Replacement Linkspan, Fishguard Port

7.0 MARINE BIODIVERSITY

7.1 Introduction

This chapter provides an assessment of the potential significant effects of the proposed development on marine ecology receptors. The following marine ecology receptors have been considered as part of the assessment:

- Nature conservation protected habitats and species; - Benthic habitats and species (including non-native species); - Plankton; - Fish and shellfish species; and - Marine mammals.

In outline, the structure of the chapter is as follows:

- Impact Assessment Approach (Section 7.2): This section includes a review of the study area and the impact assessment methods applied. - Baseline Conditions (Section 7.3): This section describes the ecological and nature conservation character of the areas around the development site. This includes areas which may be directly or indirectly affected by the proposed development. However, it also reviews the characteristics of wider areas across the local region to provide context and to inform the assessment. - Impact Assessment (Section 7.4): This section presents an assessment of the impact significance from the effects that could arise from the proposed development. This assessment is based on information on the proposed development design and baseline environment (see also Section 7.2). - Cumulative and In-combination (Section 7.5): The effects of the proposed development have been considered in conjunction with the potential effects from other plans, projects or activities. - Mitigation Measures and Monitoring (Section 7.6). Where project impacts have been assessed as having a moderate or major significance then mitigation measures are identified. This section includes reference to ‘embedded’ mitigation which form an inherent part of the project as well as to any new mitigation measures which have been identified following this assessment. - Conclusions (Section 7.7): This final section summarises the outcome of the assessment process, including residual effects in the context of any proposed mitigation measures.

7.2 Impact Assessment Approach

7.2.1 Study Area

The study area encompasses all ‘impact pathways’ or zones of influence by which the receptors could be affected. The ‘main study area’ encompasses the immediate direct and indirect effects from the proposed development. As determined in the Coastal Processes assessment (Chapter 4 of the ES) the effects on hydrodynamics and sedimentary processes are largely confined to the area within Fishguard Port. However, for some receptors a wider study area has been necessary (e.g. in respect of migratory routes) and these are defined in individual sections where necessary.

7.2.2 Impact Assessment Methodology

To facilitate the impact assessment process a standard analysis methodology has been applied. This framework has been developed from a range of sources, including The Marine Works (Environmental Impact Assessment) (Amendment) Regulations 2017, statutory guidance, consultations and ABPmer’s previous (extensive) EIA project experience. The key guidance and regulations that have been drawn upon include:

- The criteria listed in Annex III of the EC Environmental Assessment Directive (85/337 EEC as amended by 2014/52/EU); - The assessment process developed by statutory conservation agencies to provide advice on operations within European Marine Sites; and - The principles highlighted in the Charted Institute of Ecology and Environmental Management's (CIEEM) Guidelines for Ecological Impact Assessment in the UK (CIEEM,

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2006), Guidance on Impact Assessment in Marine and Coastal Environments (CIEEM, 2010) and Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater and Coastal (CIEEM, 2016).

All environmental issues have been divided into distinct ‘receiving environments’ or ‘receptors’. The effect of the proposed activity on each of these has been assessed by describing in turn: the baseline environmental conditions of each receiving environment; the ‘impact pathways’ by which the receptors could be affected; the significance of the impacts occurring and the measures to mitigate for significant adverse impacts where these are predicted.

This impact assessment framework, which is presented in the following sections, is designed to incorporate the key criteria and considerations without being overly prescriptive.

7.2.3 Stage 1 - Identify Features and Changes

The first stage has involved identifying the potential environmental changes resulting from the proposed activity and the features of interest (receptors) that are likely to be affected (which are together referred to as the impact pathway). This aspect of the assessment has been developed in consultation with Natural Resources Wales (NRW).

7.2.4 Stage 2 - Understand Change and Sensitivity

The second stage has involved understanding the nature of the environmental changes to provide a benchmark against which the changes and levels of exposure can be compared. The scale of the impacts via the impact pathways depends upon a range of factors, including the following:

- Magnitude (local/strategic); - Spatial extent (small/large scale); - Duration (short/intermediate/long-term); - Frequency; - Reversibility; - Probability of occurrence; - Confidence, or certainty, in the impact prediction; - The margins by which set values are exceeded (e.g. water quality standards); - The importance of the receptor (e.g. designated habitats and protected species); - The sensitivity of the receptor (resistance/adaptability/recoverability); - The baseline conditions of the system; and - Existing long-term trends and natural variability.

7.2.5 Stage 3 - Impact Assessment

The likelihood of a feature being vulnerable to an impact pathway has then been evaluated as a basis for assessing the level of the impact and its significance. The tables and matrices below have been used to help assess significance.

Identification and Estimation of Change and Exposure

Construction and operational phases of the development have the potential to result in a range of ‘changes’ in the environment. These changes, or impacts, may or may not affect a receiving environment (i.e. receptor). The decommissioning phase of the development has not been considered as part of the assessment (Section 7.4.1).

Whether a receiving environment can be exposed to an impact or change depends on there being a route or pathway. The magnitude of change and its ability to affect a receptor also depends on a range of other factors, such as its duration, frequency and spatial extent and the background environmental conditions in a study area:

- Duration - the length of time a change can be considered to operate over is described as being either a short or long-term period. ‘Short-term’ changes are more likely to occur as a result of activities during the construction phase (which are temporary in nature), whilst ‘long- term’ is more likely to be relevant to the operational period; - Spatial extent - the spatial extent of a change is referred to using the terms ‘immediate’, ‘local’ and ‘estuary-wide’; and

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- Frequency - the ability for a change to be repeated is described by the terms ‘infrequent’, ‘frequent’ or ‘continuous’.

Table 7.1 sets out the basic criteria which have been used to determine the magnitude of an impact for the purposes of the impact assessment. Whilst these are basic criteria, not all changes can be defined. On this basis, expert judgement based on the overall system understanding is required to ‘moderate’ the assessment to ensure consistency for each issue at different locations.

Table 7.1: Basic Criteria for Defining Magnitude Of Impact Magnitude Definition Large Estuary and coastal wide extent with scale of change greater than the natural variability with a continuous signal extending into the long-term. Medium Local spatial extent with scale of impact within the same order as the natural variability, frequently occurring in the long-term. OR Immediate spatial extent with scale of change greater than the natural variability, occurring frequently over a short timescale. Small Local spatial extent with scale of impact smaller than the natural variability, frequently occurring over a short/temporary timescale. Negligible Immediate spatial extent (development footprint), with scale of impact smaller than the natural variability, occurring infrequently over a short/temporary timescale.

Once a magnitude has been assessed, this has been combined with the probability of occurrence to arrive at an exposure score which has then been used for the next step of the assessment (Table 7.2). For example, an impact pathway with a medium magnitude of change and a high probability of occurrence would result in a medium exposure to change.

Table7.1: Exposure to Change, Combining Magnitude And Probability Of Occurrence Probability of Magnitude of Change Occurrence Large Medium Small Negligible High High Medium Low Negligible Medium Medium Medium/Low Low /Negligible Negligible Low Low Low /Negligible Negligible Negligible Negligible Negligible Negligible Negligible Negligible

Sensitivity of Receptor

An effect can only occur if a receptor is exposed to a change to which it is sensitive. Sensitivity can be described as the intolerance of a receptor to readily accept the levels of predicted environmental change to which they are exposed and essentially considers the response characteristics of the feature.

The assessment of sensitivity therefore considers the adaptability of the receptor to change and its recoverability to its former state following exposure to the impact. In this assessment sensitivity has been considered as the degree of perturbation a receptor can tolerate in response to the predicted changes to which they are exposed. Thus, if a single or combination of environmental changes is likely to elicit a response then the feature under assessment has been considered to be sensitive.

This stage has essentially provided a benchmark against which the changes and level of exposure can be compared. In some cases it may be applicable to compare the anticipated change or exposure against either baseline conditions or other relevant thresholds such as quality criteria (i.e. for water, light or noise).

Vulnerability of Receptor

The vulnerability of the receptor has been scored based on its sensitivity and the exposure to change. Table 7.3 sets out how the level of vulnerability has been determined. Where the exposure and sensitivity characteristics overlap then a vulnerability exists and an effect may occur. For example if the impact pathway previously assessed with a medium exposure to change acted on a receptor which had a high sensitivity, this would result in an assessment of high vulnerability. Where an exposure or change occurs for which the receptor is not sensitive, then no vulnerability can occur. Similarly, where a negligible exposure is identified during an impact assessment, vulnerability will always be ‘none’, no matter how sensitive the feature is.

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Table 7.2: Estimation of Vulnerability Based On Sensitivity And Exposure To Change Sensitivity of Exposure to Change Feature High Medium Low Negligible High High High Moderate None Moderate High Moderate Low None Low Moderate Low Low None None None None None None

Importance of Receptor

Estimating and categorising the significance of an effect involves a degree of subjectivity. A receiving environment may have a high or a low vulnerability, but whether the potential effect is ‘significant’ will depend on its relative ‘importance’. The importance of a feature is based on its value and rarity i.e. in terms of nature conservation, or the value to the ecosystem or economy. For this assessment Table 7.4 provides basic definitions for determining the importance of the feature being assessed.

Table 7.3: Definition of Receptor Importance Receptor Importance Definition High Receptor designated and/or of international importance. Likely to be rare with minimal potential for substitution or unable to tolerate change. May also be of high or very high socioeconomic importance. Moderate Receptor designated and/or of national importance and/or some ability to tolerate change and recover in the medium term. Likely to be relatively rare. May also be of high socioeconomic importance. Low Receptor not designated but of local to regional importance and able to tolerate the effect to a large extent, with relatively rapid rate of recovery or not designated/ of local importance but not tolerant to change. Negligible Receptor only of local importance with a high tolerance to change.

Significance Criteria

The vulnerability has then been combined with the importance of the feature of interest using Table 7.5 to identify an initial level of significance.

Table 7.4: Estimation of Significance Based On Vulnerability and Importance Importance of Vulnerability of Feature to Impact Feature High Moderate Low None High Major Moderate Minor Insignificant Moderate Moderate Moderate/Minor Minor/Insignificant Insignificant Low Minor Minor/Insignificant Insignificant Insignificant None Insignificant Insignificant Insignificant Insignificant

The significance statement provides a summation of the evaluation process and considers both adverse and beneficial effects, which may be categorised as being either insignificant, minor, moderate or major.

In summary therefore, effects can be beneficial or adverse and have been described as follows:

- Insignificant: Neutral change not having a discernible effect; - Minor: Effects that are discernible but tolerable; - Moderate: Effects that are of a local to regional nature, of medium to long-term duration and/or where effects are anticipated to potentially be above accepted guidelines/standards. Where these changes are adverse they will usually require some impact reduction or mitigation measure where feasible; or - Major: Acute effect on a national or international scale, of long-term or permanent duration, and clearly above accepted guidelines or standards (or indeed against best practice policy, or even illegal in nature). Where these changes are adverse they will generally require extensive impact reduction or mitigation.

7.2.6 Cumulative Impact and In-combination Assessment

Under The Marine Works (EIA) Regulations (Amendment) 2011 it is necessary to assess the potential cumulative impacts of a proposed activity on all environmental receptors together with other known developments in the area. Under The Conservation of Habitats and Species Regulations 2010 (as

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amended) (‘Habitats Regulations’), it is also necessary to consider the in-combination effects of a development proposal specifically on the designated features of European Sites. The cumulative impact and Habitats Regulations in-combination assessments are presented in Section 7.5.

7.2.7 Stage 4 - Impact Management, Mitigation and Monitoring

The final stage identifies any impacts that are found to be of moderate and/or major adverse significance and require mitigation measures to reduce residual impacts to environmentally acceptable levels, as far as possible. Within the assessment procedure the use of mitigation measures will alter the risk of exposure and hence will require significance to be re-assessed and thus the residual impact to be identified.

7.3 Description of Baseline Conditions

7.3.1 Nature Conservation Protected Habitats and Species

Data Sources

The principal data sources used to describe baseline conditions are as follows:

- Joint Nature Conservation Committee (JNCC) website (http://jncc.defra.gov.uk/page-4): The current status of UK designated sites; - MAGIC (Multi-Agency Geographic Information for the Countryside) Interactive Map (http://www.magic.gov.uk) : Information on the boundaries of designated sites; and - Natura 2000 standard data forms/ information sheets for each designation: Information on the species and habitats listed in the original citations.

Internationally Designated Sites

Article 3 of the Habitats Directive (92/43/EEC, as amended) requires the establishment of a European network of important high-quality conservation sites known as Special Areas of Conservation (SACs) that will contribute to conserving habitat and species identified in Annexes I and II of the Directive. The listed habitat types and species are those considered to be most in need of conservation at a European level (excluding birds). In accordance with Article 4 of the EC Birds Directive (2009/147/EC), Special Protection Areas (SPAs) are strictly protected sites classified for rare and vulnerable birds (Annex I of the Directive), and for regularly occurring migratory species. Ramsar sites are wetlands of international importance designated under the Ramsar Convention (adopted in 1971 and came into force in 1975), providing a framework for the conservation and wise use of wetlands and their resources.

The West Wales Marine candidate SAC (cSAC) is the only international nature conservation designation that overlaps with the proposed development footprint (Figure 7.1). The site is situated off the coast of Wales, running from the Llŷn peninsula in the north to Pembrokeshire in the southwest, covering 7,376 km². This site has been designated for the protection of harbour porpoise Phocoena phocoena with the conservation objectives to: (JNCC, 2017)[1]:

“avoid deterioration of the habitats of the harbour porpoise or significant disturbance to the harbour porpoise, thus ensuring that the integrity of the site is maintained and the site makes an appropriate contribution to maintaining Favourable Conservation Status for the UK harbour porpoise.”

In addition, a number of other internationally designated sites in the wider area have mobile marine features that could be potentially affected by the development. These sites are described in more detail in Table 7.6.

No designated Ramsar sites are located in Fishguard Harbour or the wider Pembrokeshire coast area.

[1] JNCC (2017) West Wales Marine / Gorllewin Cymru Forol MPA [Online] Available at: http://jncc.defra.gov.uk/page-7343 [Accessed 30/06/17]

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Table 7.5: Designated Sites for Mobile Features in the Wider Area

Designated Site Distance from Mobile Features development footprint West Wales Overlaps with Annex II species that are a primary reason for selection of Marine candidate proposed this site: SAC (cSAC) development - Harbour Porpoise Phocoena phocoena. footprint. The 16 km Annex II species that are a primary reason for selection of Pembrokeshire this site: Marine SAC - Grey seal Halichoerus grypus. Annex II species present as a qualifying feature, but not a primary reason for site selection: - Sea lamprey Petromyzon marinus; - River lamprey Lampetra fluviatilis; - Allis shad Alosa alosa; and - Twaite shad Alosa fallax. The Cardigan 16 km Annex II species that are a primary reason for selection of Bay SAC this site: - Bottlenose dolphin Tursiops truncates. Annex II species present as a qualifying feature, but not a primary reason for site selection: - Sea lamprey Petromyzon marinus; - River lamprey Lampetra fluviatilis; and - Grey seal Halichoerus grypus. Grassholm SPA 44 km Article 4.2 Qualification (79/409/EEC): - Northern Gannet Morus bassanus Skomer, 31 km Article 4.1 Qualification (79/409/EEC): Skokholm and - European Storm Petrel Hydrobates pelagicus. the Seas off Article 4.2 Qualification (79/409/EEC): Pembrokeshire - Manx Shearwater Puffinus puffinus; and SPA - Atlantic Puffin Fratercula arctica. - Lesser Black-backed Gull Larus fuscus Article 4.2 Qualification (79/409/EEC): An internationally important assemblage of birds: - 394,260 seabirds.

European Marine Sites

A European Marine Site (EMS) is the collective term used to refer to SACs and SPAs (and Ramsar sites) that are covered by tidal water and protect some of the most special marine and coastal habitats and species of European importance. They are defined by the Conservation of Habitats and Species Regulations 2010 (SI 2010/490), which transpose the EC Birds Directive (2009/147/EC) and EC Habitats Directive (92/43/EEC) into national law. NRW provides advice under Regulation 35 of the Habitats Regulations on the conservation objectives of EMSs in Wales.

The Pembrokeshire EMS has the Pembrokeshire Marine SAC as a component designation and the Cardigan Bay EMS has the Cardigan Bay SAC as a component designation.

World Heritage Sites

There are no World Heritage Sites (WHSs) located within the study area with the nearest WHS (Harlech Castle) more than 100 km from the proposed development.

Nationally Designated Sites

The UK is in the process of establishing an ‘ecologically coherent network of Marine Protected Areas (MPAs)’. This network will be made up of current MPAs as well as newly designated Marine Conservation Zones (MCZs). In 2014, the first MCZ in Welsh waters was established around Skomer Island, Pembrokeshire (> 50 km from Fishguard Port).

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The nearest Site of Special Scientific Interest (SSSI) to Fishguard Port is Strumble Head - Llechdafad Cliffs SSSI (approximately 20 km away). This site is designated for a range of features including breeding grey seals as well as seabird colonies (CCW, 2009).

The Pembrokeshire Coast National Park is located within approximately 700 m of the proposed development. The National Park was established in 1952 and is the only one in the United Kingdom to have been designated primarily because of its spectacular coastline.

There are no Areas of Outstanding Natural Beauty (AONBs) located within the study area. The nearest AONB (Gower) is located more than 70 km from the proposed development.

Biodiversity Action Plans and Priority Habitats and Species

The UK Biodiversity Action Plan (UKBAP) is the UK Government’s response to the Convention on Biological Diversity signed in 1992. It describes the UK’s biological resources and commits a detailed plan for the protection of these resources. Local Biodiversity Action Plans (LBAPs) aim to conserve biodiversity through local partnerships, taking into account both national and local priorities. Plans are designed to involve local people and organisations through the practical delivery of biodiversity conservation, and aims to promote public awareness and contribute to international conservation efforts. It should be noted that the majority of habitats and species contained on the BAP priority lists are now considered as habitats or species of principal importance for the conservation of biodiversity in England and Wales under the Natural Environment and Rural Communities (NERC) Act 2006.

Protected Species and Habitats

Various species of marine animals are protected from being killed, injured or disturbed under provisions in the Habitats Directive and Section 9(4) and Schedule 5 of the Wildlife and Countryside Act 1981 (WACA) (as amended by the Countryside and Rights of Way Act 2000). Of particular relevance to the proposed development are whales and dolphins. The presence of these species as well as impacts upon them, are further discussed in Section 7.4.6.

Additionally all dolphins, porpoise and whale species are European Protected Species (EPS) and receive protection from being killed, injured or disturbed under the Conservation of Habitats and Species Regulations 2010 (as amended).

Four marine species listed in Annex IV of the Habitats Directive are known to occur in UK coastal and offshore waters; the grey seal Halichoerus grypus, common seal Phoca vitulina, bottlenose dolphin Tursiops truncatus and harbour porpoise Phocoena phocoena. The regional presence of these species, as well as impacts upon them, are further discussed in Section 7.4.6.

