prey biomass availability of breeding seabirds of Wicklow Head SPA.
The potential for adverse impacts upon the integrity of these European sites must be mitigated against.
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5 STAGE TWO APPRAISAL FOR APPROPRIATE ASSESSMENT
The screening stage appraisal concluded that an appropriate assessment of the implications of the proposed development on the following European sites is required in view of their conservation objectives:
• Cardigan Bay/ Bae Ceredigion SAC
• North Anglesey Marine / Gogledd Môn Forol SAC
• Pembrokeshire Marine/ Sir Benfro Forol SAC
• Rockabill to Dalkey Island SAC
• West Wales Marine / Gorllewin Cymru Forol SAC
• Buckroney-Brittas Dunes and Fen SAC
• Wicklow Head SPA
• Wicklow Reef SAC
The risks identified are as follows:
5.1 UNDERWATER DISTURBANCE There is no doubt that individuals of the Annex II populations of cetaceans or pinnipeds in relation to Irish and Welsh SACs forage far and wide in their range and may from time to time journey through the foreshore licence application area. In such cases, individuals of the harbour porpoise or bottlenose dolphin communities or seal populations of the SACs discussed above could suffer physical injury, hearing damage, disturbance or displacement by underwater noise levels generated by the marine site investigations.
In applying the precautionary principle, there is a possibility that individuals of a species could be significantly affected, even if only temporarily, by the proposed site investigations. As such, mitigation measures must be applied to prevent such effects occurring. That mitigation is prescribed in Section 5.3.
5.2 WATER QUALITY There is the potential for accidental pollution to undermine the conservation targets for the Annex 1 habitats of Buckroney-Brittas Dunes and Fen SAC or Wicklow Reef SAC if they cause habitat deterioration. It has already been stated that activities will occur within 200m of Buckroney-Brittas Dunes and Fen SAC, and the reef habitat of Wicklow Reef SAC is located 4.5km north of the proposed site investigations.
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There is a possibility that accidental pollution events could undermine the conservation targets for vegetation structure or vegetation composition of sand dune or saltmarsh habitats, or ecosystem function targets for fen habitat in Buckroney-Brittas Dunes and Fen SAC.
While the Wicklow Reef SAC lies 4.5km from the proposed site investigations, when compared with further marine sites within the projects zone of influence, it is considered that given the scale and temporary nature of the proposed activities, there is potential for only a minor pollution or contamination incident in the absence of control measures. Also, as discussed previously and as detailed in Appendix 3, the currents and sedimentation around the Arklow Bank are circulatory. There is no net migration of water northwards.
Notwithstanding these observations, in applying the precautionary principle, there is a possibility that accidental pollution events could undermine the conservation targets to conserve the reef community complex of Wicklow Reef SAC in a natural condition.
The possibility of likely significant water quality effects on Annex 1 habitats of Buckroney-Brittas Dunes and Fen SAC or Wicklow Reef SAC cannot be excluded at the screening stage in the absence of mitigation measures.
As such, mitigation measures must be applied to prevent such effects occurring. That mitigation is prescribed in Section 5.3.
5.3 MITIGATION MEASURES Table 5.1 sets out the mitigation measures that are required to be implemented for the activities proposed under the marine site investigations.
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Table 5 . 1 : Mitigation Measures applied at a Stage Two appraisal for appropriate assessment
Effect The me Potential Effect Control and Mitigation Measures
Underwater • Inj ury • Risk minimisation measure A6.5 and managem ent measures contained in Section 4.3.2 of the Disturbance • Disturbance “Guidance to Manage the Risk to Marine Mammals from Man-made Sound Sources in Irish Waters” • Displacement (NPW S, 2014) shall be applied to the activities. This is current best practice, recom m ended by NPW S • Masking of sounds and applied by all stakeholders in the marine sector in Irish waters and they are appropriate to be used in this instanc e. • Trained and experienced marine mam m al observers (M M Os) shall be employed to provide effective m eans of detecting m arine m a m m als in the vicinity of the propos ed works. • Unless information specific to the licens ed activities is other wise available to infor m the mitigation process (e.g., specific sound propagation and/or attenuation data) and a distance modification has been agreed with the Regulatory Authority, the intended activities shall not commence if marine m a m m als are detected within a 500m radial distance of the site investigation sound source. This is the Monitored Zone. o M M O s must be familiar with the Irish regulatory proc edures and be provided with full details of all licence/consent conditions relevant to the perfor m anc e of their role in advanc e of activity com mencement, in order to ensure compliance. o MMOs must be dedicated to and engaged solely in monitoring an operator’s implementation of the technical guidance set out in NP W S (2014) and in conducting survey effort for marine m a m m als in acc ordance with the guidanc e. The us e of a crew m e m b er or tea m m e m b er with other responsibilities in the prescribed pre- start- up period and/or during com mencement, breaks in, or resumption of, the sound- producing activity is not considered to be a satisfactory substitute for a dedicated MM O. o A sufficient nu m ber of M M O personnel must be assigned to ensure that the role is perfor m ed effectively. Avoidanc e of observer fatigue is essential. o G ener al conditions for effective visual monitoring by M M Os are: (1) during daylight hours and (2) in good visibility extending 1km or more beyond the limits of the assigned Monitored Zone (see sections 4.3.1- 4.3.5 of the guidanc e), while (3) sea conditions for effective visual m onitoring by M M O s are W M O Sea State 4 (≈Beaufort Force 4 conditions) or less. Efficacy in the visual detection of marine mam m al species improves considerably below Sea State 3 (≈Beaufort Force 3 conditions). o M M Os must concentrate their efforts on the measures to be taken in advance of and during commencement, breaks in and resumption of the sound- producing activity. The guidance
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Effect The me Potential Effect Control and Mitigation Measures presented in NPW S (2014) does not imply that MMOs must monitor the area of operations during all daylight hours. However MMOs may be required to work for extended periods within the hours of daylight as identified via the risk assess ment process and its resulting risk management actions. o M M O s must be loc ated on an appropriate elevated platfor m from which the entire Monitored Zone can be effectively covered without any obstruction of view. Ideally MMOs should be positioned near the centre of the Monitored Zone, i.e., adjacent to the sound source. o M M Os must have appropriate equipment for their required role. MMOs must use a distance measuring (i.e., range- finding) stick, reticle binoc ulars or other accurate range- finding mechanis m to determine the distance to any marine mammals seen. o Full reporting on MMO operations and mitigation undertaken must be provided to the Regulatory Authority as outlined in Appendix 7 of NPWS (2014). o Activities shall only com mence in daylight hours where effective visual monitoring, as perform ed and deter mined by the M M O, has been achieved. W here effective visual monitoring, as deter mined by the MMO, is not possible the sound- producing activities shall be postponed until effective visual m onitoring is possible. o An agreed and clear on- site communication signal must be used between the MMO and the Works Supervisor as to whether the relevant activity m ay or may not proceed, or resume following a break (see below). It shall only proceed on positive confirmation with the MM O. o The MMO shall conduct pre- start- up constant effort monitoring at least 30 minutes before the sound- producing activity is due to commence. Sound- producing activity shall not commence until at least 30 minutes have elapsed with no marine mam m als detected within the Monitored Zone by the M M O. o This prescribed Pre- Start Monitoring shall subsequently be followed immediately by the intended activities. The delay between the end of Pre- Start Monitoring and the commencement of the intended activities must be minimised. o Once the intended activities commence, there is no requirement to halt or discontinue the activity at night- time, nor if weather or visibility conditions deteriorate nor if marine mam m als occur within the Monitored Zone. o If there is a break in intended activities for a period greater than 30 minutes (e.g., due to equipment failure, shut- down or location change) then all Pre- Start Monitoring must be undertaken in accordance with the above conditions prior to the recommencement of intended activities. Water Quality/ • Drilling muds and • Only biodegradable poly m ers to be us ed Pollution contact with seabed • Seawater is used as the preferred flushing fluid (mixed with poly m er)
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Effect The me Potential Effect Control and Mitigation Measures • increas e in water • M S D S of the drilling poly m er to be rec orded and available for inspection turbidity, sediment • D aily consu m ption of drilling poly m ers to be recorded and reported in the DPR deposition on organis ms • No anchoring of the survey vessel to take place during survey unless in an emergency • Bentonite and polymers • Proper design of drill pipes, drill casings, CPT casings in drilling muds might • All ite m s lost overboard will be recording and reported pollute seaw at er • All reasonable efforts must be taken to retrieve lost equipment • S m all localised • The us e of a vessel in plac e of a platfor m reduc es contact with the seabed disturbance to habitats • All sewage and putrescible wastes will be handled and disposed of in accordance with the regulations in in event of loss of forc e eq uip m e nt (drill rods, • Liquid organic wastes are either treated in a treat m ent plant or stored in the vessel and then collected CPT rods, sampler) and treated onshore • Localised temporary • N o s olid discharges to the sea is permitted decrease in ambient • As regards equipment used to carry out geotechnical surveys: w at er quality from o Bentonites and polymers: Only biodegradable polymers and oil to be us ed. discharge of sew ag e, o O nly pure water is to be us ed to pressurise dow n the hole CP T and sam pling tools - no grey water, putrescible additives or oil to be us ed. wastes and bilge water o Only biodegradable oil is to be used for equipm ent placed on the seafloor (seabed CPT, • Acute toxicity effects on vibrocorers, seabed frame). marine fauna, such as o Use biodegradable greases for lubricating the threads of drill pipes and rods m arine turtles, fishes o Use biodegradable vegetable oils for hydraulic systems. and seabirds, from • The injection of fluid is limited to seaw ater pum p ed on site (for coring and tubing) with an adjuvant accidental discharges of considered to be biodegradable for destructive borings hazardous m aterials • All hazardous substanc es are stored in a dedicated storage room • Oil spill from high • Substances categorized as “Danger” will be stored in a locker and may only be used with a PTW pressure hoses or • Updated MSDS will be readily accessible in storage rooms refuelling equipment • The amount of hazardous material is kept to a minimu m • Acute toxicity effects on • Hazardous substances stored, handled and disposed of in accordance with the regulations in force marine fauna from fuel • All storage facilities and handling equipment will be in good working order and designed in such a way and oil spills as to prevent and contain any s pillag e as far as practicable • Daily inspection of drill rig for damaged hoses and leaks • Proper maintenance of drilling and equipment • Use appropriate and certified hoses only
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Effect The me Potential Effect Control and Mitigation Measures • Procedures in case of bunkering, spillage, SOPEP, discussed in a toolbox before each bunker oper ation • Identified personnel trained in the use of equipment • Regular drills • Spill kits located near hydrocarbon storage areas and replenished if required • Retention around the work area W astes • Impacts generated by • W aste Managem ent Plan with procedures for minimizing, collecting, sorting, storing, processing and production treat ment and disposal disposing of garbage of wastes onshore • Garbage record book • No discharge into sea • W henever possible, consumables for drilling or offshore laboratory will be re- used (e.g core catchers). Introduction • Introduction and • V ess els must be free of non- native invasive species on their hulls and in their ballast water of establishm ent of • A Ballast W ater Managem ent Plan is to be in place for each relevant vessel used in the com pletion of invasive invasive marine species the works. marine species with consequent impacts on affecting benthic habitat com m u nities., fisheries etc.
