Gorgon Gas Development and Jansz Feed Gas Pipeline: Post-Development Coastal and Marine State and Environmental Impact Survey Report, Year 2: 2012–2013 Document No: G1-NT-REPX0005152 Revision: 0 Revision Date: 31 July 2013 Copy No: IP Security: Public © Chevron Australia Pty Ltd Document No: G1-NT-REPX0005152 Gorgon Gas Development and Jansz Feed Gas Pipeline: Revision Date:31 July 2013 Post-Development Coastal and Marine State and Environmental Impact Survey Report, Year 2: 2012–2013 Revision: 0 Table of Contents Terminology, Definitions and Abbreviations .......................................................................................... 18 Executive Summary .................................................................................................................................. 29 Coral Monitoring ................................................................................................................................ 29 Non-coral Benthic Macroinvertebrates .............................................................................................. 31 Mangroves ......................................................................................................................................... 32 Demersal Fish ................................................................................................................................... 32 Surficial Sediment ............................................................................................................................. 32 1.0 Introduction ..................................................................................................................................... 35 1.1 Proponent ................................................................................................................................ 35 1.2 Project ..................................................................................................................................... 35 1.3 Location ................................................................................................................................... 35 1.4 Environmental Approvals ........................................................................................................ 38 1.5 Purpose of this Report ............................................................................................................ 39 1.5.1 Legislative Requirements ........................................................................................ 39 1.5.2 Objectives ................................................................................................................ 39 1.5.3 Requirements .......................................................................................................... 40 1.5.4 Hierarchy of Documentation .................................................................................... 41 1.5.5 Scientific Expertise .................................................................................................. 43 1.5.6 Stakeholder Consultation ........................................................................................ 43 1.5.7 Public Availability ..................................................................................................... 43 2.0 Relevant Facilities and Areas ........................................................................................................ 44 2.1 Marine Facilities ...................................................................................................................... 44 2.1.1 Overview .................................................................................................................. 44 2.1.2 Dredging and Dredge Spoil Disposal ...................................................................... 44 2.1.3 Materials Offloading Facility (MOF) ......................................................................... 44 2.1.4 LNG Jetty ................................................................................................................. 45 2.1.5 Marine Upgrade of the Existing WAPET Landing ................................................... 45 2.2 Marine Areas ........................................................................................................................... 48 2.2.1 Marine Disturbance Footprint .................................................................................. 48 2.2.2 Dredge Management Areas and Plume Modelling.................................................. 50 2.2.3 Areas at Risk of Material or Serious Environmental Harm ...................................... 52 3.0 General Approach to Methods ....................................................................................................... 56 3.1 Introduction ............................................................................................................................. 56 3.2 Sampling Methodology ........................................................................................................... 56 3.3 Sampling Sites ........................................................................................................................ 57 3.4 Sampling Frequency ............................................................................................................... 58 3.5 Statistical Approach ................................................................................................................ 60 © Chevron Australia Pty Ltd Public Page v Printed Date: 15 July 2014 Uncontrolled when Printed Gorgon Gas Development and Jansz Feed Gas Pipeline: Document No.:G1-NT-REPX0005152 Revision Date: 31 July 2013 Post-Development Coastal and Marine State and Environmental Impact Survey Report, Year 2: 2012–2013 Revision: 0 3.5.1 Design ......................................................................................................................60 3.5.2 Rationale ..................................................................................................................61 3.6 Dredge Program Monitoring ....................................................................................................62 4.0 Hard and Soft Corals ....................................................................................................................... 63 4.1 Introduction ............................................................................................................................. 63 4.2 Scope ...................................................................................................................................... 63 4.3 Area of Coral Assemblages ....................................................................................................64 4.3.1 Methods ...................................................................................................................64 4.3.2 Results of Post-Development Survey Year 2 .......................................................... 68 4.3.3 Comparison between the Post-Development Survey Year 2 and the Marine Baseline Program Environmental State ...................................................................70 4.3.4 Discussion ...............................................................................................................72 4.4 Size-class Frequency .............................................................................................................. 74 4.4.1 Methods ...................................................................................................................74 4.4.2 Results of Post-Development Survey Year 2 .......................................................... 80 4.4.3 Comparison between the Post-Development Surveys and Marine Baseline Environmental State ................................................................................................81 4.4.4 Discussion ...............................................................................................................97 4.5 Dominant and Subdominant Taxa ..........................................................................................98 4.5.1 Methods ...................................................................................................................98 4.5.2 Results of Post-Development Survey Year 2 ........................................................100 4.5.3 Comparison between the Post-Development Surveys and Marine Baseline Program Environmental State ...............................................................................103 4.5.4 Discussion .............................................................................................................105 4.6 Recruitment Success ............................................................................................................107 4.6.1 Methods .................................................................................................................107 4.6.2 Statistical Approach for Comparison Against Baseline .........................................109 4.6.3 Results of Post-Development Survey Year 2 ........................................................111 4.6.4 Comparison between the Post-Development Surveys and Marine Baseline Program .................................................................................................................113 4.6.5 Discussion .............................................................................................................117 4.7 Survival ..................................................................................................................................119