Note: Intro -- Seaweed Biology -- Novel Insights into Ecophysiology, Ecology and Utilization -- Preface -- Contents -- Part I: Fundamental Processes and Acclimation to Abiotic Environmental Variables -- Chapter 1: Physiological and Photomorphogenic Effects of Light on Marine Macrophytes -- 1.1 Introduction -- 1.2 Photosynthesis Under Limiting Light Conditions -- 1.3 Photosynthesis Under Excessive Light Conditions -- 1.4 Effect of Ultraviolet Radiation on Zonation of Macroalgae -- 1.5 Light Absorption and Light Spectrum -- 1.6 Light as an Environmental Signal -- 1.7 Conclusive Remarks -- References -- Chapter 2: Morpho-functionality of Carbon Metabolism in Seaweeds -- 2.1 Introduction -- 2.2 Inorganic Carbon Acquisition -- 2.3 Photosynthetic Carbon Fixation -- 2.3.1 Calvin-Benson Cycle and RUBISCO -- 2.3.2 Rates of Carbon Fixation -- 2.3.3 Photorespiration -- 2.4 Light-Independent Carbon Fixation -- 2.5 Morpho-functional Aspects of Carbon Metabolism -- 2.5.1 The Role of Storage Carbohydrates -- 2.5.2 Thallus Anatomy and Long-Distance Transport of Photoassimilates -- 2.5.3 Patterns of Carbon Allocation -- 2.5.4 Concluding Remarks -- References -- Chapter 3: Seaweed Responses to Temperature -- 3.1 Introduction -- 3.2 Local Temperature Adaptation of Growth and Photosynthesis -- 3.3 Phenotypic Temperature Acclimation of Growth and Photosynthesis -- 3.4 Disruptive Temperature Stress and Thermal Tolerance -- 3.5 Temperature Control of Biogeographical Distribution Boundaries -- 3.6 Conclusion -- References -- Chapter 4: Environment and Algal Nutrition -- 4.1 Introduction -- 4.2 Meeting Nutritional Needs -- 4.2.1 Extracting Nutrients from their Environment -- 4.2.2 Neutral vs. Ionic Nutrients -- 4.2.3 N vs. P Limitation -- 4.2.4 Considering C as Just Another Nutrient -- 4.3 Uncoupling Uptake and Incorporation -- 4.4 Different Ways of N Utilization. , 4.4.1 Seaweed Diversity Linked to Nutrient Source -- 4.4.2 Slow-Growing vs. Fast-Growing Species -- 4.5 Use of Isotope Discrimination -- 4.6 Aquaculture -- 4.6.1 Nutrient Uptake at High Concentrations -- 4.7 Conclusions -- References -- Chapter 5: Seaweed Acclimation to Salinity and Desiccation Stress -- 5.1 Variability of Salinity in Seaweed Habitats -- 5.2 Effects of Salinity Stress and Desiccation on the Physiology of Seaweeds -- 5.2.1 Rate of Survival -- 5.2.2 Growth -- 5.2.3 Photosynthesis and Respiration -- 5.3 Processes of Osmotic Acclimation -- 5.3.1 Inorganic Ions -- 5.3.2 Organic Osmolytes -- 5.3.3 Biosynthesis of Organic Osmolytes -- 5.3.4 Antioxidants -- 5.3.5 Ultrastructural Changes -- 5.3.6 Self Protection -- 5.4 Salinity Ecotypes -- 5.5 Outlook -- References -- Chapter 6: Seaweed Responses to Environmental Stress: Reactive Oxygen and Antioxidative Strategies -- 6.1 Introduction -- 6.2 Stress-Induced ROS Production and Its Effects on Seaweed Performance -- 6.2.1 Seaweed Exposure to Heavy Metal Stress and Reactive Oxygen Metabolism -- 6.2.2 A Peculiar Antioxidant System in Kelp -- 6.3 Antioxidative Strategies in Seaweeds on Seasonal and Spatial Scales -- 6.3.1 SOD Activity in the Brown Seaweed Desmarestia