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Figure 7.1: Designated Nature Conservation Areas in Fishguard Harbour and the Wider Area

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7.3.2 Benthic Habitats and Species

Data Sources

The principal data sources used to describe baseline conditions are as follows:

- Fishguard Ferry Port Marine Ecology Surveys: Site specific baseline surveys for the proposed replacement linkspan undertaken in June 2017(ABPmer, 2017); - Fishguard Drop-Down Video Survey: Drop-down video survey of predominantly subtidal habitats in Goodwick Bay and the wider Fishguard area undertaken in October 2015 (Aquatic Environments, 2015); - Fishguard Harbour Littoral Biotope Mapping Survey: Phase 1 intertidal habitat survey undertaken in 2011 (Aquatic Environments, 2011); - Non-native animal species: Summary information on the status of marine non-native animal species in Wales as part of a Marine non-native species workshop undertaken in 2010 (Brazier, 2010); and - Non-native plant species: Summary information on the status of marine non-native plant species in Wales as part of a Marine non-native species workshop undertaken in 2010 (Wyn, 2010).

A broad overview focusing on benthic habitats and species in Fishguard Harbour is provided in Section 7.3.2.2). This is based on intertidal and subtidal habitat surveys that do not directly overlap with the development footprint. However, this still provided useful contextual information on habitats occurring more generally in Fishguard Harbour. The results of the site specific marine ecology surveys which focus specifically on habitats within and nearby to the proposed development footprint are then described in (Section 7.3.3.3).

Fishguard Harbour Overview

Fishguard Harbour contains a wide variety of marine habitats with the seabed consisting of mud, fine sands and gravel along with patches of boulders, cobbles and bedrock outcrops.

Intertidal Habitats

Biotope mapping of a range of intertidal habitats within Fishguard Harbour was undertaken in 2011 as part of baseline surveys for a proposed marina development (Aquatic Environments, 2011). The survey focused on intertidal habitat around Goodwick Sands. The habitat mapping involved a walk- over survey and also the collection of infaunal core samples for invertebrate analysis. The biotopes assigned were based on the Marine Habitat Classification for Britain and Ireland (MHCBI) version 04.05 (Connor et al., 2004). Summary information on the habitats and species recorded in the survey and biotopes assigned are provided in Table 7.7.

Table 7.6: Habitats and Species Identified in the Fishguard Harbour Littoral Biotope Mapping Survey

Habitats and Species Recorded Assigned Biotope Grey lichen zone LR.FLR.Lic.Y: Yellow and grey lichens on supralittoral rock Yellow lichen zone with Caloplaca thallincola LR.FLR.Lic.Y: Yellow and grey lichens on and Caloplaca marina and occasional supralittoral rock Xanthoria parietina Prasiola stipitata patch beneath a Xanthoria LR.FLR.Lic.Pra: Prasiola stipitata on nitrate- parietina encrusted bird roost enriched supralittoral or littoral fringe rock Black lichen zone LR.FLR.Lic.Ver.Ver: Verrucaria maura on very exposed to very sheltered upper littoral fringe roc Pelvetia canaliculata zone with occasional LR.LLR.F.Pel: Pelvetia canaliculata on Elminius modestus and Littorina saxatilis sheltered littoral fringe rock Green algal zone on vertical rock above Fucus LR.FLR.Eph.Ent: Enteromorpha spp. on spiralis freshwater-influenced and/or unstable upper eulittoral rock

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Habitats and Species Recorded Assigned Biotope Fucus spiralis with Catenella caespitosa LR.LLR.F.Fspi.FS: Fucus spiralis on full salinity occasional Elminius modestus barnacles and sheltered upper eulittoral rock L. saxatilis Fucus vesiculosus / barnacle / limpet / Mytilus LR.MLR.MusF.MytFves: Mytilus edulis and edulis mosaic in small boulders and cobbles Fucus vesiculosus on moderately exposed mid beneath the RIP RAP eulittoral rock. Ascophyllum nodosum with limpets and LR.LLR.F.Asc: Ascophyllum nodosum on very barnacles as a mosaic sheltered mid eulittoral rock/ LR.HLR.MusB.Sem.Sem: Semibalanus balanoides, Patella vulgata and Littorina spp. on exposed to moderately exposed or vertical sheltered eulittoral rock. A. nodosum with Polysiphonia lanosa, LR.LLR.F.Asc.FS: Ascophyllum nodosum on occasional limpets and barnacles full salinity mid eulittoral rock Limpet barnacle zone of Patella spp. and LR.HLR.MusB.Sem.Sem: Semibalanus Semibalanus balanoides dominants, with balanoides, Patella vulgata and Littorina spp. occasional Fucus vesiculosus thalli. on exposed to moderately exposed or vertical sheltered eulittoral rock Fucus vesiculosus and Ulva spp. on variable LR.LLR.FVS.FvesVS: Fucus vesiculosus on salinity stable small boulders moderately exposed to sheltered mid eulittoral rock Mixed Fucus vesiculosus and F. serratus LR.LLR.F.Fserr: Fucus serratus on full salinity mosaic with Littorina littorea, L. obtusata, lower eulittoral mixed substrata Patella sp. /LR.LLR.F.Fves: Fucus vesiculosus on moderately exposed to sheltered mid eulittoral rock Ulva spp. and red algae with occasional F. LR.FLR.Eph.EphX:Ephemeral green and red serratus on small boulders and cobbles seaweeds on variable salinity and/or disturbed eulittoral mixed substrata Fucus serratus with ectocarpacae, occasional LR.MLR.BF.Fser.R: Fucus serratus and red Chorda filum and red seaweeds such as seaweeds on moderately exposed lower Cystoclonium purpureum and Dumontia eulittoral rock contorta on cobbles and small boulders, with some muddy gravel patches. The boulders colonised by Pomatoceros sp., Lanice concheliga, L. littorea, L. obtusata/mariae. Lepidochitona cinerea, Patella sp., spirorbidae, Anemonia viridis and Venerupis senegalensis Laminaria digitata with foliose red algae, IR.MIR.KR.Ldig.Bo: Laminaria digitata and diverse lower shore dominated by Laminaria under-boulder fauna on sublittoral fringe digitata, Mastocarpus, Ulva, Palmaria, boulders Membranoptera alata, Rhodothamniella floridula, Callophyllis laciniata, Lomentaria, Cystoclonium purpureum , Cladophora sp., coralline crusts and Petrocoelis. Fauna included Balanus crenatus, B. perforatus, Alcyonidium diaphanum, Hymeniacidon sanguinea, Dynamena pumila, Electra pilosa, Littorina saxatilis, Mytilus edulis spat and Alcyonidium diaphanum. Sandy mud biotope adjacent to the northern LS.LSa.MuSa: pier and slipway LS.LSa.MuSa.MacAre: Macoma balthica and Arenicola marina in littoral muddy sand Arenicola marina polychaetes and Lanice LS.LSa.MuSa.Lan: Lanice conchilega in littoral concheliga in a fine compacted sand with sand / shallow pools containing juvenile Crangon LS.LSa.MuSa.MacAre: Macoma crangon. Occasional Macoma balthica noted balthica and Arenicola marina in littoral muddy sand

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Habitats and Species Recorded Assigned Biotope Fine rippled sand with Arenicola marina, LS.LSa.FiSa.Polychaetes in littoral fine sand spionid polychaetes and Cerastoderma edule dominating. Low on the shore Acronida brachiata, Philine aperta, Ensis sp. and Chamelea gallina were frequently noted Based on information provided in Aquatic Environments (2011).

The survey recorded sixteen distinct biotopes along the hard substrate (rocky) sections of the survey area (Figure 7.2). The habitats recorded were characterised by typical rocky shore species including Fucus seaweeds, limpets, mussels and barnacles. At the end of the breakwater structure a rich sublittoral fringe community with sponges, ascidians, hydroids and several barnacle species were present under boulders.

Two distinct sediment biotopes were also noted in the bay (Figure 7.2). The sedimentary biotope covering the largest area was LS.LSa.FiSa.Po (Polychaetes in littoral fine sand). Commonly recorded infaunal species recorded included polychaetes (such as Scoloplos armiger, Pygospio elegans and lugworm Arenicola marina) as well as bivalves (such as Macoma balthica). The sand burrowing brittlestar Acrocnida brachiata and epifaunal species including brown shrimp Crangon crangon and sea slug Philine aperta were also recorded.

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Figure 7.2: The Distribution of Intertidal Biotopes Identified as Part of the Fishguard Harbour Littoral Biotope Mapping Survey (Aquatic Environments, 2011).

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Figure7.3: The Distribution of Subtidal Biotopes Identified as Part of the Fishguard Drop-Down Video Survey (Aquatic Environments, 2015).

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Subtidal Habitats

Drop-down video surveys of Goodwick Sands and inner sections of Fishguard Harbour were undertaken in 2015 as part of baseline surveys for a proposed development (Aquatic Environments, 2015). The distribution of habitats recorded in this survey is shown in Figure 7.3. Most of the area surveyed was found to consist of the biotope SS.SSA.IMuSa.AreISa (A. marina in infralittoral fine sand or muddy sand). Along with lugworms A. marina casts and small tubed polychaete species, the sandy swimming crab Liocarcinus depurator and shore crab Carcinus maenas were also recorded. Patches of gutweed Ulva intestinalis were also recorded colonising the sediment’s surface. This was assigned to the biotope SS.SMP.KSwSS.FilG (Filamentous green seaweeds on low salinity infralittoral mixed sediment or rock biotope).

Several patches of cobbles and small boulders were observed which were assigned to IR.MIR.KR.XFoR (Dense foliose red seaweeds on moderately exposed, silted, stable infralittoral rock). Lobster Homarus gammarus and spider crabs were also recorded in this area.

Non Native Species

The Pembrokeshire coast has been colonised by a range of non-native marine species. Many of these species are thought to have been introduced through the fouling of ships hulls or as larvae in ballast water. Records of non-native species recorded on the north Pembrokshire coast which could be present in Fishguard Harbour include algae such as Bonnemaisonia hamifera and Colpomenia peregrina, polychaete worms (Ficopomatus enigmaticus and Goniadella gracilis), bivalves (such as the hard shelled clam Mercenaria mercenaria and Jenkin’s spire shell Potamopyrgus antipodarum), the mud shrimp Corophium sextonae and orange striped anemone Haliplanella lineata (Brazier, 2010; Wyn, 2010).

Proposed Development Footprint

In order to understand the marine ecological characteristics of the foreshore and subtidal habitat directly within and nearby to the proposed replacement linkspan, site specific marine ecology surveys were undertaken in June 2017 (ABPmer, 2017). The specific objectives of the survey were to map and describe the marine habitats that could be impacted by the proposed development and confirm the presence of any rare species or protected habitats in the area.

The surveys involved the following components:

- Intertidal Habitat Survey: Habitat mapping of the intertidal zone of the foreshore in the vicinity of the proposed development; and

- Subtidal Habitat Survey: The survey involved collecting samples for sedimentary (Total organic carbon (TOC), Particle Size Analysis (PSA)) and invertebrate analysis using a 0.1 m² Day Grab from six stations (Figure 7.4). In addition, an underwater camera was mounted on the grab to collect additional information about sedimentary conditions and also evidence of epifaunal species.

The methodologies used for the surveys and results are described in more detail in Appendix 7.1 at Volume III of this ES. The extent of the different biotopes mapped is shown in Figure 7.4.

Intertidal Habitats

The extreme lower shore was characterised by fronds of oarweed Laminaria digitata, red seaweeds (such as Irish moss Chondrus crispus) and sea lettuce Ulva lactuca attached to large boulders and rubble. Species such as juvenile edible crabs Cancer pagurus, broad-clawed porcelain crab Porcellana platycheles, barnacles, the star ascidian Botryllus schlosseri, sea squirts such as Aplidium nordmanni and keel worms Pomatoceros spp were recorded under the boulders. Sponges such as Hymeniacidon perlevis were also attached to boulders and concrete pillars on the lower shore.

This biotope is most appropriately assigned to IR.MIR.KR.Ldig.Bo (Laminaria digitata and under- boulder fauna on sublittoral fringe boulders). The habitat recorded under the boulders in this area is characteristic of the UK BAP Priority Habitat ‘Intertidal Under boulder Communities’ (UK Biodiversity Action Plan, 2008). This habitat is also listed as a Habitat of Principal Importance in Wales under the

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NERC Act 2006 Section 42. Patches of serrated wrack were also present on the lower shore (LR.MLR.BF.Fser.R: Fucus serratus and red seaweeds on moderately exposed lower eulittoral rock).

The lower mid shore was characterised by a zone of knotted wrack Ascophyllum nodosum covering boulders and quay wall structures in the area ((LR.LLR.F.Asc: Ascophyllum nodosum on very sheltered mid eulittoral rock). Above this habitat was spiralled wrack Fucus spiralis (LR.LLR.F.Fspi: Fucus spiralis on sheltered upper eulittoral rock). Barnacle species, the limpet Patella vulgata, the topshell Gibbula umbilicalis and periwinkles (such as the common periwinkle Littorina littorea and flat periwinkle L. obtusata) were recorded attached to rocks.

The channelled wrack Pelvetia canaliculata was recorded on the upper shore on quay wall structures along with barnacle species (LR.MLR.BF.PelB Pelvetia canaliculata and barnacles on moderately exposed littoral fringe rock). Above this zone, green algae and lichens were present (LR.FLR.Lic:Lichens or small green algae on supralittoral and littoral fringe rock).

Subtidal habitats

The habitat along the sublittoral fringe and within the shallow infralittoral directly below the quayside and rock armouring consisted of large boulders and other hard substrate with fronds of sugar kelp Saccharina latissima (synonym Laminaria saccharina) and oarweed L. digitata attached (IR.LIR.K.Lsac.Ldig: Laminaria saccharina and Laminaria digitata on sheltered sublittoral fringe rock). Other algae recorded in this zone included dead man's rope Chorda filum and sea lettuce U. lactuca. The light bulb sea squirt Clavelina lepadiformis was recorded attached to boulder structures.

The subtidal sediment habitat in the survey area consisted of slightly gravelly sand and muddy sand with TOC in the samples ranging between 0.3 and 1 % (Table 7.8). Overall, the number of taxa found in the samples ranged from 21 (Station 4) to 66 (Station 6), and the number of individuals from 890 organisms per m² (Station 5) to 15,000 organisms per m² (Station 1). The range in total species biomass in the samples was between 16 and 188 grams per m² with the bivalve Abra alba contributing most to the total biomass at all stations (with the exception of Station 4 with the bivalve Nucula hanleyi contributing most to total biomass at this site).

The most abundant polychaete worms in the samples were surface deposit feeding bristleworm polychaetes such as Aphelochaeta marioni, Chaetozone gibber and Mediomastus fragilis. The white furrow shell Abra alba was the most abundant bivalve species recorded. This species was recorded in abundances of over 5000 m² at Station 1 and 3000 m² at Station 6. Other abundant bivalve species recorded in the samples included the wavy hatchet shell Thyasira flexuosa, basket shell Corbula gibba, Nucula hanleyi and Kurtiella bidentata. Brittlestars were also recorded at all the sites with Amphiura filiformis the most commonly recorded species. These marine species that have been described dominated the assemblage and contributed almost entirely to the total abundances of organisms recorded at the stations. In addition a range of crustaceans were recorded in the samples in low abundances including the common shrimp C. crangon and amphipods such as Harpinia antennaria.

The subtidal sediment habitat is most appropriately assigned to the biotope SS.SSa.CMuSa: Circalittoral muddy sand. This habitat is characterised by a wide variety of polychaetes, bivalves such as A. alba and Nucula spp, and echinoderms such as Amphiura spp. (Conner et al., 2004). Several small patches of sugar kelp S. latissim were also present on the sand (SS.SMp.KSwSS.LsacR.S: Laminaria saccharina and filamentous red algae on infralittoral sand) (Figure 7.4).

Large spider crabs Maja brachydactylus were also recorded in this area on both rocky and sandy habitats.

Environmental Statement 7/15 April 2018 Replacement Linkspan, Fishguard Port

Table 7.7: Subtidal Benthic Survey Results

Station Sediment Type OC No. of Taxa No. of Individuals Total Biomass Key Characterising Species (%) (per m²) (per m²) (g per m²) (number per m² shown in brackets) 1 Slightly gravelly 1.06 50 15,000 188.2 - Polychaete Aphelochaeta marioni (1,060) sand - Polychaete Chaetozone gibber (2,470) - Polychaete Mediomastus fragilis (3,240) - Bivalve Nucula hanleyi (180) - Wavy hatchet shell (bivalve) Thyasira flexuosa (470) - Bivalve Kurtiella bidentata (310) - White furrow shell (bivalve) Abra alba (5,480) - Basket shell (bivalve) Corbula gibba (260) 2 Slightly gravelly 0.49 66 9,090 106.5 - Polychaete Aphelochaeta marioni (1,710) muddy sand - Polychaete Chaetozone gibber (2,320) - Polychaete Mediomastus fragilis (750) - Polychaete Euclymene oerstedii (230) - Bivalve Nucula hanleyi (350) - Wavy hatchet shell (bivalve) Thyasira flexuosa (300) - Bivalve Kurtiella bidentata (190) - White furrow shell (bivalve) Abra alba (1,110) - Basket shell (bivalve) Corbula gibba (440) - Brittlestar Amphiura filiformis (220) 3 Slightly gravelly 0.32 36 2,040 31.5 - Polychaete Chaetozone gibber (480) muddy sand - Bivalve Nucula hanleyi (200) - White furrow shell (bivalve) Abra alba (460) - Basket shell (bivalve) Corbula gibba (240) 4 Slightly gravelly 0.41 21 1,080 20.1 - Bivalve Nucula hanleyi (320) muddy sand - White furrow shell (bivalve) Abra alba (290) - Basket shell (bivalve) Corbula gibba (150) 5 Slightly gravelly 0.39 27 8,90 16 - Bivalve Nucula hanleyi (130) sand - White furrow shell (bivalve) Abra alba (220) 6 Slightly gravelly 0.8 45 10,620 185 - Polychaete Aphelochaeta marioni (180) muddy sand - Polychaete Chaetozone gibber (2130) - Polychaete Mediomastus fragilis (500) - Polychaete Euclymene oerstedii (330) - Bivalve Nucula hanleyi (510) - Wavy hatchet shell (bivalve) Thyasira flexuosa (670) - Bivalve Kurtiella bidentata (330) - White furrow shell (bivalve) Abra alba (3,230) - Basket shell (bivalve) Corbula gibba (440) - Brittlestar Ophiuroidea (130) - Brittlestar Amphiura filiformis (610)

Environmental Statement 7/16 April 2018 Replacement Linkspan, Fishguard Port

Figure 7.4: The Location of Grab Samples and the Habitats Recorded in the Proposed replacement Linkspan Marine Ecology Surveys

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7.3.3 Plankton

The main data sources used to describe baseline conditions are as follows:

- Plankton Ecology of the Irish Sea: Overview of plankton ecology in the Irish Sea as part of the Offshore Energy Strategic Environmental Assessment (SEA) (Kennington and Rowlands, 2005); and - South Hook Combined Heat and Power Station Environmental Statement: Information on the ecology of plankton in Wales compiled as part of the baseline study for the South Hook Combined Heat and Power Station (QPI Global Ventures Limited, 2013).

A broad contextual overview, focusing on plankton in the wider eastern Irish Sea region is provided in Section 7.3.3.1). A description of the plankton assemblages expected to occur within Fishguard Harbour is then provided in Section 7.3.3.2.

