6.
Offshore Biological EnvironmentOffshore Biological Environment
6. Offshore Biological EnvironmentOffshore Biological Environment
6.1.8. Proposed Approach to the Environmental Impact AssessmentProposed Approach to the Environmental Impact Assessment
- The methodology set out in section 4 will be followed when preparing the Benthic Subtidal Ecology chapter of the Array EIA Report. The following guidance documents will also be considered with regard to benthic subtidal ecology:
- Refining the criteria for defining areas with a ‘low resemblance’ to Annex I stony reef (Golding, 2020);
- Guidelines for EcIA in the UK and Ireland. Terrestrial, Freshwater and Coastal (Chartered Institute of Ecology and Environmental Management (CIEEM), 2019);
- Guidance on Environmental Considerations for Offshore Wind Farm Development (OSPAR, 2008);
- Best methods for identifying and evaluating Sabellaria spinulosa and cobble reef (Limpenny et al., 2010);
- Defining and Managing Sabellaria spinulosa Reefs (Gubbay, 2007);
- Identification of the Main Characteristics of Stony Reef Habitats under the Habitats Directive (Irving, 2009);
- SNH (now NatureScot) guidance: Guidance on Survey and Monitoring in Relation to Marine Renewables Deployments in Scotland – Volume 5: Benthic Habitats (Saunders et al., 2011); and
- Guidelines for data acquisition to support marine environmental assessments of offshore renewable energy projects (Judd, 2012).
- Specific to marine ecology, the CIEEM (2019) guidelines will be followed in order to identify important ecological features (IEFs). Assessments of the identified IEFs will be presented in the baseline characterisation of each relevant technical section. To reflect topic specific interests, the CIEEM (2019) guidelines will be used to produce criteria defining the value of each IEF and will include specific consideration of PMFs within the benthic subtidal ecology study area. Regarding the characterisation of the benthic subtidal ecology baseline, FeAST will be utilised to inform the sensitivity of benthic receptors in the impact assessment section of the Benthic Subtidal Ecology chapter of the Array EIA Report.
- A detailed baseline characterisation of the Array will be presented in the Benthic Subtidal Ecology Technical Report, which will expand on the high-level baseline characterisation presented in this Scoping Report (see Appendix 6). The Benthic Subtidal Ecology Technical Report will use site-specific survey data and the most recent desktop sources which are briefly summarised in this Scoping Report (see Appendix 6 for further details). This report will inform the Benthic Subtidal Ecology chapter of the Array EIA Report.
6.1.9. Potential Cumulative EffectsPotential Cumulative Effects
- There is potential for the predicted impacts to interact with those from other activities in the regional benthic subtidal ecology study area (including the Proposed offshore export cable corridor(s) and Proposed onshore export cable corridor(s)), and result in cumulative effects on benthic subtidal ecology. However, the predicted effects from the Array on benthic receptors are considered to be localised to within the footprint of the Array. The approach to the cumulative effects assessment is presented in section 4.3.7.
6.1.10. Potential Transboundary ImpactsPotential Transboundary Impacts
- Appendix 3 presents the transboundary impacts screening which has been carried out for the Array. This screening exercise identified that there is no potential for transboundary impacts upon benthic subtidal ecology due to construction, operational and maintenance, and decommissioning of the Array.
6.1.11. Scoping Questions to ConsulteesScoping Questions to Consultees
- Do you agree with the two study areas presented for benthic subtidal ecology?
- Do you agree that the existing data available to describe the benthic subtidal ecology baseline remains sufficient to describe the physical environment in relation to the Array? Are there any further desktop datasets which you would recommend are included?
- Do you agree that all potential impacts ( Table 6.2 Open ▸ ) have been identified for benthic subtidal ecology?
- Do you agree that the designed in measures described provide a suitable means for managing and mitigating the potential effects of the Array on the benthic receptors?
- Do you agree that the identified impacts in Table 6.5 Open ▸ should be scoped out of the Array EIA Report?
6.1.12. Next StepsNext Steps
- The topic specific next step is to agree upon the assessment approach for benthic subtidal ecology and the potential impacts that will be assessed during the EIA process. This includes presenting the sensitivities of the receptors that will be used in the assessment to stakeholders. These impacts will be quantified using an MDS.
- In the event that any impacts cannot be quantitively assessed, they will be discussed with key stakeholders. The process for post-Scoping consultation is presented in the dSEP in Appendix 1. It is expected that post-Scoping consultation with regard to benthic subtidal ecology will be limited.
6.2. Fish and Shellfish EcologyFish and Shellfish Ecology
6.2.1. IntroductionIntroduction
- This section of this Scoping Report presents the relevant fish and shellfish ecology data sources and baseline in the vicinity of the Array and the wider fish and shellfish ecology study area and considers the scope of assessment on fish and shellfish ecology from the construction, operation and maintenance, and decommissioning of the Array.
