Operation and maintenance phase

Magnitude of impact

320. The operation and maintenance activities of the cumulative projects will overlap with the operation and maintenance phase of the Proposed Development and may lead to temporary subtidal habitat loss/disturbance of up to 32,276,397 m2.
321. Table 9.32   Open ▸ and Figure 9.11   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1, Eastern Link 2 and Eyemouth disposal site.
322. During the operation and maintenance phase of the Proposed Development, the other Tier 2 wind farms will reach their decommissioning age before the Proposed Development reaches its decommissioning age in 2066. The operation lifetime of Inch Cape is expected to be up to 35 years, with construction ending in 2025 and decommissioning expected in 2060 (Inch Cape Offshore Limited, 2018). The operation lifetime of Neart na Gaoithe is expected to be 25 years, with construction ending in 2023 and decommissioning expected in 2048 (Mainstream Renewable Power, 2019). Seagreen 1 and Seagreen 1A Project has an operation and maintenance phase of 25 – 30 years which will lead to its decommissioning in 2048 – 2053 (Seagreen Wind Energy, 2012).
323. The maximum design scenario for habitat loss from the cumulative offshore wind farms has been considered in this cumulative assessment, with the total areas of seabed affected by this impact presented in Table 9.34   Open ▸ . However, this is considered to be precautionary as activities associated with the operation and maintenance of the Proposed Development (and the other developments considered here) will occur intermittently throughout the lifetime of the Proposed Development and therefore are unlikely to completely overlap with the decommissioning periods of the other offshore wind farms. Furthermore, Inch Cape Offshore Wind Farm and Neart na Gaoithe Offshore Wind Farm assume in their environmental statements that the decommissioning process will produce similar levels of temporary habitat disturbance to their construction phase however this is likely to be an over estimation because not all of the infrastructure is likely to be removed from the seabed in the final plans (Inch Cape Offshore Limited, 2018; Mainstream Renewable Power, 2019). The EIA for Seagreen 1 however does not make this assumption and provide specific values (Seagreen Wind Energy, 2012). Values for the Seagreen 1A Project have been determined by the project specific assessment undertaken by RPS (further detail in paragraph 304).
324. The environmental assessment for Seagreen 1A Export Cable Corridor provides no values for the operation and maintenance of the cable; however, it is expected to be small in comparison with the Proposed Development and the other offshore wind farms considered. The impacts during decommissioning are expected to be similar, and less significant, than those predicted during installation (Seagreen Wind Energy Ltd., 2021).
325. The environmental appraisals for Eastern Link 1 (National Grid Electricity Transmission and Scottish Power Transmission, 2022) and Eastern Link 2 (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022) do not provide detail regarding the temporary habitat disturbance of their maintenance activities. They do however expect it to be highly reduced from the construction phase and repair works are likely to be highly localised to the area of concern and therefore the spatial extent of any impacts would be small in extent.
326. Currently it is unknown when the Eyemouth disposal site may close therefore to ensure the worst-case scenario it has been assumed it will still be open and the area of temporary habitat loss can be seen in Table 9.34   Open ▸ (Marine Scotland, 2018).
327. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Table 9.34: Total Area and Component Parts of Temporary Habitat Loss/Disturbance of the Relevant Cumulative Projects in the Operation and Maintenance Phase of the Proposed Development

Sensitivity of the receptor

328. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 70 to 89.

Marine Species

329. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
330. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish IEFs is therefore considered to be medium.
331. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area.
332. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of sandeel is therefore considered to be medium.

Diadromous Species

333. Diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

334. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of most fish and shellfish IEFs (including herring) is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
335. For Nephrops and European lobster, the magnitude of the cumulative impact is deemed to be low and the sensitivity is considered to be medium. However, the significance of effect will not be greater than that assumed for the Proposed Development alone for the reasons outlined above.
336. For sandeel the magnitude of the cumulative effect is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

337. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

338. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning phase

339. There are no Tier 2 projects active in the Proposed Development decommissioning phase to consider for cumulative impacts based on current knowledge. Any programme changes resulting in decommissioning overlap with the Proposed Development are considered in paragraph 294.

