NOT PROTECTIVELY MARKED SUPPORTING DOCUMENT FOR BACKGROUND CONTEXT AND INFORMATION ONLY: Hinkley Point C Development Site Environmental Statement – Volume 2 (October 2011) Chapter 19 – Marine Ecology (Appendices to Chapter 19 can be found on the Hinkley Point C New Nuclear Power Station page of the National Infrastructure Planning Website: infrastructure.planninginspectorate.gov.uk/projects/south- west/Hinkley-point-c-new-nuclear-power-station) NNB Generation Company (HPC) Limited Registered in England and Wales. Registered No. 6937084 Registered Office: 90 Whitfield Street, London, W1T 4EZ Template No. NNB-308-REP-000723 NOT PROTECTIVELY MARKED Development Hinkley Point C Consent Order Application Environmental Statement Doc Ref 4.3 October 2011 Environmental Statement - Volume 2 Hinkley Point C Development Site NOT PROTECTIVELY MARKED NNB Generation Company (HPC) Limited Registered in England and Wales. Registered No. 6937084 Registered Office: 90 Whitfield Street, London, W1T 4EZ Template No. NNB-308-REP-000723 NOT PROTECTIVELY MARKED NOT PROTECTIVELY MARKED CHAPTER 19: MARINE ECOLOGY NOT PROTECTIVELY MARKED NOT PROTECTIVELY MARKED NOT PROTECTIVELY MARKED NOT PROTECTIVELY MARKED CONTENTS 19. MARINE ECOLOGY........................................................................................................7 19.1 Introduction......................................................................................................................7 19.2 Legislation and Policy....................................................................................................10 19.3 Methodology..................................................................................................................18 19.4 Baseline Environment....................................................................................................31 19.5 Scope of Assessment....................................................................................................71 19.6 Assessment of Impacts .................................................................................................75 19.7 Cumulative Assessment ..............................................................................................146 19.8 Management Controls and Mitigation Measures .........................................................148 19.9 Residual Impacts.........................................................................................................158 19.10 Proposed Monitoring Measures...................................................................................163 19.11 Summary of Impacts....................................................................................................168 19.12 Conclusions.................................................................................................................175 References...............................................................................................................................176 TABLES Table 19.1: Marine Ecology - Sources of Potential Interactions with Defined Project Activities for a Range of Key Receptors .................................................................................8 Table 19.2: Summary of Consultation Meetings Undertaken to Determine Scope and Nature of Marine Ecological Assessment and Survey Work .............................................10 Table 19.3: BEEMS Scientific Advisory Reports bearing on Methodology and Approach........20 Table 19.4: Feeder Reports Utilised in Preparing the Hinkley Point Marine Ecology Synthesis20 Table 19.5: Criteria used to Determine Sensitivity and Value for Marine Ecology....................25 Table 19.6: Criteria for Determining Magnitude for Effects on Marine Ecology........................26 Table 19.7: Total Estimated Areas (in km2) of Mean Annual Temperature Uplift due to Thermal Plumes from Different Power Station Intake/Outfall Configurations and Operational Regimes (from Ref. 19.59).................................................................28 Table 19.8: Estimated Areas (in km2) of Intertidal Habitat Impacted by Mean Annual Temperature Uplift Due to Thermal Plumes from Different Power Station Operational Regimes, Utilising Offshore Hinkley Point C Discharge Location (from Ref. 19.59).............................................................................................................30 Table 19.9: Key Features of the Severn Estuary and Bristol Channel Relevant to the Marine Ecology of Hinkley Point (after Ref. 19.17)............................................................32 Table 19.10: Commonly Encountered Bird Species Recorded as Feeding in Bridgwater Bay, ordered by dominance (from Ref. 19.51)...............................................................46 