Regional Overview

Plankton can be split into two broad groups, phytoplankton and zooplankton. Phytoplankton are primary producers. Being mostly autotrophic, thus requiring light to photosynthesise, the majority of phytoplankton are found within the upper water column commonly referred to as the photic zone. Zooplankton are heterotrophic and generally form the next trophic level of the marine food web. Zooplankton are categorised into holoplankton that are permanent members of the zooplankton and meroplankton that spend only part of their life (often the developmental stages) as zooplankton (Kennington and Rowlands, 2005).

Coastal waters of the eastern Irish Sea tend to be first to respond to the changes in temperature, hydrographic and light regimes during the early spring months. It is in these regions that the spring phytoplankton bloom first occurs and peaks between March and June. Along the estuarine coasts of the eastern Irish Sea, chlorophyll a concentrations can be above 50 µg/l. Spring bloom chlorophyll concentrations in more saline waters of the eastern Irish Sea tend to be in the region of 5-15 µg/l. The composition of phytoplankton in the eastern Irish Sea during the main growth season tends to be ubiquitous, with diatoms dominating until silicate becomes depleted at which point nanoflagellates may become dominant. Dinoflagellates are also a common phytoplankton type and tend to be most abundant in early and late summer (Kennington and Rowlands, 2005).

With respect to zooplankton within the Irish Sea it is noted that copepods comprise nearly 70 % of all the zooplankton (Kennington and Rowlands, 2005). The zooplankton community is also characterised by other groups of planktonic crustacea including appendicularians (small filter feeding pelagic tunicates), larvae of a range of benthic organisms (mesozooplankton), chaetognaths and gelatinous zooplankton e.g. jellyfish (Kennington and Rowlands, 2005).

Fishguard Harbour

Information on the composition of plankton species in Fishguard Harbour is limited but the plankton assemblage would be expected to be similar to that found more widely in Welsh continental waters. Phytoplankton in continental shelf seas in this region was found to be dominated by the diatom (Thalassiosira spp.) in April and May, followed by the dinoflagellates Ceratium fusus and C. furca during the summer months. The main components of zooplankton appear to be copepods (Acartia clause, Pseudocalanus elongates and Temora longicornis). In inshore areas the larvae of benthic species are also well represented for limited periods, particularly cirripedes (barnacles) in April and echinoderms (urchins and starfish) also in April and again in July and August (QPI Global Ventures Limited, 2013).

7.3.4 Fish and Shellfish

Data Sources

A number of key data sources have been reviewed to describe the fish and shellfish ecology of Fishguard Harbour and the wider region:

- The Marine Conservation Society (MCS) Basking Shark Watch 20-year Report: The results of public sightings data collected between 1987-2006 (MCS, 2007); - Spawning and nursery grounds of selected fish species in UK waters: During the late 1990s, a collaborative project between the Centre for Environment, Fisheries and Aquaculture

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Science (CEFAS), the Fisheries Research Service, the UK Offshore Operator's Association (UKOOA), the Scottish Fishermen's Association (SFF) and the National Federation of Fishermen's Organisations (NFFO) produced Fisheries Sensitivity Maps in British Waters. This report (Coull et al., 1998) included maps of the main spawning and nursery grounds for 14 commercially important species (cod, haddock, whiting, saithe, Norway pout, blue whiting, mackerel, herring, sprat, sandeels, plaice, lemon sole, sole and Norway lobster). This data has since been updated by CEFAS using more recent survey data and additional analyses to complement the original maps (Ellis et al., 2012); - South Hook Combined Heat and Power Station Environmental Statement: Information on the ecology of fish species in Pembrokshire compiled as part of the baseline study for the South Hook Combined Heat and Power Station (QPI Global Ventures Limited, 2013); - Wave Dragon Pre-Commercial Wave Energy Device Environmental Statement. Information on the ecology of fish in Pembrokshire compiled as part of the baseline study for the Wave Dragon energy device (PMSS, 2007); and - NRW Migratory Fish Data for the River Gwaun: The results of the most recently available electrofishing monitoring surveys undertaken by NRW on the River Gwaun (a tributary which enters Fishguard Harbour). As part of this monitoring, fish surveys were undertaken in 2005, 2007 and 2011.

A number of other surveys and scientific studies on fish and shellfish have also been included in the baseline review where appropriate.

Fish are highly mobile species with certain species utilising extensive foraging ranges and showing large seasonal changes in distribution. Therefore, in order to understand and compare different populations which might be affected by the proposed development, data have been analysed at two different spatial scales in an iterative manner. First, the distribution and ecology of demersal fish, pelagic fish, elasmobranchs, diadromous fish and shellfish within Pembrokeshire are each reviewed in more detail below (Sections 7.3.4.2). The review has primarily focused on key species which are of either commercial and/ or of conservation importance. Information on the fish assemblage occurring specifically within Fishguard Harbour is then described in more detail in Section 7.3.4.3.

Legislation, Planning Policy and Guidance

Certain fish species are protected under a range of legislation including the EU Habitats Directive, the Wildlife and Countryside Act 1981 (and amendments) and the Bern Convention, as well as being on the OSPAR threatened species list, International Union for Conservation of Nature (IUCN) red list and UK BAP Priority Species. The species potentially occurring in Fishguard Harbour and Fishguard Bay which are afforded the highest level of protection include:

- European eel: UK BAP/NERC, OSPAR listed and on the global red list, Protected under the Eels (England and Wales) Regulations 2009; - Atlantic salmon: UKBAP/NERC, Appendix III of Bern Convention; Annexes II, V of the EC Habitats Directive, OSPAR; - Sea and river lamprey: Annexes II, V of the EC Habitats Directive, UK BAP/NERC, Appendix III of Bern Convention (river lamprey), OSPAR (sea lamprey); - Shad species: UK BAP/NERC, Appendix III Bern Convention, Annexes II and V EC Habitats Directive, Wildlife and Countryside Act; - Brown/sea trout: UK BAP/NERC - Atlantic cod: Vulnerable (IUCN red list); OSPAR threatened / declining, UK BAP (grouped)/NERC; and - Thornback ray: OSPAR threatened / declining.

Regional Overview

Demersal Bony Fish Species

Demersal species are bottom-dwelling or mid-water fish that have a close association with the seabed.

Commonly occurring commercially important flatfish species occurring in the Pembrokeshire region include plaice Pleuronectes platessa, flounder Platichthys flesus and dab Limanda limanda. Other commercially important species present in the area include sole Solea solea, turbot Psetta maxima

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and brill Scophthalmus rhombus (QPI Global Ventures Limited, 2013; PMSS, 2007; Kay and Dipper, 2009).

Commonly occurring roundfish species include whiting Merlangius merlangus and cod Gadus morhua with other gadoids such as ling Molva molva, pollack Pollachius pollachius and saithe Pollachius virens also recorded, particularly around rocky reefs.

Other demersal species which occur around rocky reefs in the region include conger eel, gurnards, wrasse (Labridae), clingfish and goby (Gobidae) (QPI Global Ventures Limited, 2013; PMSS, 2007; Kay and Dipper, 2009).

The study area is considered to be a low intensity nursery ground for whiting anglerfish and plaice. The study area is considered to be a high intensity spawning ground for sole and a low intensity spawning ground for whiting, plaice, cod and sandeel (Figure 7.5) (Ellis et al., 2012).

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Figure 7.5a: Spawning and Nursery Grounds in Fishguard Bay

Environmental Statement 7/21 April 2018 Replacement Linkspan, Fishguard Port

Figure 7.5b: Spawning and Nursery Grounds in Fishguard Bay

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Pelagic Bony Fish (Osteichthyes) Species

Pelagic species are free-swimming fish that inhabit the mid-water column. They tend to have little association with the seabed and as a result are often distributed over widespread and indistinct grounds, often forming large shoals. Pelagic fish, such as clupeids (herring and sprats) and mackerel are important prey resources for seabirds and marine mammals (DECC, 2009).

Mackerel Scomber scombrus, herring Clupea harengus and sprat sprattus sprattus are commonly recorded pelagic species recorded in the Pembrokshire area (QPI Global Ventures Limited, 2013; PMSS, 2007; Kay and Dipper, 2009).

The study area is considered to be a low intensity nursery ground for mackerel (Ellis et al., 2012) (Figure 7.5). In addition, estuaries in the region such as Milford Haven are nursery area for sea bass Dicentrarchus labrax.

Elasmobranchs

Commonly recorded elasmobranchs include the thornback ray Raja clavata and small-spotted catshark Scyliorhinus canicula (QPI Global Ventures Limited, 2013; PMSS, 2007; Kay and Dipper, 2009). Other species occurring in the area include tope Galeorhinus galeus and spotted ray Raja montagui.

The study area is considered to be a high intensity nursery ground for spotted ray and thornback ray (Figure 7.6) (Ellis et al., 2012). Basking sharks Cetorhinus maximus are recorded in the wider study area although sightings densities are not as high as in hotspot areas such as parts of the Inner Hebrides, Clyde Sea, the Isle of Man and close inshore around Devon and Cornwall (MCS, 2007).

Diadromous Fish Species

Diadromous fish migrate between salt and freshwater. Species recorded in the River Gwaun which is a tributary with its mouth entering into Fishguard Harbour include Atlantic salmon Salmo salar, sea trout S. trutta) and European eel Anguilla anguilla (Figure 7.6). In addition, rivers in the wider study area such as the River Teifi and River Cleddau have been found to support the river lamprey Lampetra fluviatilis and sea lamprey Petromyzon marinu. There are few records of both the allis and twaite shad species in Pembrokeshire with the current status of these species in the area uncertain.

1000 900

800 700 600 500 400 Atlantic salmon 300 Fish Fish Total Count 200 Brown/sea trout 100 European eel 0 14/07/2005 26/07/2005 31/08/2007 27/07/2011 Gwaun

Figure 7.6: Electro-fishing counts of migratory fish on the river Gwuan as part of NRW fish monitoring.

Atlantic salmon are an anadromous species which migrate to freshwater to spawn, whilst spending most of its life in the marine environment. Spawning usually takes place in November or December and a nest (redd) is excavated in the gravel of the riverbed by the female, the eggs are deposited, fertilised by the attendant male(s), and then covered over with gravel. After some weeks, depending on the water temperature, the eggs hatch into alevins, which, after they have used up the food

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material in the yolk sac, become fry. These fry move up to the surface of the gravel and become the main juvenile stage of parr. After one to four years in the river, dependent on growth rate, parr become smolts, which move down the river to the sea generally from April to June. The main marine feeding grounds for salmon from Wales are around the Faroe Islands and off the west coast of Greenland. Most salmon return the following summer after one winter spent feeding at sea. The UK and Irish Atlantic salmon population comprises a significant proportion of the total European stock (Malcolm et al., 2010). Atlantic salmon migrate through Fishguard Harbour to and from the River Gwaun.

The life cycle of the migratory sea trout (which is also recorded in Fishguard Harbour) is similar to that of salmon. However, in contrast to the salmon, the majority of sea trout survives spawning and will return to their natal spawning river on numerous occasions during their life time.

River lamprey and sea lamprey are both anadromous species, spawning in freshwater but completing part of their lifecycle in estuaries or at sea (Henderson, 2003; Maitland, 2003). The sea lamprey adult growth phase is short and lasts around two years. In this time the species is parasitic, feeding on a variety of marine and anadromous fishes, including shad, herring, salmon, cod, haddock and basking sharks. The rarity of capture in coastal and estuarine waters suggests that marine lampreys are solitary hunters and widely dispersed at sea. Unlike sea lamprey, the growth phase of river lamprey is primarily restricted to estuaries. After one to two years in estuaries, river lamprey stop feeding in the autumn and move upstream into medium to large rivers, usually migrating into fresh water from October to December (Maitland, 2003). Information on the presence of lamprey species in the River Gwaun is limited with no evidence to suggest these species are present in this river. However, lamprey species have been recorded in other rivers in the wider area including the River Teifi and River Cleddau.

European eel is a catadromous species which migrates to the marine environment (Sargasso Sea) to spawn. Juvenile European eels (elvers) migrate into estuaries and rivers during late winter and early spring. European eel has been recorded in the River Gwaun.

Shellfish Species

This section focuses on shellfish species (i.e. molluscs or crustaceans which are consumed by humans). Information on other macrofauna is reviewed in Section 7.3.2 (Benthic Habitat and Species).

The study area supports commercially exploitable stocks of edible crabs Cancer pagurus, velvet crabs (Necora puber and European lobsters Homarus gammarus (QPI Global Ventures Limited, 2013; PMSS, 2007; Kay and Dipper, 2009).

7.3.4.1 Fishguard Harbour

Site specific information on the fish assemblage found in Fishguard Harbour is limited although based on the nature of the habitat in this area it is likely to consist of species common to harbours in this region including wrasse species, gobies, mullet species and flounder. Shellfish species include European lobster, edible crab and cockles.

The main migratory species which would be expected to be recorded passing through the area based on the known distribution and abundance of these species are Atlantic salmon, sea trout and European eel.

7.3.5 Marine Mammals

Data Sources

The principal data sources used to describe baseline conditions are as follows:

- Common and Grey Seal Movements at Sea: Analysis of over 20 years of at-sea movement data and count data from these species to produce high resolution, broad-scale maps of distribution (Jones et al., 2015);

- The Atlas of the Marine Mammals of Wales: The most comprehensive information on the distribution of marine mammals in Welsh waters is provided in the Atlas of the Marine

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Mammals of Wales (Baines and Evans, 2012). The study compiled and analysed data from sixteen projects including a total of 216,031 km of effort from vessel and aerial surveys and 13,399 hours of land-based effort, spanning the 20-year period 1990-2009. It includes data collected by the Sea Watch Foundation (SWF), JNCC (Joint Nature Conservation Committee) and the WDC (Whale and Dolphin Conservation); - The Identification of Discrete and Persistent Areas of Relatively High Harbour Porpoise Density in the Wider UK Marine Area: The report presents the results of 18 years of survey data in the Joint Cetacean Protocol (JCP) undertaken to inform the identification of discrete and persistent areas of relatively high harbour porpoise density in the UK marine area. This identification was needed in fulfilment of obligations required by the EU Habitats Directive (Heinänen and Skov, 2015); - Analysis of Long-Term Effort-Related Land-Based Observations of Harbour Porpoise and Bottlenose Dolphin: Analysis of over 75,000 hours of watches and circa 50, 000 associated sightings of bottlenose dolphin and harbour porpoise from 678 sites around the coasts of Britain in order to determine whether areas of persistent high occurrence of the two species can be identified (Evans et al., 2015); and - The Case for the Protection of Harbour Porpoises in and around the Tidal Features of Strumble Head (Benson, 2015).

Legislation, Planning Policy and Guidance

All cetaceans (whales and dolphins) are protected under Schedule 5 of the Wildlife and Countryside Act 1981 (and amendments), under which it is an offence to take, injure or kill these species. Disturbance in their place of rest, shelter or protection is also prohibited. All species of cetacean are protected under the EU Habitats Directive 1992 at Annex IV and under the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). Harbour porpoise and bottlenose dolphin are also protected under Annex II of the Habitats Directive 1992. In addition, harbour porpoise is also listed as an OSPAR threatened species listed in Appendix II of the Bonn Convention (Convention on the Conservation of Migratory Species of Wild Animals) 1982.

Seals are protected under the Conservation of Seals Act 1970 (taking effect in England, Scotland, Wales). Grey and common seals are also listed in Annex II of the EU Habitats Directive 1992 and are protected from disturbance both inside and outside the designated sites. In addition, grey seal is listed as an Appendix III species under the Bern Convention, which prohibits the deliberate disturbance/capture/killing of species and disturbance of their breeding grounds.

Overview

Over eighteen species of cetacean have been recorded in Wales since 1990 (Baines and Evans, 2012). Of these, two species (harbour porpoise Phocoena phocoena and bottenose dolphin Tursiops truncates) occur regularly within inshore areas in the local area including around Fishguard Harbour. With regard to seal species, grey seals Halichoerus grypus are recorded breeding and foraging along the Pembrokeshire coast including near Fishguard Harbour. Records of common (harbour) seal Phoca vitulina are rare in West Wales (Baines and Evans, 2012).

The NRW screening opinion for the proposed development (NRW ref SC1605 dated 13 December 2016) stated that while the presence of marine mammals should be acknowledged as part of the impact assessment there was ‘no need to reproduce information on seals/porpoises and their use of the area’ as ‘marine mammals are known to pass through the harbour’. On this basis only brief contextual summary information has been provided below for the three commonly occurring species in the area (i.e. harbour porpoise, bottlenose dolphin and grey seal);

- Harbour porpoise: High densities of the species occur in the region (Heinänen and Skov, 2015). For example, Strumble Head near Fishguard Harbour has been shown to support an important population of harbour porpoise (Benson, 2015). - Bottlenose dolphin: The highest densities of bottlenose dolphin sightings in Wales occur in Cardigan Bay which forms the core range of the inshore resident population in Wales (Baines and Evans, 2012). Bottlenose dolphins are regularly recorded in the vicinity of Fishguard Harbour but few sightings of bottlenose dolphins have been recorded west of Fishguard (Baines and Evans, 2012; Evans et al., 2015; Seawatch Foundation, 2015).

- Grey seal: Within the West Wales grey seal breeding population, the majority of pup production occurs on Ramsey Island, Skomer Island and along the North Pembrokeshire

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mainland coast, between St David’s Head and the Teifi Estuary (Strong et al., 2006). Approximately 300 and 470 pups are typically born annually on Ramsey Island and along the North Pembrokeshire coast including around Strumble Head near Fishguard Harbour (Strong et al., 2006; CCW, 2009). At sea usage of the region by foraging seals is considered to be relatively high (Jones et al., 2015).

7.4 Impact Assessment

7.4.1 Introduction

This section has assessed the impacts associated with the reclamation, piling, dredge and other works in the construction phase on marine ecology receptors. Dredged material will either be used within the reclaim or removed and sent to landfill. Therefore, no impact pathways for the disposal of dredged material at sea are considered within this assessment.

While the assessment has primarily focused on the reclamation and piling scenario as the overall environmental impacts on marine biodiversity features are considered to be greater for this scenario, an alternative scenario of a full piled replacement linkspan was also assessed. For each scenario, the reclaim and pile scenario is considered firstly before a brief discussion of the full piled scenario. The two scenarios being considered as part of the assessment are:

• Reclamation and Piling: Construction of the replacement linkspan through reclamation (and associated revetment) with piling used only for the dolphins and bank seat (24 tubular piles). This scenario would require dredging within the area of proposed reclaim and rock armour revetment using a bucket dredger (approximately 10,000 m3 of sediment)

• Piling Only: This scenario involves no reclamation but instead a replacement linkspan that is constructed entirely on piles (the original 24 for the bankseat and dolphins with the addition of 26 for the approach structure). This scenario will involve reduced dredging which would be restricted to around the bank seat area only (1,000 m3 of sediment).

The duration of piling has been assumed to be the same under both scenarios.

The proposed development will not change the existing maintenance dredging regime for the ferry berth which is currently undertaken in accordance with an existing marine licence. In addition, the same ferry type and services will continue to run from the replacement linkspan. Therefore, operational impacts associated with maintenance dredging and ferry vessel movements (such as changes to seabed habitat, water quality and the spread of non-native species due to ballast water and hull fouling) are not considered further in the assessment.