Tier 3

Construction phase

Magnitude of impact

340. The only Tier 3 project which has been identified in the CEA with the potential to result in cumulative temporary habitat loss with the Proposed Development is the Cambois connection.
341. Values for the temporary habitat disturbance/loss associated with the construction of the Cambois connection are detailed in Table 9.35   Open ▸ . The values for the Cambois connection are based on information presented in the Scoping Report submitted in September 2022.

Table 9.35: Total Area and Component Parts of Temporary Habitat Loss/Disturbance of the Relevant Tier 3 Cumulative Impact Projects in the Construction Phase of the Proposed Development

342. Figure 9.11   Open ▸ shows that the Cambois connection extends far beyond the fish and shellfish ecology cumulative study area, therefore the majority of this disturbance will not spatially overlap with the Proposed Development. Up to 180 km of Cambois connection cables (i.e. four cables each up to 45 km in length) may however be installed within the Proposed Development array area which could result in up to 4.5 km2 of repeat disturbance within the Proposed Development array area previously impacted during the construction of the Proposed Development. The disturbance associated with the Cambois connection cable installation will however be highly localised (25 m width of potential disturbance) and so the potential for repeat disturbance is considered low and unlikely to lead to an increase in the magnitude than predicted for the Proposed Development alone.
343. The cumulative impact is predicted to be of regional spatial extent, medium term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

344. The sensitivity of fish and shellfish IEFs is as described in section 9.11, paragraphs 67 to 85.

Significance of the effect

Marine Species

345. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of most fish and shellfish IEFs (including herring) is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
346. For Nephrops and European lobster, the magnitude of the cumulative impact is deemed to be low and the sensitivity is considered to be medium. However, the significance of effect will not be greater than that assumed for the Proposed Development alone for the reasons outlined above.
347. For sandeel the magnitude of the cumulative effect is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

348. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

349. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Operation and maintenance phase

350. The only Tier 3 project which has been identified in the CEA with the potential to result in cumulative temporary habitat loss with the operation and maintenance of the Proposed Development is the Cambois connection. There are no specific values for the operation and maintenance phase of Cambois connection as the assessment of habitat loss which will occur during the operation and maintenance phase of the Proposed Development has not yet been completed, therefore values are unavailable. No quantification of Tier 3 cumulative impacts is possible at this stage and as a result, no assessment of the cumulative impacts of these projects can be made.

Decommissioning phase

351. There are no Tier 3 projects active in the Proposed Development decommissioning phase to consider for cumulative impacts based on current knowledge. Any programme changes resulting in decommissioning overlap with the Proposed Development are considered in paragraph 294.

Cumulative Increased suspended sediment concentrations and associated sediment deposition

352. Increased SSC and associated deposition may arise due to the seabed preparation, installation of the wind turbines and OSP/Offshore convertor substation platform foundations, the installation and/or maintenance of inter-array cables and the offshore export cables and associated decommissioning activities. Should the other projects cited take place concurrently with the Proposed Development construction or maintenance, there is potential for cumulative increased turbidity levels.