6.2.2. Study AreaStudy Area
- As fish and shellfish are spatially and temporally variable, a broad study area has been defined for the purposes of the baseline characterisation and subsequent Array Environmental Impact Assessment (EIA) Report ( Figure 6.3 Open ▸ ). The fish and shellfish ecology study area encompasses the site boundary and a surrounding area defined by the boundary of the northern North Sea ( Figure 6.3 Open ▸ ). The fish and shellfish ecology study area provides a wider context for the spatially and temporally variable species and populations, including diadromous fish, which are known to occur within the Array. This area was considered appropriate as it will ensure the characterisation of all fish and shellfish receptors within the northern North Sea and is, therefore, large enough to consider all direct (e.g. habitat loss/disturbance within the site boundary) and indirect impacts (e.g. subsea noise over a wider area) associated with the Array on the identified receptors.
6.2.3. Baseline EnvironmentBaseline Environment
- This section provides a brief summary of the baseline environment of the fish and shellfish ecology study area. A more detailed description is provided in Appendix 8.
Fish assemblage
- The fish and shellfish ecology study area includes demersal, pelagic, diadromous, and elasmobranch fish species, including commercial and non-commercial species. Demersal species include cod Gadus morhua, haddock Melanogrammus aeglefinus, whiting Merlangius merlangus, plaice Pleuronectes platessa, lemon sole Microstomus kitt and sandeel Ammodytidae spp. Pelagic species include herring Clupea harengus, mackerel Scomber scrombus and sprat Sprattus sprattus. Elasmobranch species, such as spotted ray Raja montagui, thornback ray R. clavata, tope shark Galeorhinus galeus, small-spotted catshark Scyliorhinus canicula, spurdog Squalas acanthias, thorny skate Amblyraja radiata and cuckoo ray Leucoraja naevus, among others, have been observed in the fish and shellfish ecology study area (Coull, et al., 1998, Daan et al., 2005, Baxter et al., 2011, Ellis et al., 2012).
- As set out in Appendix 8, a site-specific epibenthic beam trawl survey, comprising ten individual trawls, were conducted within the site boundary in July 2022. During these surveys, 16 fish species were observed, with the most abundant being the long rough dab Hippoglossoides platessoides, followed by plaice, common dab Limanda limanda, Norway pout Trisopterus esmarkii, lemon sole, sandeel Ammodytes marinus, and grey gurnard Eutrigla gurnardus.
Figure 6.3: Site Boundary and Fish and Shellfish Ecology Study Area
- Between 2011 and 2020, site-specific epifaunal beam trawl surveys were undertaken across the Berwick Bank and Seagreen 1 Offshore Wind Farms (formerly known as Seagreen Alpha and Bravo), located approximately 56 km and 50 km from the Array, respectively. They recorded a range of demersal species, such as common dab, long rough dab, lesser sandeel A. tobianus, Raitt’s sandeel A. marinus, four-bearded rockling Enchelyopus cimbrius, pogge Agonus cataphractus, butterfish Pholis gunnellus, Norwegian topknot Phrynorhombus norvegicus, reticulated dragonet Callionymus reticulatus, common dragonet Callionymus lyra, lemon sole, bullrout Myoxocephalus scorpius, and goby species (Gobiidae spp.). Commercial species such as plaice, whiting, cod, and red gurnard Chelidonichthys cuculus, were also recorded, as were smooth sandeel Gymnammodytes semisquamatus and greater sandeel Hyperoplus lanceolatus, and one elasmobranch species, the cuckoo ray (Seagreen, 2012, 2018, SSER, 2022).
Diadromous fish species
- Diadromous fish (i.e. species that migrate between freshwater and the marine environment for breeding) could potentially migrate to and from rivers in the vicinity of the Array and, therefore, may migrate through the site boundary during certain periods of the year. Based on information on diadromous fish populations on the east coast of Scotland, the Berwick Bank and Seagreen 1 Offshore Wind Farm impact assessments identified eight diadromous fish species which have the potential to occur in offshore areas within the vicinity of the Array or coastal areas along the east of Scotland. These species were Atlantic salmon Salmo salar, sea trout S. trutta, sea lamprey Petromyzon marinus, river lamprey Lampetra fluviatilis, European eel Anguilla anguilla, allis shad Alosa alosa, twaite shad A. fallax, and sparling (European smelt) Osmerus eperlanus (Seagreen, 2018; SSER, 2022). It should be noted that river lamprey and sparling are primarily coastal species and are, therefore, unlikely to interact with the Array. The species that are therefore considered as having the greatest potential to be present within the vicinity of the Array are Atlantic salmon, sea trout, European eel, sea lamprey and allis and twaite shad.
