Biological Opinion for Polar Bears (Ursus maritimus) and Conference Opinion for Pacific Walrus (Odobenus rosmarus divergens) on the Chukchi Sea Incidental Take Regulations Prepared by: U.S. Fish and Wildlife Service Fairbanks Fish and Wildlife Field Office 110 12th Ave, Room 110 Fairbanks, Alaska 99701 May 20, 2013 1 Table of Contents Introduction ................................................................................................................................5 Background on Section 101(a)(5) of MMPA ...........................................................................6 The AOGA Petition .................................................................................................................6 History of Chukchi Sea ITRS ..............................................................................................7 Relationship of ESA to MMPA ...........................................................................................7 MMPA Terms: ........................................................................................................................7 ESA Terms: ............................................................................................................................8 The Proposed Action ...................................................................................................................8 Information Required to Obtain a Letter of Authorization .......................................................9 Specific Measures of LOAs ................................................................................................... 10 Types of Industry Activities that may Receive LOAs ............................................................ 11 Offshore Activities ............................................................................................................ 12 Exploratory Drilling ...................................................................................................... 12 Seismic Operations ........................................................................................................ 12 Shallow Hazard Surveys ................................................................................................ 12 Marine Geophysical Surveys ......................................................................................... 12 Geotechnical Surveys .................................................................................................... 12 Offshore Environmental Studies .................................................................................... 12 Onshore Activities ............................................................................................................. 13 Exploratory Activities .................................................................................................... 13 Onshore Environmental Studies ..................................................................................... 13 The Action Area ........................................................................................................................ 13 Status of the Species.................................................................................................................. 13 Climate Change ..................................................................................................................... 13 Polar Bears ............................................................................................................................ 15 Status and Distribution ...................................................................................................... 15 Life History ....................................................................................................................... 16 Range-wide Threats, Stressors, and Uncertainties .............................................................. 17 Summary ........................................................................................................................... 18 Pacific Walruses .................................................................................................................... 18 Abundance and Distribution .............................................................................................. 18 Foraging Behavior and Diet ............................................................................................... 19 Walrus Communication/Hearing ....................................................................................... 20 2 Range-Wide Threats, Stressors, and Uncertainties ............................................................. 20 Use of Coastal Haulouts in Summer .............................................................................. 21 Reduced Availability of Benthic Prey ............................................................................ 21 Subsistence Harvest ....................................................................................................... 23 Other Influences ................................................................................................................ 25 Walrus Research ............................................................................................................ 25 Disease .......................................................................................................................... 25 Pollution and Contaminants ........................................................................................... 26 Other Activities ............................................................................................................. 26 Summary ........................................................................................................................... 26 Environmental Baseline ............................................................................................................ 26 Polar Bears ............................................................................................................................ 27 Alaska-Chukotka Stock ..................................................................................................... 29 Southern Beaufort Sea Stock ............................................................................................. 29 Threats and Possible Stressors in the Action Area .............................................................. 30 Loss of Sea Ice .............................................................................................................. 30 Subsistence Harvest ....................................................................................................... 30 Oil and Gas Activities .................................................................................................... 31 Polar Bear Research....................................................................................................... 31 Other Activities ............................................................................................................. 32 Environmental Contaminants ......................................................................................... 32 Pacific Walruses .................................................................................................................... 32 Loss of Sea Ice .................................................................................................................. 34 Subsistence Harvest ........................................................................................................... 35 Oil and Gas Activities ....................................................................................................... 35 Noise ................................................................................................................................. 37 Effects of the Proposed Action .................................................................................................. 38 Direct and Indirect Effects on Polar Bears and Pacific Walruses ............................................ 38 Interdependent and Interrelated Actions on Polar Bears and Pacific Walruses ....................... 38 Effects of Interdependent and Interrelated Actions on Polar Bears ......................................... 39 Expected Frequency of Encounters .................................................................................... 39 Disturbance Effects on Polar Bears .................................................................................... 40 Disturbance from Land/Water Operations ...................................................................... 40 Disturbance from Aircraft .............................................................................................. 40 3 Noise from Seismic Surveys .......................................................................................... 41 Mitigation Measures .......................................................................................................... 41 Oil Spills ........................................................................................................................... 42 Deterrence Activities and Intentional Take Authorizations ................................................ 42 Conclusion ........................................................................................................................ 44 Effects of Interdependent and Interrelated Actions on Pacific Walruses ................................. 44 Expected Frequency