Tier 2

Construction phase

Magnitude of impact

353. The magnitude of the increase in SCC and associated deposition arising from the installation of wind turbines and OSP/Offshore convertor substation platform foundations, inter-array cables and offshore export cables during the construction phase, has been assessed as low for the Proposed Development alone, as described above in paragraph 113 et seq.
354. The construction phase of the Proposed Development coincides with the construction phases for Seagreen 1A Project. Construction of its 36 wind turbines will be completed by the end of 2025, which will lead to an overlap with the construction phase of the Proposed Development.
355. The Inch Cape Offshore Wind Farm will be in the final year of construction, with the installation of the offshore export cable being programmed for the period of overlap. The cable path is located to the east of the Proposed Development and should trenching activities be undertaken simultaneously the sediment plumes would not interact with those from the Proposed Development.
356. During the Proposed Development’s construction phase the Neart na Gaoithe Offshore Wind Farm and the Seagreen 1A Export Cable Corridor will be in operation and maintenance phase and maintenance activities may result in increased SCC, however these activities would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development.
357. The Eastern Link 1 Cable has Scottish landfall near Thorntonloch Beach, East Lothian. The landfall installation is proposed to be by HDD and although it is not yet confirmed which subsea trenching techniques will be used to install the cables, it is anticipated that mechanical ploughing or cutting and/or water jetting or Mass Flow Excavation (MFE) techniques will be used at different points along the route, in response to the seabed sediment conditions. Installation of the cables into soft sediments will seek to achieve a target burial depth of at least 1.5 m to 2 m and below the depth of mobile sediments depending on the nature of the seabed and potential hazards. Significant impacts of sediment plumes arising from cable laying activities are not anticipated. These installation parameters are similar to those for the Proposed Development offshore export cable installation and therefore the magnitude of the impact on the fish and shellfish receptors is anticipated to be low.
358. The Eastern Link 2 Cable runs to the east of the Proposed Development, skirting the FFBC MPA. For the extent of the overlap with the fish and shellfish ecology cumulative study area this is an offshore marine cable. The preferred subsea cable protection method is burial through trenching. It is not yet confirmed what subsea trenching equipment will be used to install the cables; however, it is anticipated similar methods to those proposed for Eastern Link 1 may be required, but this is dependent on the seabed conditions present within the offshore export cable corridor: It is anticipated that the magnitude of the impact on the fish and shellfish receptors would be low.
359. The CEA considers sea disposal of dredged material at the Eyemouth disposal site, located 31 km and 16.5 km from the Proposed Development array area and Proposed Development export cable corridor respectively. If offshore cable installation and dredge material dumping coincided, both resultant plumes would be advected on the tidal currents. The plumes would travel in parallel, and not towards one another, and are unlikely to interact in the event that offshore cables installation coincides with the use of the licensed sea disposal site (see volume 3, appendix 7.1).
360. The cumulative impact is predicted to be of local spatial extent, short term duration and intermittent and of high reversibility. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

361. The sensitivity of fish and shellfish IEFs is summarised below and is as described in section 9.11, paragraphs 120 to 128.

Marine Species

362. Based on the increase in sensitivity of herring eggs to the smothering effects of increased sediment deposition, herring is deemed to be of medium vulnerability, high recoverability and of regional importance, and therefore the sensitivity of this receptor is considered to be medium.
363. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of these IEFs is therefore considered to be low.

Diadromous Species

364. Diadromous fish species IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

365. For most fish and shellfish IEFs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
366. For herring, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

367. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

368. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning phase

369. As per the maximum design scenario, during the decommissioning phase all structures above the seabed would be removed. It is proposed to remove all export, inter-array and inter-connector cables and scour protection where possible and appropriate to do so. During decommissioning cables would be removed by similar processes as undertaken during installation therefore increases in suspended sediment concentrations would be of a similar form and magnitude. Following decommissioning, changes in suspended sediments concentration and sedimentation would return to baseline levels as it is anticipated that all structures above the seabed level will be completely removed and no further operation to disturb the seabed would be required. Therefore, refer to the assessment undertaken for the construction phase.

Tier 3

Construction phase

Magnitude of Impact

370. During the construction phase of the Proposed Development there is the potential for cumulative impacts with three Tier 3 cable installations. The Cambois connection is a 170 km offshore cable route extending southwards from the Proposed Development array area. Scoping indicates the project will consist of up to four cables installed in 2 m wide trenches up to 3 m in depth. Installation techniques may include jet trenching or cable ploughing, as ground conditions dictate. Site preparation will be required, such as boulder and sand wave clearance as part of the 36-month construction programme.
371. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and of high reversibility. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

372. The sensitivity of fish and shellfish IEFs is as described in section 9.11, paragraphs 120 to 128.

Significance of the effect

Marine Species

373. For most fish and shellfish IEFs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
374. For herring, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

375. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

376. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning phase

377. As per the maximum design scenario, during the decommissioning phase all structures above the seabed would be removed. It is proposed to remove all export, inter-array and inter-connector cables and scour protection where possible and appropriate to do so. Therefore, there is no contact with the seabed during decommissioning and subsequently no impact on the changes of SCC and sedimentation for cumulative impacts. During decommissioning cables would be removed by similar processes as undertaken during installation therefore increases in suspended sediment concentrations would be of a similar form and magnitude. Following decommissioning, changes in suspended sediments concentration and sedimentation would return to baseline levels as it is anticipated that all structures above the seabed level will be completely removed and no further operation to disturb the seabed would be required. Therefore, refer to the assessment undertaken for the construction phase.

