Whale Sharks: Biology, Ecology, and Conservation

Cover
Half Title
Series Page
Title Page
Copyright Page
Table of Contents
Preface
Acknowledgments
Editors
Contributors
Chapter 1 How and Why Is the Whale Shark the World’s Largest Fish?
1.1 Introduction
1.2 The Whale Shark Body Plan
1.3 Just How Big Is the Whale Shark?
1.4 How Big Is the Whale Shark Relative to Other Large Marine Animals?
1.5 Why Is the Whale Shark So Large?
1.6 Why Isn’t the Whale Shark Larger?
1.7 Can Size Save the Whale Shark?
1.8 Conclusions
Acknowledgments
References
Chapter 2 Whale Shark Reproduction, Growth, and Demography
2.1 Introduction
2.2 Reproductive Mode and Embryonic Development
2.3 Reproductive Anatomy in the Whale Shark
2.3.1 Female Reproductive Anatomy and Maturity
2.3.2 Male Reproductive Anatomy and Maturity
2.4 Reproductive Cycle, Seasonality, and Behavior
2.4.1 Female Reproductive Cycle and Seasonality
2.4.2 Male Reproductive Cycle and Seasonality
2.5 Size at Birth and Early Growth
2.6 Estimating Age and Growth
2.6.1 Vertebral Aging
2.6.2 Field-Based Growth Estimates
2.7 Body Condition and Health Assessment
2.8 Population Productivity
2.8.1 Estimating Productivity
2.8.1.1 Annual Reproductive Output
2.8.1.2 Age at First Reproduction
2.8.1.3 Survivorship
2.8.2 Productivity Results
2.9 Conclusions
Acknowledgments
References
Chapter 3 Whale Shark Sensory Biology and Neuroanatomy
Introduction
3.2 Sensory Systems
3.2.1 Introduction
3.2.2 Hearing
3.2.3 Chemoreception
3.2.3.1 Olfaction (smell)
3.2.3.2 Gustation (taste)
3.2.4 Vision
3.2.5 Mechanoreception (touch)
3.2.6 Electroreception
3.3 The Brain and Its Implications for Behavior
3.3.1 Introduction
3.3.2 Anatomy
3.3.3 Neuroecology: Understanding the Neurological Basis of Behavior
3.3.3.1 Encephalization
3.3.3.2 Brain Organization
3.3.3.3 Ontogenetic Shifts: Does Brain Organization Change with Growth?
3.4 Summary and Future Directions
Acknowledgments
References
Chapter 4 Parasites and Other Associates of Whale Sharks
4.1 Introduction
4.2 Microbial Symbionts
4.2.1 Viruses
4.2.2 Bacteria
4.2.3 Fungi
4.2.4 Protistan parasites
4.3 Metazoan Parasites
4.3.1 Copepoda
4.3.1.1 Pandarus rhincodonicus Norman, Newbound and Knott, 2000
4.3.1.2 Prosaetes rhinodontis (Wright, 1876)
4.3.1.3 Lepeophtheirus acutus Heegaard, 1943
4.3.2 Isopoda
4.3.2.1 Gnathia trimaculata Coetzee, Smit, Grutter and Davies, 2009
4.3.3 Platyhelminthes
4.3.3.1 Wenyonia rhincodonti Malhotra, Jaiswal, Singh, Capoor and Malhotra, 2011
4.3.3.2 Paronatrema boholana Eduardo, 2010
4.3.4 Hirudinea
4.4 Associates
4.4.1 Surfers and Drafters
4.4.2 Scratchers
4.4.3 Suckers
4.4.4 Shelterers
4.4.5 It’s Complicated
4.5 Conclusions
Acknowledgments
References
Chapter 5 Genetic Population Structure of Whale Sharks
5.1 What Is a Population?
5.1.1 Why Population Structure Matters
5.1.2 Determining Population Structure
5.1.2.1 Field Studies of Populations
5.1.2.2 Biochemical and Genetic Analysis of Populations
5.1.2.3 Using Genetics to Study Wild Populations
5.1.2.4 Genetic Analysis of Whale Shark Populations
5.2 Genetic Markers for Population Analysis
5.2.1 Genetic Diversity and Differentiation
5.2.2 Mitochondrial DNA Analysis
5.2.3 Microsatellite Analysis
5.2.4 Visual Representations of Population Data
5.3 Population Analysis of Whale Sharks
5.3.1 Field Studies of Whale Shark Populations
5.3.2 Mitochondrial DNA Analysis of Whale Shark Populations
5.3.3 Microsatellite Analysis of Whale Shark Populations
5.3.4 Emerging Genetic Technologies
5.4 Conclusions from Whale Shark Genetic Analyses
5.5 Integrating Field and Genetic Studies of Population Structure
5.6 Genomic Analysis in Whale Sharks
5.7 Future Challenges in Whale Shark Population Analysis
Acknowledgments
Glossary
References
Chapter 6 Whale Shark Movements and Migrations
6.1 Introduction
6.2 Tracking Animals in the Ocean
6.3 Vertical Movements of Whale Sharks
6.4 Horizontal Movements of Whale Sharks
6.4.1 Case Study: Ningaloo Reef
6.4.2 Case Study: Galapagos
6.5 Climate Change
6.6 Future Perspectives
Acknowledgments
References
Chapter 7 Population Ecology of Whale Sharks
7.1 Introduction
7.2 Identifying Individual Sharks
7.2.1 Photographic Identification
7.2.2 Citizen Science
7.2.3 Data Mining with Artificial Intelligence
7.3 Population Ecology
7.3.1 Constellations
7.3.2 Segregated Populations
7.3.3 Size Segregation
7.3.4 Sexual Segregation
7.3.5 Transit vs Feeding Areas
7.4 Life Cycle Hypothesis
7.4.1 “The Lost Years”