anceps Along a Depth Gradient: A Case Study in Antarctica -- 6.3.2 Seasonal Changes in SOD Activity in Seaweeds from an Arctic Fjord -- 6.4 Oxidative Bursts: Reactive Oxygen and Interspecific Interaction -- 6.5 Summary -- References -- Part II: Biotic Interactions -- Chapter 7: Competition, a Major Factor Structuring Seaweed Communities -- 7.1 Competition Theory -- 7.2 Competition Among Marine Macroalgae -- 7.2.1 Overview -- 7.2.2 Competition for Light -- 7.2.3 Competition for Space -- 7.2.4 Competition for Nutrients -- 7.3 Competition in Complex Environments -- 7.3.1 Synergistic Effects of Different Factors. , 7.3.2 The Importance of Competition in Maintaining Marine Forests -- 7.3.3 Competition in the Face of Climate Change -- 7.4 Concluding Remarks -- References -- Chapter 8: Grazers on Benthic Seaweeds -- 8.1 Common Classification Systems of Grazers -- 8.2 Digestive Adaptations in Grazers -- 8.3 Grazer Impacts on Seaweeds and Seaweed Communities -- 8.4 Seaweed Defenses Against Grazing -- 8.5 Effects of Seaweed Chemical Defenses on Herbivores and Communities -- 8.6 Climate Change Effects on Seaweed-Herbivore Interactions -- 8.7 Conclusions -- References -- Chapter 9: Chemical Ecology of Seaweeds -- 9.1 Overview -- 9.2 Sensory Chemical Ecology -- 9.2.1 Chemical Communication -- 9.2.2 Environmental Sensing -- 9.3 Chemical Defense -- 9.3.1 Defenses Against Predation -- 9.3.2 Defenses Against Pathogens -- 9.3.3 Defenses Against Biofouling -- 9.3.4 Allelopathy -- 9.4 Outlook -- References -- Chapter 10: Bacterial Communities on Macroalgae -- 10.1 Introduction -- 10.2 Microbial Communities Associated with Macroalgae -- 10.3 Host-Specific Microbial Communities on Macroalgae? -- 10.4 A Model of Surface Colonization on Macroalgae -- 10.5 Conclusions -- References -- Chapter 11: Intimate Associations Between Epiphytes, Endophytes, and Parasites of Seaweeds -- 11.1 Introduction -- 11.2 Ecology and Biology of Close Biotic Interactions of Seaweeds -- 11.2.1 Epiphytes -- 11.2.2 Pigmented Endophytes -- 11.2.2.1 Endophytes in Red Algae -- 11.2.2.2 Endophytes in Brown Algae -- 11.2.2.3 Endophytes in Green Algae -- 11.2.2.4 Life History Stages of Seaweeds as Endophytic Filaments in Other Taxa -- Kelp Gametophytes in Red Filamentous Algae -- Green Algal Endophytes as Alternate Life History Phases of Acrosiphonia Species -- 11.2.3 Eukaryotic Parasites and Pathogens -- 11.2.3.1 Adelphoparasites and Alloparasites of Red Algae. , 11.2.3.2 Fungal and Oomycete Parasites and/or Pathogens -- 11.3 Cross-Talk Between Host and Colonizers and Defenses Against Colonization -- 11.3.1 Cross-Talk Involved in Host Colonization -- 11.3.2 ``Ménages à trois,´´ Quorum Sensing Mediated Bacterial-Macroalgal Interactions Modulate Colonization -- 11.3.3 Allelopathic Interactions and Induced Defenses -- 11.4 Impacts of Close Associations -- 11.4.1 Community Context -- 11.4.2 Implications to Seaweed Mariculture -- 11.4.3 Fouling -- 11.5 Summary and Prospects -- References -- Chapter 12: Invasive Marine Seaweeds: Pest or Prize? -- 12.1 Introduction -- 12.2 Biological Traits of Invasive Seaweeds -- 12.2.1 