Photosynthesis in the Marine Environment

About the authors ix

Preface xi

About the companion website xiii

Part I Plants and the Oceans 1

Introduction 1

Chapter 1 The evolution of photosynthetic organisms in the oceans 5

Chapter 2 The different groups of marine plants 15

2.1 Cyanobacteria 16

2.2 Eukaryotic microalgae 17

2.3 Photosymbionts 23

2.4 Macroalgae 27

2.5 Seagrasses 34

Chapter 3 Seawater as a medium for photosynthesis and plant growth 39

3.1 Light 40

3.2 Inorganic carbon 45

3.3 Other abiotic factors 52

Summary notes of Part I 55

Part II Mechanisms of Photosynthesis, and Carbon Acquisition in Marine Plants 57

Introduction to Part II 57

Chapter 4 Harvesting of light in marine plants: The photosynthetic pigments 61

4.1 Chlorophylls 61

4.2 Carotenoids 63

4.3 Phycobilins 64

Chapter 5 Light reactions 67

5.1 Photochemistry: excitation, de-excitation, energy transfer and primary electron transfer 67

5.2 Electron transport 74

5.3 ATP formation 76

5.4 Alternative pathways of electron flow 77

Chapter 6 Photosynthetic CO2-fixation and -reduction 81

6.1 The Calvin cycle 81

6.2 CO2-concentrating mechanisms 89

Chapter 7 Acquisition of carbon in marine plants 95

7.1 Cyanobacteria and microalgae 96

7.2 Photosymbionts 101

7.3 Macroalgae 104

7.4 Seagrasses 118

7.5 Calcification and photosynthesis 122

Summary notes of Part II 124

Part III Quantitative Measurements, and Ecological Aspects, of Marine Photosynthesis 127

Introduction to Part III 127

Chapter 8 Quantitative measurements 129

8.1 Gas exchange 131

8.2 How to measure gas exchange 133

8.3 Pulse amplitude modulated (PAM) fluorometry 137

8.4 How to measure PAM fluorescence 142

8.5 What method to use: Strengths and limitations 146

Chapter 9 Photosynthetic responses, acclimations and adaptations to light 157

9.1 Responses of high- and low-light plants to irradiance 157

9.2 Light responses of cyanobacteria and microalgae 163

9.3 Light effects on photosymbionts 164

9.4 Adaptations of carbon acquisition mechanisms to light 169

9.5 Acclimations of seagrasses to high and low irradiances 169

Chapter 10 Photosynthetic acclimations and adaptations to stress in the intertidal 175

10.1 Adaptations of macrophytes to desiccation 175

10.2 Other stresses in the intertidal 181

Chapter 11 How some marine plants modify the environment for other organisms 183

11.1 Epiphytes and other 'thieves' 183

11.2 Ulva can generate its own empires 185

11.3 Seagrasses can alter environments for macroalgae and vice versa 187

11.4 Cyanobacteria and eukaryotic microalgae 189

Chapter 12 Future perspectives on marine photosynthesis 191

12.1 'Harvesting' marine plant photosynthesis 191

12.2 Predictions for the future 192

12.3 Scaling of photosynthesis towards community and ecosystem production 194

Summary notes of Part III 197

References 199

Index 203