Report of the Western Gray Whales Rangewide Workshop Western Gray Whales: Status, Threats And The Potential For Recovery 21 - 24 September 2008, Tokyo, Japan International Union for Conservation of Nature May 2009 Citation: IUCN. Western Gray Whales: Status, Threats And The Potential For Recovery. Report of the Western Gray Whales Rangewide Workshop, Tokyo, September 2008. Unpublished report, 45 pp. REPORT OF THE WESTERN GRAY WHALE RANGEWIDE WORKSHOP Page 2 CONTENTS 1. WELCOME AND OPENING REMARKS ................................................................................................................ 5 1.1 WELCOME, INTRODUCTION OF PARTICIPANTS ........................................................................................................... 5 1.3 ADOPTION OF AGENDA .............................................................................................................................................. 5 1.4 DOCUMENTS AVAILABLE .......................................................................................................................................... 5 1.5 DEVELOPMENT OF AN EFFECTIVE CONSERVATION PLAN FOR WESTERN GRAY WHALES ............................................. 5 2. POPULATION BIOLOGY .......................................................................................................................................... 6 2.1 POPULATION STRUCTURE .......................................................................................................................................... 6 2.1.1Differences between eastern and western populations .................................................................................... 6 2.1.2 Structure within the western population ......................................................................................................... 6 2.2 POPULATION BIOLOGY .............................................................................................................................................. 7 2.3 PHENOLOGY AND DISTRIBUTION ............................................................................................................................... 7 2.4 FEEDING ECOLOGY .................................................................................................................................................. 11 2.5 CAUSES OF NATURAL MORTALITY........................................................................................................................... 12 2.6 POPULATION STATUS IN 2007.................................................................................................................................. 13 2.7 HEALTH ASSESSMENT OF POPULATION .................................................................................................................... 13 2.8 HEALTH ASSESSMENT OF INDIVIDUALS TAKEN AS BYCATCH................................................................................... 13 2.9 ABUNDANCE, TRENDS AND POPULATION MODELLING ............................................................................................. 14 2.9.1. Research programmes and data ................................................................................................................... 14 2.9.2. Population assessments ................................................................................................................................ 14 2.9.3. Forward projections: prospects for recovery .............................................................................................. 14 2.9.4. Uncertainties in the population assessment ................................................................................................. 15 2.9.5. Use of additional data .................................................................................................................................. 15 2.9.6. Conclusions and recommendations .............................................................................................................. 15 2.10 INFORMATION FROM 2008 FIELD SEASON .............................................................................................................. 15 2.11 INFORMATION NEEDS AND METHODS TO ADDRESS THESE ..................................................................................... 16 2.11.1 Satellite tagging .......................................................................................................................................... 16 3. IDENTIFICATION AND QUANTIFICATION OF ACTUAL AND POTENTIAL THREATS TO THE POPULATION ................................................................................................................................................. 18 3.1 MORTALITY AS A DIRECT RESULT OF HUMAN ACTIVITY .......................................................................................... 18 3.1.1 Entanglement or entrapment in fishing gear ................................................................................................. 18 3.1.2 Vessel strikes ................................................................................................................................................. 22 3.1.3 Deliberate killing .......................................................................................................................................... 23 3.2 DISEASE, HARMFUL ALGAL BLOOMS, ICE ENTRAPMENT .......................................................................................... 23 3.3 INFORMATION NEEDS AND METHODS TO ADDRESS THESE ....................................................................................... 23 3.4 HUMAN ACTIVITIES THAT INDIRECTLY AFFECT THE ABILITY OF THE POPULATION TO RECOVER (HABITAT DEGRADATION) ................................................................................................................................................ 24 3.4.1 Noise and other related disturbances............................................................................................................ 24 3.4.2 Chemical contamination including oil .......................................................................................................... 25 3.4.3 Reduction of prey availability ....................................................................................................................... 26 3.5 CHANGING ENVIRONMENTAL CONDITIONS RELATED TO CLIMATE CHANGE AND OTHER PROCESSES ....................... 27 3.6 OTHER INDIRECT HUMAN EFFECTS .......................................................................................................................... 28 3.7 SYNERGISTIC EFFECTS ............................................................................................................................................ 28 3.8 INFORMATION NEEDS AND METHODS TO ADDRESS THESE ....................................................................................... 28 4. THREAT ELIMINATION AND MITIGATION .................................................................................................... 29 4.1 PRIORITISATION OF ACTUAL AND POTENTIAL THREATS IDENTIFIED UNDER ITEM 3 ................................................. 29 4.2 POTENTIAL AND ACTUAL MITIGATION MEASURES (INCLUDING RESEARCH NEEDS) ................................................. 30 4.2.1 Fishing-related mortality and disturbance.................................................................................................... 30 4.2.2 Vessel-related mortality and disturbance...................................................................................................... 32 4.2.3 Chemical-related effects, including oil ......................................................................................................... 32 4.2.4 General approaches (e.g. MPAs) .................................................................................................................. 32 4.3 MONITORING OF EFFECTIVENESS OF MITIGATION MEASURES (INCLUDING CONSIDERATION OF ENFORCEMENT ISSUES) ............................................................................................................................................................ 32 5. STRUCTURE AND COMPONENTS OF A CONSERVATION PLAN FOR WESTERN GRAY WHALES .. 32 6. CONCLUSIONS AND RECOMMENDATIONS .................................................................................................... 33 6.1 STATUS AND MONITORING ...................................................................................................................................... 33 6.2THREATS AND IMPROVED MITIGATION ..................................................................................................................... 33 REPORT OF THE WESTERN GRAY WHALE RANGEWIDE WORKSHOP Page 3 6.2.1 Essential scientific knowledge for mitigation ................................................................................................ 33 6.3 ENTRAPMENT AND MORTALITY............................................................................................................................... 34 6.3.1 Release of entangled whales ......................................................................................................................... 34 6.3.2 Necropsy data ............................................................................................................................................... 35 6.4 IMPROVED INFORMATION FROM OUTSIDE THE KNOWN FEEDING GROUNDS ............................................................. 35 7.