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6 CONCLUSION OF THE HABITATS DIRECTIVE APPRAISALS
Having regard to the relevant legislation and the methodology followed, a Stage One Screening appraisal was undertaken as to whether or not the proposed development is likely to have a significant effect on thirty one SACs and nine SPAs as described in Table 4.1.
LSEs could be excluded at screening stage for thirty two European sites, without further evaluation and analysis, or the application of measures intended to avoid or reduce the harmful effects of the proposed development on the sites concerned.
LSEs could not be excluded at screening stage for eight European sites, without further evaluation and analysis, or the application of measures intended to avoid or reduce the harmful effects of the proposed development on the sites concerned.
The possibility of likely significant underwater disturbance effects on the following could not be excluded:
• Individuals of the bottlenose dolphin population of Cardigan Bay/ Bae Ceredigion SAC outside of the site
• Individuals of the harbor porpoise population of North Anglesey Marine / Gogledd Môn Forol SAC outside of the site
• Individuals of the grey seal population of Pembrokeshire Marine/ Sir Benfro Forol SAC outside of the site
• Individuals of the harbor porpoise population of Rockabill to Dalkey Island SAC outside of the site
• Individuals of the harbor porpoise population of West Wales Marine / Gorllewin Cymru Forol SAC outside of the site
The possibility of likely significant water quality or subsequent habitat deterioration effects on the following could not be excluded:
• vegetation structure or composition of sand dune or saltmarsh habitats, or ecosystem function targets for fen habitat in Buckroney-Brittas Dunes and Fen SAC
• reef community complex of Wicklow Reef SAC
• prey biomass available for the foraging Kittiwake population of Wicklow Head SPA
A subsequent Stage Two appraisal of the implications of the proposed development on European sites allowed the introduction of measures intended to avoid or reduce the harmful effects of the proposed development on European sites, and these measures are set out in Table 5.1
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These measures ensure that the proposed development will not undermine the conservation objectives of the sites concerned, and as such will not adversely affect the integrity of any European site.
Accordingly, the competent authority may conclude, beyond reasonable scientific doubt, that the proposed development will not adversely affect the integrity of any European site.
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APPENDIX 1: FORESHORE LICENCE MAP
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5849404 XY7# 5849404 XY7# .! Borehole & CPT XYXW 7# 7# XW "J Floating Lidar 5 .! Trial Pit ^ XW .! !(k ^ Drawing Title FORESHORE LICENCE MAP XW7# 7#XW Projection WGS 1984_UTM ZONE 30N Datum WGS 84 Date 10/09/2019 5844404 .! 5844404 XW .! Drawn By GS XW^7# Reviewed By CB 7# XW Approved By PD .! "JXW7# 0 1.25 2.5 Lower Left Corner 4 XW .! km Scale 1:111,000 277475.87,5839817.20 3 © OpenStreetMap (and) contributors, CC-BY-SA
276978 282978 288978 294978 300978 306978 5839404
APPENDIX 2: CONSERVATION OBJECTIVES
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Table A1: Qualifying Interests and Conservation objectives of SACs considered
Site Code Site Name Conservation Objectives
IE002274 Wicklow Reefs Conservation Objectives Specific Version 1.0 (02/07/2013) SAC To maintain the favourable conservation condition of 1. no. Annex 1 habitat type SA C, as defined by 3 no. attributes and targets; and of 1 no. Annex II species in the SAC, as defined by 2 no. attributes and targets. Annex I Habitat Reefs [1170] Attribute Measure Target
H abitat area H ectares The permanent area is stable or increasing, subject to natural processes. H abitat distribution Occurrence Distribution is stable or increasing, subject to natural processes. C o m m u nity structure Biological Conserve the following community types in a natural composition condition: Intertidal reef com munity complex; and Subtidal reef com munity complex.
IE001766 Magherabeg Conservation Objectives Specific Version 1.0 (27/03/2017) Dunes SAC To maintain the favourable conservation condition of 6. no. Annex 1 habitat type SA C, as defined by a range of attributes and targets. Annex I Habitats Annual vegetation of drift lines [1210]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence N o decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc M aintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: typical Percentage cover Maintain the presence of species- poor communities species and subcommunities at a with typical species: sea rocket (Cakile m aritima), sea representative sandwort (Honckenya peploides), prickly saltwort number of (Salsola kali) and oraches (Atriplex spp.). monitoring stops
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Site Code Site Name Conservation Objectives
Vegetation composition: Percentage cover N egative indicator species (including non- native negative indicator species species) to represent less than 5% cover.
Embyronic shifting dunes [2110]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence N o decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: plant Percentage cover More than 95% of sand couch grass (Elytrigia health of foredune grasses juncea) and/or lyme- grass (Leymus arenarius) should be healthy (i.e. green plant parts above ground and flowering heads present). Vegetation composition: typical Percentage cover M aintain the presence of species- poor communities species and subcommunities at a representative with typical species: sand couch grass (Elytrigia number of juncea) and/or lyme- grass (Leymus arenarius). monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover.
Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers
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Site Code Site Name Conservation Objectives
Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: plant Percentage cover More than 95% of marram grass (Ammophila health of dune grasses arenaria) and/or lymegrass (Leymus arenarius) should be healthy (i.e. green plant parts above ground and flowering heads present). Vegetation composition: typical Percentage cover M aintain the presence of species- poor communities species and subcommunities at a representative dominated by marram grass (Ammophila arenaria) number of and/or lymegrass (Leymus arenarius). monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover.
Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] Atlantic decalcified fixed dunes (Calluno- Ulicetea) [2150]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation structure: bare ground Percentage cover Bare ground should not exceed 10% of foxed dune habitat, subject to natural processes.
Vegetation structure: sward C entimeters Mintain structural varitaion withn sward. height
Vegetation composition: typical Percentage cover Maintain range of subcom munities with typical species and subcommunities at a representative species listed in Delaney et al. (2013). number of monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover. Vegetation composition: Percentage cover No more than 5% cover or under control. scrub/trees
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Site Code Site Name Conservation Objectives
Petrifying springs with tufa formation (Cratoneurion) [7220] Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes. H abitat distribution Occurrence N o decline, subject to natural processes.
Hydrological regime: height of Meters; meters M aintain appropriate hydrological regimes. w ater table; water flow per second W ater quality- nitrate level m g/l No increase from baseline nitrate level an dless than 10 m g/l.
W ater quality - phosphate level µg/l No increase from baseline phosphate level and less than 15µg/l.
Vegetation composition: positive Number per spring At least three positive/high quality indicator species indicator species as listed in Lyons and Kelly (2016) and no loss from baseline number Vegetation composition: negative Cover (DAF O R Potentially negative indicator species should not be indicator species scale) Dominant or Abundant; invasive species should be absent.
Vegetation structure: sward C entim etres Field layer height between 10cm and 50cm (except height for bryophyte- dominated ground <10cm). Physical structure: Percentage cover Cover should not be Dominant or Abundant. trampling/dung Cover (DAFOR scale).
IE000729 Buckroney- Conservation Objective Specific Version 1.0 (27/03/2017) Brittas Dunes To maintain the favourable conservation condition of 10 no. Annex 1 habitat type in the SAC, as defined by a range SAC of attributes and targets. Annex I Habitat Annual vegetation of drift lines [1210]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence N o decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc M aintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers
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Site Code Site Name Conservation Objectives
Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: typical Percentage cover Maintain the presence of species- poor communities species and subcommunities at a with typical species: sea rocket (Cakile maritima), sea representative sandwort (Honckenya peploides), prickly saltwort number of (Salsola kali) and oraches (Atriplex spp.). monitoring stops Vegetation composition: Percentage cover N egative indicator species (including non- native negative indicator species species) to represent less than 5% cover.
Perennial vegetation of stony banks [1220]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence N o decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc M aintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: typical Percentage cover M aintain the typical vegetated shingle flora including species and sub- com munities at a the range of sub- com munities within the different representative zones. number of monitoring stops Vegetation composition: Percentage cover N egative indicator species (including non- native negative indicator species species) to represent less than 5% cover.
Mediterranean salt meadows (Juncetalia maritimi) [1410]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes.
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Site Code Site Name Conservation Objectives
Physical structure: sediment Presence/absenc M aintain the natural circulation of sediments and supply e of physical organic matter, without any physical obstructions. barriers Physical structure: creeks and Occurrence M aintain creek and pan structure, subject to natural pans processes includig erosion and succession..
Physical struucture: flooding Hectares flooded; M aintain natural tidal regime. regime frequency
Vegetation structure: zonation Occurence M aintain the range of coastal habitats incluidng transitional zones, subject to natural processes including erosionn and succession. Vegtation structure: vegetation C entim etres M aintain structural variation in the sward. height
Vegtation structure: vegetation Percentage cover Maintain more than 90% of the area outside of creeks cover at a vegetated. representative number of monitoring stops Vegetation composition: typical Percentage cover Maintain range of subcom munities with typical species and subcommunities at a species listed in McCorry and Ryle (2009). representative number of monitoring stops Vegetation composition: H ectares There is no record of common cordgrass (Spartin a negative indicator species - anglica) in the SAC and its establishment should be Spartina anglica prevented
Embryonic shifting dunes [2110]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession.
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Site Code Site Name Conservation Objectives
Vegetation composition: plant Percentage cover More than 95% of sand couch grass (Elytrigia health of foredune grasses juncea) and/or lyme- grass (Leymus arenarius) should be healthy (i.e. green plant parts above ground and flowering heads present). Vegetation composition: typical Percentage cover M aintain the presence of species- poor communities species and subcom munities at a representative with typical species: sand couch grass (Elytrigia number of juncea) and/or lyme- grass (Leymus arenarius). monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover.
Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: plant Percentage cover More than 95% of marram grass (Ammophila health of dune grasses arenaria) and/or lymegrass (Leymus arenarius) should be healthy (i.e. green plant parts above ground and flowering heads present). Vegetation composition: typical Percentage cover M aintain the presence of species- poor communities species and subcommunities at a representative dominated by marram grass (Ammophila arenaria) number of and/or lymegrass (Leymus arenarius). monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover.
Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] Atlantic decalcified fixed dunes (Calluno- Ulicetea) [2150]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession.
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Site Code Site Name Conservation Objectives
H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation structure: bare ground Percentage cover Bare ground should not exceed 10% of fixed dune habitat, subject to natural processes.