It is anticipated that during decommissioning the structures installed as part of the replacement linkspan will remain in situ, providing it is environmentally stable. Therefore any effects on the marine environment from the structure in situ will be similar to those considered as part of the assessment. However, given that there would be no further vessels unloading at the replacement linkspan it is predicted that there would therefore be a reduction in vessel traffic and the associated potential impacts. Therefore, decommissioning has not been considered further as part of the assessment.

The impact assessment has been informed by the results of the Coastal Processes assessment (ES Chapter 4) and the Water Quality assessment (ES Chapter 6). The subsequent impacts on designated features, benthos, plankton, fish and marine mammals are covered in Sections 7.4.2 to 7.4.6.

7.4.2 Nature Conservation - Protected Habitats and Species

This section considers the potential impact on marine features of qualifying nature conservation designations. Consideration has been given to assessing site specific variations and potential disturbance in accordance with NE and CCW (2007) guidance and under Section 125 and 126 of the Marine and Coastal Access Act 2009. In addition, under the Conservation of Habitats and Species Regulations 2010, further consideration has been given as to whether the proposed development has the potential to result in a likely significant effect (LSE) on internationally designated sites.

Environmental Statement 7/26 April 2018 Replacement Linkspan, Fishguard Port

Specifically, there is the potential for a LSE on mobile SAC interest features that could be using areas directly or indirectly affected by the proposed development. Benthic habitats and species, plankton, fish and shellfish, and marine mammal features of international designations are discussed in Sections 7.4.3, 7.4.4 7.4.5 and 7.4.6 respectively. Additionally, a Habitats Regulations Assessment signposting document is provided as Appendix 7.2 at ES Volume III. BAP species and habitats are assessed in the respective species group sections, if applicable.

One SSSI has been identified within the wider study area as being potentially impacted by the proposed development. This site (Strumble Head - Llechdafad Cliffs SSSI) has grey seal as a mobile species. Grey seals are assessed in section 7.4.6.

No MCZs, WHSs or AONBs have been identified as being at risk from the proposed development and are therefore not considered further in this assessment. Priority Habitats and Species are assessed in the respective species group sections, if applicable (i.e. Sections 7.4.3 to 7.4.6).

Accordingly, all features for which the sites are designated have been assessed in the relevant sections elsewhere in this ES. Consequently, no impact pathways are considered in this section relating to nature conservation receptors.

7.4.3 Benthic Habitats and Species

This section assesses the potential for impacts on benthic ecology receptors as a result of the development.

Scoped Out

The proposed development will not change the existing maintenance dredging regime for the ferry berth which is currently undertaken in accordance with an existing marine licence. In addition, the same ferry type and services will continue to run from the replacement linkspan. Therefore, operational impacts associated with maintenance dredging and ferry vessel movements are not considered further in the assessment. The following specific pathways have also been scoped out of requiring further detailed assessment:

- Noise disturbance (construction): During construction there is the potential for noise disturbance to benthic species. Piling, dredging and vessel movements will produce underwater noise at or above background conditions. Our understanding of the potential effects of underwater noise on invertebrates is relatively underdeveloped (Hawkins et al., 2015). There is, however, increasing evidence to suggest that benthic invertebrates respond to sediment vibration (Roberts et al., 2016). For example, blue mussels Mytilus edulis vary valve gape, oxygen demand and clearance rates (Spiga et al., 2016; Roberts et al., 2016) and hermit crabs Paganus bernhardus shift their shell and at very high amplitudes, leave their shell, examine it and then return (Roberts et al., 2016). The vibration levels at which these responses were observed generally correspond to levels measured near anthropogenic operations such as pile driving and up to 300 m from explosives testing (blasting) (Roberts et al., 2016). A range of behavioural effects have also been recorded in decapod crustaceans, including a change in locomotion activity, reduction in antipredator behaviour and change in foraging habits (Tidau and Briffa, 2016). However, population level and mortality effects are considered unlikely. Furthermore, no blasting will be undertaking during the construction of the replacement linkspan; this pathway has therefore been scoped out of the assessment. - Changes to water quality through accidental spillages (construction): The magnitude of any spillage event is likely to be small. Furthermore, due to existing management procedures and the adherence to best practice during construction the probability of an accidental spillage event occurring is predicted to be low and as such this pathway has been scoped out of the assessment. - Direct changes to benthic habitats as a result of the use of jack up barges during construction: Changes to benthic habitats as a result of the use of jack up barges are expected to be highly localised (restricted to around each jack up leg) and temporary. On this basis this pathway has been scoped out of the assessment.

Environmental Statement 7/27 April 2018 Replacement Linkspan, Fishguard Port

Scoped In

The key impact pathways for both direct and indirect changes during and post construction are addressed as follows:

- Direct Loss of Benthic Habitats and Species as Result of the proposed development; - Direct Changes to Benthic Habitats and Species as Result of the Dredging; - Smothering During Construction; - Changes in Water Quality During Construction; - The Potential Introduction of Non-Native Species during Construction; - Indirect Changes In Habitat Extent And Quality as a Result of the replacement Linkspan Structure; and - Spread of Non-Native Species as a Result of the replacement Linkspan Structure.

Direct Loss of Benthic Habitats and Species as Result of the proposed development

General Scientific Context

The impact of direct habitat loss (e.g. piling or land reclamation) mainly relates to the temporary or permanent physical removal of substratum and associated organisms from the seabed.

Both intertidal and subtidal habitats are sensitive to physical loss at locations where new structures are introduced onto the sea bed (i.e. within the development ‘footprint’ of these structures). The significance of such losses will vary on a site by site basis in response to differences in the extent and duration of the losses as well as the relative value of the habitats in question. The value of the habitats is, in turn, reflected by the species that are present and level of statutory and non-statutory protection afforded to them. As any effects are very much dependent upon site specific considerations, a generic scientific review is not appropriate in this case and the focus of the impact assessment is based on site-specific considerations.

Project Impact Assessment

The proposed development will involve reclamation works, immediately adjacent to the quay wall. This reclamation area will be faced with a rock armour revetment. The reclamation and revetment will result in the physical loss of 0.34 ha of marine habitat in which approximately 0.04 ha consist of intertidal rocky shore habitat with the remaining habitat consisting of subtidal habitat.

The footprint off habitat loss in both the subtidal and intertidal is considered negligible in the context of extent of the overall amount of similar marine habitats found locally in Fishguard Harbour and the Fishguard Bay area. In addition, most of the habitats and species recorded are generally considered commonly occurring and are not listed as nationally rare or protected under conservation designations. However, small areas of intertidal habitat characteristic of the UK BAP Priority Habitat ‘Intertidal Underboulder Communities’ which is also listed as a Habitat of Principal Importance in Wales under the NERC Act 2006 Section 42 were recorded in the footprint (approximately 0.009 hectares (ha)) (Section 7.3.2).

Based on the evidence provided above, the magnitude of potential impacts is considered to be small and although the probability of occurrence is high, the overall exposure is assessed as low. The sensitivity of species to direct habitat loss due to reclamation is considered to be high for all marine habitats and species within the footprint (given the lack of recoverability following reclamation), leading to moderate vulnerability.

The importance of intertidal and subtidal habitats in the footprint of the development is low generally although the localised areas of intertidal foreshore characteristic of BAP/NERC Act Section 42 ‘Intertidal Underboulder Communities’ habitat is considered to be of moderate importance. On this basis, the impact of direct habitat loss as a result of the reclamation to the of BAP/NERC Act Section 42 ‘Intertidal Under boulder Communities’ habitat is considered to be moderate to minor and the impacts to marine habitats more generally are considered minor to insignificant.

In order to reduce the significance of the impact on the BAP/NERC Act Section 42 ‘Intertidal Underboulder Communities’ characteristic habitat suitable boulders should be placed on the bottom of the rock revetment at lower shore elevations similar to those lost as part of the reclaim. With this

Environmental Statement 7/28 April 2018 Replacement Linkspan, Fishguard Port

mitigation measure in place the impact on this habitat is considered to be insignificant. This mitigation measure is discussed in greater detail in Section 7.6.

The piling only scenario will result in a smaller loss of marine habitat than the reclamation scenario (<0.005 ha). The impact of this highly localised, negligible loss is considered to be insignificant. Direct Changes to Benthic Habitats and Species as Result of the Dredging

General Scientific Context

Dredging causes a direct physical removal of subtidal sediments, causing a modification to the existing subtidal habitat. The fauna associated with the removed material will therefore be damaged, killed or relocated to the disposal ground.

The speed of recovery of the temporarily disturbed areas is dependent on the scale and timing of the disturbance, the life histories of species and the stability and diversity of the benthic community present. For example, while the bivalve Abra spp. is vulnerable to physical disturbance, the species is considered to have a high recoverability due to a high fecundity and larval dispersal rate (Marine Ecological Surveys Limited, 2008). Furthermore, a regularly disturbed sedimentary habitat with a low diversity benthic assemblage is likely to recover more quickly (i.e. return to its disturbed or ‘environmentally-stressed’ baseline condition) than a stable habitat with a pre-existing mature and diverse assemblage.

In general, where studies have been undertaken to understand the effects of physical disturbance they have shown recolonisation of deposited sediments by animals to be quite rapid. Sites are initially colonised by short lived, fast growing, opportunistic species (‘r-selected’) that are tolerant of high levels of disturbance; infaunal species dominate, particularly polychaetes worms. In time, these are succeeded by longer lived, slower growing species with a lower tolerance for disturbance (Newell et al., 1998; Tillin et al., 2011). Rates of recovery reported in reviewed literature suggest that a recovery time of six to nine months is characteristic of many estuarine muds where frequent disturbance of the deposits precludes the establishment of long-lived communities. In contrast, a community of sands and gravels may take two to three years to establish, depending on the proportion of sand and level of environmental disturbance by waves and currents (Newell et al., 1998; Bolam, and Rees, 2003).

Project Impact Assessment

It is proposed that up to 10,000 m³ of sediment will be dredged within the area of proposed reclaim and rock armour revetment using a bucket dredger. However, the area of proposed dredging is entirely within the reclamation footprint. Therefore, species and habitats within this area will be lost as a result of the reclaim, regardless of the dredging activity. On this basis, changes to benthic habitat and species as a result of the direct physical removal of sediment are not considered further with respect to the design scenario involving reclamation. However, dredging as part of the piling only scenario would involve the dredging of approximately 1,000 m3 of material from around the bank seat area covering approximately 0.09 ha. Dredging as part of this scenario is considered in more detail below.

The footprint of the proposed dredge covers a very small area. Although the proposed dredge would remove an area of material that has never been dredged before, the localised area of dredge is in close proximity to the existing berth pocket. These berth pocket margins are still dynamic environments, subject to relatively high levels of disturbance from vessel related disturbance as a result of adjacent maintenance dredging works and the commercial use of Fishguard Harbour. Many of the subtidal infaunal species recorded in the vicinity of the proposed development are considered tolerant to disturbance and have a high recoverability (ABPmer, 2017).

Applying the project impact assessment methodology and based on the information above, the magnitude of the change to the subtidal habitat and associated benthic species is considered to be small and although the probability of occurrence is high the overall exposure is assessed as low. Given that the sensitivity, vulnerability and importance of the subtidal habitat and associated benthic communities affected are considered to be low, the overall effect is insignificant.

Environmental Statement 7/29 April 2018 Replacement Linkspan, Fishguard Port

Smothering During Construction

General Scientific Context

Sediments dispersed during coastal works, dredging and disposal has potential to resettle over the seabed. This potential blanketing or smothering of benthic species, may cause stress, reduced rates of growth or reproduction and in the worst cases the effects may be fatal (Bray et al., 1997; White, 2008).

Habitats within estuarine and coastal environments have highly fluctuating conditions including the resuspension and deposition of sediments on a daily basis (through tidal action), lunar cycles (due to the differing influences of spring and neap tides) and on a seasonal basis (due to storm activity and conditions of extreme waves). Subtidal and intertidal habitats are, therefore, characterised by such perturbations and the biological communities of these environments are well adapted to survival under fluctuating conditions.

If the amount of sediment deposited is too great to allow species to survive burial, then recovery occurs via re-colonization and/or migration to the new sediment surface (Bolam et al., 2006a; 2006b). In general, the rate of recovery is dependent upon just how stable and diverse the assemblage was in the first place. A regularly disturbed sedimentary habitat with a low diversity benthic assemblage is likely to recover more quickly (i.e. return to its disturbed or ‘environmentally-stressed’ baseline condition) than a stable habitat with a pre-existing mature and diverse assemblage. Bolam et al. (2004), for instance, concluded that the relatively rapid recovery which they observed (at a location on the Crouch Estuary) was due to the opportunistic nature of the invertebrate assemblages and the dispersive behaviour of the dominant species that were there before the materials was placed over them. Furthermore, in cases where the quantity and type of sediment deposited does not differ greatly from natural sedimentation, e.g. of similar particle size, the effects are likely to be relatively small as many of the species are capable of migrating up through the deposited sediments (Budd, 2004).

An expert workshop that convened to assess the sensitivity of marine features considered that subtidal sediment was not sensitive (high resistance and high resilience) to the deposition of 5 cm of fine material in a single event (Tillin et al., 2010). A previous review by the University of Hull also concluded that benthic invertebrates in sediments are able to adapt and readjust if sediment laid is placed as thin veneers over several days although they can also tolerate moderate amounts (20 cm) of material being deposited at one time (IECS, 2001).

Project Impact Assessment

It is proposed that up to 10,000 m³ of sediment will be dredged within the area of proposed reclaim and rock armour revetment using a bucket dredger. The coastal processes assessment in Chapter 4 of this ES predicts the maximum amount of sedimentation as a result of dredging to be in the order of <2.1 mm outside of the reclamation area. In addition, negligible sedimentation (at levels considered less than during dredging) could also occur as a result of other construction activities such a piling.

Deposition of sediment as a result of dredging will therefore be highly localised and barely measurable against background variability. Magnitude of change is therefore assessed as small. Probability of occurrence is high and thus the overall exposure to change is low. Intertidal and subtidal marine species within this area are considered tolerant to the predicted very low levels of levels of deposition (Marine Ecological Surveys Limited, 2008; Tillin et al., 2010; IECS, 2001). Sensitivity of benthic species within the vicinity of the proposed development to smothering is therefore assessed as low. The benthic habitats and associated species that overlap with the changes brought about during construction and dredging are commonly occurring in the local area and generally of low conservation concern. Therefore, importance is assessed as low. The overall effect of smothering on benthic features is considered to be insignificant.

The piling only scenario will result in even lower and more localised deposition than the reclaim scenario described above. On this basis, the overall effect of smothering on benthic features as part of the piling only scenario is considered to be insignificant.

Environmental Statement 7/30 April 2018 Replacement Linkspan, Fishguard Port

Changes in Water Quality During Construction

General Scientific Context

Elevated suspended sediment concentrations

Dredging activities result in the suspension of disturbed sediment and subsequent deposition of material (e.g. by screening and overspill from the hopper) (Newell et al., 1998). Changes in Suspended Sediment Concentrations (SSC) can lead to changes in subtidal habitat and benthic communities through changes in sediment availability. A reduction in the amount of sediment carried in suspension will reduce the amount of sediment available to subtidal habitats (e.g. mudflats). Conversely increases in suspended sediment will increase the amount of sediment available to subtidal communities. These changes may alter the composition of the biological assemblage associated with this receptor.

Increased suspended sediments may favour the development of suspension feeders such as bivalves over other species. However, it should be noted that many benthic invertebrates can switch feeding modes depending on environmental conditions. The negative effects of suspended sediment may be particularly important during larval settlement in spring, with settling stages potentially being more sensitive to effects such as scour. However, this is generally thought to be of less concern where fauna are adapted to naturally high levels of suspended sediments (Boyd et al., 2004).

Dissolved Oxygen

The resuspension of sediments containing organic material can cause oxygen depletion within the water column. The subsequent settling of this organic rich sediment can deplete sediment oxygen levels thereby affecting benthic species. The response of benthic species to low concentrations of dissolved oxygen is determined by a range of factors, including the duration of exposure, water temperature and the presence of other pollutants.

Release of contaminants

Benthic habitats and species are sensitive to toxic contamination (where concentrations of contaminants exceed sensitivity thresholds). Toxic contamination during construction can occur as a result of the release of synthetic contaminants such as fuels and oils or through the resuspension of sediment during dredging which can lead to the release and mobilisation of sediment-bound contaminants into the water column. These include both toxic contaminants, such as heavy metals, pesticides and hydrocarbons, and non-toxic contaminants, such as nutrients. In particular, there is a risk that any uncontrolled releases of materials or sediments into the water column could make contaminants temporarily available for uptake by marine organisms. Over the longer-term any such releases could also become stored in the surface sediments of benthic habitats for future benthic uptake.

Suspension-feeding organisms may be particularly vulnerable to pollutants in the water column due to their dependence on filtration. High levels of chemical contaminants can potentially cause genetic, reproductive and morphological disorders in marine species. Contaminants may also have combined effects. Studies have suggested links between contamination with Polycyclic aromatic hydrocarbons (PAH’s), Polychlorinated Biphenyl (PCBs), amines and metals and a range of disorders (MacDonald and Ingersoll, 2010). Increased incidence of tumours, neoplasia, DNA damage, polyploidy, hypoploidy, hermaphoditism and reduced immune response have all been reported in marine invertebrates in areas of high levels of pollution (Hannam et al., 2010; Catalano et al., 2012; Hesselman et al., 1988; Nacci and Jackim, 1989; Gardner et al., 1992; Schaeffer, 1993; Barsiene, 1994). Another highly researched pollutant is Tributyltin (TBT), which has toxic effects in a wide variety of biota, whereas inorganic tin is less toxic. TBT effects include lethal toxicity and effects on growth, reproduction, physiology, and behaviour. Several of the negative effects are due to interferences with the endocrine function, as occurs in the phenomenon imposex. Imposex is the superimposition of male organs onto females of gastropods, which are normally a dioecious species (Borja et al., 2012).

Sub-lethal effects of chemical contamination on marine invertebrates can reduce the fitness of individual species. Lethal effects may allow a shift in community composition to one dominated by pollution-tolerant species such as oligochaete worms (Elliott et al., 1998). A reduction in community species richness is associated with elevated levels of pollutants. Contamination with PAHs, for

Environmental Statement 7/31 April 2018 Replacement Linkspan, Fishguard Port

example, leads to high levels of mortality in amphipod and shrimp species, and decreased benthic diversity (Long et al., 1995). Similar reductions in diversity are linked with heavy metal contamination (Dauvin, 2008). Polychaete worms are thought to be quite tolerant of heavy metal contamination, whereas crustaceans and bivalves are considered to be intolerant (Rayment, 2002).

Project Impact Assessment

Elevated suspended sediment concentrations

The coastal processes assessment (Chapter 4 of the ES) predicts that there will be a negligible, temporary and localised increase in SSC as a result of the dredging plume (only exceeding more than 20 mg/l in a small area near to the proposed reclamation area for a short duration with increases barely measurable outside of this area).