- No further site-specific surveys are proposed to inform the diadromous fish impact assessment. For the purposes of this Scoping Report, it will be assumed that the species mentioned in paragraph 353 are likely to be present within the fish and shellfish ecology study area during migration at key stages of their life cycles. This includes smolt migration from natal rivers and adult migration to spawning habitats. The aim of the impact assessment is to determine whether construction, operation and maintenance, or decommissioning activities have the potential to disrupt migration of these species. Therefore, migratory seasons will be an important element of the baseline characterisation and will be collated through desktop data sources (Malcolm et al., 2010, 2015, Godfrey et al., 2015, Hume, 2017, Lothian et al., 2017, Newton et al., 2017, Gardiner et al., 2018, Seagreen, 2018). More information on the timings of migration for diadromous fish species relevant to the Array is provided in Appendix 8.
- The River Dee Special Area of Conservation (SAC), River South Esk SAC, and River Spey SAC are designated for Annex II Atlantic salmon and the symbiotic freshwater pearl mussel Margaritifera margaritifera as primary features. Although freshwater pearl mussels are not found in the offshore environment, they depend on the Atlantic salmon smelting population during their parasitic larval stage (Taeubert and Geist, 2017). Therefore, freshwater pearl mussel populations may be indirectly affected if Atlantic salmon are adversely affected by the Array.
Shellfish assemblage
- The population structure of shellfish stocks around the UK is not well understood, with assessments largely based on previous fishing and landings data (Mesquita et al., 2016). Therefore, commercial landing data in the area provides an overview of species likely to be present. There are consistently high landings of Norway lobster Nephrops norvegicus, and medium to low landings of European lobster Hommarus gammarus, brown crab Cancer pagurus, velvet swimming crab Necora puber, king scallop Pecten maximus, whelks Buccinum undatum, razor clam Solen spp., surf clam Spisula spp., clams Mya arenaria, squid Loligo spp. and octopi Ommastrephidae (Mesquita et al., 2016, 2017, Marine Scotland, 2021a). Occasionally caught species include green crab Carcinus maenas, common prawn Palaemon serratus and queen scallop Aequipecten opercularis (Marine Scotland, 2021a).
- During the site-specific benthic surveys conducted across the site boundary (Appendix 7), horse mussels Modiolus modiolus were observed scattered across the south-east and along the edge of the site boundary, however no M. modiolus beds were identified. Queen scallops were also recorded.
Spawning and/or nursery grounds
- Potential nursery and spawning grounds were identified by Coull et al. (1998), for a range of species in the North Sea. These grounds were based on larvae, egg and benthic habitat survey data. In 2012, Ellis et al. reviewed this data for several species in the fish and shellfish ecology study area and provided updated data on the spatial distribution of low and high intensity nursery and spawning grounds.
- Species with known spawning periods and nursery habitats identified within the fish and shellfish ecology study area are summarised in Table 6.6 Open ▸ and Apx. Table 7.3.
Table 6.6: Key Species with Geographic Spawning and Nursery Grounds which Overlap with the Site Boundary. Spawning and Nursery Intensity Specified Where Available. Adapted from Coull et al. (1998) and Ellis et al. (2012)
Designated sites
- The site boundary does not overlap with any designated sites but there are several protected areas for fish and shellfish features within the fish and shellfish ecology study area. These sites are presented in Apx Table 8.4 Open ▸ . A full screening of the National Site Network and European sites with qualifying fish and shellfish features will be undertaken in the LSE Screening Report for the Array. Relevant fish and shellfish features will be fully considered and assessed in the fish and shellfish ecology chapter of the Array EIA Report, with the assessment on the European designated sites itself provided in the Report to Inform Appropriate Assessment (RIAA) accompanying the consent application.
6.2.4. Potential Array ImpactsPotential Array Impacts
- A number of potential impacts which may occur during the construction, operation and maintenance, and decommissioning phases of the Array in the absence of designed in measures on fish and shellfish ecology have been identified in Table 6.7 Open ▸ .
Table 6.7: Potential Impacts Identified for Fish and Shellfish Ecology in the Absence of Designed In Measures
6.2.5. Designed In MeasuresDesigned In Measures
- The following designed in measures have been considered in the identification of potential impacts that have been scoped into the Array assessment, including how these can reduce potential for impact ( Table 6.9 Open ▸ ):
- implementation of soft-start and ramp-up measures for piling;
- development of, and adherence to, an appropriate Code of Construction Practice (CoCP);
- development of, and adherence to, an EMP, including Marine Pollution Contingency Plan (MPCP); and
- development of, and adherence to, a Decommissioning Programme.
- The significance of the effects on fish and shellfish ecology may result in the requirement for additional mitigation. This will be consulted upon with the statutory consultees throughout the EIA and consultation processes. It is possible that particular mitigation may be required for species such as herring, which are particularly sensitive to subsea noise. This will be discussed via the EIA and consultation processes.
6.2.6. Relevant ConsultationsRelevant Consultations
- A summary of the key points of agreement with relevant stakeholders and Statutory Nature Conservation Bodies (SNCBs) during the Array Scoping workshop is presented in Table 6.8 Open ▸ .
Table 6.8: Summary of Key Consultation on the Scoping Assessment for the Array