Vegetation structure: sward C entimeters Mintain structural varitaion within sward. height
Vegetation composition: typical Percentage cover M aintain range of subcom munities with typical species and subcommunities at a representative species listed in Delaney et al. (2013). number of monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover. Vegetation composition: Percentage cover No more than 5% cover or under control. scrub/trees
Dunes with Salix repens ssp. argentea (Salicion arenariae) [2170]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation structure: bare ground Percentage cover Bare ground should not exceed 10% cover, subject to natural processes.
Vegetation structure: sward C entimeters M aintain structural varitaion within sward. height
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Site Code Site Name Conservation Objectives
Vegetation composition: typical Percentage cover M aintain range of subcom munities with typical species and subcommunities at a representative species listed in Delaney et al. (2013). number of monitoring stops Vegetation composition: cover Percentage cover; Maintain more than 10% cover of creeping willow and height of Salix repens centimetres (Salix repens); vegetation height should be in the average range of 5- 20cm. Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species (including at a representative species) to represent less than 5% cover. Hippophae rhamnoides) number of monitoring stops Vegetation composition: Percentage cover For trees and scrub other than creeping willow (Salix scrub/trees repens), there should be no more than 5% cover or their presence should be under control.
Humid dune slacks [2190]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Physical structure: hydrological W ater table levels; M aintain natural hydrological regime. and flooding regime groundwater fluctuations (metres) Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession Vegetation structure: bare ground Percentage cover Bare ground should not exceed 5% of dune slack habitat, with the exception of pioneer slacks which can have up to 20% bare ground. Vegetation structure: vegetation C entim etres M aintain structural variation within sward. height Vegetation composition: typical Percentage cover M aintain range of subcom munities with typical species and subcommunities at a representative species listed in Delaney et al. (2013). number of monitoring stops
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Site Code Site Name Conservation Objectives
Vegetation composition: cover of Percentage cover Maintain less than 40% cover of creeping willow Salix repens (Salix repens). Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover. Vegetation composition: Percentage cover No more than 5% cover or under control. scrub/trees
Alkaline fens [7230]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes. H abitat distribution Occurrence N o decline subject to natural processes.
Ecosystem function: soil Soil pH an d Maintain soil nutrient status within natural range. nutrients appropriate nutrient levels at a representative number of monitoring stops Ecosystem function: peat Flood duration M aintain active peat formation, where appropriate. form ation
Ecosystem function: hydrology M etres M aintain appropriate natural hydrological regimes necessary to support the natural structure and functioning of the habitat. Ecosystem function: water W ater chemistry M aintain appropriate water quality, particularly qu ality measures nutrient levels, to support the natural structure and functioning of the habitat. C o m m u nity diversity Abundance of variety Maintain variety of vegetation com munities, subject of vegetation to natural processes communities Vegetation composition: Nu m ber of species at At least one brown moss species present at each nu mber of positive indicator a representative m onitoring stop. species (brown mosses) number of 2m x 2m monitoring stops Vegetation composition: Nu m ber of species at Nu m ber of positive vascular plant indicator species nu mber of positive indicator a representative present at each monitoring stop is at least two for species (vascular plants) number of 2m x 2m sm all- sedge flushes and at least three for black monitoring stops bog- rush (Schoenus nigricans) flush and bottle sedge (Carex rostrata) fen.
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Site Code Site Name Conservation Objectives
Vegetation composition: cover Percentage cover at a Total cover of negative indicator species less than of positive indicator species representative 1%. number of 2m x 2m monitoring stops Vegetation composition: Percentage cover at, Total cover of non- native species less than 1%. nonnative species and in local vicinity of, a representative number of 2m x 2m monitoring stops Vegetation composition: native Percentage cover in Cover of scattered native trees and shrubs less trees and shrubs local vicinity of a than 10%. representative number of monitoring stops Vegetation com position: soft Percentage cover in Total cover of soft rush (Juncus effusus) and rush and common reed cover local vicinity of a common reed (Phragmites australis) less than representative 10%. number of monitoring stops Vegetation structure: height Percentage of Proportion of live leaves and/or flowering shoots of leaves/shoots at a vascular plants that are more than 5c m above the representative ground surface should be at least 50%. number of 2m x 2m monitoring stops Physical structure: disturbed Percentage cover at, Cover of disturbed bare ground less than 10%. bare ground and in local vicinity of, a representative number of 2m x 2m monitoring stops Physical structure: drainage Percentage area in Area showing signs of drainage as a result of local vicinity of a drainage ditches or heavy trampling less than 10%. representative number of monitoring stops Physical structure: tufa Percentage cover in Disturbed proportion of vegetation cover where tufa formations local vicinity of a is present is less than 1%. representative number of 2m x 2m monitoring stops
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Site Code Site Name Conservation Objectives
Indicators of local Occurrence and No decline in distribution or population sizes of distinctiveness population size rare, threatened or scarce species associated with the habitat.
IE001742 Kilpatrick Conservation Objectives Specific Version 1.0 (21/03/2017) San dhills SA C To maintain the favourable conservation condition of 5. no. Annex 1 habitat type SA C, as defined by a range of attributes and targets. Annex I Habitats Annual vegetation of drift lines [1210]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence N o decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc M aintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: typical Percentage cover Maintain the presence of species- poor communities species and subcom munities at a with typical species: sea rocket (Cakile maritima), sea representative sandwort (Honckenya peploides), prickly saltwort number of (Salsola kali) and oraches (Atriplex spp.). monitoring stops Vegetation composition: Percentage cover N egative indicator species (including non- native negative indicator species species) to represent less than 5% cover.
Embryonic shifting dunes [2110]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers
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Site Code Site Name Conservation Objectives
Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: plant Percentage cover More than 95% of sand couch grass (Elytrigia health of foredune grasses juncea) and/or lyme- grass (Leymus arenarius) should be healthy (i.e. green plant parts above ground and flowering heads present). Vegetation composition: typical Percentage cover M aintain the presence of species- poor communities species and subcommunities at a representative with typical species: sand couch grass (Elytrigia number of juncea) and/or lyme- grass (Leymus arenarius). monitoring stops Vegetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover.
Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]
Attribute Measure Target H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation composition: plant Percentage cover More than 95% of marram grass (Ammophila health of dune grasses arenaria) and/or lymegrass (Leymus arenarius) should be healthy (i.e. green plant parts above ground and flowering heads present). Vegetation composition: typical Percentage cover M aintain the presence of species- poor communities species and subcommunities at a representative dominated by marram grass (Ammophila arenaria) number of and/or lymegrass (Leymus arenarius). monitoring stops Vegetation composition: negative Percentage cover Negative indicator species (including non- native indicator species species) to represent less than 5% cover. Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130] Atlantic decalcified fixed dunes (Calluno- Ulicetea) [2150]
Attribute Measure Target
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Site Code Site Name Conservation Objectives
H abitat area H ectares Area stable or increasing, subject to natural processes, including erosion and succession. H abitat distribution Occurrence No decline or change in habitat distribution, subject to natural processes. Physical structure: functionality Presence/absenc Maintain the natural circulation of sediment and and sediment supply e of physical organic matter, without any physical obstructions. barriers Vegetation structure: zonation Occurrence M aintain the range of coastal habitats including transitional zones, subject to natural processes including erosion and succession. Vegetation structure: bare ground Percentage cover Bare ground should not exceed 10% of fixed dune habitat, subject to natural processes.
Vegetation structure: sward C entimeters Mintain structural varitaion within sward. height
Vegetation composition: typical Percentage cover M aintain range of subcom munities with typical species and subcommunities at a representative species listed in Delaney et al. (2013). number of monitoring stops V egetation composition: negative Percentage cover N egative indicator species (including non- native indicator species species) to represent less than 5% cover. Vegetation composition: Percentage cover No more than 5% cover or under control. scrub/trees
IE003000 R ockabill to Conservation Objectives Specific Version 1.0 (07/05/13) Dalkey Island To maintain the favourable conservation condition of 1 no. Annex 1 habitat type in the SAC, as defined by 3 no. SAC attributes and targets; and of 1 no. Annex II species in the SA C, as defined by 2 no. attributes and targets.
Annex I habitat Reefs [11701]
Attribute Measure Target Habitat areas H ectares The permanent area is stable or increasing, subject to natural processes Habitat Distribution Occurrence Distribution is stable or increasing, subject to natural processes. Community Structure Biological Conserve the following com munity types in a natural composition condition: Intertidal reef community complex; and Subtidal reef community complex
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Site Code Site Name Conservation Objectives
Annex II Species Harbour porpoise (Phocoena phocoena) [1351]
Attribute Measure Target Access to suitable habitat N u m ber of artificial Species range within the site should not be restricted by barriers artificial barriers to site use. Disturbance Level of impact Human activities should occur at levels that do not adversely affect the harbour porpoise community at the site
UK0030398 N orth Anglesey The Conservation Objectives for the site are: SAC To ensure that the integrity of the site is maintained and that it makes the best possible contribution to maintaining Favourable Conservation Status (F CS) for Harbour Porpoise in UK waters. Annex II Species Harbour porpoise (Phocoena phocoena) [1351] In the context of natural change, this will be achieved by ensuring that: H arbour porpoise is a viable component of the site; There is no significant disturbance fo the species: and The condition of supporting habitats and processes, and the availability of prey is maintained.
UK0030397 W est Wales The Conservation Objectives for the site are: M arine SA C To ensure that the integrity of the site is maintained and that it makes the best possible contribution to maintaining Favourable Conservation Status (FCS) for Harbour Porpoise in UK waters. Annex II Species Harbour porpoise (Phocoena phocoena) [1351] In the context of natural change, this will be achieved by ensuring that: H arbour porpoise is a viable component of the site; There is no significant disturbance of the species: and The condition of supporting habitats and processes, and the availability of prey is maintained.
UK0013116 Pembrokshire Annex II species are a primary reason for selection of this site. M arine SA C Grey seal Halichoerus grypus [1364] Pembrokeshire in south- west Wales is representative of grey seal Halichoerus grypus colonies in the south- western part of the breeding range in the UK. It is the largest breeding colony on the west coast south of the Solway Firth, representing over 2% of annual UK pup production.
UK0012712 Cardigan Bay Annex II species are a primary reason for selection of this site. Bottlenose dolphin Tursiops truncatus [1349]
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Site Code Site Name Conservation Objectives
The bottlenose dolphin Tursiops truncatus population of Cardigan Bay off the west coast of Wales has been estimated to consist of around 125 individuals. The dolphins appear to use the inshore waters of Cardigan Bay for both feeding and reproduction, and in the summer months calves and juveniles are often observed with adult individuals or groups.