Seaweed Invasions Are Mostly Human-Mediated -- 12.3 The Identification of Introduced Seaweeds Is Not Always Easy -- 12.3.1 Relevant Taxonomic Units in Seaweeds Molecular Ecology -- 12.3.2 Case Study: Sargassum Muticum -- 12.3.3 Case Study: Undaria Pinnatifida -- 12.3.4 Case Study: Asparagopsis Armata -- 12.3.5 Case Study: Asparagopsis Taxiformis -- 12.3.6 Case Study: Codium Fragile ssp. Tomentosoides -- 12.3.7 Case Study: Caulerpa spp. -- 12.3.8 Assessing Seaweed Introductions -- 12.4 Are Introduced Species a Pest or Prize? A Crab´s Tale -- 12.4.1 Commercially Used Invasive Seaweeds -- 12.4.2 Gracilaria salicornia -- 12.4.3 Eucheuma and Kappaphycus spp. -- 12.4.4 Asparagopsis Species -- 12.4.5 Caulerpa Species -- 12.4.6 Ulva Species -- 12.4.7 Undaria pinnatifida -- 12.4.8 Codium Fragile Subspecies Tomentosoides -- 12.5 Conclusions -- References -- Part III: Structure and Function of the World´s Main Seaweed Systems -- Chapter 13: Seaweeds and Their Communities in Polar Regions -- 13.1 Introduction -- 13.2 Biodiversity and Biogeographical Relationships of Antarctic and Arctic Seaweeds -- 13.3 Physiological Adaptations to the Environment -- 13.3.1 Seasonal Development and Physiological Performance. , 13.3.2 Radiation Climate and Depth Zonation -- 13.3.3 Temperature Requirements and Geographic Distribution -- 13.3.4 Effect of Salinity, Temperature, and Desiccation on Supra- and Eulittoral Seaweeds -- 13.4 Ecology of Polar Seaweed Communities -- 13.4.1 Biomass, Depth Distribution, and Productivity -- 13.4.2 Elemental and Nutritional Content -- 13.4.3 Defenses Against Herbivory and Biofouling in Polar Seaweeds -- 13.4.4 Trophic Interactions -- 13.5 Impact of Global Climate Changes on Seaweeds and Their Communities -- 13.6 Conclusion -- References -- Chapter 14: Cold-Temperate Seaweed Communities of the Southern Hemisphere -- 14.1 The Regions and Their Basic Abiotic Conditions -- 14.1.1 Southwestern South America Region -- 14.1.2 Southeastern South America Region -- 14.1.3 Victoria-Tasmania Region -- 14.1.4 Southern New Zealand Region -- 14.1.5 Sub-Antarctic Islands Region -- 14.2 Structure and Function of Seaweed Communities -- 14.2.1 Southwestern South America Region (Chile) -- 14.2.2 Southeastern South America Region (Argentinean Patagonia) -- 14.2.3 Victoria-Tasmania Region -- 14.2.4 Southern New Zealand Region -- 14.2.5 Sub-Antarctic Islands Region -- 14.3 Biogeographical Processes -- 14.3.1 Cold-Temperate Kelps as Biogeographical Models -- 14.4 Major Differences with Cold Temperate Regions of the Northern Hemisphere -- 14.5 Concluding Remarks -- References -- Chapter 15: Warm Temperate Seaweed Communities: A Case Study of Deep Water Kelp Forests from the Alboran Sea (SW Mediterranean Sea) and the Strait of Gibraltar -- 15.1 Introduction: Kelp Forests and Kelp Beds in the Alboran Sea and the Strait of Gibraltar -- 15.2 Abiotic Factors Affecting Distribution of Kelps in the Alboran Sea and the Strait of Gibraltar -- 15.2.1 Substratum -- 15.2.2 Hydrodynamics -- 15.2.3 Irradiance -- 15.2.4 Temperature -- 15.2.5 Inorganic Nutrients. , 15.3 Growth and Reproduction.