Table 19.11: Potential Prey of Regularly Occurring Bird Species in the Bridgwater Bay Intertidal Area (table adapted from Ref. 19.114) ...................................................47 Volume 2 Hinkley Point C − Chapter 19 Marine Ecology | October 2011 1 NOT PROTECTIVELY MARKED NOT PROTECTIVELY MARKED Table 19.12: Dietary Constituents of Birds Utilising Stert Flats during 2010 and early 2011, as Identified from Microscopic and Molecular Analyses of Bird Faeces (Ref. 19.54).50 Table 19.13: Migratory Movements of Diadromous Species found within the Severn Estuary, showing Important Months and Directions of Movement.......................................58 Table 19.14: Catch of Fish by 2m Beam Trawl (tows standardised to 1000m2) (Ref. 19.33) .....62 Table 19.15: Species Caught during the Intertidal Fish Survey..................................................63 Table 19.16: Average Annual (between 2004 and 2008) Weights (kg) and Values (£) of Fish Landings by ICES Statistical Rectangle ................................................................66 Table 19.17: Allowable and Utilised Effort for the Principal Salmon Net Fisheries in 2007 ........68 Table 19.18: Summary of Salmon Net Catches Numbers Landed, 1999-2006..........................68 Table 19.19: Provisional Net and Rod Salmon Catches (including released fish) by Region for the 2007 Season ...................................................................................................69 Table 19.20: The Number of Days of Porpoise Recordings at the BEEMS Acoustic Recording Stations around Hinkley Point (from Ref. 19.57) during Initial Survey Period of 77 Days ......................................................................................................................71 Table 19.21: Vessel Sound Frequencies and Source Levels.....................................................95 Table 19.22: Hearing Frequency Range for Fish Species of Conservation Importance in the Area around Hinkley Point (Ref. 19.164)...............................................................96 Table 19.23: Key Operational Impacts and Receptors.............................................................102 Table 19.24: Calculated Thermal Plume Areas at the Bed, for Particular Excess Temperatures104 Table 19.25: Incidence of Hourly Intervals of Occlusion of Estuarine Cross Sectional Area >25% from Annual Analysis (Ref.19.59)..............................................................107 Table 19.26: Predicted Total Annual Impingement (numbers of fish as, EAV, and total number of shrimp) of Key Species at HPC and HPB for Selected Species for an Abstraction Rate of 125m3.s-1 via HPB-type Intake Structures, Without Mitigation (Data from Ref. 19.43).........................................................................................121 Table 19.27: Equivalent Adult Value (EAV) of Predicted Annual Fish Impingement at Hinkley Point C Power Station at Maximum Cooling Water Demand of 125m3.s-1, Without Mitigation.............................................................................................................123 Table 19.28: Population Estimates of Lamprey (Mean ± s.d.) (Ref. 19.212)............................134 Table 19.29: Smallest Sizes of Various Fish Species Excluded by a 5mm Screen Mesh (Ref. 19.238) .......................................................................................................136 Table 19.30: Crangon Crangon: Annual Impingement and Entrainment Impact of HPC Options Compared with HPB............................................................................................141 Table 19.31: Survival rates of entrained fish and crustacean from EMU cooling water passage simulation experiments (Ref. 19.225)..................................................................142 Table 19.32: Presence (+) of Fish Eggs and Larvae Detected in Ichthyoplankton Surveys off Hinkley Point in 2008 and 2009...........................................................................143 Table 19.33: Predicted Entrainment of Fish Eggs and Larvae between February and June 2010 at Hinkley Point C (based on the Ref. 19.34) in relation to the abundance in the Trevose spawning area .................................................................................144 2 Volume 2 Hinkley Point C − Chapter 19 Marine Ecology | October 2011 NOT PROTECTIVELY MARKED NOT PROTECTIVELY MARKED Table 19.34: Analysis of the HPB Impingement Catch showing % of Fish that would Remain Vulnerable to Capture with the Reduced Intake Velocities Modelled for the EA’s LVSE Design and the Proposed HPC Intake Design ..........................................154 Table 19.35: Assumed Proportional Effects of Intake System Mitigations (Mitigation Factors) 157 Table 19.36: Predicted