IE000204 Lambay Island Conservation Objectives Specific Version 1.0 (22/07/13) SAC To maintain the favourable conservation condition of 2 no. Annex 1 habitat type in the SA C, as defined by a range of attributes and targets; and of 2 no. Annex II species in the SA C, as defined by 5 no. attributes and targets. Annex II Species Grey seal (Halichoerus grypus) [1364]
Attribute Measure Target Access to suitable habitat Nu m ber of artificial Species range within the site should not be restricted by barriers artificial barriers to site use. Breeding Breeding sites The breeding sites should be maintained in a natural behaviour condition.
Moulting behaviour Moult haul- out sites The moult haul- out sites should be maintained in a natural condition. Resting behaviour Resting haul- out The resting haul- out sites should be maintained in a sites natural condition. Disturbance Level of impact Human activities should occur at levels that do not adversely affect the grey seal population at the site
Harbour seal (Phoca vitulina) [1365]
Attribute Measure Target Access to suitable habitat Nu m ber of artificial Species range within the site should not be restricted by barriers artificial barriers to site use. Breeding behaviour Breeding sites The breeding sites should be maintained in a natural condition. Moulting behaviour Moult haul- out sites The moult haul- out sites should be maintained in a natural condition. Resting behaviour Resting haul- out The resting haul- out sites should be maintained in a sites natural condition. Disturbance Level of impact Human activities should occur at levels that do not adversely affect the harbour seal population at the site
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Site Code Site Name Conservation Objectives
000707 Saltee Islands Conservation Objectives Specific Version 1.0 (21/10/2011) SAC To maintain the favourable conservation condition of 5 no. Annex 1 habitat type in the SA C, as defined by a range of attributes and targets; and of 1 no. Annex II species in the SA C, as defined by 6 no. attributes and targets. Annex II Species Grey Seal (Halichoerus grypus) [1364]
Attribute Measure Target Access to suitable habitat Number of artificial barriers Species range within the site should not be restricted by artificial barriers to site use.
Breeding behaviour Breeding sites The breeding sites should be m aintained in a natural condition. Moulting behaviour Moult haul‐ out sites The moult haul‐ out sites should be m aintained in a natural condition.
Resting behaviour Resting haul‐ out sites The resting haul‐ out sites should be m aintained in a natural condition.
Population composition Number of cohorts The grey seal population occurring within this site should contain adult, juvenile and pup cohorts annually.
Disturbance Level of impact Human activities should occur at levels that do not adversely affect the grey seal population.
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Site Code Site Name Conservation Objectives
IE000781 Slaney River Conservation Objectives Specific Version 1.0 (21/10/2011) Valley SAC To maintain the favourable conservation condition of 3 no. Annex 1 habitat type in the SA C, as defined by a range of attributes and targets; and of 3 no. Annex II species in the SA C, as defined by 6 no. attributes and targets. Annex II Species Atlantic Salmon (Salmo salmar) [1106]
Attribute Measure Target Distribution: extent of anadromy % of river accessible 100 % of river channels down to secon d order accessible from estuary.
Adult spawning fish Number Conservation Limit (CL) for each system consistently exceeded. Salmon fry abundance Number of fry/5 minutes Maintain or exceed 0+ fry mean catchment‐ electrofishing wide abundance threshold value. Currently set at 17 salmon fry/5 min sampling.
Out‐ migrating smolt abundance Number No significant decline. Number and distribution of redds Number and occurrenc No decline in number and distribution of spawning redds due to anthropogenic causes. W ater quality EPA Q value At least Q4 at all sites sampled by EPA
Lampetra planeri (Brook Lamprey) [1096] Attribute Measure Target Distribution % of river accessible Access to all watercourses down to first order streams.
Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas Lampetra fluviatilis (River Lamprey) [1099] Attribute Measure Target
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Site Code Site Name Conservation Objectives
Distribution: extent of anadromy % of river accessible Greater than 75 % of main stem and major tributaries down to second order accessible from estuary Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas River Lamprey (Lampetra fluviatilis) [1099] Attribute Measure Target Distribution: extent of anadromy % of river accessible Greater than 75 % of main stem and major tributaries down to second order accessible from estuary Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Nu m ber of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas
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Site Code Site Name Conservation Objectives
IE 002162 River Barrow Conservation Objectives Specific Version 1.0 (19/07/2011) and River Nore To maintain the favourable conservation condition of 12 no. Annex 1 habitat type in the SAC, as defined by a range SAC of attributes and targets; and of 3 no. Annex II species in the SA C, as defined bya range of. attributes and targets. Annex II Species Atlantic Salmon (Salmo salmar) [1106] Attribute Measure Target Distribution: extent of anadromy % of river accessible 100% of river channels down to second order accessible from estuary.
Adult spawning fish Number Conservation Limit (CL) for each system consistently exceeded. Salmon fry abundance Number of fry/5 minutes M aintain or exceed 0+ fry mean catchment‐ electrofishing wide abundance threshold value. Currently set at 17 salmon fry/5 min sampling.
Out‐ migrating smolt abundance Number No significant decline. Number and distribution of redds Number and occurrenc No decline in number and distribution of spawning redds due to anthropogenic causes. W ater quality EPA Q value At least Q4 at all sites sampled by EPA
Brook Lamprey (Lampetra planeri) [1096] Attribute Measure Target Distribution % of river accessible Access to all watercourses down to first order streams.
Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas River Lamprey (Lampetra fluviatilis) [1099] Attribute Measure Target
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Site Code Site Name Conservation Objectives
Distribution: extent of anadromy % of river accessible Greater than 75 % of main stem and major tributaries down to second order accessible from estuary Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in More than 50% of sample sites positive. 2nd order channels (and greater), downstream of spawning areas
IE002299 River Boyne Conservation Objectives Generic Version 6.0 (21/02/2018) and River To maintain the favourable conservation condition of 2 no. Annex 1 habitat type in the SAC, as defined by a range Blackwater of attributes and targets; and of 2 no. Annex II species in the SA C, as defined bya range of. attributes and targets. SAC Annex II Species Atlantic Salmon (Salmo salmar) [1106]
Attribute Measure Target Distribution: extent of anadromy % of river accessible 100% of river channels down to second order accessible from estuary.
Adult spawning fish Number Conservation Limit (CL) for each system consistently exceeded. Salmon fry abundance Number of fry/5 minutes M aintain or exceed 0+ fry mean catch ment‐ electrofishing wide abundance threshold value. Currently set at 17 salmon fry/5 min sampling.
Out‐ migrating smolt abundance Number No significant decline. Number and distribution of redds Number and occurrenc No decline in number and distribution of spawning redds due to anthropogenic causes. W ater quality EPA Q value At least Q4 at all sites sampled by EPA
River Lamprey (Lampetra fluviatilis) [1099]
Attribute Measure Target
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Site Code Site Name Conservation Objectives
Distribution: extent of anadromy % of river accessible Greater than 75 % of main stem and major tributaries down to second order accessible from estuary Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas Conservation attributes and targets have not been published.
IE002137 Lower River Consrvation Objectives Specific Version 1.0 (28/03/2017) Suir SAC To maintain the favourable conservation condition of 8 no. Annex 1 habitat type in the SA C, as defined by a range of attributes and targets; and of 4 no. Annex II species in the SA C, as defined bya range of. attributes and targets. Annex II Species Atlantic Salmon (Salmo salmar) [1106]
Attribute Measure Target Distribution: extent of anadromy % of river accessible 100% of river channels down to second order accessible from estuary.
Adult spawning fish Number Conservation Limit (CL) for each system consistently exceeded. Salmon fry abundance Nu m ber of fry/5 minutes M aintain or exceed 0+ fry mean catch ment‐ electrofishing wide abundance threshold value. Currently set at 17 salmon fry/5 min sampling.
Out‐ migrating smolt abundance Number No significant decline. Number and distribution of redds Number and occurrenc No decline in number and distribution of spawning redds due to anthropogenic causes. W ater quality EPA Q value At least Q4 at all sites sampled by EPA Brook Lamprey (Lampetra planeri) [1096] Attribute Measure Target
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Site Code Site Name Conservation Objectives
Distribution % of river accessible Access to all watercourses down to first order streams.
Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas River Lamprey (Lampetra fluviatilis) [1099] Attribute Measure Target Distribution: extent of anadromy % of river accessible Greater than 75 % of main stem and major tributaries down to second order accessible from estuary Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present. Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 2/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas Petromyzon marinus (Sea Lamprey) [1095] Attribute Measure Target Distribution: extent of anadromy % of river accessible Greater than 75 % of main stem and major tributaries down to second order accessible from estuary Population structure of juveniles Nu m ber of age/size groups At least three age/size groups of brook/river lamprey present.
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Site Code Site Name Conservation Objectives
Juvenile density in fine sediment Juveniles/m² Mean catchment juvenile density of brook/river lamprey at least 1/m²
Extent and distribution of spawning m² and occurrence No decline in extent and distribution of habitat spawning beds. Availability of juvenile habitat Number of positive sites in M ore than 50 % of sample sites positive. 2nd order channels (and greater), downstream of spawning areas
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Table A2: Special Conservation Interests and Conservation objectives of SPAs considered
Site Code Site Name Conservation Objectives
UK9013061 Anglesey Terns Dr aft Conservation Objectives (12/2015) SPA Breeding population of Arctic tern (Sterna paradisae) Breeding population of common tern (Sterna hirundo) Breeding population of roseate tern (Sterna dougallii) Breeding population of sandwich tern (Sterna sandvicensis) 1. The size of the population should be stable or increasing, allowing for natural variability, and sustainable in the long term. 2. The distribution of the population should be being maintained, or where appropriate increasing. 3. There should be sufficient habitat, of sufficient quality, to support the population in the long term. 4. Factors affecting the population, or its habitat should be under appropriate control.
IE004080 Boyne Estuary Conservation Objectives Specific Version 1.0 (26/02/2013) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special C onservation Interests for this SPA Shelduck (Tadorna tadorna) [A048] Oystercatcher (Haematopus ostralegus) [A130] Golden Plover (Pluvialis apricaria) [A140] Grey Plover (Pluvialis squatarola) [A141] Lapwing (Vanellus vanellus) [A142] Knot Calidris (canutus) [A143] Sanderling (Calidris alba) [A144] Black- tailed Godwit (Limosa limosa) [A156] Redshank (Tringa tetanus) [A162] Turnstone (Arenaria interpres) [A169]
Attribute Measure Target Population trend Percentage change Long term population trend stable or increasing. Distribution Range, timing and intensity of No significant decrease in the range, timing use of areas or intensity of use of areas by these birds other than that occurring from natural patterns of variation. Little Tern (Sterna albifrons) [A195]
Attribute Measure Target Breeding population Number No significant decline. abundance: apparently occupied nests (AONs)
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Site Code Site Name Conservation Objectives
Productivity rate: fledged Mean number No significant decline. young per breeding pair Distribution: breeding Nu m ber; location; area No significant decline. colonies (Hectares) Prey biomass available Kilogrammes No significant decline.
