1 Introduction |
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1.1 Hypoxia and the Northern Gulf of Mexico — A Brief Overview |
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1.2 Science and Management Goals for Reducing Hypoxia |
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1.4 The Study Group's Approach |
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2 Characterization of Hypoxia |
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2.1 Historical Patterns and Evidence for Hypoxia on the Shelf |
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2.2.1 Oxygen Budget: General Considerations |
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2.2.2 Vertical Mixing as a Function of Stratification and Vertical Shear |
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2.2.3 Changes in Mississippi River Hydrology and Their Effects on Vertical Mixing |
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2.2.4 Zones of Hypoxia Controls |
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2.2.5 Shelf Circulation: Local Versus Regional |
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2.3 Role of N and P in Controlling Primary Production |
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2.3.1 Nitrogen and Phosphorus Fluxes to the NGOM Background |
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2.3.2 N and P Limitation in Different Shelf Zones and Linkages Between High Primary Production Inshore and the Hypoxic Regions Farther Offshore |
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2.4 Other Limiting Factors and the Role of Si |
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2.5 Sources of Organic Matter to the Hypoxic Zone |
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2.5.1 Sources of Organic Matter to NGOM: Post 2000 Integrated Assessment |
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2.5.2 Advances in Organic Matter Understanding: Characterization and Processes |
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2.5.3 Synthesis Efforts Regarding Organic Matter Sources |
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2.6 Denitrification, P Burial, and Nutrient Recycling |
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2.7 Possible Regime Shift in the Gulf of Mexico |
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2.8 Single Versus Dual Nutrient Removal Strategies |
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2.9 Current State of Forecasting |
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3 Nutrient Fate, Transport, and Sources |
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3.1 Temporal Characteristics of Streamflow and Nutrient Flux |
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3.1.1 MARB Annual and Seasonal Fluxes |
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3.1.2 Subbasin Annual and Seasonal Flux |
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3.2 Mass Balance of Nutrients |
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3.3 Nutrient Transport Processes |
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3.3.2 Freshwater Wetlands |
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3.3.3 Nutrient Sources and Sinks in Coastal Wetlands |
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3.4 Ability to Route and Predict Nutrient Delivery to the Gulf |
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3.4.4 Discussion and Comparison of Models |
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4 Scientific Basis for Goals and Management Options |
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4.2 Setting Targets for Nitrogen and Phosphorus Reduction |
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4.3 Protecting Water Quality and Social Welfare in the Basin |
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4.3.1 Assessment and Review of the Cost Estimates from the CENR Integrated Assessment |
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4.3.2 Other Large-Scale Integrated Economic and Biophysical Models for Agricultural Nonpoint Sources |
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4.3.3 Research Assessing the Basin-Wide Co-benefits |
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4.3.4 Principles of Landscape Design |
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4.4 Cost-Effective Approaches for Nonpoint Source Control |
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4.4.1 Voluntary Programs – Without Economic Incentives |
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4.4.2 Existing Agricultural Conservation Programs |
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4.4.3 Emissions and Water Quality Trading Programs |
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4.4.4 Agricultural Subsidies and Conservation Compliance Provisions |
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4.4.6 Eco-labeling and Consumer Driven Demand |
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4.5 Options for Managing Nutrients, Co-benefits, and Consequences |
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4.5.1 Agricultural Drainage |
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4.5.2 Freshwater Wetlands |
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4.5.3 Conservation Buffers |
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4.5.5 Animal Production Systems |
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4.5.6 In-Field Nutrient Management |
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4.5.7 Effective Actions for Other Nonpoint Sources |
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4.5.8 Most Effective Actions for Industrial and Municipal Sources |
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4.5.9 Ethanol and Water Quality in the MARB |
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4.5.10 Integrating Conservation Options |
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5 Summary of Findings and Recommendations |
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5.1 Characterization of Hypoxia |
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5.2 Nutrient Fate, Transport, and Sources |
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5.3 Goals and Management Options |
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Appendices |
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References |
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Subject Index |
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