Lipids in Aquatic Ecosystems (eBook)

Michael T. Arts is a research scientist with Environment Canada at the National Water Research Institute in Burlington, Ontario, Canada. Michael T. Brett is a professor in the Department of Civil and Environmental Engineering at the University of Washington in Seattle. Martin J. Kainz is a research scientist at the WasserCluster - Biologische Station Lunz; an inter-university center dedicated to freshwater sciences research and education, in Lunz am See, Austria.    

Foreword 5
Contents 8
Contributors 10
Lipids in Aquatic Ecosystems 14
Introduction 14
References 19
Algal Lipids and Effect of the Environment on their Biochemistry 20
1.1 Introduction 20
1.2 Lipid Composition of Algae 21
1.3 Effects of the Environment on Algal Lipid Biochemistry 30
1.4 Nutrients and Nutrient Regimes 35
1.5 Conclusions 39
References 39
Formation and Transfer of Fatty Acids in Aquatic Microbial Food Webs: Role of Heterotrophic Protists 44
2.1 Introduction 44
2.2 Biosynthesis Pathways of Polyunsaturated Fatty Acids in Heterotrophic Protists 48
2.3 Variability of Heterotrophic Protist Lipid Composition 52
2.4 Conclusion 55
References 56
Ecological Significance of Sterols in Aquatic Food Webs 62
3.1 Introduction 62
3.2 Occurrence of Sterols 62
3.3 Biosynthesis of Sterols 65
3.4 Physiological Properties of Sterols 65
3.5 Nutritional Requirements 66
3.6 Ecological Implications: Competition and Succession in Zooplankton 71
3.7 Sterols and Carbon Transfer in Aquatic Food Webs 73
3.8 Sterol Mediated Trophic Upgrading 75
3.9 Sterols from Aquatic Sources and Their Potential Role in Human Nutrition 75
3.10 Perspectives 76
3.11 Conclusions 78
References 79
Fatty Acids and Oxylipins as Semiochemicals 84
4.1 Introduction 84
4.2 FA and FA Esters as Toxins, Allelopathic Metabolites, and Food Web Effectors 86
4.3 Oxylipins in Aquatic Chemical Ecology 90
4.4 Grazer Counter-Defense: Behavioral Avoidance, Adaptive Strategies, and Detoxification 100
4.5 Algal Producers 101
4.6 Other FA-Related Semiochemicals 102
4.7 Summary and Conclusions 103
References 104
Integrating Lipids and Contaminants in Aquatic Ecology and Ecotoxicology 112
5.1 Introduction 112
5.2 Trophic Transfer of Contaminants in Aquatic Food Webs 115
5.3 Trophic Transfer of Lipids 122
5.4 Concurrent Flow of Lipids and Contaminants 123
5.5 Conclusions 126
References 127
Crustacean Zooplankton Fatty Acid Composition 134
6.1 Introduction 134
6.2 Zooplankton Taxonomic Differences in Fatty Acid Composition 137
6.3 Phytoplankton Fatty Acid Composition as Food for Zooplankton 141
6.4 Dietary Impacts on Zooplankton Fatty Acid Composition 145
6.5 Homeostatic Fatty Acid Composition Responses 153
6.6 Fatty Acid Turnover Times in Freshwater and Marine Zooplankton 155
6.7 Zooplankton Reproductive Investment in Fatty Acids 156
6.8 Temperature Impacts on Zooplankton Fatty Acids: The Homeoviscous Response 158
6.9 Starvation Impacts on Zooplankton Fatty Acids 159
6.10 Unanswered Questions 159
6.11 Conclusions 161
References 161
Fatty Acid Ratios in Freshwater Fish, Zooplankton and Zoobenthos – Are There Specific Optima? 166
7.1 Introduction 166
7.2 Methods 169
7.3 n-3/n-6 and DHA/ARA Ratios in Freshwater Metazoans 169
7.4 Concluding Remarks 182
References 183
Preliminary Estimates of the Export of Omega- 3 Highly Unsaturated Fatty Acids ( EPA + DHA) from Aquatic to Terrestrial Ecosystems 198
8.1 Introduction 198
8.2 HUFA in Aquatic and Terrestrial Ecosystems 199
8.3 Required Measurements 204
8.4 HUFA Content of Aquatic Organisms 205
8.5 Case Study I: Estimating the Export of Aquatic HUFA to Terrestrial Predators ( Bears) in the Pacific Rim 209
8.6 Case Study II: Humans and Fisheries 211
8.7 Case Study III: Estimation of the Export of HUFA Through Aquatic Insect Emergence 212
8.8 Case Study IV: Estimation of Aquatic HUFA Import to Terrestrial Ecosystems Through Birds 214
8.9 Case Study V: Can HUFA Export from Aquatic Ecosystems Meet the HUFA Requirements of Terrestrial Animals? 216
8.10 Ocean Contribution 218
8.11 Assumptions and Underestimates 220
8.12 Conclusions and Perspectives 220
References 222
Biosynthesis of Polyunsaturated Fatty Acids in Aquatic Ecosystems: General Pathways and New Directions 230
9.1 Introduction 230
9.2 Primary Production of Polyunsaturated Fatty Acids 231
9.3 Polyunsaturated Fatty Acid Metabolism in Invertebrates 238
9.4 Production of Highly Unsaturated Fatty Acids in Fish 239
9.5 Concluding Remarks 249
References 251
Health and Condition in Fish: The Influence of Lipids on Membrane Competency and Immune Response 256
10.1 The Influence of Lipids on Health and Condition 256
10.2 The Influence of Lipids on Membrane Fluidity and Other Membrane Properties 256
10.3 Modulatory Effects of Dietary Fatty Acids on Teleost Immune Response 264
10.4 Future Directions 269
References 270
Lipids in Marine Copepods: Latitudinal Characteristics and Perspective to Global Warming 276
11.1 Introduction 276
11.2 Lipid Patterns of Copepods from Different Latitudinal Regions 278
11.3 Essential Fatty Acids and Phospholipid Structure 289
11.4 Impact of Global Warming on Lipid Dynamics 292
11.5 Conclusions and Perspectives 294
References 295
Tracing Aquatic Food Webs Using Fatty Acids: From Qualitative Indicators to Quantitative Determination 300
12.1 Introduction 300
12.2 Characteristics and Constraints on Lipid Biosynthesis, Digestion, and Deposition as They Relate to Tracing Trophic Relationships 302
12.3 Tracing Trophic Pathways Using Lipids and Fatty Acids 306
12.4 Summary, Conclusions, and the Future 320
References 323
Essential Fatty Acids in Aquatic Food Webs 328
13.1 Introduction 328
13.2 Definition of Essential Fatty Acids 329
13.3 Effects of Essential Fatty Acids 331
13.4 Mechanisms of the Effects of Dietary Essential Fatty Acids 333
13.5 Are N-6 PUFA Essential Fatty Acids in Aquatic Food Webs? 337
13.6 Ratios and Groups of Essential Fatty Acids in Food Webs 338
13.7 Conclusions 340
References 340
Human Life: Caught in the Food Web 346
14.1 Life in the web 346
14.2 Evidence of Impaired Neural Development 353
14.3 Evidence of Impaired Cardiovascular Development 357
14.4 Which DNA-Coded Proteins Discriminate N- 3 and N- 6 Structures? 359
14.5 Making a Better Future 366
References 367
Name Index 374
Subject Index 385