Barriers to connectivity Number; location; shape; area No significant increase. (hectares) Disturbance at the breeding Level of impact Human activities should occur at levels that site do not adversely affect the breeding little tern population.
IE004172 D alkey Islands Conservation Objectives Generic Version 6.0 (21/02/18) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special C onservation Interests for this SPA
Special Conservation Interests R oseate Tern (Sterna dou gallii) [A192] Common Tern (Sterna hirundo) [A193] Arctic Tern (Sterna paradisaea) [A194]
Conservation attributes and targets have not been published. UK9013121 Abedaron Conservation Objectives Version 2.0 (27/03/08) Coast and To maintain or restore the favourable conservation condition of the bird species listed as Qualifying species for this Bardsey Island SPA SPA M anx Shearwater (Puffinus puffinus) [A013] The vision for this feature is for it to be in a favourable conservation status, where all of the following conditions are satisfied: Breeding population of Manx shearwater (confined to Ynys Enlli) is stable or increasing. R eproductive rates remain stable. Deaths from the lighthouse attractions, fencing and other infrastructure are minimal. N o ground predators are introduced. N esting birds are not disturbed by restoration works on boundary walls or recreational activities. All factors affecting the achievement of these conditions are under control.
Chough (Pyrrhocorax pyrrhocorax) [A346] The vision for this feature is for it to be in a favourable conservation status, where all of the following conditions are satisfied: The breeding population of chough is at least 14 pairs, or 5% of the GB population. The wintering population of chough is at least 28 individuals, or 5 % of the GB population. Sufficient suitable habitat is present to support the populations.
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Site Code Site Name Conservation Objectives
Breeding population is stable or increasing. Productivity is stable. Non- breeding flocks are stable or increasing (su m m er and winter). Breeding and non- breeding birds use Ynys Enlli for feeding throughout the year. Chough feeding habitats are themselves in a favourable conservation status and that the specified and operational limits and grazing prescriptions for these habitats incorporate chough feeding requirements (i.e. sward height and bare ground). Disturbance of breeding and feeding chough is minimal. The factors affecting the feature are under control.
IE004113 Howth Head Conservation Objectives Generic Version 6.0 (21/02/2018) Coast SPA To maintain or restore the favourable conservation condition of the bird species listed as Special C onservation Interests for this SPA Special Conservation Interests Kittiwake (Rissa tridactyla) [A188]
Conservation attributes and targets have not been published. IE004117 Ireland’s Eye Conservation Objectives Generic Version 6.0 (21/02/2018) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special C onservation Interests for this SPA Special Conservation Interests Cormorant (Phalacrocorax carbo) [A017] H erring Gull (Larus argentatus) [A184] Kittiwake (Rissa tridactyla) [A188] Guillemot (Uria aalge) [A199] R azorbill (Alca torda) [A200]
Conservation attributes and targets have not been published.
Irish Sea Front Draft Conservation Objectives Version 4.0 (07/16) SPA To avoid significant deterioration of the habitats of the qualifying species or significant disturbance to the qualifying species, subject to natural change, thus ensuring that the integrity of the site is maintained in the long term and m akes an appropriate contribution to achieving the aims of the Birds Directive for the qualifying species.
This contribution would be achieved through delivering the following objectives for the sites qualifying feature:
Avoid significant mortality, injury and disturbance of the qualifying feature, so that the distribution of the species and ability to use the site are maintained in the long- term; M aintain the habitats and food resources of the qualifying feature in favourable condition. Ensure access to the site from linked breeding colonies.
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Site Code Site Name Conservation Objectives
IE004118 Keeragh Conservation Objectives Generic Version 6.0 (21/02/2018) Islands SP A To maintain or restore the favourable conservation condition of the bird species listed as Special C onservation Interests for this SPA
Special Conservation Interests Cormorant (Phalacrocorax carbo) [A017]
Conservation attributes and targets have not been published. IE004009 Lady’s Islan d Conservation Objectives Generic Version 6. 0 (21/02/2018) Lake SP A To maintain or restore the favourable conservation condition of the bird species listed as Special C onservation Interests for this SPA Special Conservation Interests Gadwall (Anas Strepera) [A051] Black- headed Gull (Chroicocephalus ridibundus) [A179] Sandwich Tern (Sterna sandvicensis) [A191] Roseate Tern (Sterna dougallii) [A192] Common Tern (Sterna hirundo) [A193] Arctic Tern (Sterna paradisae) [A194] Conservation attributes and targets have not been published. IE004069 Lambay Island Conservation Objectives Generic Version 6.0 (21/02/2018) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA Special Conservation Interests Fulmar (Fulmarus glacialis) [A009] Cormorant (Phalacrocorax carbo) [A017] Shag (Phalacrocorax aristotelis) [A018] Greylag Goose (Anser anser) [A043] Lesser Black- backed Gull (Larus fuscus) [A183] H erring Gull (Larus argentatus) [A184] Kittiwake (Rissa tridactyla) [A188] Guillemot (Uria aalge) [A199] R azorbill (Alca torda) [A200] Puffin (Fratercula arctica) [A204] Conservation attributes and targets have not been published. UK9020327 Northern Dr aft Conservation Objectives (01/2019) Cardigan Bay To achieve favourable conservation status all the following, subject to natural processes, need to be fulfilled and SPA maintained in the long- term. If these objectives are not met restoration measures will be needed to achieve favourable conservation status. Red- throated diver (Gavia stellata) [A001]
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Site Code Site Name Conservation Objectives
The size of the population should be stable or The wintering population of Red- throated diver should increasing, allowing for natural variability, an d be stable or increasing, for a peak mean of 1,186 sustainable in the long term. individuals (2000/01- 2003/04). There should be sufficient habitat, of sufficient quality, The foraging habitat of this species should not to support the population in the long term. decrease significantly, and its quality should remain unaffected by anthropogenic factors.
IE004014 R ockabill SPA Conservation Objectives Specific Version 1.0 (08/05/2013) To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA Purple Sandpiper (Calidris maritima) [A148]
Attribute Measure Target Population trend Percentage change Long term population trend stable or increasing. Distribution Range, timing and intensity of use of No significant decrease in the range, timing or areas intensity of use of areas by purple sandpiper other than that occurring from natural patterns of variation.
Roseate Tern (Sterna dougallii) [A192] Com mon Tern (Sterna hirundo) [A193] Arctic Tern (Sterna paradisaea) [A194]
Attribute Measure Target Breeding population Number No significant decline. abundance: apparently occupied nests (AONs) Productivity rate: fledged Mean number No significant decline. young per breeding pair Distribution: breeding Number; location; area No significant decline. colonies (hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Number; location; shape; No significant decline. area (hectares) Disturbance at breeding site Level of impact Human activities should occur at levels that do not adversely affect the breeding roseate tern population.
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Site Code Site Name Conservation Objectives
IE004002 Saltee Islands Conservation Objectives Specific Version 1.0 (21/10/2011) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA Fulmar (Fulmarus glacialis) [A009]
Attribute Measure Target Breeding population Number No significant decline. abundance: apparently occupied sites (AOSs) Productivity rate Mean number No significant decline. Distribution: breeding Number; location; area No significant decline. colonies (hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Number; location; shape; No significant increase. area (hectares) Disturbance at breeding site Level of impact No significant increase Disturbance at marine areas Level of impact No significant increase. im mediately adjacent to the colony
Gannet (Morus bassanus) [A016] Cormorant (Phalacrocorax carbo) [A017] Shag (Phalacrocorax aristotelis) [A018] Lesser Black‐ backed Gull (Larus fuscus) [A183] Herring Gull (Larus argentatus) [A184] Kittiwake (Rissa tridactyla) [A188]
Attribute Measure Target Breeding population Number No significant decline. abundance: apparently occupied sites (AONs) Productivity rate Mean number No significant decline. Distribution: breeding Number; location; area No significant decline. colonies (hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Nu m ber; location; shape; No significant increase. area (hectares) Disturbance at breeding site Level of impact No significant increase
G uillem ot (Uria aalge) [A199] R a zor bill (Alca torda) [A200]
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Site Code Site Name Conservation Objectives
Attribute Measure Target Breeding population Number No significant decline. abundance: individual adult Productivity rate Mean number No significant decline. Distribution: breeding Number; location; area No significant decline. colonies (hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Number; location; shape; No significant increase. area (hectares) Disturbance at the breeding Level of impact No significant increase. site Disturbance at marine areas Level of impact No significant increase. im mediately adjacent to the colony
Puffin (Fratercula arctica) [A204]
Attribute Measure Target Breeding population Number No significant decline. abundance: apparently occupied burrow (AOB) Productivity rate Mean number No significant decline. Distribution: breeding Number; location; area No significant decline. colonies (hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Number; location; shape; No significant increase. area (hectares) Disturbance at the breeding Level of impact No significant increase. site Disturbance at marine areas Level of impact No significant increase. im mediately adjacent to the colony Occurrence of mammalian Level of impact Absent or under control. predators
IE004122 Skerries Islan d Conservation Objectives Generic Version 6.0 (21/02/18) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA. Special Conservation Interests Cormorant (Phalacrocorax carbo) [A017] Shag (Phalacrocorax aristotelis) [A018] Light- bellied Brent Goose (Branta bernicla hrota) [A046]
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Site Code Site Name Conservation Objectives
Purple Sandpiper (Calidris maritima) [A148] Turnstone (Arenaria interpres) [A169] H erring Gull (Larus argentatus) [A184] Conservation attributes and targets have not been published. IE004024 South Dublin Conservation Objectives Specific Version 1.0 (09/03/15) Bay and River To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Tolka Estuary Interests for this SPA. SPA Light- bellied Goose (Branta bernicla hrota) [A046] Oystercatcher (Haematopus ostralegus) [A130] Ringed Plover (Charadrius hiaticula) [A137] Grey Plover (Pluvialis squatarola) [A141] Knot (Calidris canutus) [A143] Sanderling (Calidris alba) [A144] Dunlin (Calidris alpina alpina) [A149] Bar- tailed Godwit (Limosa lapponica) [A157] Redshank (Tringa tetanus) [A162] Black- headed Gull (Chroicocephalus ridibundus) [A179] Attribute Measure Target Population trend Percentage change Long term population trend stable or increasing. Distribution R ange, timing and intensity of No significant decrease in the range, timing or use of areas intensity of use of areas by these birds, other than that occurring from natural patterns of variation
Roseate Tern (Sterna dougallii) [A192] Arctic Tern (Sterna paradisaea) [A194]
Attribute Measure Target Passage population: Number No significant decline. individuals Distribution: roosting areas Number; location; area No significant decline. (hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Number; location; shape; No significant increase. area (hectares) Disturbance at roosting site Level of impact Human activities should occur at levels that do not adversely affect the numbers of roseate tern am ong the post- breeding aggregation of terns. Common Tern (Sterna hirundo) [A193] Attribute Measure Target
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Site Code Site Name Conservation Objectives
Breeding population Number No significant decline. abundance: apparently occupied sites (AONs) Productivity rate Mean number No significant decline. Passage population: Number No significant decline. individuals Distribution: breeding Number; location; area No significant decline. colonies (Hectares) Distribution: roosting areas Number; location; area No significant decline. (Hectares) Prey biomass available Kilogrammes No significant decline. Barriers to connectivity Number; location; shape; No significant increase. area (hectares) Disturbance at breeding site Level of impact Human activities should occur at levels that do not adversely affect the breeding com m on tern population. Disturbance at roosting site Level of impact Human activities should occur at levels that do not adversely affect the numbers of common tern among the post- breeding aggregation of terns.
