| | Request by Scripps Institution of Oceanography for an Incidental |
| | 1,01 | | MB | Harassment Authorization to Allow the Incidental Take of |
| | 115 | | stron | Marine Mammals during a Low-Energy Marine Seismic Survey |
| | on the Louisville Ridge in the Southwest Pacific Ocean, |
| | January–February 2006 |
| | 4961 | | ID | LGL Limited |
| | 2005 | | rok |
| | TABLE OF CONTENTS |
| | SUMMARY . vi |
| | I. OPERATIONS TO BE CONDUCTED . 1 |
| | Overview of the Activity 1 |
| | Vessel Specifications .1 |
| | Airgun Description.3 |
| | Description of Operations 6 |
| | Bathymetric Sonar and Sub-bottom Profiler.6 |
| | Bathymetric Sonar.6 |
| | Sub-bottom Profiler .7 |
| | II. DATES, DURATION, AND REGION OF ACTIVITY. 7 |
| | III. SPECIES AND NUMBERS OF MARINE MAMMALS IN AREA . 7 |
| | IV. STATUS, DISTRIBUTION AND SEASONAL DISTRIBUTION OF AFFECTED SPECIES OR |
| | STOCKS OF MARINE MAMMALS . 9 |
| | Pinnipeds .10 |
| | Odontocetes .11 |
| | Mysticetes 26 |
| | V. TYPE OF INCIDENTAL TAKE AUTHORIZATION REQUESTED.32 |
| | VI. NUMBERS OF MARINE MAMMALS THAT MAY BE TAKEN .32 |
| | VII. ANTICIPATED IMPACT ON SPECIES OR STOCKS .33 |
| | (a) Summary of Potential Effects of Airgun Sounds 33 |
| | Tolerance 33 |
| | Masking 34 |
| | Disturbance Reactions . 34 |
| | Hearing Impairment and Other Physical Effects 37 |
| | Strandings and Mortality 40 |
| | (b) Possible Effects of Bathymetric Sonar Signals41 |
| | Masking 41 |
| | Behavioral Responses 41 |
| | Hearing Impairment and Other Physical Effects 42 |
| | (c) Possible Effects of Sub-bottom Profiler Signals 42 |
| | Masking 43 |
| | Behavioral Responses 43 |
| | Hearing Impairment and Other Physical Effects 43 |
| | (d) Numbers of Marine Mammals that Might be “Taken by Harassment” 43 |
| | Basis for Estimating “Take by Harassment” for 2006 SW Pacific Ocean Study . 44 |
| | Potential Number of “Exposures” to ³160 and ³170 dB. 48 |
| | Number of Different Individuals That Might be Exposed to ³160 and ³170 dB . 51 |
| | Conclusions 51 |
| | VIII. ANTICIPATED IMPACT ON SUBSISTENCE .53 |
| | IX. ANTICIPATED IMPACT ON HABITAT.53 |
| | X. ANTICIPATED IMPACT OF LOSS OR MODIFICATION OF HABITAT ON MARINE MAMMALS .59 |
| | |
| | XI. MITIGATION MEASURES 59 |
| | Marine Mammal Monitoring 60 |
| | Proposed Safety Radii 60 |
| | Mitigation During Operations .61 |
| | XII. PLAN OF COOPERATION62 |
| | XIII. MONITORING AND REPORTING PLAN.62 |
| | Vessel-based Visual Monitoring 63 |
| | Reporting .64 |
| | XIV. COORDINATING RESEARCH TO REDUCE AND EVALUATE INCIDENTAL TAKE65 |
| | XV. LITERATURE CITED .65 |
| | Marine Mammals and Acoustics.65 |
| | Fish and Invertebrates .79 |
| | APPENDIX A: REVIEW OF POTENTIAL IMPACTS OF AIRGUN SUNDS ON MARINE MAMMALS |
| | .82 |
| | (a) Categories of Noise Effects.82 |
| | (b) Hearing Abilities of Marine Mammals .83 |
| | Toothed Whales 83 |
| | Baleen Whales 83 |
| | Pinnipeds 84 |
| | Sirenians . 84 |
| | (c) Characteristics of Airgun Pulses .85 |
| | (d) Masking Effects of Seismic Surveys86 |
| | (e) Disturbance by Seismic Surveys 87 |
| | Baleen Whales 88 |
| | Toothed Whales 91 |
| | Pinnipeds 93 |
| | (f) Hearing Impairment and Other Physical Effects.95 |
| | Temporary Threshold Shift (TTS) 96 |
| | Permanent Threshold Shift (PTS) . 99 |
| | (g) Strandings and Mortality .100 |
| | (h) Non-auditory Physiological Effects .101 |
| | Literature Cited102 |