Appendix B-4: NMFS Biological Opinion Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion for Construction of the Tongass Narrows Project (Gravina Access) NMFS Consultation Number: AKRO-2019-03432 Action Agencies: Alaska Department of Transportation and Public Facilities (ADOT&PF) on behalf of the Federal Highway Administration (FHA) National Marine Fisheries Service, Office of Protected Resources, Permits and Conservation Division (PR1) Affected Species and Determinations: Is Action Likely Is Action Likely Is Action to Adversely To Destroy or Likely To ESA-Listed Species Status Affect Species or Adversely Jeopardize Critical Modify Critical the Species? Habitat? Habitat? Humpback whale (Megaptera Threatened Yes No N/A novaeangliae) Mexico DPS Consultation Conducted By: National Marine Fisheries Service Issued By: James W. Balsiger, Ph.D. Administrator, Alaska Region Date: December 19, 2019 Ketchikan Tongass Narrows Project- Revised Biological Opinion ECO# AKRO-2019-03432 TABLE OF CONTENTS List of Tables .................................................................................................................................. 4 List of Figures ................................................................................................................................. 5 Terms and Abbreviations ................................................................................................................ 6 1. Introduction ............................................................................................................................. 8 1.1 Background ...................................................................................................................... 9 1.2 Consultation History ...................................................................................................... 10 2. Description of the Proposed Action and Action Area .......................................................... 11 2.1 Proposed Action ............................................................................................................. 11 2.1.1 Proposed activities: project components ................................................................. 11 2.1.2 Proposed activities: construction methods .............................................................. 21 2.1.3 Changes to proposed activities from February 2019 opinion ................................. 29 2.1.4 Description of sound propagation ........................................................................... 30 2.1.5 Acoustic sources - single activity ........................................................................... 31 2.1.6 Acoustic sources - simultaneous activities ............................................................. 33 2.1.7 Acoustic thresholds ................................................................................................. 40 2.1.8 Mitigation measures ................................................................................................ 47 2.2 Action Area .................................................................................................................... 67 3. Approach to the Assessment ................................................................................................. 70 4. Rangewide Status of the Species and Critical Habitat .......................................................... 72 4.1 Climate Change .............................................................................................................. 72 4.2 Status of Listed Species.................................................................................................. 73 4.2.1 Humpback whale (Megaptera novaeangliae) ......................................................... 74 5. Environmental Baseline ........................................................................................................ 80 5.1 Physical Environment .................................................................................................... 81 5.2 Fish and Essential Fish Habitat ...................................................................................... 81 5.3 Marine Vessel Activity................................................................................................... 82 5.4 Fishery Interactions Including Entanglements ............................................................... 84 5.5 Pollution ......................................................................................................................... 84 5.6 Climate and Ocean Regime Change............................................................................... 85 5.7 Coastal Zone Development ............................................................................................ 86 5.8 In-Water Noise ............................................................................................................... 86 5.9 Competition for Prey ...................................................................................................... 86 6. Effects of the Action ............................................................................................................. 87 2 Ketchikan Tongass Narrows Project- Revised Biological Opinion ECO# AKRO-2019-03432 6.1 Project Stressors ............................................................................................................. 87 6.2 Stressors Unlikely to Occur or Likely to Have Negligible Impacts on ESA-listed Species ...................................................................................................................................... 88 6.2.1 Injury or disturbance due to construction vessel traffic .......................................... 88 6.2.2 Disturbance to seafloor ........................................................................................... 89 6.2.3 Introduction of pollutants into waters ..................................................................... 90 6.2.4 Overwater shading and effects to prey.................................................................... 90 6.2.5 Loss of marine mammal habitat .............................................................................. 90 6.2.6 Indirect effects of increasing accessibility of Gravina Island ................................. 90 6.3 Stressors Likely to Adversely Affect ESA-listed Species ............................................. 91 6.4 Exposure Analysis .......................................................................................................... 91 6.4.1 Exposure to noise from pile driving activities ........................................................ 91 6.4.2 Exposure to vessel noise ......................................................................................... 94 6.5 Response Analysis.......................................................................................................... 95 6.5.1 Responses to major noise sources (pile driving/removal activities) ....................... 95 6.5.2 Probable responses to major noise sources (pile driving activities) ..................... 104 6.5.3 Responses to vessel traffic and noise .................................................................... 105 6.5.4 Probable responses to vessel traffic and noise ...................................................... 108 7. Cumulative Effects.............................................................................................................. 108 8. Integration and Synthesis .................................................................................................... 109 8.1 Mexico DPS Humpback Whale Risk Analysis ............................................................ 109 9. Conclusion .......................................................................................................................... 110 10. Incidental Take Statement................................................................................................ 111 10.1 Amount of Extent of Take ........................................................................................ 112 10.2 Effect of the Take ..................................................................................................... 113 10.3 Reasonable and Prudent Measures ........................................................................... 113 10.4 Terms and Conditions ............................................................................................... 113 11. Conservation Recommendations ..................................................................................... 115 12. Reinitiation of Consultation ............................................................................................. 115 13. Data Quality Act Documentation and Pre-dissemination Review ................................... 115 13.1 Utility ........................................................................................................................ 115 13.2 Integrity .................................................................................................................... 116 13.3 Objectivity ................................................................................................................ 116 14. References ........................................................................................................................ 117 3 Ketchikan Tongass Narrows Project- Revised Biological Opinion ECO# AKRO-2019-03432 LIST OF TABLES Table 1. Summary of Tongass Narrows Project phases