IE004186 The Murrough Conservation Objectives Generic Version 6.0 (21/02/18) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA. Special Conservation Interests Red- throated Diver (Gavia stellata) [A001] Greylag Goose (Anser anser) [A043] Light- bellied Brent Goose (Branta bernicla hrota) [A046] Wigeon (Anas Penelope) [A050] Teal (Anas cracca) [A052] Black- headed Gull (Chroicocephalus ridibundus) [A179] H erring Gull (Larus argentatus) [A184] Little Tern (Sterna albifrons) [A195] Conservation attributes and targets have not been published.
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Site Code Site Name Conservation Objectives
IE004019 The Raven SP A Conservation Objectives Specific Version 1.0 (21/03/2012) To maintain the favourable conservation condition of these birds in The Raven SPA, which is defined by the following list of attributes and targets: Red‐throated Diver (Gavia stellata) [A001] Cormorant (Phalacrocorax carbo) [A017] C om m on Scoter (Melanitta nigra) [A065] Grey Plover (Pluvialis squatarola) [A141] Sanderling (Calidris alba) [A144] Greenland White‐fronted goose (Anser albifrons flavirostris) [A395] Attribute Measure Target Population trend Percentage change Long term population trend stable or increasing. Distribution Number and range of areas used by There should be no significant decrease in the w aterbirds nu mbers or range of areas used by waterbird species, other than that occurring from natural patterns of variation
IE004076 W exford Conservation Objectives Specific Version 1.0 (21/03/12) Harbour and To maintain the favourable conservation condition of these birds in W exford Harbour and Slobs SPA, which is Slobs SPA defined by the following list of attributes and targets: Little Gr ebe (Tachybaptus ruficollis) [A004] Great Crested Grebe (Podiceps cristatus) [A005] Cormorant (Phalacrocorax carbo) [A017] Grey Heron (Ardea cinerea) [A028] Bewick's Swan (Cygnus columbianus) [A037] Whooper Swan (Cygnus cygnu) [A038] Light‐ bellied Brent Goose (Branta bernicla hrota) [A046] Shelduck (Tadorna tadorna) [A048] Wigeon (Anas Penelope) [A050] Teal (Anas cracca) [A052] M allard (Anas platyrhynchos) [A053] Pintail (Anas acuta) [A054] Scaup (Aythya marila) [A062] Goldeneye (Bucephala clangula) [A067] Red‐ breasted Merganser (Mergus serrator) [A069] Coot (Fulica atra) [A125] Oystercatcher (Haematopus ostralegus) [A130] Golden Plover (Pluvialis apricaria) [A140] Grey Plover ( Pluvialis squatarola) [A141] Lapwing (Vanellus vanellus) [A142] Knot (Calidris canutus) [A143]
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Site Code Site Name Conservation Objectives
Sanderling (Calidris alba) [A144] Du nlin (Calidris alpina) [A149] Black‐tailed G od wit (Limosa limosa) [A156] Bar‐tailed G od wit (Limosa lapponica) [A157] Curlew (Nu menius arquata) [A160] Redshank (Tringa tetanus) [A162] Black‐ headed Gull (Chroicocephalus ridibundus) [A179] Lesser Black‐ backed Gull (Larus fuscus) [A183] Greenland White‐fronted goose (Anser albifrons flavirostris) [A395]
Attribute Measure Target Population trend Percentage change Long term population trend stable or increasing. Distribution Number and range of areas used by There should be no significant decrease in the w aterbirds nu mbers or range of areas used by waterbird species, other than that occurring from natural patterns of variation
Hen Harrier (Circus cyaneus) [A082] Attribute Measure Target Roost attendance: Number No significant decline. individual hen harriers Suitable foragin g hectares No significant decline. habitat
R oost site: condition Area (hectares); structure The roost site should be maintained in a suitable condition. Disturbance at the Level of impact Human activities should occur at levels that do roost site not adversely affect the Hen Harrier winter roost population.
Little Tern (Sterna albifrons) [A195] Attribute Measure Target Breeding population Number No significant decline. abundance: apparently occupied nests (AONs) Productivity rate: fledged Mean number No significant decline. young per breeding pair
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Site Code Site Name Conservation Objectives
Distribution: breeding Nu m ber; location; area No significant decline. colonies (Hectares) Prey biomass available Kilogrammes No significant decline.
Barriers to connectivity Number; location; shape; area No significant increase. (hectares) Disturbance at the breeding Level of impact Human activities should occur at levels that site do not adversely affect the breeding little tern population.
IE004127 Wicklow Head Conservation Objectives Generic Version 6.0 (21/02/18) SPA To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA: Special Conservation Interests Kittiwake (Rissa tridactyla) [A188] Conservation attributes and targets have not been published.
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APPENDIX 3: PHYSICAL PROCESSES BASELINE REPORT
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ARKLOW BANK WIND PARK
Physical Environment Factual Report
EOR0731 Arklow Bank Wind Park Rev: 03 19 January 2020
rpsgroup.com
Physical Environment Factual Report
Document status
Review Version Purpose of document Authored by Reviewed by Approved by date
03 Factual Report NRS MW MB 19/01/2020
Approval for issue
Dr Malcolm Brian 19 January 2020
© Copyright RPS Group Plc. All rights reserved.
The report has been prepared for the exclusive use of our client and unless otherwise agreed in writing by RPS Group Plc, any of its subsidiaries, or a related entity (collectively 'RPS'), no other party may use, make use of, or rely on the contents of this report. The report has been compiled using the resources agreed with the client and in accordance with the scope of work agreed with the client. No liability is accepted by RPS for any use of this report, other than the purpose for which it was prepared. The report does not account for any changes relating to the subject matter of the report, or any legislative or regulatory changes that have occurred since the report was produced and that may affect the report. RPS does not accept any responsibility or liability for loss whatsoever to any third party caused by, related to or arising out of any use or reliance on the report.
RPS accepts no responsibility for any documents or information supplied to RPS by others and no legal liability arising from the use by others of opinions or data contained in this report. It is expressly stated that no independent verification of any documents or information supplied by others has been made. RPS has used reasonable skill, care and diligence in compiling this report and no warranty is provided as to the report’s accuracy. No part of this report may be copied or reproduced, by any means, without the prior written consent of RPS.
Prepared by: Prepared for:
RPS SSE Renewables
Dr Naomi Shannon Senior Engineer
Elmwood House, 74 Boucher Road, Red Oak South, South County Business Park Belfast, BT12 6RZ, Northern Ireland Leopardstown, Dublin, D18 W688
T +44 (0) 2890 667914 T +353 (0) 1 655 6128 E [email protected] E
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Contents INTRODUCTION ...... 1 BASELINE CONDITIONS...... 3 2.2 Bathymetry ...... 3 2.3 Hydrography...... 6 2.3.1 Tidal Flows ...... 6 2.3.2 Wave Climate ...... 7 2.3.3 Littoral Currents ...... 12 2.4 Sedimentology ...... 15 2.4.2 Sediment Transportation ...... 16 2.4.3 Suspended Sediments ...... 28 SUMMARY...... 30
Figures Figure 1-1: Physical processes study area – brown ellipse ...... 1 Figure 1-2: Model domain - yellow outline ...... 2 Figure 2-1: Bathymetric data (right) detail of INFOMAR dataset (inset) ...... 4 Figure 2-2: Model bathymetry ...... 5 Figure 2-3: Detail of model bathymetry at site with existing Phase 1 turbine locations ...... 6 Figure 2-4: Location of calibration data presented ...... 2 Figure 2-5: Comparison of model and recorded data BODC location A (spring left, neap right) ...... 3 Figure 2-6: Comparison of model and recorded data BODC location B (spring left, neap right) ...... 3 Figure 2-7: Comparison of model and recorded data Admiralty diamond location 1468A (spring left, neap right) ...... 3 Figure 2-8: Comparison of model and recorded data Admiralty diamond location 1787B (spring left, neap right) ...... 3 Figure 2-9: Tidal flow patterns - mid-flood ...... 5 Figure 2-10: Tidal flow patterns - mid-ebb ...... 6 Figure 2-11: Wave rose for east Arklow Bank ...... 7 Figure 2-12: Wave rose for north (left) and east (right) model boundaries ...... 8 Figure 2-13: Wave rose for south model boundary ...... 8 Figure 2-14: Wind rose for Arklow Bank ...... 9 Figure 2-15: Wave climate 1:1 year storm from 015° at HW (left) & LW (right) ...... 10 Figure 2-16: Wave climate 1:1 year storm from 105° at HW (left) & LW (right) ...... 11 Figure 2-17: Wave climate 1:1 year storm from 195° at HW (left) & LW (right) ...... 12
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Figure 2-18: Littoral current 1:1 year storm from 195° - flood tide ...... 13 Figure 2-19: Littoral current 1:1 year storm from 195° - ebb tide ...... 14 Figure 2-20: Seabed classification GSI ...... 16 Figure 2-21: Admiralty Chart 1787 & Arklow Bank Survey 2016 Bathymetry ...... 17 Figure 2-22: Sand waves at the southern tip of Arklow Bank ...... 18 Figure 2-23: Residual current spring tide ...... 20 Figure 2-24: Potential net sediment transport - spring tide ...... 21 Figure 2-25: Rate of bed level change- mid flood spring tide ...... 22 Figure 2-26: Rate of bed level change - mid ebb spring tide ...... 23 Figure 2-27: Residual current spring tide with 1:1 year storm from 195° ...... 24 Figure 2-28: Potential net sediment transport - spring tide with 1:1 year storm from 195° ...... 25 Figure 2-29: Rate of bed level change - mid flood spring tide with 1:1 year storm from 195° ...... 26 Figure 2-30: Rate of bed level change - mid ebb spring tide with 1:1 year storm from 195° ...... 27 Figure 2-31: Distribution of average non-algal Suspended Particulate Matter ...... 29
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INTRODUCTION This report presents information relating to the physical environment and coastal processes for the Arklow Bank.
