DOGGER BANK Environmental Statement Chapter 12
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March 2014 Environmental Statement Chapter 12 - Marine and Intertidal Ecology Application Reference: 6.12 DOGGER BANK TEESSIDE A & B Cover photograph: Installation of turbine foundations in the North Sea F-OFL-CH-012 Issue 4.1 Chapter 12 Page ii © 2014 Forewind DOGGER BANK TEESSIDE A & B Document Title Dogger Bank Teesside A & B Environmental Statement – Chapter 12 Marine and Intertidal Ecology Forewind Document Reference F-OFL-CH-012 Issue 4.1 Date March 2014 Drafted by Royal HaskoningDHV (Jonny Lewis) Checked by Ben Orriss Date / initials check 21 February 2014 Approved by Angela Lowe Date / initials approval 21 February 2014 Forewind Approval Date / Reference approval Gareth Lewis 14 February 2014 F-OFL-CH-012 Issue 4.1 Chapter 12 Page iii © 2014 Forewind DOGGER BANK TEESSIDE A & B Title: Contract No. (if applicable) Dogger Bank Teesside A & B Draft Environmental Statement Chapter Onshore Offshore 12 Marine and Intertidal Ecology Document Number: Issue No: Issue Date: F-OFL-CH-012 4.1 28 February 2014 Status: Issued for 1st. Technical Review Issued for PEI3 Issued for 2nd. Technical Review Issued for Application Submission Prepared by: Checked by: Royal HaskoningDHV (Jonathan Lewis) Ben Orriss Approved by: Signature / Approval (Forewind) Approval Date: Angela Lowe 14 February 2014 Gareth Lewis Revision History Date Issue No. Remarks / Reason for Issue Author Checked Approved 31 May2013 1 Issued for 1st Technical review JL AL AMP 08 July 2013 2 Issued for 2nd Technical review JL AL AL 23 August 2.1 Issued for Approval JL AL AL 2013 08 October 3 Issued for PEI 3 JL AL RAH 2013 07 February 4 Pre-DCO Submission Review JL BLO AL 2014 28 February 4.1 DCO Submission JL BLO AL 2014 F-OFL-CH-012 Issue 4.1 Chapter 12 Page iv © 2014 Forewind DOGGER BANK TEESSIDE A & B Contents 1. Introduction ................................................................................................................. 1 2. Guidance and Consultation ........................................................................................... 2 2.1. Legislation, policy and guidance ......................................................................... 2 2.2. Consultation ........................................................................................................ 4 3. Methodology ............................................................................................................... 12 3.1. Study area ........................................................................................................ 12 3.2. Characterisation of existing environment – methodology .................................. 12 3.3. Assessment of impacts – methodology ............................................................. 28 4. Existing Environment .................................................................................................. 32 4.1. Dogger Bank Teesside A & B and the Dogger Bank Teesside A & B Export Cable Corridor ................................................................................................... 32 4.2. Intertidal ............................................................................................................ 54 4.3. Biotopes and habitats ....................................................................................... 55 4.4. Habitats and species of conservation importance ............................................. 61 5. Assessment of Impacts – Worst Case Definition ........................................................ 75 5.1. General ............................................................................................................. 75 5.2. Construction Scenarios ..................................................................................... 75 5.3. Operation Scenario ........................................................................................... 76 5.4. Decommissioning scenarios ............................................................................. 77 5.5. Realistic Worst case Scenario .......................................................................... 77 6. Assessment of Impacts during Construction ............................................................... 85 6.1. General ............................................................................................................. 85 6.2. Physical disturbance to habitats and species and temporary habitat loss ........ 85 6.3. Increased suspended sediment concentration and sediment deposition .......... 94 6.4. Release of sediment contaminants resulting in potential effects on benthic ecology ............................................................................................................. 99 6.5. Increased suspended sediment concentration leading to impacts on plankton and primary productivity .................................................................................. 101 6.6. Physical disturbance to intertidal habitats and species during landfall works . 102 F-OFL-CH-012 Issue 4.1 Chapter 12 Page v © 2014 Forewind DOGGER BANK TEESSIDE A & B 6.7. Potential construction phase impacts on the Dogger Bank cSAC ................... 103 6.8. Potential construction phase impacts on sites of marine conservation interest .... ............................................................................................................. 107 6.9. Monitoring of construction phase impacts ....................................................... 110 7. Assessment of Impacts during Operation ................................................................. 112 7.1. Permanent loss of habitat via placement of project infrastructure (foundations, cable protection, scour protection) .................................................................. 112 7.2. Temporary impact on benthos due to physical disturbance caused by maintenance activities ..................................................................................... 116 7.3. Change in hydrodynamics and inter-related effects on benthos ..................... 117 7.4. Increase in suspended sediment concentration due to scour associated with foundations ..................................................................................................... 119 7.5. Increase in sediment deposition following increase in suspended sediment concentration due to scour associated with foundations ................................. 121 7.6. Introduction of new habitat in the form of foundation structures, leading to potential colonisation ...................................................................................... 122 7.7. Effect of electromagnetic fields on benthic communities ................................. 125 7.8. Potential operational phase impacts on the Dogger Bank cSAC .................... 126 7.9. Potential operational phase impacts on sites of marine conservation interest 128 7.10. Monitoring of operational phase impacts ........................................................ 130 8. Assessment of Impacts during Decommissioning ..................................................... 132 8.1. Increased suspended sediment concentration and sediment deposition ........ 132 8.2. Loss of species colonising hard structures ..................................................... 132 8.3. Temporary disturbance to habitats via removal of cables ............................... 133 8.4. Potential decommissioning phase impacts on the Dogger Bank cSAC .......... 133 8.5. Monitoring of decommissioning phase impacts............................................... 134 9. Inter-relationships...................................................................................................... 135 10. Cumulative Impacts ................................................................................................... 136 10.1. CIA strategy and screening ............................................................................. 136 10.2. Temporary disturbance to marine habitats during construction (seabed preparation, cable installation, vessel jacking-up etc.) .................................... 143 F-OFL-CH-012 Issue 4.1 Chapter 12 Page vi © 2014 Forewind DOGGER BANK TEESSIDE A & B 10.3. Increased suspended sediment concentration and sediment deposition during construction phase .......................................................................................... 144 10.4. Permanent loss of marine habitats via installation of project infrastructure associated with offshore wind farm development and other activities ............. 145 10.5. Increased suspended sediment concentration and sediment deposition during operational phase. .......................................................................................... 146 10.6. Direct impact via vessel activity (jacking-up and anchoring in operational phase) ............................................................................................................. 147 10.7. Cumulative impact of introduction of hard substrates in form or foundations / scour & cable protection into a mainly sedimentary environment (southern North Sea) ............................................................................................................. 148 10.8. Impact on the Dogger Bank cSAC via cumulative impacts ............................. 148 11. Transboundary Effects .............................................................................................. 151 12. Summary ............................................................................................................