The predicted increases in SSC will be temporary and of a similar magnitude to those which occur naturally in Fishguard Harbour (e.g. during storm events). Thus in physical terms, the plumes resulting from any construction dredging activities are expected to have a minimal and very localised effect on SSC in the vicinity of the proposed development. Magnitude of change is therefore assessed as small. Probability of occurrence is high and thus the overall exposure to change is low. Based on the evidence provided above, sensitivity of benthic habitats and species within the vicinity of the proposed development to increases in suspended sediments are considered to be low given that these receptors are well adapted to survival under fluctuating sediment conditions. Vulnerability is therefore assessed as low. The benthic habitats and associated species that overlap with the changes brought about during construction and dredging are commonly occurring in the local area and generally of low conservation concern. Therefore, importance is assessed as low. The overall effect of suspended sediments on benthic habitats and species is considered to be insignificant.

The piling only scenario will result in even lower and more localised elevated suspended sediment concentrations than the reclaim scenario described above. On this basis, the overall effect of suspended sediments on benthic habitats and species as part of the piling only scenario is considered to be insignificant.

Release of contaminants

The proposed development has the potential to remobilise contaminants that may be trapped within the sediments. The likelihood of mobilising sediments and contaminated sediments and the magnitude of any effect is dependent upon the level of contamination and the volume of material being removed; the proximity of the activity to the feature; the type of activity occurring; the manner in which that activity is pursued (including the extent and duration); the particle size of the disturbed sediments (contaminants tend to be associated with finer particles) and the hydrodynamic conditions.

Chemical sediment analysis has been undertaken on a number of samples within the area proposed for dredging. This has indicated that there are negligible to very low levels of contamination in the surface sediments of the dredge footprint (at levels below UK guidelines and internationally recognised standards such as Cefas Action Levels 1 and 2).

Given that the overall level of contamination in the proposed dredge area is low and the extent of sediment dispersal as a result of the dredge is considered to be spatially limited, significant elevations in the water column contamination are not anticipated. Based on these factors, the magnitude of change to subtidal habitat and species is considered to be small. Subsequently, exposure of benthic habitats and species to potential contaminants is assessed as negligible. These benthic features are already exposed to comparable levels of contamination from routine maintenance dredging in the wider area. Sensitivity is thus assessed as negligible. The benthic habitats and species that overlap with any potential changes brought about through disturbance of contaminated sediment are commonly occurring in the local area and generally of low conservation concern, therefore importance is assessed as low. Overall, the potential impact to benthic habitats and species arising as a result of disturbance of contaminated sediments is considered to be insignificant.

The piling only scenario will result in even lower sediment disturbance and dispersal than the reclaim scenario described above. On this basis, the overall effect of the release of contaminants on benthic habitats and species as part of the piling only scenario is considered to be insignificant.

The Potential Introduction of Non-Native Species

Environmental Statement 7/32 April 2018 Replacement Linkspan, Fishguard Port

General Scientific Context

Non-native, or invasive, species are described as ‘organisms introduced by man into places outside of their natural range of distribution, where they become established and disperse, generating a negative impact on the local ecosystem and species’ (International Union for Conservation of Nature (IUCN, 2011). The ecological impacts of such ‘biological invasions’ are considered to be the second largest threat to biodiversity worldwide, after habitat loss and destruction. In the last few decades marine and freshwater systems have suffered greatly from invasive species as a result of increased global shipping (Carlton and Geller, 1993).

The introduction and spread of non-native species can occur either accidentally or by intentional movement of species as a consequence of human activity (Ruiz and Carlton, 2003 cited in Pearce et al., 2012). The main pathway for the potential introduction of non-native species is via fouling of vessels’ hulls, transport of species in ballast or bilge water and the accidental imports from materials brought into the system as a result of the development. Pathways involving vessel movements (fouling of hulls and ballast water) have been identified as the highest potential risk routes for the introduction of non-native species (Carlton, 1992; Pearce et al., 2012), which agrees with the fact that areas with a high volume of shipping traffic are hotspots for non-native species in British waters (Pearce et al., 2012).

The fouling of a boat hull and other below-water surfaces can be reduced through the use of protective coatings applied to the hull. These coatings usually contain a toxic chemical (such as copper) or an irritant (such as pepper) that discourages organisms from attaching. Other coatings, such as those that are silicone-based, provide a surface that is more difficult to adhere to firmly, making cleaning of the hull less laborious. The type and concentration of coatings that can be applied to a boat hull is regulated, and can vary from country to country. Maintenance of hulls through regular cleaning will minimise the number of fouling organisms present. Hull cleaning can take place on land or in-water. In both cases, care needs to be taken to prevent the organisms from being released into the water. By following best management practices, the impact of the cleaning procedure on the environment can be minimised.

Non-native invasive species also have the potential to be transported via ship ballast water. Seawater may be drawn into tanks when the ship is not carrying cargo, for stability, and expelled when it is no longer required. This provides a vector whereby organisms may be transported long distances. In 2004 the International Maritime Organisation (IMO) adopted the ‘International Convention for the Control and Management of Ships’ Ballast Water and Sediments’, which introduced two performance standards seeking to limit the risk of non-native invasive species being imported (including distances for ballast water exchange and standards for ballast water treatment). The Convention came into force in September 2017.

The UK is bound by international agreements such as the Convention on Biological Diversity, the United Nations Convention on the Law of the Sea, the Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention 1979), the Convention on the Conservation of European Wildlife and Natural Habitat (Bern, 1979) and the Habitats and Birds Directives. All of these include provisions requiring measures to prevent the introduction of, or control of, non-native species, especially those that threaten native or protected species (JNCC, 2004). Additionally, Section 14(1) of the Wildlife and Countryside Act (WCA) (1981) makes it illegal to release, or allow to escape into the wild, any animal which is not ordinarily resident in Great Britain and is not a regular visitor to Great Britain in a wild state, or is listed in Schedule 9 to the Act. These commitments are expected to be subject to greater international enforcement over time.

In addition, a new European Union Regulation came into force on 1 January 2015 which seeks to prevent and manage the introduction and spread of invasive non-native species. In July 2016, the European Commission adopted the first EU list of 37 invasive alien species, and the associated restrictions and obligations came into force on 3 August 2016.

Project Impact Assessment

As discussed above, non-native species have the potential to be transported into the study area on ships’ hulls during the construction phase of the proposed development. The fouling of a boat hull and other below-water surfaces can be reduced through the use of protective coatings applied to the hull. These coatings usually contain a toxic chemical (such as copper) or an irritant (such as pepper) that discourages organisms from attaching. Other coatings, such as those that are silicone-based, provide

Environmental Statement 7/33 April 2018 Replacement Linkspan, Fishguard Port

a surface that is more difficult to adhere to firmly, making cleaning of the hull less laborious. The type and concentration of coatings that can be applied to a boat hull is regulated, and can vary from country to country. Maintenance of hulls through regular cleaning will minimise the number of fouling organisms present. Hull cleaning can take place on land or in-water. In both cases, care should be taken to prevent the organisms from being released into the water. By following best management practices, the impact of the cleaning procedure on the environment can be minimised.

Non-native invasive species also have the potential to be transported via ship ballast water. Seawater may be drawn into tanks when the ship is not carrying cargo, for stability, and expelled when it is no longer required. This provides a vector whereby organisms may be transported long distances.

In view of existing and near future commitments and considerations, the probability of the introduction and spread of non-native species from construction phase is considered to be low. However, given that the magnitude of change is unknown, magnitude ranges from negligible to large depending upon the scale and nature of any non-native species introduction, thus the exposure ranges from negligible to low at worst. The sensitivity of all intertidal and subtidal receptors to non-native species introductions is expected to range from low to moderate. Vulnerability is therefore considered to be low. In addition, importance is considered to be low given the habitats and species are commonly occurring in the local area and generally of low conservation concern. The overall impact is therefore considered to be insignificant.

The potential introduction of non-native species is expected to be similar for the piling only scenario with the overall impact considered to be insignificant.

However, in order to manage potential non-native species risks as a result of the proposed development, a Biosecurity Plan will be produced. Within Wales and England, best practices guidance has been developed on how to manage marine biosecurity risks at sites and when undertaking activities through the preparation and implementation of biosecurity plans (Cook et al., 2014). This guidance will be followed when developing the Biosecurity Plan.

Indirect Changes in Habitat Extent and Quality as a Result of the Linkspan Structures

General Scientific Context

Hydrodynamic changes (flow speeds, flow direction, waves, water levels) within an estuary or coastal region, or around a new development, may lead to changes in the pattern of emersion, immersion and also erosion or accretion of marine sedimentary habitats such as mudflats and sandbanks. These in turn have the potential to affect habitat quality and result in changes to the diversity, abundance and biomass of plankton, macroalgae and intertidal and subtidal habitats and species.

Project Impact Assessment

The hydrodynamic and sediment regime changes that are predicted to occur as a result of the proposed replacement linkspan are assessed fully in Chapter 4. The replacement linkspan is expected to cause a marginal change in flow speeds (which is not expected to exceed ±0.005 m/s) away from the immediate area of the proposed replacement linkspan. Such changes are unlikely to result in any significant changes to local sediment transport in the region. Only localised and negligible changes in wave climate were also predicted.

Given these highly localised and small scale predicted effects on the hydrodynamic and sedimentary processes, the magnitude of change on intertidal and subtidal species is considered to be small to negligible. Although the probability of occurrence is high the overall exposure is assessed as negligible to low, at worst. These marine habitats are well adapted to the level of change in conditions expected and therefore sensitivity is assessed as low and vulnerability is assessed as low. Given that the benthic habitats and associated species that overlap with the predicted hydrodynamic and sedimentary changes are commonly occurring in the local area (and generally of low conservation concern), the importance of benthic ecology receptors is low and thus the overall impact on benthic habitats and features is considered to be insignificant.

Hydrodynamic changes resulting from the piling only scenario is expected to be lower than the reclaim scenario described above (due to the reduced area of footprint available to cause changes in

Environmental Statement 7/34 April 2018 Replacement Linkspan, Fishguard Port

flow rates and wave climate). On this basis, the overall effect as part of the piling only scenario is considered to be insignificant.

Spread of Non-Native Species as a Result of the Linkspan Structures

General Scientific Context

As described in Section 7.4.3.6, non-native, or invasive, species are ‘organisms introduced by man into places outside of their natural range of distribution, where they become established and disperse, generating a negative impact on the local ecosystem and species’ (IUCN, 2011). The introduction of non-native species has the potential to alter interactions within existing assemblages. Potential effects on native species include; competition for space and resources; alteration of substrata and water conditions; predation and depletion of native species; smothering of native species; consumption of pelagic larvae and loss of prey and refuge. The introduction of non-native species can occur either accidentally or by the intentional movement of species as a consequence of human activity (Ruiz and Carlton, 2003 cited in Pearce et al., 2012).

Project Impact Assessment

The introduction of a new surface in the marine environment, such as the quay wall, has the potential to facilitate the encroachment of invasive non-native species. This is because the surface could provide a fresh surface for invasive non-native species to potentially colonise with limited initial competition from indigenous species. Such spread of non-native species could lead to a reduction in population numbers and biodiversity of the region. However, it is noted that there is already a widespread presence of artificial hard substrates in Fishguard Harbour. Furthermore, as noted in the baseline review (Section 7.3.2.2) several non-native species are already widespread throughout Pembrokeshire, including a range of epifaunal species which attach to hard substrate (e.g. algae B. hamifera and C. peregrina and the orange striped anemone H. lineata.

Therefore, although the probability of colonisation by non-native species is likely to be high, the magnitude of change will be small, due to the relatively small area of reclaim, the widespread presence of existing berthing infrastructure and the prevalence of non-natives throughout the local area. Exposure to change is therefore considered to be low. The sensitivity of all intertidal and subtidal receptors to non-native species introductions is expected to range from low to moderate. Vulnerability is therefore considered to be low. In addition, importance is considered to be low given the habitats and species are commonly occurring in the local area and generally of low conservation concern. The overall impact is therefore considered to be insignificant. Consequently, the overall impact for the introduction and spread of non-native species due to the new hard surfaces as a result of the replacement linkspan is considered to be insignificant.

The piling only scenario will result in a broadly similar extent of surface area for non-native species to colonise. On this basis, the overall impact for the introduction and spread of non-native species due to the new hard surfaces as part of the piling only scenario is considered to be insignificant.

7.4.4 Plankton

Scoped Out

The following pathways have been scoped out of requiring further detailed assessment:

- Water quality during construction: Construction activity (including dredging) may increase SCC and release toxic contaminants bound in sediments. This can cause changes in a range of water quality parameters including turbidity and dissolved oxygen level. However, changes at this scale will not produce lethal or sub-lethal effects in plankton. The potential for accidental spillages will also be negligible during all phases through following established industry guidance and protocols. Potential water quality impacts on plankton have therefore been scoped out of the assessment. - Loss of habitat: There is the potential for impacts to plankton as a direct result of the proposed development and also indirectly arising from changes to hydrodynamic and sedimentary transport regimes. However, plankton which inhabit the pelagic zone and free- floating in the water column are not considered sensitive to the scale of seabed habitat loss predicted and will not be impacted by indirect changes resulting from hydrodynamic and sedimentary transport regimes.

Environmental Statement 7/35 April 2018 Replacement Linkspan, Fishguard Port

Scoped In

No potential impacts to plankton have been scoped into the assessment.

7.4.5 Fish and Shellfish

This section assesses the potential for impacts on fish and shellfish receptors as a result of the development.

Scoped Out

The proposed development will not change the existing maintenance dredging regime for the ferry berth which is currently undertaken as part of an existing marine licence. In addition, the same ferry type and services will continue to run from the replacement linkspan. Therefore, operational impacts associated with maintenance dredging and ferry vessel movements are not considered further in the assessment. In addition, the following specific pathways have been scoped out of requiring further detailed assessment:

- Loss of habitat as a result of the proposed development: The footprint of the proposed development will cover a localised area that only constitutes a very small fraction of the known ranges of local fish populations. Furthermore, very few shellfish species which are only present at very low levels of abundance have been recorded within the vicinity of the proposed development. The potential for impacts to fish and shellfish feeding, nursery and spawning habitats has therefore been scoped out of this assessment.

Scoped In

The proposed development has the potential to affect fish and shellfish receptors through a number of impact pathways:

- Changes in Water Quality during Construction; and - Noise Disturbance during Construction.

Changes in Water Quality on During Construction

General Scientific Context

Elevated suspended sediment concentrations

Increased suspended sediments can lead to physiological effects in adult finfish resulting from the abrasion of sediment particles on gill tissues, causing reduced gill function and possible mortality. Such effects on fish are considered to occur at suspended sediment levels of around 10,000 mg/l (Britwell, 2000). High SSC levels may impact spawning and nursery grounds through damage to eggs and planktonic larvae, as well as causing abrasion or clogging of the fragile gills of larval and juvenile fish, resulting in mortality or reduced growth rates.

Elevated suspended sediments can also influence the movements and migrations of fish. However, fish in high latitude coastal areas typically have to contend with variable turbidity and often poor visual conditions, resulting from fluctuations in ambient light levels, suspended sediments and in the light transmission properties of the water. For example, concentrations as high as 9,000 mg/l, for example, have been recorded in the path of salmon runs in the Usk Estuary (Alabaster, 1993). Similarly the lamprey and shad species have been known to successfully pass through estuaries with extremely high suspended sediments and, therefore, can be considered tolerant of turbid conditions (Scottish Government, 2010).). The mobile nature of fish species generally allows avoidance of areas of adverse conditions which are unlikely to significantly affect a population provided such conditions are temporary.

Organic enrichment and oxygen depletion

The resuspension of sediments containing organic material can cause oxygen depletion within the water column. The subsequent settling of this organic rich sediment can deplete the sediments of oxygen and affect shellfish and benthic prey items used by fish. The response of fish to low concentrations of dissolved oxygen is determined by a range of factors, including the duration of

Environmental Statement 7/36 April 2018 Replacement Linkspan, Fishguard Port

exposure, water temperature and the presence of other pollutants. The duration of any low dissolved oxygen event is a key factor in determining its effect. Most fish would survive an extremely low concentration of dissolved oxygen, such as 2 mg/l, for a few minutes, but a longer exposure would start to have sub-lethal and eventually lethal effects (ABP Research, 2000).

Release of contaminants

The potential release of contaminants during construction and dredging activities may result in them becoming available for uptake by any fish and/or shellfish in the water column or on surface sediments. There is an indirect risk to some finfish species as sediment-bound contaminants may be temporarily bioaccumulated in the tissues of certain fish prey, such as polychaete worms and marine bivalves, and made available for uptake by feeding fish. Demersal fish species, such as dab and flounder, which remain close to the seabed and feed mainly on benthic organisms, would experience a higher exposure to contaminated sediments than pelagic fish such as herring.

Project Impact Assessment

Elevated suspended sediments

The coastal processes assessment (Chapter 4 of the ES) predicts that there will be a negligible, temporary and localised increase in SSC as a result of the dredging plume (only exceeding more than 20 mg/l in a small area near to the proposed reclamation area for a short duration with increases barely measurable outside of this area).

The temporary and highly localised increases in SSC will be of a magnitude comparable to that which occurs under the present maintenance dredging regime and which can occur naturally in Fishguard Harbour (e.g. during storm events). Thus in physical terms, the plumes resulting from any construction dredging activities are expected to have a minimal and local effect on SSC in the vicinity of the proposed development. Therefore, while the probability of a localised change is high, magnitude of change and consequently exposure to change is assessed as negligible.

As noted in the preceding section, fish and shellfish within Fishguard Harbour are well adapted to living in an area with variable and sometimes relatively high suspended sediment loads. Fish feed on a range of food items and, therefore, their sensitivity to a temporary change in the availability of a particular food resource is considered to be low. Their high mobility enables them to move freely to avoid areas of adverse conditions and to use other food sources in the harbour. Commercial shellfish beds do not overlap with the plumes generated during dredging and are not considered to be sensitive to the scale of these changes. Sensitivity of fish and shellfish is therefore assessed as low at worst and consequently vulnerability is also assessed as none. Therefore, while the overall importance of certain fish and shellfish species is high (i.e. for fish species of conservation interest such as Atlantic salmon, lamprey species and European eel), the impact is considered to be insignificant.

The piling only scenario will result in even lower and more localised elevated suspended sediment concentrations than the reclaim scenario described above. On this basis, the overall effect of suspended sediments on fish and shellfish as part of the piling only scenario is considered to be insignificant.

Organic enrichment and oxygen depletion

Increases in SSC will be brief and localised and there is not expected to be a significant reduction in dissolved oxygen. The probability of a localised effect is therefore medium to high but the magnitude of change is considered to be negligible, leading to a negligible exposure to change. Therefore, while the sensitivity of fish and shellfish is low to moderate and certain species have a high nature conservation importance (e.g. migratory Atlantic salmon and lamprey) any impact will be insignificant.

The piling only scenario would result in even lower and more localised organic enrichment and oxygen depletion than the reclaim scenario described above. On this basis, the overall effect of organic enrichment and oxygen depletion on fish and shellfish as part of the piling only scenario is considered to be insignificant.

Environmental Statement 7/37 April 2018 Replacement Linkspan, Fishguard Port

Release of contaminants

Chemical sediment analysis has been undertaken on a number of samples within the area proposed for dredging. This has indicated that there are negligible to very low levels of contamination in the surface sediments of the dredge footprint (at levels below UK guidelines and internationally recognised standards such as Cefas Action Levels 1 and 2).

