1 2 ANTHROPOGENIC UNDERWATER NOISE: IMPACTS ON MARINE AND COASTAL 3 BIODIVERSITY AND HABITATS, AND MITIGATION AND MANAGEMENT MEASURES 4 5 6 7 8 9 10 DRAFT TECHNICAL SERIES 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 Table of Contents 42 43 FOREWORD ........................................................................................ Error! Bookmark not defined. 44 ACKNOWLEDGEMENTS ...................................................................................................................... 45 EXECUTIVE SUMMARY .................................................................................................................... 4 46 1. BACKGROUND AND INTRODUCTION .................................................................................... 8 47 Underwater Noise and the Convention on Biological Diversity ....................................................... 10 48 2. UNDERWATER SOUND: CHARACTERISTICS, RELEVANCE AND TRENDS .................. 12 49 Overview of Underwater Sound ....................................................................................................... 12 50 Natural Underwater Sound ............................................................................................................... 15 51 The Importance of Sound for Marine Organisms ............................................................................. 16 52 The Increase in Anthropogenic Underwater Sound .......................................................................... 18 53 3. SOURCES AND TYPES OF UNDERWATER ANTHROPOGENIC NOISE ........................... 20 54 Explosives ......................................................................................................................................... 20 55 Industrial Activities ........................................................................................................................... 22 56 Seismic Exploration .......................................................................................................................... 24 57 Sonar ................................................................................................................................................. 25 58 Ships and Smaller Vessels ................................................................................................................ 28 59 Acoustic Deterrent and Harrassment Devices .................................................................................. 30 60 Other Anthropogenic Sources ........................................................................................................... 31 61 4. KNOWN AND POTENTIAL IMPACTS OF UNDERWATER NOISE ..................................... 33 62 Impacts on Marine Mammals ........................................................................................................... 34 63 Injury and Physical Effects ........................................................................................................... 35 64 Masking......................................................................................................................................... 38 65 Behavioural Changes .................................................................................................................... 41 66 Effects on Marine Fishes .................................................................................................................. 47 67 Injury and Physical Effects ........................................................................................................... 48 68 Behavioural Responses ................................................................................................................. 53 69 Masking......................................................................................................................................... 57 70 Impacts on Other Marine Organisms ................................................................................................ 63 71 Marine Turtles ............................................................................................................................... 63 72 Marine Invertebrates ..................................................................................................................... 64 73 Seabirds ......................................................................................................................................... 68 74 5. Mitigation and Management of Underwater Noise ....................................................................... 70 75 Mitigation Measures and Procedures ................................................................................................ 71 76 Impulsive Noise Mitigation .......................................................................................................... 72 77 Continuous Sound Mitigation ....................................................................................................... 97 78 Monitoring and Mapping Tools ...................................................................................................... 102 2 79 Acoustic and Species Distribution Mapping ............................................................................... 102 80 Passive and Active Acoustic Monitoring .................................................................................... 105 81 Management Frameworks and International Agreements .............................................................. 107 82 Management Frameworks ........................................................................................................... 108 83 International Agreements and Processes ..................................................................................... 113 84 Setting Standards and Guidelines at the National / International level ........................................... 120 85 National and International Standards .......................................................................................... 120 86 Summary ......................................................................................................................................... 122 87 6. FUTURE RESEARCH NEEDS ................................................................................................. 127 88 Anthropogenic Sources and Ambient Noise ................................................................................... 128 89 Baseline Biological Information ..................................................................................................... 129 90 Noise Impacts on Marine Biodiversity ........................................................................................... 130 91 Mitigation and Management ........................................................................................................... 132 92 7. CONCLUSIONS ......................................................................................................................... 137 93 Annexes .............................................................................................................................................. 140 94 Annex 1: Impacts of low-frequency noise on fishes ................................................................ 141 95 Annex 2: Impacts of low-frequency noise on marine invertebrates ........................................ 143 96 97 98 99 3 100 EXECUTIVE SUMMARY 101 Introduction and Background 102 Anthropogenic noise in the marine environment has increased markedly over the last 100 or so 103 years as anthropogenic use of the oceans has grown and diversified. Technological advances in 104 vessel propulsion and design, the development of marine industry and the increasing and more diverse 105 human use of the marine environment have all resulted in a noisier underwater realm. Long-term 106 measurements of ocean ambient sound indicate that low frequency anthropogenic noise has increased, 107 which has been primarily attributed to commercial shipping. As well as an increase in commercial 108 shipping, the last half century has also seen an expansion of industrial activities in the marine 109 environment, including oil and gas exploration and production, commercial fishing, and more recently, 110 the development of marine renewable energy. An increase in the number of small motorised vessels in 111 coastal areas has also been reported, where they can dominate some coastal acoustic environments such 112 as partially enclosed bays, harbours and estuaries. 113 114 Anthropogenic noise has gained recognition as a major global pollutant and an important stressor 115 for marine life and acknowledged as an issue that needs to be addressed. The impacts of sound on 116 marine mammals have received particular attention, especially impacts from military use of active 117 sonar, and industrial seismic surveys that coincide with cetacean mass stranding events. Extensive 118 investigation mainly over the last decade by academia, industry, government agencies and international 119 bodies has resulted in a number of reviews of the effects of sound on marine fauna. The issue of 120 underwater noise and its effects on marine biodiversity has received increasing attention at the 121 international level, with recognition by a number of international and regional bodies and organisations. 122 123 Sound is a mechanical disturbance that travels through an elastic medium (e.g., air, water or solids). 124 Water is an excellent medium for