Cumulative Injury and/or Disturbance to Fish and Shellfish From Underwater Noise and Vibration

Tier 2

Construction phase

Magnitude of impact

378. The Proposed Development, together with the projects and plans identified in Table 9.32   Open ▸ , may lead to injury and/or disturbance to fish and shellfish from underwater noise and vibration. The other projects and plans screened into the assessment are: Inch Cape Offshore Wind Farm and Seagreen 1A Project. Cumulative effects of underwater noise on fish and shellfish IEFs have the potential to occur as a result of the Proposed Development, together with the Inch Cape Offshore Wind Farm and Seagreen 1A.
379. These projects include similar construction activities as those described for the Proposed Development alone including piling of wind turbine and OSP/Offshore convertor substation platform foundations. As outlined in paragraph 187, all other noise sources including cable installation and foundation drilling will result in much lower noise levels than piling and will not represent a risk to injury or cause significant disturbance to fish and shellfish, such that they would result in cumulative effects with or from other projects. As such, the scope of this assessment focusses on piling noise, which represents the greatest risk to fish and shellfish receptors. The construction phases of Inch Cape Offshore Wind Farm and Seagreen 1A Project overlap the construction phase of the Proposed Development with construction for Inch Cape Offshore Wind Farm predicted to end in 2025 and Seagreen 1A Project predicted to end in 2025. However, during the time where construction phases overlap, there is the potential for cumulative effects. The construction figures for the Seagreen 1A Project in Table 9.36   Open ▸ accounts for piling associated with 36 wind turbines which make up Seagreen 1A Project.

Table 9.36:  Piling Parameters of the Relevant Cumulative Projects in the Construction Phase of the Proposed Development

380. Seagreen Alpha/Bravo Offshore Wind Farm Environmental Statement (Seagreen Wind Energy, 2012) reported that the maximum range for auditory injury for the most sensitive fish species (group 4 species) was 260 m. The Inch Cape Offshore Wind Farm Environmental Statement (Inch Cape Offshore Limited, 2018) reported injury ranges from piling activity on the most sensitive fish species (group 4 species) as follows:

• mortality and mortal injury: approximately 5 km2;
• recoverable injury: approximately 17 km2; and
• TTS: approximately 1,738 km2.
  381. Neither Inch Cape Offshore Wind Farm nor Seagreen Alpha/Bravo Offshore Wind Farm Environmental Statements predicted significant effects on fish and shellfish receptors. Any effects were predicted to be temporary and reversible following cessation of piling activities. Additionally, the injury ranges reported are likely to be conservative as soft start measures will be implemented as part of the Inch Cape Offshore Wind Farm and Seagreen 1A Project construction programmes, which will reduce the risk of injury considerably. Due to the minor overlap in construction phases of the Proposed Development and Inch Cape Offshore Wind Farm and Seagreen 1A Project, it is unlikely that cumulative effects will result in effects of greater significance than as assessed for the Proposed Development alone (see paragraph 152 et seq.).
  382. The cumulative impact is predicted to be of regional spatial extent, short term duration and intermittent and of high reversibility. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

383. The sensitivity of fish and shellfish IEFs is summarised below and is as described in section 9.11, paragraphs 159 to 196.

Marine Species

384. Based on the increase in sensitivity of herring eggs to underwater noise, herring is deemed to be of medium vulnerability, high recoverability and of regional importance, and therefore the sensitivity of this receptor is considered to be medium.
385. Sprat, cod and sandeel are deemed to be of medium vulnerability, high recoverability and regional to national importance. The sensitivity of the receptor is therefore, considered to be medium.
386. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of these IEFs is therefore considered to be low.