7.4.2 The Hungry Years
7.4.3 Open Water
7.5 Summary
References
Chapter 8 Whale Shark Foraging, Feeding, and Diet
8.1 Introduction
8.2 Foraging Strategies
8.2.1 Returning to Predictable Feeding Hotspots
8.2.2 Large-Scale Movements away from Feeding Hotspots
8.3 Senses Involved in Foraging and Feeding
8.4 Feeding Mechanics
8.5 Feeding Behaviors
8.5.1 Passive Feeding
8.5.2 Active Feeding
8.5.3 Stationary Feeding
8.5.4 Other Feeding Behaviors
8.6 Whale Shark Prey Species
8.6.1 Methods of Identifying Prey
8.6.2 Identified Prey Items
8.6.3 Size and Biomass
8.7 Potential Prey
8.7.1 Methods for Indirect Diet Analyses
8.7.2 Potential Prey Items
8.7.3 Caveats of Diet Reconstruction from Whale Shark Tissue Samples
8.8 Ecological Role of Whale Sharks
8.9 Summary
References
Chapter 9 Lessons from Care of Whale Sharks in Public Aquariums
9.1 Introduction
9.2 A Brief History of Whale Sharks in Public Aquariums
9.3 Habitat Design
9.4 Acquisition/Disposition Techniques
9.5 Behavior and Its Management
9.6 Veterinary Care
9.7 Diet, Feeding, and Nutrition
9.8 Growth and Reproduction
9.9 Conclusions
Acknowledgments
References
Chapter 10 Whale Shark Tourism as an Incentive-Based Conservation Approach
10.1 Introduction
10.2 Global Assessment of Whale Shark Tourism
10.2.1 Wild Sites
10.2.2 Provisioned Sites
10.2.3 Seapen Tourism
10.2.4 Aquarium Tourism
10.3 Economic Valuation of Whale Shark Tourism
10.4 Whale Sharks and Ecotourism
10.4.1 Impacts of Tourism on Whale Sharks
10.4.2 Community Involvement
10.4.3 Building Environmental Awareness
10.4.4 Tourist Satisfaction
10.4.5 Is Whale Shark Tourism Ecotourism?
10.5 Management Challenges
10.6 Management Best Practices
10.6.1 Managing Impacts
10.6.2 Best Practices for Whale Shark Tourism
10.7 Conclusion
References
Chapter 11 Global Threats to Whale Sharks
11.1 Introduction
11.2 Why Are Whale Sharks in Danger?
11.3 Fisheries
11.3.1 Historical Catches
11.3.2 Commercial Fishing and International Trade
11.3.3 Bycatch in Tuna Fisheries
11.3.4 Bycatch in Coastal Net Fisheries
11.3.5 Can Whale Sharks be Fished Sustainably?
11.4 Boat Strikes
11.5 Tourism Interactions
11.5.1 Behavioral Change and Physical Impacts
11.5.2 Artificial Provisioning and Artisanal Captivity
11.6 Marine Pollution
11.7 Climate Change
11.8 Threat Classification
11.8.1 Energy Production and Mining
11.8.2 Transportation and Service Corridors
11.8.3 Biological Resource Use
11.8.4 Human Intrusions and Disturbance
11.8.5 Pollution
11.8.6 Climate Change and Severe Weather
11.8.7 Prioritization of Ongoing Threats
11.9 Conclusions
References
Chapter 12 Conservation of Whale Sharks
12.1 Introduction
12.1.1 A History of Concern
12.1.2 Contemporary Threats