Given that the overall level of contamination in the proposed dredge area is low and the extent of sediment dispersal as a result of the dredge is considered to be spatially limited, significant elevations in the water column contamination are not anticipated. Based on these factors, the magnitude of change to fish and shellfish species is therefore considered to be small. Subsequently, exposure of fish and shellfish species to potential contaminants is assessed as low. Given that the probability of occurrence is low the overall exposure is assessed as negligible. Therefore, although the sensitivity of fish and shellfish is considered to be low to moderate and the overall importance is considered to range from low to high, depending on the ecological value and protected status of individual species, the impact is considered to be insignificant.

The piling only scenario would result in even lower sediment disturbance and dispersal than the reclaim scenario described above. On this basis, the overall effect of the release of contaminants on fish and shellfish as part of the piling only scenario is considered to be insignificant.

Noise Disturbance on Fish During Construction

General Scientific Context

The extent to which intense underwater sound might cause an adverse environmental impact in a particular fish species is dependent upon the level of noise, its frequency, duration and/or repetition (Hastings and Popper, 2005). The range of potential effects from intense sound sources, such as pile driving, includes immediate death, permanent or temporary tissue damage and hearing loss, behavioural changes and masking effects. Tissue damage can result in eventual death or may make the fish less fit until healing occurs, resulting in lower survival rates. Hearing loss can also lower fitness until hearing recovers. Behavioural changes can potentially result in animals avoiding migratory routes or leaving feeding or reproduction grounds with potential population level consequences. Biologically important sounds can also be masked where the received levels are marginally above existing background levels (Hawkins and Myrberg Jr, 1983). The ability to detect and localise the source of a sound is of considerable biological importance to many fish species, and is often used to assess the suitability of a potential mate or during territorial displays and during predator prey interactions.

To evaluate the potential effects of noise on fish it is necessary to understand how marine construction noise propagates underwater and the potential response of different fish species to received levels of noise.

Underwater noise propagation

The process of noise travelling through a medium is referred to as noise propagation. The propagation of underwater noise is a very complex process and therefore predicting the received levels at distance from a source is extremely difficult. Use is generally made of theoretical models or empirical models based on field measurements.

A simple logarithmic spreading model can be used to predict the propagation of sound pressure with range from the source (NPL, 2014). This model is represented by a logarithmic equation and incorporates factors for noise attenuation and absorption losses. The advantage of this model is that it is simple to use and quick to provide first order calculations of the received SPL with distance from the source due to geometric spreading.

Equation 1 Simple logarithmic spreading model:

L(R) = SL – N log10(R) - αR

- L(R) is the sound pressure level (SPL) at distance R from a source (i.e. the received level) and is generally expressed in terms of decibels (dB) for a reference pressure of 1 µPa and a reference range of 1 m (dB re 1 µPa m);

Environmental Statement 7/38 April 2018 Replacement Linkspan, Fishguard Port

- R is the distance in metres from the source to the receiver; - SL is the Source Level (i.e. the level of sound generated by the source) also generally expressed as dB re 1 µPa m; and - N is a factor for attenuation due to geometric spreading; and - α is a factor for the absorption of sound in water and boundaries (i.e. the sediment or water surface) in dB m-1.

The Environment Agency has compiled observed data representing factors for attenuation (N coefficient) and absorption (α coefficient) which were presented at the Institute of Fisheries Management (IFM) Conference on 23 May 2013. These observed data were collected for a range of construction projects undertaken in shallow water riverine, estuarine and coastal locations as follows:

- Russian River New Bridge in Geyserville, California (Illinworth and Rodkin, 2007); - San Rafael Sea Wall in San Francisco Bay, California (Illinworth and Rodkin, 2007); - Scroby Sands Offshore Wind Farm located off the coast of Great Yarmouth (Nedwell et al., 2007a); - North Hoyle Offshore Wind Farm in Liverpool Bay (Nedwell et al., 2007a); - Kentish Flats Offshore Wind Farm located off the coast of Kent (Nedwell et al., 2007a); - Burbo Bank Offshore Wind Farm in Liverpool Bay (Nedwell et al., 2007a); - Barrow Offshore Wind Farm located south west of Walney Island (Nedwell et al., 2007a); and - Belvedere Energy-from-Waste Plant on Thames Estuary (measurements collected by Subacoustech Ltd on behalf of the Environment Agency and Costain).

These provide a mean N coefficient of 17.91 (Standard Deviation (SD) 3.05) and α coefficient of 0.00523 dB m-1 (SD 0.00377 dB m-1) based on 11 and 9 observations respectively. The Environment Agency has in the past recommended the application of these model input values in underwater noise assessments undertaken in estuaries (e.g. URS Scott Wilson, 2011). These values are therefore considered to be appropriate to use for this assessment.

It is important to recognise that there are a number of limitations associated with the use of simple logarithmic spreading models (NPL, 2014). Such models do not account for changes in bathymetry, and therefore are not able to predict the changes in sound propagation caused by sand banks and shallow coastal areas. In addition, they do not include frequency dependence explicitly, and so cannot predict the increased loss at high frequencies due to increased sound absorption. Farcas et al. (2016) also demonstrated how use of these simple models in complex environments typical of coastal and inland waters can underestimate noise levels close to the source and substantially overestimate noise levels further from the source. In other words, they can underestimate the risk of injury or disturbance to marine fauna close to the source whilst giving the impression that a larger area would be affected.

Although this equation generally represents a simplistic model of propagation loss, its use is an established approach in EIAs that has been widely accepted by UK regulators in the past. Furthermore, the National Marine Fisheries Service (NMFS) in the United States requires use of the practical spreading model in the NMFS pile driving calculator to assess the potential impacts of pile driving on fish. The simple logarithmic spreading model is therefore considered appropriate to use for the assessment of noise associated with the replacement linkspan development.

Characteristics of marine construction noise

The greatest underwater noise levels generated during the construction of the replacement linkspan development will arise from percussive (or impact) piling. Impact piling involves a large weight or “ram” being dropped or driven onto the top of the pile, driving it into the seabed. Impact piling is impulsive in character with multiple pulses occurring at blow rates in the order of 30 to 60 impacts per minute. Typical source levels range from peak SPL of 190 to 245 dB re 1 μPa (DPTI, 2012). Most of the sound energy usually occurs at lower frequencies between 100 Hz and 1 kHz. Factors that influence the source level include the size, shape, length and material of the pile, the weight and drop height of the hammer, and the seabed material and depth.

The Environment Agency has developed a model of observed source level of percussive piling of tubular piles versus pile diameter which was presented at the Institute of Fisheries Management Conference on 23 May 2013.

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Equation 2 Observed source level versus pile diameter:

SL = 10.973Ln(PD) + 231.74

- SL is provided as unweighted peak-to-peak SL in dB re 1 µPa-1 m; and - PD is the pile diameter in metres.

This model has been derived from 21 observations of publicly available percussive piling noise data, primarily from Subacoustech studies but also the California Department of Transportation (Caltrans) compendium of pile driving sound data (Illingworth & Rodkin, 2007) and Institute for Technical and Applied Physics (ITAP) (Matuschek and Betke, 2009). Based on this equation, the 500 to 1100 mm steel tubular piles that are proposed to be used during the construction of the replacement linkspan development are predicted to have an estimated mean unweighted peak SL of 218 to 227 dB re 1 μPa m. There might be two piling rigs involved in the installation of the steel tubular piles which would marginally increase the estimated mean unweighted peak SL to 221 to 230 dB re 1µPa m. These SLs were derived from the model of observed SL versus pile diameter that was developed by the Environment Agency (Equation 2).

The construction of the replacement linkspan development will also involve the percussive piling of sheet piles. There are no published estimates of source levels for the impact piling of sheet piles. A near-source (10 m from the source) peak sound pressure is available from measurements of pile driving of 0.6 m AZ steel sheet piles (Illinworth & Rodkin, 2007). Back-calculating to 1 m using the simple logarithmic spreading model (equation 1) provides an estimated peak SL of 223dB re 1 µPa m.

A vibratory hammer is likely to be used at the beginning of the piling process prior to percussively driving the piles to the specified depth or resistance. Vibratory hammers use oscillatory hammers that vibrate the pile, causing the sediment surrounding the pile to liquefy and allow pile penetration (ICF Jones & Stokes and Illingworth & Rodkin, 2009). Peak sound pressure levels for vibratory hammers can exceed 180 dB; however, the sound from these hammers rises relatively slowly. The vibratory hammer produces sound energy that is spread out over time and is generally 10 to 20 dB lower than impact pile driving. Although peak sound levels can be substantially less than those produced by impact hammers, the total energy imparted can be comparable to impact driving because the vibratory hammer operates continuously and requires more time to install the pile.

Bucket dredging will be required during the construction of the replacement linkspan development. The dredging process involves a variety of sound generating activities which can be broadly divided into sediment excavation, transport and placement of the dredged material at the disposal site (CEDA, 2011; WODA, 2013; Jones and Marten, 2016). Only one study has been found in the available literature for sound emissions from a bucket/ clamshell dredger (Dickerson et al., 2001). The majority of the sounds recorded were in the 20-1,000 Hz frequency range. A peak received level of 107 dB re 1 µPa at 150 m for 91.5 Hz was recorded when the bucket was striking the seabed. This equates to a peak SL of 190 dB re 1 µPa m.

Rock breakers may be required during construction of the replacement linkspan. There is only one known measurement of the underwater noise recorded from operations with a ‘rock pecker’ operating above the water column (Subascoustech, 2008). A peak received level of 154 dB re 1 µPa at 400 m was observed when the rock pecker was hammering against the concrete dockside which equates to a peak SL of 203 dB re 1 µPa m. At present there are no data available for rock pecker operations where the impact head is below the waterline. Engineering works in coastal environments using blasting to remove unwanted hard substrate1 have been recorded to produce peak SL in the region of 246 dB re 1 µPa m with most of the sound energy concentrated around 500 Hz (Urquhart and Hall, 2005).

Fish hearing sensitivity

There is a wide diversity in hearing structures in fish which leads to different auditory capabilities across species (Webb et al., 2008). All fish can sense the particle motion2 component of an acoustic field via the inner ear as a result of whole-body accelerations (Radford et al., 2012), and noise detection (‘hearing’) becomes more specialised with the addition of further hearing structures.

1 The blasting event that was recorded involved 30 kg of explosives in 3 holes. 2 Particle motion is a back and forth motion of the medium in a particular direction; it is a vector quantity that can only be fully described by specifying both the magnitude and direction of the motion, as well as its magnitude, temporal, and frequency characteristics.

Environmental Statement 7/40 April 2018 Replacement Linkspan, Fishguard Port

Particle motion is especially important for locating sound sources through directional hearing (Popper et al., 2014; Hawkins et al., 2015; Nedelec et al., 2016). Although many fish are also likely to detect sound pressure3, particle motion is considered equally or potentially more important (Hawkins and Popper, 2016).

From the few studies of hearing capabilities in fishes that have been conducted, it is evident that there are potentially substantial differences in auditory capabilities from one fish species to another (Hawkins and Popper, 2016). Since it is impossible to determine hearing sensitivity for all fish species, one approach to understand hearing has been to distinguish fish groups on the basis of differences in their anatomy and what is known about hearing in other species with comparable anatomy. Categories proposed by Popper et al. (2014) for each of the key fish species found in the study area are included in Table 7.9.

Table 7.8: Categorisation of key fish species in the study area according to Popper et al. (2014) criteria Swim bladder or air cavities Swim bladder does not aid No swim bladder aid hearing hearing Allis shad (Alosa alosa) Atlantic salmon (Salmo salar) Dab (Limanda limanda) Herring (Clupea harengus) European eel (Anguilla anguilla) Gobies (Gobius spp.) Pollack (Pollachus pollachius) Plaice (Pleuronectes platessa), Twaite shad (Alosa fallax) Sea bass (Dicentrarchus labrax) River lamprey (Lampetra Sea trout (Salmo trutta) fluviatilis) Whiting (Merlangius merlangus) Sandeels e.g. lesser sandeel (Ammodytes tobianus) Sea lamprey (Petronmyzon marinus) Thornback ray (Raja clavata)

The first category comprises fish that have special structures mechanically linking the swim bladder to the ear. These fish are sensitive primarily to sound pressure, although they also detect particle motion (Hawkins and Popper, 2016). They have a wider frequency range, extending to several kHz and generally show higher sensitivity to sound pressure than fishes in the other categories.

The second category comprises fish with a swim bladder where the organ does not appear to play a role in hearing. Some of the fish in this category are considered to be more sensitive to particle motion than sound pressure (see below) and show sensitivity to only a narrow band of frequencies, namely the salmonids (Salmonidae) (Hawkins and Popper, 2016). This second category also comprises fishes with swim bladders that are close, but not intimately connected, to the ear, such as codfishes (Gadidae) and eels (Anguillidae). These fishes are sensitive to both particle motion and sound pressure, and show a more extended frequency range, extending up to about 500 Hz (Popper and Coombs, 1982; Jerkø et al., 1989; Popper and Fay, 2011; Hawkins and Popper, 2016).

The third category comprises fishes lacking swim bladders that are sensitive only to sound particle motion and show sensitivity to only a narrow band of frequencies (e.g. flatfishes and sharks skates and rays). Particle motion rather than sound pressure is considered to be potentially more important to fish without swim bladders and salmonids. Acoustic particle motion in the water and seabed, for example, has been shown to induce behavioural reactions in sole (Mueler-Blenkle et al., 2010). However, there is no published literature on the levels of particle motion generated during construction activities (e.g. pile-driving and dredging) and the distance at which they can be detected. This may be due to the fact that there are far fewer devices (and less skill in their use) for detection and analysis of particle motion compared to hydrophone devices for detection of sound pressure (Martin et al., 2016). Direct measurements of particle motion have also been hampered by the lack of guidance on data analysis methods.

Particle velocity can be calculated indirectly from sound pressure measurements using rather simple models. However, such estimates of sound particle velocity are only valid in environments that are distant from reflecting boundaries and other acoustic discontinuities. These conditions are rarely met in the shelf-sea and shallow-water habitats that most aquatic organisms inhabit and that are applicable to the study area (Nedelec et al., 2016).

3 Pressure fluctuations in the medium above and below the local hydrostatic pressure; it acts in all directions and is a scalar quantity that can be described in terms of its magnitude and its temporal and frequency characteristics.

Environmental Statement 7/41 April 2018 Replacement Linkspan, Fishguard Port

Responses of fish to noise

Peak SPL criteria have been developed for pile driving to allow for the assessment of potential mortality and recoverable injury (Popper et al., 2014). These guidelines are based on an understanding that fish will respond to sounds and their hearing sensitivity. However, there is a lack of specific data on exposure or received levels that enable guideline thresholds to be provided for all fish hearing groups identified in Table 7.9.

The onset of behavioural responses to noise is much more difficult to quantify as reactions are likely to be strongly influenced by behavioural context and the effect of a particular response is often unclear (Hawkins and Popper, 2014; Hawkins et al., 2015). In other words, behaviour may be more strongly related to the particular circumstances of the animal, the activities in which it is engaged, and the context in which it is exposed to sounds (Ellison et al., 2012). For example, a startle or reflex response to the onset of a noise source does not necessarily lead to displacement from the ensonified area. This uncertainty is further compounded by the limitations of observing fish behavioural responses in a natural context. Few studies have conducted behavioural field experiments with wild fish and laboratory experiments may not give a realistic measure of how fish will respond in their natural environment.

There are many data gaps that preclude the setting of specific sound exposure criteria, especially for behavioural response by fishes (Popper et al., 2014; Hawkins and Popper, 2016). A behavioural threshold could be adopted using observed responses of fish to impulsive sounds. Recent work has been undertaken by Hawkins et al. (2014) reporting behavioural responses of schools of wild sprat and mackerel to playbacks of pile driving. At a single-pulse peak-to-peak SPL of 163 dB re 1 μPa (equivalent to peak SPL of 157 dB re 1 μPa), schools of sprat and mackerel were observed to disperse or change depth on 50 % of presentations. Sprat and mackerel have specialised hearing structures, and are likely to have similar acoustic characteristics to the clupeid species in the study area, namely herring, twaite shad and allis shad. Other species in the study area lack any hearing specialisations and therefore this threshold is likely to be an indicator of more subtle behavioural responses in these fish.

Potential behavioural effects in the past have also been inferred by comparing the received sound level with the auditory threshold of marine fauna. Richardson et al. (1995) and Thomsen et al. (2006), for example, have used received levels of noise in comparison with the corresponding hearing thresholds of marine fauna in order to estimate the range of audibility and zones of influence from underwater sound sources. This form of analysis has been taken a stage further by Nedwell et al. (2007b), where the underwater noise is compared with receptor hearing threshold across the entire receptor auditory bandwidth in the same manner that the dB(A) is used to assess noise sources in air for humans. These include behavioural thresholds, where received sound levels around 90 dB above hearing threshold (dBht) are considered to cause a strong behavioural avoidance, levels around 75 dBht a moderate behavioural response and levels around 50 dBht a minor response.

The dBht criteria have been applied in a number of offshore renewables EIAs and have been recognised to be of some value in published peer-reviewed papers (Thompson et al., 2013; Popper et al., 2014). Furthermore, the Environment Agency has previously recommended it to be used in impact assessments in coastal/estuarine environments (e.g. ABPmer, 2012; URS Scott Wilson, 2011). However, it is worth noting that the dBht criteria have not been validated by experimental study and have not been published in an independent peer reviewed paper. The dBht approach does not take into account potential for sound sensitivity to changes with that of the life stage of the organism, time of year, animal motivation, or other factors that might affect hearing and behavioural responses to sound (Hawkins and Popper, 2016). Furthermore, the dBht criteria are based on measures of inner ear responses and should rather be based on behavioural threshold determinations (Popper et al., 2014; Hawkins and Popper, 2016). The dBht criteria should therefore be used and interpreted with a high level of caution.

A summary of the published and unpublished impact criteria that have been applied to this assessment based on the above review is provided in Table 7.10 and Table 7.11.

Environmental Statement 7/42 April 2018 Replacement Linkspan, Fishguard Port

Table 7.9: Fish response peak SPL4 criteria applied to percussive piling Fish hearing group Mortality/ potential mortal Behaviour/ displacement injury/ recoverable injury > 207 dB re 1 μPa > 157 dB re 1 μPa Swim bladder involved in hearing

(primarily pressure detection) > 50 dBht Swim bladder is not involved in > 75 dBht hearing (particle motion > 90 dBht detection) No swim bladder (particle motion > 213 dB re 1 μPa detection)

Project Impact Assessment

Piling

Dolphins will be constructed adjacent to the edge of the proposed linkspan. Each dolphin will be constructed using either; tubular steel or concrete piles (both raking and vertical piles) with a reinforced pile cap or a gravity concrete caisson positioned on a prepared bed. The number of piles and size of the reinforced concrete dolphins will be determined during detailed design stage however, it is anticipated that a maximum of 24 steel tubular piles between 500 and 1100 mm diameter may be employed to support the structures on the underlying rock (see Chapter 2). There is also the potential requirement for sheet piling (0.6 m AZ piles) for up to 35 m to replace the revetment return behind the linkspan. The methodology used to install the piles could be either vibro or percussive (impact/hammer) piling.