Diadromous Species

387. Diadromous fish species IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

388. For most fish and shellfish IEFs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
389. For herring, sprat, cod and sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

390. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

391. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Cumulative Long-term subtidal habitat loss

Tier 2

Construction and Operation and Maintenance Phase

Magnitude of impact

392. Long-term habitat loss will occur directly under all structures on the seabed, associated scour protection and cable protection, where this is required. Magnitude has been considered for the construction and operation and maintenance phases combined as the structures will be placed during construction and will be in place, with habitat loss continuing during the operation and maintenance phase. The installation of the projects outlined in Table 9.32   Open ▸ Table 9.32:              Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Cumulative Effects on Fish and Shellfish Ecology may lead to long-term subtidal habitat loss of up to 15,014,156 m2 within the fish and shellfish ecology CEA study area. Table 9.32:              Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Cumulative Effects on Fish and Shellfish Ecology Table 9.32   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, and Seagreen 1 and Seagreen 1A. The Seagreen 1A Export Cable Corridor Environmental Statement does not present a specific value for long term habitat loss, however, it is assumed that 20% of the cable length will require rock protection as a maximum design scenario.

The presence of offshore infrastructure at the Inch Cape Offshore Wind Farm may result in 2,470,000 m2 of long-term subtidal habitat loss (Inch Cape Offshore Limited, 2018). The presence of offshore infrastructure at Neart na Gaoithe Offshore Wind Farm may result in a total of 361,000 m2 of long-term habitat loss (Mainstream Renewable Power, 2019) The long term habitat loss values for the Seagreen 1A Project have been produced as part of the project specific assessment which was undertaken by RPS (further detail in paragraph 304). The presence of offshore infrastructure at Seagreen 1 may result in a total of 2,026,045 m2 of long-term habitat loss (Seagreen Wind Energy, 2012) and the Seagreen 1A Project may result in a total of 158,055 m2 of long-term habitat loss. The Seagreen 1A Export Cable Corridor Environmental Statement does not present a specific value for long term habitat loss, however, it is assumed that cable protection will be 6 m wide and may be required for up to 20% of the 110 km offshore export cable (Seagreen Wind Energy Ltd., 2021). Eastern Link 1’s environmental appraisal does not provide specific values for long term habitat loss except to state rock berm of a 7 m width will be installed. The cables installed as a result of Eastern Link 2 (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022) will result in 2,200,200 m2 of long term habitat loss. Additionally, only 24% of the 176 km Eastern Link 1 cable and only 18% of the 436 km Eastern Link 2 cables will be within the Proposed Development fish and shellfish study area therefore only a proportion of the overall impact will be cumulative. The details of the activities resulting in long-term subtidal habitat loss from each wind farm can be found in Table 9.37   Open ▸ . The total cumulative habitat loss would represent only a small proportion (i.e. <1%) of the fish and shellfish habitats within the area considered in this CEA.

393. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and not reversible during the construction and operation and maintenance phase of the relevant projects. It is predicted that the impact will affect the fish and shellfish receptors directly. The magnitude is therefore, considered to be low.

Table 9.37: Total Area and Component Parts of Long-Term Subtidal Habitat Loss of the Relevant Cumulative Projects in the Construction and Operation and Maintenance Phases of the Proposed Development

Sensitivity of the receptor

394. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 207 to 218.

Marine Species

395. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
396. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish IEFs is therefore considered to be medium.
397. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of these fish and shellfish receptor is therefore considered to be medium.
398. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area and project boundaries for other projects considered in the CEA.