12.1.3 The IUCN Red List of Threatened Species
12.2 International Legal and Management Frameworks
12.2.1 United Nations Convention on the Law of the Sea
12.2.2 Convention on the Conservation of Migratory Species of Wild Animals
12.2.3 Convention on International Trade in Endangered Species of Wild Fauna and Flora
12.2.4 Convention on Biological Diversity
12.2.5 FAO International Plan of Action for the Conservation and Management of Sharks
12.2.6 Regional Fisheries Management Organizations
12.3 National Legal Protections
12.3.1 Species Protection
12.3.2 Marine Protected Areas
12.4 Whale Sharks as Conservation Icons
12.4.1 Flagship Species
12.4.2 Umbrella Species
12.4.3 Key Biodiversity Areas
12.5 The Road to Recovery
12.5.1 The IUCN Green Status of Species
12.5.2 Building a Green Status Assessment
12.5.2.1 Whale Shark Distribution and Spatial Units
12.5.2.2 Contemporary Regional Red List Assessments
12.5.2.3 Western Indian Ocean
12.5.2.4 Southeast Asia
12.5.2.5 Eastern Pacific Ocean
12.5.2.6 Ecological Functionality
12.5.3 Species Recovery Score Calculation
12.5.4 Conservation Impact Metrics
12.5.4.1 Conservation Legacy
12.5.4.2 Conservation Dependence
12.5.4.3 Conservation Gain
12.5.4.4 Recovery Potential
12.6 Conservation Planning
12.6.1 Preparing a Conservation Plan
12.6.1.1 Threat Identification and Prioritization
12.6.2 Implementing the Plan
12.7 Looking Forward
12.7.1 Closing the Gaps in Existing Protections
12.7.2 ‘Big Data’ for Habitat-Based Conservation
12.7.3 Planning for Action
12.8 Conclusions
References
Chapter 13 Outstanding Questions in Whale Shark Research and Conservation
13.1 Introduction
13.2 What Is the Genomic Basis of Gigantism in Whale Sharks, and How Does That Relate to Planktivory and Endothermy?
13.3 How Often Do Whale Sharks Breed?
13.4 How Does the Whale Shark Sense Its Environment and How Are These Signals Processed in the Brain?
13.5 What Is the Nature of the Relationships of Different Species of Microbes, Parasites, and Fishes That Associate with Whale Sharks?
13.6 How Can We Apply Genetic and Genomic Methods to Definitively Identify Population Structure at a Global Scale?
13.7 How Can We Obtain Longer and More Detailed Movement Tracks?
13.8 What Drives Sexual Segregation in Constellations?
13.9 What Do Neonates, Adults, Females, and Transient Whale Sharks Feed on?
13.10 How Can We Take Advantage of Whale Sharks in Aquariums to Fill Knowledge Gaps?
13.11 How Can We Ensure That Whale Shark Tourism Develops Sustainably?
13.12 How Problematic Is Plastic Pollution for Whale Sharks?
13.13 How Can the Whale Shark’s Recovery Potential Be Improved?
13.14 Are Whale Sharks Still a Mysterious Species?
References
Index