Arklow Bank is a shallow water sandbank in the Irish Sea that is situated approximately 13 km off the coast near Arklow. The Bank is approximately 25 km long, orientated roughly north-south and experiences very strong currents, sediment transport and breaking waves.
The following sections outline the physical conditions associated with the study area which is defined as one tidal excursion from the development as shown in Figure 1-1. The tidal excursion was quantified by utilising the calibrated numerical model described in Section 2. Neutrally buoyant particles were released across the extent of the site and the excursion of these particles was examined over the course of a spring tide cycle. This area formed the focus of the study however the model extent and analysis was not limited to this area.
Figure 1-1: Physical processes study area – brown ellipse
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To aid in the study, numerical modelling techniques were used to describe tide, wave and sediment transport regimes. The MIKE suite of software was employed, as a single model mesh could be used to simulate these processes both individually and in combination. The model domain is shown in Figure 1-2. The MIKE powered by DHI suite of models is a widely used industry standard modelling suite developed by the Danish Hydraulic Institute (DHI). It has been approved for use by industry and government bodies including the EPA. The MIKE suite is a modular system that contains a number of different but complementary modules encompassing different gridding approaches and representing different physical processes.
Figure 1-2: Model domain - yellow outline
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BASELINE CONDITIONS This section outlines the numerical modelling undertaken in order to determine the baseline conditions. It describes the physical environment in terms of sea state and sediment transport regimes.
2.2 Bathymetry The dimensions of this shallow offshore sandbank measure about 25 km by 2.5 km. On the Bank, water depths vary between 0.6 m and 25 m relative to lowest astronomical tide (LAT), with shallower areas particularly occurring in the vicinity of the existing Phase 1 turbines. The general morphology of this feature is oriented roughly in a north-south direction as illustrated on the Admiralty Chart 1121 presented in Figure 1-1. There is a large variation in depth within the site boundary, beyond the Bank water depths are in excess of 40 m LAT.
Model domain had full bathymetry data coverage and was populated using in excess of 100 data files. The numerical model was developed utilising all the available bathymetric surveys; this included data from the European Inspire project provided by INFOMAR, a joint programme between the Geological Survey Ireland and the Marine Institute, which incorporated high resolution surveys of the Bank and environs. Additionally the data collected from routine surveys undertaken for the maintenance of the existing Phase 1 turbines was incorporated.
The Codling and Arklow Banks along with the nearshore region were surveyed in 2016 by INFOMAR using the rib RV Geo to survey the shallow water regions. This data was supplemented with the Celtic Voyager data collected during surveys undertaken in 2011 and 2012. This data covered much of the model area however some older data from 2007 - 2009 was also utilised. In nearshore areas a number of smaller hydrographic surveys and LiDAR datasets were used.
Where additional data was required, digital chart data supplied by C-Map was included. The data was prioritised in order so that the most recent data was used where there was data overlay and all data was adjusted to the mean sea level datum. Figure 2-1 illustrates a section of the model domain and the bathymetric data incorporated whilst the inset shows the detail of the Arklow Bank survey data.
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Figure 2-1: Bathymetric data (right) detail of INFOMAR dataset (inset)
The crest of the Arklow Bank consists of a smooth seabed with areas of localised bedforms, attributed to the high current regime. Water depths vary along the Bank crest and beyond the Bank crest water depths increase, with the gradient of the crest slope being more pronounced on the eastern side. The sand waves on the extremities of the Bank are visible in the inset in Figure 2-1.
The resolution of the model bathymetry was designed to represent these bed forms for the accurate simulation of tidal currents. This included Arklow Bank and the surrounding bathymetry incorporating Seven Fathoms Bank to the west, India and Codling Banks to the north and Blackwater Bank to the south. Additionally the model resolution was increased to <5 m across the banks and over the licenced area in order that the wave breaking across the banks could be replicated and also to enable the influence of scour protection on the existing Phase 1 turbines to be included within the sediment transport modelling.
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The extent of the domain was designed to provide the basis for a model which could be utilised for tide, wave and sediment transport modelling. The model extends north, south and offshore beyond the adjacent banks to ensure that the influence of these banks is included in the detailed model. The northern and southern extents are also at sites where the tidal range is larger providing a more stable model. Figure 2-2 shows the variation in bathymetry across the model domain whilst Figure 2-3 shows the detail of the study area and illustrates the location of the existing Phase 1 turbines with respect to the licenced area.
Figure 2-2: Model bathymetry
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Figure 2-3: Detail of model bathymetry at site with existing Phase 1 turbine locations
2.3 Hydrography 2.3.1 Tidal Flows UK Hydrographic Office states that the mean tidal range at the Standard Port of Arklow is approx. 0.5 m with the following characteristics in meters referenced to Chart Datum (CD):
• Lowest Astronomical Tide (LAT) : +0.2 • Mean Sea Level (MSL): +1.0
• Mean Low Water Springs (MLWS): • Mean High Water Neaps (MHWN): +1.2 +0.6 • Mean High Water Springs (MHWS): • Mean Low Water Neaps (MLWN): +0.9 +1.4
• Highest Astronomical Tide (HAT): +1.6
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However in the region of Arklow Bank it may be double this value due to the different spatial location of the gauging station within the Harbour in relation to the amphidromic point near Courtown, and the effects of bathymetry at the Bank. Storm surge may increase surface elevations i.e. water levels by up to 1.0 m for the 50 year event.
The Arklow Bank is subject to very strong tidal currents with the general direction of flow in the offshore regions of the Bank towards the NNE during flood and towards SSW during ebb. Spring tidal current speeds are in excess of 2 m/s towards the north end of the Bank on both flood and ebb tides whilst to the south the peak tidal currents are around 1.7 m/s1.
The tidal flow simulations which form the basis of the study were undertaken using the MIKE21 FM flexible mesh modelling system. The FM Module is a 2-dimensional, depth averaged hydrodynamic model which simulates the water level variations and flows in response to a variety of forcing functions in lakes, estuaries and coastal areas. The water levels and flows are resolved on a mesh covering the area of interest when provided with bathymetry, bed resistance coefficient, wind field, hydrodynamic boundary conditions, etc.
The tidal model was driven using boundary conditions extracted from the RPS Irish Sea Surge model which is used for live storm surge forecasting on behalf of the OPW. These boundaries were fully defined ‘flather’ boundaries for which both surface elevation and current vectors are specified. The model was calibrated using the following data sources:
Admiralty tidal diamonds
Data sourced from the British Oceanographic Data Centre (BODC)
Data collected during borehole drilling collected by Sure Partners Ltd in 20002
A sample of the calibration data is presented in the following figures as illustrated in Figure 2-4. In each case the measured data is shown in dark blue and black with the spring tide plot on the left and neap on the right. The first figures Figure 2-5 and Figure 2-6 relate to data from the BODC database and the model is seen to correlate well in both current speed and direction for the range of tides experienced at these locations.
The second datasets presented in Figure 2-7 and Figure 2-8 relate to Admiralty tidal diamonds for locations east of the Arklow Bank. This data is published in a generalised format i.e. there are 14 sets of hourly current speed data referenced to high water Dublin for spring and neap tides and a single set of current direction values. These values therefore do not relate to a known time period or specific tidal range.
1 Admiralty Chart 1787 Carnsore Point to Wicklow Head, UK Hydrographic Office
2 Offshore Windfarm Development, Arklow Bank, Exploratory Borehole Records, Sure Partners Ltd, September 2000
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The Admiralty data (shown by points) correlate well with the modelled current directions and neap tidal current speed, with the modelled spring currents being slightly lower. This is expected as the field data was generally collected using drogues which measure the higher surface current speeds than those simulated in a depth averaged model.
Figure 2-4: Location of calibration data presented
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Figure 2-5: Comparison of model and recorded data BODC location A (spring left, neap right)
Figure 2-6: Comparison of model and recorded data BODC location B (spring left, neap right)
Figure 2-7: Comparison of model and recorded data Admiralty diamond location 1468A (spring left, neap right)
Figure 2-8: Comparison of model and recorded data Admiralty diamond location 1787B (spring left, neap right)
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The numerical model output demonstrates that tidal currents are greatly increased along the Bank and adjacent shallows to the north of the Bank. These currents diminish rapidly as the tide flows into deeper waters on either side of the Bank. Figure 2-9 shows the tidal patterns during mid-flood on a spring tide whilst Figure 2-10 illustrates the ebb tide. These figures demonstrate how the tidal flows are deflected across the Bank due to depth limitation; the residual tidal flows and how they drive sediment transport regimes are examined in the following Section 2.4.
It should be noted that the baseline tidal simulations were undertaken with the existing Phase 1 turbines included as 5 m diameter pier structures within the model.
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Figure 2-9: Tidal flow patterns - mid-flood
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Figure 2-10: Tidal flow patterns - mid-ebb
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2.3.2 Wave Climate Breaking waves are often present on parts of the Bank, even during low swell conditions. There is a dominance of southerly waves attributed to large Atlantic swells entering the Irish Sea via the St Georges Channel and the dominance of westerly winds. This is shown in Figure 2-11 which presents the significant wave height and directionality of waves to the east of the Arklow Bank from the UK Met Office database.
Figure 2-11: Wave rose for east Arklow Bank
The nearshore wave climate is influenced by shallowing water depths as waves enter the Irish Sea. Waves are refracted towards the coast with the majority of waves coming from SSW (SW to SSE). Large waves (exceeding 2 m) have been recorded for nearly all directions between 0 and 300 degrees. Due to the shallow bathymetry at the Arklow Bank it is apparent that a large proportion of the waves break when reaching the Bank, as they are higher than the breaker index 0.78 d, where d is the water depth. The Bank therefore acts as a natural breakwater and the influence of the Bank on the wave climate is examined further in the numerical modelling.
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An analysis was undertaken to determine the offshore conditions for which waves reach the site from all directions. Twenty-two years of data were obtained from the European Centre for Medium-range Weather Forecasting’s (ECMWF’s) operational dataset for locations on the north, east and southern boundaries of the model domain. The wave roses for these sites are presented in Figure 2-12 for the north and east and Figure 2-13 for the south. Extreme value analysis was undertaken for the principle sectors to determine the 1 in 1 and 1 in 50 year offshore wave climate. These were then used as boundary conditions within the wave modelling to determine the resultant wave climate at the site.
Figure 2-12: Wave rose for north (left) and east (right) model boundaries
Figure 2-13: Wave rose for south model boundary
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In addition to boundary wave data it was necessary to analyse the wind field to include the contribution of local wind seas. For this a point at the site was extracted from the National Oceanic and Atmospheric Administration (NOAA) global database which holds 40 years of reanalysis data. The wind rose for this period is presented in Figure 2-14.