Percussive piling is known to generate the highest noise levels and, therefore, the assessment has focussed on the potential noise effects of this type of approach as a worst case. The largest (1100 mm) steel tubular piles are predicted to generate the highest peak SL (peak SL of 227 dB re 1 μPa m) and therefore this SL has been used to assess the worst case effects on fish.

The logarithmic noise propagation model (Equation 1) was run using this SL to determine the unweighted received levels with range. These received levels represent unweighted metrics as recommended in NPL (2014). Table 7.12 shows the results of this analysis at various distances from the source of piling. Within 500 m from the source of piling, the received levels of noise will be comparable to the source level generated by a medium sized vessel.

The SL generated by the largest steel tube piles is above the published criteria for lethal effects and recoverable physical injury (Table 7.10). The distance at which the received level of noise is within the limits of injury is 13 m in fish with a swim bladder and 6 m in fish with no swim bladder. The distance at which the received level is within the limits of a behavioural reaction in all fish is 2 km.

Table 7.10: Unweighted received levels during percussive piling Range (m) Unweighted Received Levels (dB re 1 μPa m) 1 227 10 209 50 196 100 191 250 183 500 176

The constrained nature of the study area will ensure elevated levels of underwater noise during construction remain largely within Fishguard Harbour. The smaller inner breakwater within the harbour will act as a screen/barrier, limiting the propagation of noise reaching the coastline near the river Gwaun mouth. However, elevated levels of noise that have the potential to cause a behavioural response in fish (approximately 163 dB re 1 μPa m) are still anticipated to be experienced around the approach to the river Gwaun between Saddle Point and Castle Point. Fish with a swim bladder involved in hearing (e.g. allis shad and twaite shad) may exhibit a moderate behavioural reaction in

4 All criteria are presented as sound pressure even for fish without swim bladders since no data for particle motion exist (Popper et al., 2014).

Environmental Statement 7/43 April 2018 Replacement Linkspan, Fishguard Port

this area (e.g. change in swimming direction or depth). Fish with a swim bladder that is not involved in hearing (e.g. Atlantic salmon, sea trout and European eel) are likely to display a milder behavioural reaction and fish without a swim bladder (e.g. sea lamprey and river lamprey) are anticipated to only show very subtle changes in behaviour at this location.

The logarithmic noise propagation model was also run to estimate the distance from the source of noise at which different dBht response thresholds for differing fish hearing categories (Table 7.9) are reached. The results of this analysis are shown in Table 7.12. These are included here for illustrative purposes but are not analysed further given the significant limitations of the dBht metric discussed in Section 7.4.5.4.

Table 7.11: Approximate distances dBht behavioural response thresholds in fish are reached during percussive piling

Fish hearing group 50 dBht 75 dBht 90 dBht 6,453 m 2,877 m 1,250 m Swim bladder involved in hearing (primarily pressure detection) Swim bladder is not 3,529 m 856 m 194 m involved in hearing (particle motion detection) No swim bladder 856 m 59 m 9 m (particle motion detection)

The effects of piling noise on fish also need to be presented in terms of the duration of exposure. It is anticipated that the piling work could extend to approximately six months, with an allowance for adverse weather and tidal conditions. Furthermore, impact piling will not take place continuously. It is currently proposed that any piling activities (vibro or impact) will only take place at certain times, namely: Monday to Friday (07:00-19:00) and Saturday (08:00-13:00) with no significant construction noise activities being permitted outside of these hours. In this way, the actual proportion of impact piling is estimated to be at worst 39 % (assuming no stoppages and based on a 12 hour working day) over any given construction week. In other words, any fish occurring in Fishguard Harbour at the time of piling will be exposed a maximum of up to 39 % of the time.

The construction programme may overlap with the migratory period of Atlantic salmon smolts (Section 7.3.4.2). Migratory fish moving between the river Gwaun and the sea are unlikely to be passing within such close proximity to the piling activity that injury will be caused to these species. However, behavioural response could occur as far as the approach to the river Gwaun. Magnitude and consequently exposure to change is therefore considered to be medium. The sensitivity of Atlantic salmon is considered to be moderate and the overall importance of this species is considered to be high given its nature conservation interest. Therefore, the temporary noise impact during construction has been assessed as moderate adverse on Atlantic salmon.

Juvenile European eels (elvers) migrate into estuaries and rivers during late winter and early spring and therefore the construction programme may overlap with the migratory period for this species. Magnitude and consequently exposure to change is therefore considered to be medium. The sensitivity of European eel is considered to be moderate and the overall importance of this species is considered to be high given its nature conservation interest. Therefore, the temporary noise impact during construction has been assessed as moderate adverse on European eel.

In terms of other fish commonly occurring in the harbour, the impact is considered to be minor to insignificant. This is based on these other fish having a range of sensitivities from low to high, and a generally low importance in terms of nature conservation status.

These assessments have been based on a worst-case assumption that there will be percussive piling throughout the construction period. In practice the main approach will be to use vibro piling wherever possible with percussive piling only being used where absolutely necessary. In addition, all piling will involve the use of soft start procedures. Further information on these ‘embedded’ mitigation measure mitigation measures is provided in Section 7.6. With these measures in place the impact is

Environmental Statement 7/44 April 2018 Replacement Linkspan, Fishguard Port

considered to be minor for Atlantic salmon and European eel. The impact is considered insignificant for all other species.

The piling only scenario would result in the same underwater noise effects as the reclaim scenario. On this basis, with the mitigation measures described above, the overall effect of underwater noise is considered to be minor for Atlantic salmon and European eel and insignificant for all other species.

Bucket dredging

To date, auditory and non-auditory injuries have not been observed or documented to occur in association with dredging (Thomsen et al., 2009; WODA, 2013). Popper et al. (2014) recommended sound exposure guidelines for fish species relating to continuous noise sources (such as dredging and shipping). This study concluded that the risk of mortality and injury in fish from these noise sources is low. However, there was considered to be a high risk of potential behavioural responses occurring in the direct vicinity for fish species considered to be hearing sensitive and a moderate risk in other fish species.

Noise impacts on fish are restricted to behavioural changes through avoidance, which are limited to a localised area around the dredger for most species. As the dredger vessel is moving, fish are not physically constrained; they will be able to move away from the source of the noise and return once dredging activity has ceased. Furthermore, such a behavioural avoidance reaction in fish close to the dredger may be beneficial in terms of avoiding any risk of direct physical injury and/or entrainment by the dredger.

Based on these factors, the magnitude of the change due to dredging noise is considered to be negligible and the probability of a change during operation is considered to be high. The sensitivities of fish to underwater noise is considered to range from low (fish with no swim bladder) to high (fish with swim bladders involved in hearing). Taking these factors into account, the overall exposure and vulnerability of will be negligible and none respectively. Overall, therefore, the impact of dredging noise is considered to be insignificant.

Rock breakers

Rock breakers may be required for the demolition of the existing concrete approach and support structures to facilitate the installation of the replacement linkspan. The size/type of rock pecker required will be determined during detailed design stage.

The logarithmic noise propagation model (Equation 1) was run using these SL to determine the unweighted received levels with range. Table 7.13 shows the results of this analysis at various distances from the source of demolition works. The sound pressure levels generated by a rock pecker are comparable to a medium sized vessel within around 50 m of the source of breaking (Table 7.14).

There are no published criteria for rock breaking but the criteria developed by Popper et al. (2014) for pile driving are considered to be reasonably representative given the similar impulsive nature of these noise sources. The SL generated by rock breaking would be below the published piling criteria for lethal effects and recoverable physical injury (Table 7.10).

During rock breaking, a behavioural reaction in fish is limited to within less than 1 km and therefore will not affect fish using the approach to the river Gwaun between Saddle Point and Castle Point.

Environmental Statement 7/45 April 2018 Replacement Linkspan, Fishguard Port

Table 7.13: Unweighted received levels during rock breaking Range (m) Unweighted Received Levels (dB re 1 μPa m) 1 203 10 185 50 172 100 167 250 159 500 152

The construction programme may overlap with the migratory period of Atlantic salmon smolts and juvenile European eels (Section 7.3.4.2). The sound pressure levels generated during any rock breaking are not anticipated to result in injury in fish or significant effect on the behaviour of migratory fish using the river Gwaun.

In terms of other fish commonly occurring in the harbour, the impact is considered to be minor/ insignificant. This is based on these other fish having a range of sensitivities from low to high, and a generally low importance in terms of nature conservation status.

7.4.6 Marine Mammals

This section assesses the potential for impacts on marine mammal receptors as a result of the development.

Scoped Out

The proposed development will not change the existing maintenance dredging regime for the ferry berth which is currently undertaken as part of an existing marine licence. In addition, the same ferry type and services will continue to run from the replacement linkspan. Therefore, operational impacts associated with maintenance dredging and ferry vessel movements are not considered further in the assessment. In addition, the following specific pathways have been scoped out of requiring further detailed assessment:

- Loss of habitat as a result of the proposed development: There is the potential for impacts to marine mammal foraging habitat as a direct result of the proposed development and also indirectly arising from changes to hydrodynamic and sedimentary transport regimes. However, habitat loss and change as a result of the proposed development will only constitute a very small fraction of the known foraging ranges of these highly mobile species. The potential for impacts to marine mammal foraging habitat has therefore been scoped out of the assessment. - Changes in water quality during construction: The plumes resulting from dredging and other construction works are expected to have a minimal and local effect on SSC in the vicinity of the proposed development. Marine mammals are well adapted to turbid conditions and therefore not sensitive to the scale of changes in SSC predicted during construction. The extent of sediment dispersal is not expected to cause significant elevations in water column contamination. In addition, the temporary and localised changes in water column contamination levels are considered unlikely to produce lethal and sub-lethal effects in these highly mobile species (the concentrations required to produce these effects are generally acquired through long-term, chronic exposure to prey species in which contaminants have bioaccumulated). Furthermore, potential for accidental spillages will also be negligible during all phases through following established industry guidance and protocols. The potential for water quality impacts to marine mammal during construction has therefore been scoped out of the assessment. - Collision risk and visual disturbance during construction: Vessel movement in construction is unlikely to produce disturbance stimuli which will be discernible above the already high levels of anthropogenic activity in Fishguard Harbour. Vessels will also mainly be stationary or travelling at low speeds making the risk of collision very low. Furthermore, through regular exposure to vessel movements, marine mammals utilising the area will routinely need to avoid collision and are also expected to be habituated to high levels of disturbance stimuli. Therefore, the associated pathways from collision risk and visual disturbance have been scoped out of the assessment.

Environmental Statement 7/46 April 2018 Replacement Linkspan, Fishguard Port

Scoped In

The proposed development has the potential to affect marine mammal receptors through the following impact pathway:

- Noise Disturbance during Construction

Noise Disturbance during Construction.

General Scientific Context

The impacts of noise on marine mammals can broadly be split into lethal and physical injury, auditory injury and behavioural response. The possibility exists for lethality and physical damage to occur at very high exposure levels, such as those typically close to offshore impact piling operations. A permanent threshold shift (PTS) is permanent hearing damage caused by very intensive noise or by prolonged exposure to noise. A temporary threshold shift (TTS) involves a temporary reduction of hearing capability caused by exposure to noise. At lower sound pressure levels it is more likely that behavioural responses to underwater sound will be observed. These reactions may include the animals leaving the area for a period of time, or a brief startle reaction. Masking effects may also occur at lower levels of noise. Masking is the interference with the detection of biologically relevant communication signals such as echolocation clicks or social signals. Masking has been shown in acoustic signals used for communication among marine mammals (see Clark et al., 2009). Masking may in some cases hinder echolocation of prey or detection of predators. If the signal-to-noise ratio prevents detection of subtle or even prominent pieces of information, inappropriate or ineffective responses may be shown by the receiving organism.

A review of underwater noise propagation and the characteristics of marine construction noise relevant to the linkspan development has already been provided in Section 7.4.5.4 and is therefore not repeated here. This section reviews the sensitivity of different marine mammals species to noise and the available response criteria that have been used to inform the impact assessment.

Marine mammal hearing sensitivity

In comparison to fish, marine mammals are more sensitive to noise at higher frequencies and generally have a wider range of hearing than fish (i.e. their hearing ability spans a larger range of frequencies). The hearing sensitivity and frequency range of marine mammals varies between different species and is dependent on their physiology. For example, odontocete cetaceans (toothed whales, porpoises and dolphins) are particularly sensitive to high frequencies.

Responses of marine mammals to noise

NOAA (2016) provides technical guidance for assessing the effects of underwater anthropogenic (human-made) sound on the hearing of marine mammal species. Specifically, the received levels, or acoustic thresholds, at which individual marine mammals are predicted to experience changes in their hearing sensitivity (either temporary or permanent) for acute, incidental exposure to underwater anthropogenic sound sources are provided. These thresholds update and replace the previously proposed criteria in Southall et al. (2007) for preventing auditory/physiological injuries in marine mammals.

The NOAA (2016) thresholds are categorised according to marine mammal hearing groups. The key marine mammals species found in the study area comprise harbour porpoise, grey seal and bottlenose dolphin. According to NOAA (2016), harbour porpoise is categorised as a high-frequency (HF) cetacean, grey seal is categorised as a phocid pinniped (PW) and bottlenose dolphin as a mid- frequency (MF) cetacean.

The acoustic thresholds for the onset of TTS and PTS due to impulsive sound sources (e.g. impact pile drivers and rock breakers) for these marine mammal groups are presented in Table 7.14. There are no equivalent SPL behavioural response criteria that would represent the sources of impulsive noise during the linkspan development. Behavioural reactions to acoustic exposure are less predictable and difficult to quantify than effects of noise exposure on hearing or physiology as reactions are highly variable and context specific (Southall et al., 2007). A number of field observations of cetaceans and pinnipeds to multiple pulse and nonpulse sounds have been made and are reviewed by Southall et al. (2007). The results of these studies are considered too variable and

Environmental Statement 7/47 April 2018 Replacement Linkspan, Fishguard Port

context-specific to allow single disturbance criteria for broad categories of taxa and of sounds to be developed. However, the data provide an indication of the levels of received noise that may result in a moderate behavioural reaction (e.g. avoidance of sound source, startle response). These indicative levels have therefore been applied in this assessment as an approximation of the potential scale of disturbance to marine mammal species.

Table 7.14: Marine mammal response peak SPL criteria applied to percussive piling Marine mammal PTS TTS Behavioural species Harbour porpoise 202 dB re 1 μPa 196 dB re 1 μPa 145 dB re 1 μPa Grey seal 218 dB re 1 μPa 212 dB re 1 μPa 195 dB re 1 μPa Bottlenose dolphin 230 dB re 1 μPa 224 dB re 1 μPa 175 dB re 1 μPa

Another way to evaluate the responses of marine mammals and the likelihood of behavioural responses is by comparing the received sound level against species specific hearing threshold levels. Further information on the dBht metric and its limitations is provided in Section 7.4.5.4 and is therefore not repeated here.

Project Impact Assessment

Piling

As discussed in Section 7.4.5.4, the logarithmic noise propagation model (Equation 1) was run to determine the unweighted received levels with range of percussive piling of 1100 mm steel tubular piles. Table 7.11 shows the results of this analysis at various distances from the source of piling.

The SL generated by these piles is above the published criteria for PTS and TTS in harbour porpoise and grey seal and above the criteria for TTS but not PTS in bottlenose dolphin (Table 7.15). Table 7.15 shows the approximate distances at which these injury criteria are reached. The distance at which the received level of noise is below the limits of PTS is 24 m in harbour porpoise and 3 m in grey seal. The distance at which the received level of noise is below the limits of TTS is 52 m in harbour porpoise, 7 m in grey seal and 2 m in bottlenose dolphin. Harbour porpoise is very sensitive to underwater noise and may display a behavioural reaction over 3 km from the source of piling. Bottlenose dolphin is anticipated to exhibit a behavioural reaction within several hundred metres of the piling and pinnipeds (i.e. grey seal) is the least sensitive to underwater noise, with behavioural reactions limited to tens of metres. Behavioural responses of these species could include responses could involve movement away from a sound source, aggressive behaviour related to noise exposure (e.g. tail/flipper slapping, fluke display, abrupt directed movement), visible startle response and brief cessation of reproductive behaviour (Southall et al., 2007).

Environmental Statement 7/48 April 2018 Replacement Linkspan, Fishguard Port

Table 7.15: Approximate distances marine mammal response peak SPL criteria are reached during percussive piling Marine mammal PTS TTS Behavioural species Harbour porpoise 24 52 3,529 Grey seal 3 7 59 Bottlenose dolphin - 2 552

The logarithmic noise propagation model was also run to estimate the distance from the source of noise at which different dBht response thresholds for each of the marine mammal species occurring in the study area are reached. The results of this analysis are shown in Table 7.17. These are included here for illustrative purposes but are not analysed further given the significant limitations of the dBht metric discussed in Section 7.4.5.4.

Table 7.16: Approximate distances dBht behavioural response thresholds in marine mammal species are reached during percussive piling Marine mammal 50 dBht 75 dBht 90 dBht species Harbour porpoise 5,686 m 2,272 m 856 m Grey seal 5,235 m 1,936 m 663 m Bottlenose dolphin 5,838 m 2,389 m 928 m

The effects of piling noise on marine mammals also need to be presented in terms of the duration of exposure. It is proposed that the piling work will take place over approximately six months, with an allowance for adverse weather and tidal conditions. Furthermore, impact piling will not take place continuously. It is currently proposed that any piling activities (vibro or impact) will only take place at certain times, namely: Mon-Friday (07:00-19:00) and Saturday (08:00-13:00) with no significant construction noise activities being permitted outside of these hours. In this way, the actual proportion of impact piling is estimated to be at worst 39 % (assuming no stoppages and based on a 12 hour working day) over any given construction week. In other words, any marine mammal occurring in Fishguard Harbour at the time of piling will be exposed a maximum of up to 39 % of the time.

It is also important to consider that the area in which the construction will take place already experiences shipping, as well as maintenance dredging and, therefore, marine mammals are likely to be habituated to a certain level of anthropogenic background noise.

Applying the standard impact assessment criteria, the probability of occurrence is high. Percussive piling is predicted to cause injury effects within very close proximity of the proposed development and strong behavioural responses over a much wider area. However, whilst established logarithmic propagation models have been applied, these do not take account of local bathymetry or environmental variables. The constrained nature of the study area will ensure elevated levels of underwater noise during construction largely remain within the Fishguard Harbour. In this respect the outer breakwater will act as a screen/barrier, generally limiting the propagation of noise reaching the marine environment outside the harbour including around Stumble Head. Although marine mammal species are regularly recorded in Fishguard Bay, it is considered unlikely that they will be observed directly offshore from the Fishguard Ferry Port. On a precautionary basis, the magnitude of the change is considered at worst to be high during percussive piling. The sensitivity of marine mammal species to percussive piling noise is considered to be high and their importance is considered to be high given the level of protection that they are afforded. Therefore, the temporary noise during construction has been assessed as major adverse during percussive piling.

These assessments have been based on a worst-case assumption that there will be percussive piling throughout the construction period. In practice the main approach will be to use vibro piling wherever possible with percussive piling only being used where absolutely necessary. In order to further reduce the significance of the impact during piling for marine mammals, soft-start procedures will be used and JNCC “Statutory nature conservation agency protocol for minimising the risk of injury to marine mammals during piling” (JNCC, 2010) will be followed during any percussive piling. These measures are described in more detail in Section 7.6. With these measures in place, residual impacts on marine mammals from piling noise are assessed as being of minor significance.