Diadromous Species

399. Diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

400. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
401. For European lobster and Nephrops, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
402. For sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms

Diadromous Species

403. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

404. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Tier 3

Magnitude of impact

405. The only Tier 3 project which have been identified in the CEA with the potential to result in cumulative long-term habitat loss with the Proposed Development is the Cambois connection.
406. The values for the Cambois connection and the predicted extent of long term habitat loss associated with this project is presented in Table 9.38   Open ▸ and are based on information presented in the Cambois connection Scoping Report (SSER, 2022e) submitted in October 2022.
407. The installation of the Tier 2 and 3 projects may lead to cumulative long term subtidal habitat loss of up to 13,119,956 m2 or 0.16% of the fish and shellfish ecology CEA study area.
408. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Table 9.38: Total Area and Component Parts of Long Term Subtidal Habitat Loss of the Relevant Cumulative Projects in Tier 3 the Construction and Operation and Maintenance Operation and Maintenance Phases of the Proposed Development

Sensitivity of the receptor

409. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 207 to 218.

Significance of the effect

Marine Species

410. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
411. For European lobster and Nephrops, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
412. For sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

413. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

414. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Cumulative Electromagnetic Fields from subsea electrical cabling

Tier 2

Operation and maintenance phase

Magnitude of impact

415. The operation and maintenance activities of the cumulative projects will overlap with the operation and maintenance phase of the Proposed Development and may impact fish and shellfish IEFs. Table 9.32   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1 and Eastern Link 2. As outlined in Table 9.15   Open ▸ , the Proposed Development may use a combination of HVAC and HVDC cables.
416. Inch Cape Offshore Wind Farm has the potential to produce EMF from 553 km of inter-array cables suitably buried and protected where burial is not possible. Additionally, the offshore export cables are approximately 83 km for each six cables, therefore the offshore export cables total length is 498 km. In combination with the Proposed Development this equates to 3,084 km of subsea cabling. This project will use a combination of HVAC and HVDC, however the design was not yet finalised in the environmental statement.
417. Neart na Gaoithe Offshore Wind Farm has the potential to produce EMF from 66 km of offshore export cables as well as 140 km of inter-array cables. In combination with the Proposed Development this equates to 2,506 km of subsea cabling. This project will use a combination of HVAC and HVDC, however the design was not yet finalised in the environmental statement.
418. Seagreen 1 and Seagreen 1A Project has the potential to produce EMF from 710 km of inter-array cables and 530 km of offshore export cables resulting in 1,240 km of subsea cabling. This arrangement included HVAC and HVDC however the design was not yet finalised in the environmental statement. Seagreen 1A Export Cable Corridor Environmental Statement does not provide details of the cable specifications used, but provides an approximate cable length of 110 km, which will have the potential to cause EMF effects
419. Eastern Link 1 has the potential to produce EMF from two 176 km HVDC cables resulting in up to 352 km of subsea cabling (National Grid Electricity Transmission and Scottish Power Transmission, 2022). Eastern Link 2 has the potential to produce EMF from two 436 HVDC cables resulting in up to 872 km of subsea cabling structures (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022).
420. The potential for cumulative impact of EMF on fish and shellfish IEFs during the Proposed Development operation and maintenance phase results from up to 6,112 km of subsea cabling, including the cables in the Proposed Development fish and shellfish ecology study area.
421. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and not reversible during the operation and maintenance phase (only at the decommissioning stage) of the relevant projects. It is predicted that the impact will affect the fish and shellfish IEFs directly. The magnitude is therefore, considered to be low. This can be concluded as EMF effects are confined to the close vicinity of cables. While the sediments in which cables are buried will not reduce the strength of EMF, the burial of cables does increase the distance between cables and fish and shellfish IEFs, with greater attenuation of EMFs with greater distance from the cable, thereby potentially reducing the effect of EMFs on those IEFs (see paragraph 233 et seq.).

Table 9.39: Total Cable Length of the Relevant Cumulative Projects in the Operation and Maintenance Phases of the Proposed Development (Seagreen 1A Export Cable Corridor not Included in Cumulative Length)

Sensitivity of the receptor

422. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 241 to 254.

Marine Species

423. Marine fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low (most fish and shellfish IEFs) to medium (decapod crustaceans and elasmobranchs).

Diadromous Species

424. Diadromous fish IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

425. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
426. For European lobster and Nephrops edible crab and elasmobranchs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

427. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

428. No additional fish and shellfish ecology mitigation is considered necessary as the predicted effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.