Figure 2-14: Wind rose for Arklow Bank
The wave modelling was undertaken using the spectral wave model, MIKE 21 SW, to provide a full wave climate and wave breaking across Arklow Bank. The waves were computed on the same grid as the tidal flows. The model resolves the wave field by simulating wind generation of waves within the model domain and the propagation of externally generated swell waves through the domain. The model setup ensured that the detail of both locally generated wind waves and swell conditions from further afield were captured.
The following set of figures show the wave climate for three 1 in 1 year return period events; from approximately a northerly (015°), easterly (105°) and southerly (195°) direction. In each case the figure presented on the left denotes high water (HW) spring tide whilst the right-hand figure shows the low water (LW) scenario. As with the tidal modelling, the existing Phase 1 turbine towers were included as structures within the modelling.
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Figure 2-15 shows the waves approaching from the north and demonstrates how, even though they do not directly cross the Bank, they are affected by the shallow bathymetry to the north which results in a localised increase in wave heights. The easterly event, Figure 2-16, is the smallest of the three, given that it is a fetch limited wind-sea. It clearly demonstrates that the reduction in water depth over the Bank during low tide has a significant impact on wave breaking which in turn results in the incident wave heights being reduced by as much as c.35%.
Finally, Figure 2-17 for the dominant SSW direction shows the largest wave climate where swell conditions combine with locally wind generated waves. It will be seen that the direction of the waves diverge slightly after interacting with the Bank owing to the combined effect of refraction and shoaling but still continue to propagate inshore. In general the Bank does not significantly alter the directionality of the waves however wave heights are significantly reduced by the presence of this feature. This is particularly marked with events from easterly through to south-westerly directions and during periods of low water where wave breaking is increased.
Figure 2-15: Wave climate 1:1 year storm from 015° at HW (left) & LW (right)
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Figure 2-16: Wave climate 1:1 year storm from 105° at HW (left) & LW (right)
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Figure 2-17: Wave climate 1:1 year storm from 195° at HW (left) & LW (right)
2.3.3 Littoral Currents The MIKE suite facilitates the coupling of models. The depth averaged hydrodynamic model, used for the tidal modelling, coupled with the spectral wave model provides a full wave climate incorporating the impact of water levels and currents on waves and wave breaking. Using this the littoral currents i.e. those currents driven by tidal, wave and meteorological forces were examined.
The 1 in 1 year storm from 195° was simulated with the inclusion of spring tides and the resulting mid-flood and mid-ebb currents are presented in Figure 2-18 and Figure 2-19 respectively. These correspond with the (calm) tidal plots presented in Section 2.3.1, Figure 2-9 and Figure 2-10. As expected the presence of the north going waves increase the currents on the flood tide whilst reducing them on the ebb.
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Figure 2-18: Littoral current 1:1 year storm from 195° - flood tide
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Figure 2-19: Littoral current 1:1 year storm from 195° - ebb tide
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2.4 Sedimentology The Arklow Bank is sand and gravel dominated with mobile surface sediments3,4. Medium sand is mainly located at upper levels (<15 m) with a gravel-sand with gravel fractions located at greater depths. The surrounding sea floor of the study area is littered with sand and gravel deposits. The precise origins of the Bank is unclear and may be a combination of coastal erosion deposits from the shoreline, remnants of a former coastline and/or reworking of glacial seabed deposits.
The substratum ranges from sandy shell to gravel to the west, north and south of the Bank to coarse shell and gravel and some rock to the east of the Bank. The Bank itself consists of mainly sand, cobbles with shells and pebbles at the northern end of the Bank and fine sand at the southern end. Below the Bank core, quaternary soils predominantly consist of very dense sand, gravel and gravelly sand. A thin clay layer was encountered in only one of the initial borings at the north end of the Bank carried out by Sure Partners Ltd in 2000.
This evidence is further supported in the Geological and geotechnical desk study undertaken for this project4 which includes a full review of available data, including Geological Survey Ireland (GSI) data on seabed substrate as shown in Figure 2-20. The representative soil profile derived in the desk study was used to inform the sediment transport modelling and a candidate sediment was identified. This was a fine sand with 0.25 mm average diameter and a relative density of 40%. For the surface layers of the cores 80% of the sand was of 0.25 mm diameter and all samples were between 0.06 mm and 1 mm.
3 Offshore Windfarm Development, Arklow Bank, Exploratory Borehole Records, Sure Partners Ltd, September 2000
4 Geological and Geotechnical Desk Top Study, Arklow Bank OWF, Report No.: C928R01-02, Cathie Associates Ltd, 2018
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Figure 2-20: Seabed classification GSI
2.4.2 Sediment Transportation Given the nature of the strong tidal current regime in the area it is likely that tidal flows are the primary factor that governs the movement of sediment and hence the morphological form of the Bank. Some studies5,6 suggest the Bank has apparently moved slightly eastward. It should be noted that Admiralty Charts are prepared using a Transverse Mercator projection and effectively linearise longitude and latitude scales and therefore care must be taken when plotting survey data directly. When the soundings from the Admiralty chart are transferred to the same projection as the survey these changes are not apparent. Figure 2-21 demonstrates that in the Admiralty data and survey data collected by INFOMAR in 2016 the Banks are aligned.
5 Effect of Wind Farm Structures on the Arklow Bank Seabed, J. Murphy & B Dollard on behalf of Sure Engineering Europe 2001
6 Panigrahi J.K. et al, Coastal morphological modelling to assess the dynamics of Arklow Bank, Ireland, International Journal of Science Research, September 2009
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Figure 2-21: Admiralty Chart 1787 & Arklow Bank Survey 2016 Bathymetry
On the Bank, the presence of sand waves provides evidence of seabed sediment transport occurring in a north-easterly direction to the west of the Bank and south-easterly to the east. Sand waves are present on all sides of the Bank, and can measure up to 150 m wave length and up to 10 m amplitude. This is further illustrated in Figure 2-22 where an area of the 2016 survey showing the southern tip, at the limit of the site boundary, is presented in greater detail.
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Figure 2-22: Sand waves at the southern tip of Arklow Bank
The MIKE 21 Sediment Transport module enables assessment of bed sediment transport rates and initial rates of bed level change for non-cohesive sediment resulting from currents or combined wave-current flows. It was used to determine the sediment transport pattern on and around Arklow Bank. The model combines inputs from both the hydrodynamic model and, if required, the wave propagation model. It used sediment sizes and gradation as discussed in the previous section to determine the bed level changes and sediment transport rates.
The model domain was setup with a layer of mobile bed material as described by the borehole logs. Where each of the existing Phase 1 turbines are located, an area of fixed bed was provided to represent the scour protection; extending in a 10 m radius from the turbine. This was initially overlain by a thin layer of sand to avoid numerical instability. Additionally the turbine towers were also included as sub-scale structures within the model.
Two sediment transport scenarios were examined, one relating to calm conditions and a second relating to the 1 in 1 year return period event from 195°. In each case the evaluations were undertaken over the course of a spring tide. These simulations included a period for the hydrodynamics and wave fields to stabilise and develop across the domain, i.e. a “warm- up” period.
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For each scenario three aspects were examined. Firstly the residual current, which is the net flow over the course of the tidal cycle. This is effectively the driving force of the sediment transport. The second aspect was the potential annual sediment transport as a result of this residual current. The net sediment transported during the tidal cycle was used to assess the annual net load. These net values do not provide a full picture of the transport mechanism so the third aspect was the transport process at different periods in the tidal cycle.
For the tidal current alone the residual current is presented in Figure 2-23. It is characterised by a clockwise current around the Bank. The resultant transport rate, Figure 2-24, further illustrates that although the bed is mobile the Bank itself is relatively stable. The mechanism is illustrated in Figure 2-25 and Figure 2-26 where the western side of the Bank is eroded on the ebb tide and accretes on the flood; with the reverse occurring on the eastern side of the Bank. This correlates with numerous studies undertaken on Arklow Bank7.
When a storm approaches from the south the flood tide currents are enhanced by the wave climate. This is reflected in an increase in the residual currents and thus an increase in net annual sediment transport capacity as illustrated in Figure 2-27 and Figure 2-28 respectively. Similarly the figures showing the changes in bed level mid tide indicate increases on both faces of the Bank particularly in relation to erosion; Figure 2-29 shows the flood tide whilst Figure 2-30 indicates the mid ebb stage.
7 Panigrahi J.K. et al, Coastal morphological modelling to assess the dynamics of Arklow Bank, Ireland, International Journal of Science Research, September 2009
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Figure 2-23: Residual current spring tide
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Figure 2-24: Potential net sediment transport - spring tide
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Figure 2-25: Rate of bed level change- mid flood spring tide
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Figure 2-26: Rate of bed level change - mid ebb spring tide
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Figure 2-27: Residual current spring tide with 1:1 year storm from 195°
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Figure 2-28: Potential net sediment transport - spring tide with 1:1 year storm from 195°
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Figure 2-29: Rate of bed level change - mid flood spring tide with 1:1 year storm from 195°
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Figure 2-30: Rate of bed level change - mid ebb spring tide with 1:1 year storm from 195°
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2.4.3 Suspended Sediments Sediment in the study area is dominated by sand or slightly gravelly sand. Recent sampling campaigns8 in the area confirm that the Bank is made up of sandy sediments with around 90% of the sediment composition being between 2 mm and 63 µm. The significant proportion of relatively fine material coupled with the high energy in the region would indicate an area with potentially high background levels of suspended sediment particularly during storm events. However the principle driver for morphological changes to the Bank will be due to the bedload; with the Bank being a highly dynamic system as discussed in the previous section.
The CEFAS Climatology Report 20169 shows the spatial distribution of average non-algal Suspended Particulate Matter (SPM) for the majority of the UK continental shelf. For the period 1998-2005 the largest plumes are associated with large rivers such as the Thames estuary, the Wash and Liverpool Bay, which show mean values of SPM above 30 mg/l. Using this study, it is estimated that the average SPM associated with the Arklow Bank over this period is approximately 10 mg/l to 15 mg/l as shown in Figure 2-31. The higher levels are experienced more commonly in the winter months however, due to the tidal influence, even during summer months the levels remain elevated.
8 Arklow Energy Limited, Dumping at Sea Permit Application: Material Analysis Report, May 2016
9 CEFAS, Suspended Sediment Climatologies around the UK, December 2016
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Figure 2-31: Distribution of average non-algal Suspended Particulate Matter
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SUMMARY Arklow Bank is an important natural breakwater which acts to reduce the incident wave heights through the combined effect of shoaling and refraction.
This report has outlined the baseline characteristics of the Bank and environs in terms of coastal processes. This includes tidal current, wave climate and sediment transport under both calm and storm conditions.
The numerical modelling has supported the theory that although the bed, which is medium sand, is mobile the Bank itself is dynamically stable. This is due to the circulating nature of the residual currents.
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