The piling only scenario would result in the same underwater noise effects as the reclaim scenario. On this basis, with the mitigation measures described above, the overall effect of underwater noise is considered to be minor for marine mammals.

Environmental Statement 7/49 April 2018 Replacement Linkspan, Fishguard Port

Bucket dredging

To date, auditory and non-auditory injuries have not been observed or documented to occur in association with dredging (Thomsen et al., 2009; WODA, 2013). There is a scarcity of studies quantifying behavioural impacts from dredging (Thomsen et al., 2011), with documented effects limited to behavioural changes in grey and bowhead whales (Richardson et al., 1995), and a recent investigation by Diederichs et al. (2010) showing that harbour porpoises temporarily avoided an area of sand extraction off the Island of Sylt in Germany. Diederichs et al. (2010) found that, when the dredging vessel was closer than 600 m to the porpoise detector location, it took three times longer before a porpoise was again recorded than during times without sand extraction. However, after the ship left the area, the clicks resumed to the baseline rate.

Overall, noise impacts of dredging on marine mammals are restricted to behavioural changes through avoidance, which are limited to a relatively localised area. Marine mammals are not physically constrained in the harbour and will be able to move away from the source of the noise and return once dredging activity has ceased. Furthermore, such a behavioural avoidance reaction in marine mammals may be beneficial in terms of avoiding any risk of direct physical injury by the dredger.

Based on these factors, the magnitude of the change due to dredging noise is considered to be negligible and the probability of a change is considered to be high. Hearing damage is unlikely to occur at the sound frequencies and intensities associated with dredging and the main effect that could be expected in the affected zone would be a short-term mild behavioural avoidance. Sensitivity of marine mammals is therefore considered to be low. Their importance is considered to be high given the level of protection that they are afforded. Taking these factors into account, the overall exposure and vulnerability of marine mammals will be negligible and none respectively. Overall, therefore, the impacts of dredging noise are considered to be insignificant.

Rock breakers

As discussed in Section 7.4.5.4, the logarithmic noise propagation model (Equation 1) was run to determine the unweighted received levels with range of rock breaking. Table 7.13 shows the results of this analysis at various distances from the source of demolition activities.

Table 7.17 shows the approximate distances at which injury and behavioural criteria are reached during rock breaking.

The SL generated during rock breaking is above the published criteria for TTS in harbour porpoise within a very short distance of the proposed development and below all other injury criteria (Table 7.17). Behavioural effects are anticipated to occur within approximately 1 km in harbour porpoise and a short distance in grey seal and bottlenose dolphin.

Table 7.17: Approximate distances marine mammal response peak SPL criteria are reached during rock breaking Marine mammal PTS TTS Behavioural species Harbour porpoise - 3 928 Grey seal - - 3 Bottlenose dolphin - - 36

Applying the standard impact assessment criteria, the probability of occurrence is high. However, whilst established logarithmic propagation models have been applied, these do not take account of local bathymetry or environmental variables. The constrained nature of the study area will ensure elevated levels of underwater noise during construction largely remain within the Fishguard Harbour. In this respect the outer breakwater will act as a screen/barrier, generally limiting the propagation of noise reaching the marine environment outside the harbour including around Stumble Head. Although marine mammal species are regularly recorded in Fishguard Bay, it is considered unlikely that they will be observed directly offshore from the Fishguard Ferry Port.

The sound pressure levels generated during any rock breaking are not anticipated to result in injury in marine mammals and effects on behaviour are relatively localised. The magnitude of the change is therefore considered at worst to be small during rock breaking. The sensitivity of marine mammal species to rock breaking is considered to be moderate and their importance is considered to be high

Environmental Statement 7/50 April 2018 Replacement Linkspan, Fishguard Port

given the level of protection that they are afforded. Therefore, the temporary noise during rock breaking has been assessed as minor adverse.

7.5 Cumulative and in-combination

The development of the proposed development will take place alongside other plans, projects and activities. These have the potential to result in additional or modified impacts on the same receptors as those identified for the proposed development alone, resulting in a cumulative and/or in- combination impact.

Industry standards for conducting cumulative and in-combination impact assessments include a guidance note published by the MMO (2014) and Natural England (2014). This section considers that a cumulative / in-combination assessment needs to take account of the total effects of all pressures acting upon all relevant receptors in seeking to assess the overall cumulative / in-combination significance. Additionally, consideration is given to any other activities and plans or projects, including any impacts that do not directly overlap spatially, but may indirectly result in a cumulative / in- combination impact. By looking at all potential impacts, the information provided in this section addresses the requirements under the EIA Directive and also informs the assessment of in- combination impacts in line with the requirements of the Habitats Directive under one assessment.

The Marine Works (EIA) Regulations 2007 as amended by the Marine Works (EIA) (Amendment) Regulations 2011 specifically refer to ‘cumulative’ effects, while the Habitats Regulations refers to ‘in-combination’ effects. However, in practice, both need to be interpreted as referring to cumulative and in-combination effects because the assessments, whether for EIA or for Habitat Regulations Assessment (HRA), need to understand the combined influence of all environmental pressures acting upon the relevant receptors in seeking to assess the significance of environmental effects. On this basis, the main difference between the cumulative assessment for EIA and the in-combination assessment for HRA is the range of receptors included in the assessment. For the purposes of this ES, the range of features needs to cover both environmental receptors (including protected interest features) and other human activities and interests that might be affected, while the HRA focuses solely on the relevant features potentially affected within internationally designated sites.

The following project has the potential to impact on marine ecology receptors;

- Fishguard Harbour Marina Development: The development proposes to reclaim 16 ha of foreshore across the entire south of the harbour and extending north along the western edge to the extent of the existing Stena Quay. The platform will be used for potential future port expansion along with a residential area, an offshore marina area and parking areas. To accommodate boats at all states of the tide, the marina will be dredged to -3.0 m using a cutter-section dredger. Two breakwaters will also be built to protect the marina from wave action. Material from the dredge will be used entirely to form the reclaimed platform. Piling of pontoon structures will be undertaken using vibrating hammer where possible for a duration of three months. The Marine Licence application is ref: CML1604.

Table 7.18 identifies any potential overlap of the, projects with the marine ecology receptors considered within this ES. Consideration is given to the relevant pathways and an assessment undertaken of potential effects for each receptor.

Table 7.18: Summary of Predicted Cumulative and In-combination Effects

Receptors Summary of Predicted Cumulative and In-combination Effects Benthic During Construction Habitats and Species Cumulative/in-combination effects could occur to marine ecology as a result of any activity or project in addition to the proposed development, which affects/disturb seabed habitats, SSCs, water quality and non-native species introductions.

The proposed development along with the proposed reclamation as part of the Fishguard Harbour Marina Development have the potential to result in cumulative/in- combination effects on loss and/or damage to benthic habitats. The proposed Fishguard Harbour Marina Development will result in the loss of approximately 16 ha of foreshore. The proposed linkspan replacement will result in the loss of approximately 0.35 ha of marine habitat of which approximately 0.04 ha consists of

Environmental Statement 7/51 April 2018 Replacement Linkspan, Fishguard Port

Receptors Summary of Predicted Cumulative and In-combination Effects intertidal rocky shore habitat (with the remaining habitat consisting of subtidal habitat). The EIA for the proposed Fishguard Harbour Marina Development assessed the impacts of intertidal habitat loss as minor (AXIS, 2011). Consent under the Marine Works (Environmental Impact Assessment) Regulations 2007 was granted by NRW in June 2017 (NRW, 2017) with the impacts identified within the ES considered to be ‘adequately identified, described and assessed’. The loss of habitats as a result of the proposed development is small in comparison to the Fishguard Harbour Marina Development and has been assessed as insignificant to minor5. Data suggests that both areas of habitat consist of commonly occurring benthic assemblages that are generally of low conservation importance. Additionally, it is likely the changes will be relatively small when compared to the extent of benthic habitats in the wider study area. Therefore, significant cumulative effects on marine ecology receptors due to loss or damage to benthic species or habitats will not occur.

The effects on benthic habitats and species due to dredging related activity as part of the Fishguard Harbour Marina Development was assessed as being of minor adverse significance. The small amount of dredging activity required as part of the linkspan development was also assessed as insignificant. The effects of increased SSC (and subsequent re-deposition) and water quality changes from both developments are likely to be minimal, local and of short duration. Therefore, there is not expected to be a cumulative/in-combination effect.

The new hard structures proposed as part of the Fishguard Harbour Marina Development reclamation will provide areas of colonisation surface for subtidal and/or intertidal species in Fishguard Harbour. Together with the proposed development, these changes could result in potential cumulative/in-combination impacts in relation to the potential colonisation by non-native species. However, there is already a widespread presence of artificial hard substrates within Fishguard Harbour and furthermore, several non-native species are widespread throughout Pembrokeshire. Therefore, there are not considered to be significant cumulative effects.

Given the highly localised changes anticipated as a result of the proposed development, there is limited potential for cumulative/in-combination effects. Therefore, when considering the scale of other activities and plans, no significant impacts are expected. Fish and Cumulative/in-combination effects could occur to fish and shellfish as a result of any shellfish activity or project in addition to the proposed development which potentially affects feeding ability/ resources or causes disturbance during construction phase.

During construction of the Fishguard Harbour Marina Development and the replacement linkspan, there could be increases in SSC which have the potential to result in cumulative/in-combination effects to fish and shellfish receptors. Activities such as feeding foraging opportunities of visual predators, survival of pelagic eggs and larvae of fish, and migrations and movements of fish could all potentially be affected by an increase in SSC. However, the effects of suspended sediment plumes are likely to be temporary, given the high potential for dispersal within Fishguard Harbour, and the footprint of the plume will be localised around the developments. Furthermore, most fish species can avoid these areas and return after the plume has settled.

Piling and dredging during both the proposed development and Fishguard Harbour Marina Development could potentially cause underwater disturbance impacts to fish. With respect to the Fishguard Harbour Marina Development, the assessment predicted that piling operations would be very unlikely to affect migratory fish (such as Atlantic salmon) entering the Afon Gwaun due to the distance from the noise source. Nevertheless, in order to protect fish a range of mitigation measures including the use of a bubble curtains and soft start procedures were proposed.

5 The loss as a result of the reclamation to the of BAP/NERC Act Section 42 ‘Intertidal Under boulder Communities’ habitat is considered to be moderate to minor and the impacts to marine habitats more generally are considered minor to insignificant. However, with suitable mitigation measures in place, the impacts to ‘Intertidal Under boulder Communities’ is considered to be insignificant.

Environmental Statement 7/52 April 2018 Replacement Linkspan, Fishguard Port

Receptors Summary of Predicted Cumulative and In-combination Effects There was also a preference for the use of vibro piling, with impact piling (which produces higher noise levels) only to used where necessary (NRW, 2017). Vibro piling is also proposed to be used where possible as part of the linkspan replacement. In addition, soft start procedures will also be implemented. With these measures in place, residual impacts to fish were assessed as insignificant to minor.

Dredging during both developments is only predicted to cause very minor disturbance to fish in the direct vicinity of the dredger.

Therefore, assuming appropriate mitigation measures are followed during construction of the development, cumulative/in-combination noise effects are considered to be at worst minor adverse. Marine Cumulative/in-combination effects could occur to marine mammals as a result of any Mammals activity or project in addition to the proposed development which causes disturbance during construction works.

Marine mammals can be vulnerable to noise and visual stimuli which act as a barrier, thereby preventing movement to key foraging or nursery grounds. Piling noise and other activities during the construction phase have been shown to elicit behavioural responses that could lead to displacement in marine mammals.

With respect to the Fishguard Harbour Marina Development, the use of bubble nets, soft-start piling procedures and JNCC piling protocols were identified as mitigation during percussive piling that should be included within a CEMP to minimise the risk to marine mammals (NRW, 2017). Soft start procedures and JNCC piling protocols during percussive piling is also proposed as mitigation for the proposed development. For both proposed developments, vibro piling (which produces lower source noise levels than percussive piling) is also proposed to be used where possible.

Dredging during both developments is only predicted to cause very minor disturbance to marine mammals in the direct vicinity of the dredger.

Therefore, assuming appropriate mitigation measures are followed during construction of the development, cumulative/in-combination noise effects are considered to be at worst minor adverse.

7.6 Mitigation and Monitoring

7.6.1 Mitigation

In order to reduce the level of impact for those pathways which have been assessed as being of moderate or major adverse significance, a number of mitigation measures have been identified which are described in more detail below.

Benthic habitats and species

In order to reduce the impact associated with the loss of the small area of BAP/NERC Act Section 42 ‘Intertidal Underboulder Communities’ habitat as a result of the reclaim suitable boulders will be placed on the bottom of the rock revetment. The area of predicted loss of this habitat covers approximately 0.009 ha. Therefore, boulders covering approximately this extent should be placed at lower shore elevations similar to those lost as part of the reclaim. These boulders should generally be of a shape to allow a sufficient gap on the underside of the boulder to support an under-boulder community.

Fish

Embedded mitigation measures that will be applied to reduce the impacts of underwater noise disturbance on sensitive fish species include:

- Soft Start: The use of a soft start to piling (the gradual increase of piling power, incrementally, until full operational power is achieved) will be required as part of the piling methodology. The use of soft start gives species the opportunity to move away before the onset of full impact strikes. The extent and duration of the soft start will be agreed with NRW.

Environmental Statement 7/53 April 2018 Replacement Linkspan, Fishguard Port

- Vibro Piling: Vibro piling is proposed to be used where possible (which produces lower source noise levels than percussive piling) and is likely to constitute the majority of the piling operations. However, in certain circumstances percussive piling might be required.

Marine Mammals

As discussed above vibro piling and soft start procedures will be used where possible to reduce noise disturbance impacts. However, in order to further reduce the significance of the impact to marine mammals it is recommended that JNCC “Statutory nature conservation agency protocol for minimising the risk of injury to marine mammals during piling” (JNCC, 2010) will be followed during percussive piling. The key procedures highlighted in this document include the following:

- Establishment of a ‘mitigation zone’ of a pre-defined radius (e.g. 500 m) around the site, prior to any percussive piling. Within this mitigation zone, observations of marine mammals would be undertaken by a Marine Mammal Observer (MMO); - Prior to the commencement of percussive piling a search should be undertaken by the MMO to determine that no marine mammals are within the mitigation zone. Percussive piling activity should not be commenced if marine mammals are detected within the mitigation zone or until after an agreed period after the last visual detection; - During percussive piling, the MMO should observe the mitigation zone to determine that no marine mammals are within this area. Construction workers will be alerted if marine mammals are identified and it is recommended that pilling activity cease whilst any marine mammals are within the mitigation zone. Piling can recommence when the marine mammal exits the mitigation zone and there is no further detection after an agreed period of time; and - If there is a pause in percussive piling operations for any reason over an agreed period of time, then another search (and soft-start procedures) should be repeated before activity recommences. If, however, the mitigation zone has been observed while piling has ceased and no marine mammals have entered the zone, activity can recommence immediately.

7.7 Conclusions

The chapter has identified a number of marine ecology receptors and pathways in which potential impacts arising from the proposed development could occur. Table 7.19 summarises the impact significance and also highlights monitoring or additional mitigation which is required.

Environmental Statement 7/54 April 2018 Replacement Linkspan, Fishguard Port

Table 7.19: Summary of Potential Impacts, Mitigation, Residual Impacts and Confidence

Receptor Potential Impact Impact Mitigation/Monitoring Residual Confidence Pathway Significance Significance Benthic Habitats Direct Loss of Benthic Moderate to minor Placement of boulders on Insignificant (both High: Baseline conditions and potential impacts and Species Habitats and Species (reclaim scenario) the bottom of the rock scenarios) on benthic receptors are well understood. revetment as mitigation for Insignificant (piling the loss of BAP/NERC Act only scenario). Section 42 ‘Intertidal Underboulder Communities’ habitat within the reclaim. Direct Changes to Insignificant (piling No mitigation or monitoring Insignificant (piling High: Baseline conditions and potential impacts Benthic Habitats and only scenario) required. only scenarios) on benthic receptors are well understood. Species Smothering During Insignificant (both No mitigation or monitoring Insignificant (both Moderate: There is a degree of uncertainty Construction scenarios) required scenarios) associated with any modelling predictions relating to changes in hydrodynamics and sediment regime. The impact to benthic habitats from smothering is well documented through a large number of scientific studies on this subject. Changes in Water Insignificant (both No mitigation or monitoring Insignificant (both Moderate: There is a degree of uncertainty Quality during scenarios) required scenarios) associated with any modelling predictions Construction relating to changes in hydrodynamics and sediment regime. The potential impacts of water quality on benthic receptors are also well understood, through a large amount of scientific evidence on this subject. The Potential Insignificant (both Development of a Insignificant to minor Moderate: Scientific understanding of the Introduction of Non- scenarios) Biosecurity Plan (both scenarios) introduction of non-native species is generally Native Species good although some uncertainty still surrounds the level of risk associated with the introduction of species. Indirect Changes in Insignificant (both Insignificant (both Moderate: There is a degree of uncertainty Habitat Extent and scenarios) scenarios) associated with any modelling predictions Quality relating to changes in hydrodynamics and sediment regime. Spread of Non-Native Insignificant (both No mitigation or monitoring Insignificant to minor Moderate: Scientific understanding of the Species scenarios) required (both scenarios) introduction of non-native species is generally good although some uncertainty still surrounds the level of risk associated with the introduction of species.

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Receptor Potential Impact Impact Mitigation/Monitoring Residual Confidence Pathway Significance Significance Fish and Shellfish Changes in Water Insignificant (both No mitigation or monitoring Insignificant (both High: The assessment is based on the analysis Quality during scenarios) required scenarios) of sediment samples from the field and detailed Construction modelling. The potential impacts of water quality on fish and shellfish receptors are well understood, through a large amount of scientific evidence on this subject. Noise Disturbance Moderate to - Soft start procedures Insignificant to minor Moderate: The underwater noise model is during Construction insignificant (both during piling. (both scenarios) based on theoretical parameters and there is scenarios) - Use of vibro piling where limited empirical evidence of the behavioural possible. effects of noise on fish. Marine Mammals Noise Disturbance Major (both - Soft start procedures Minor (both Moderate: The underwater noise model is during Construction scenarios) during piling. scenarios) based on theoretical parameters and there is - Use of vibro piling where limited empirical evidence of the behavioural possible. effects of noise on marine mammals. - Following JNCC protocol for minimising the risk of injury to marine mammals during percussive piling Cumulative and Benthic Habitats and Insignificant (both No additional mitigation Insignificant (both Moderate: There is limited scientific In-combination Species scenarios) required scenarios) understanding of the interplay between different Effects physical factors and subsequent biological interactions with different projects cumulatively. Fish and Shellfish Minor (both No additional mitigation Minor (both Moderate: There is limited scientific scenarios) required scenarios) understanding of the interplay between different physical factors and subsequent biological interactions with different projects cumulatively. Marine Mammals Minor (both No additional mitigation Minor (both Moderate: There is limited scientific scenarios) required scenarios) understanding of the interplay between different physical factors and subsequent biological interactions with different projects cumulatively.

Environmental Statement 7/56 April 2018 Replacement Linkspan, Fishguard Port

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