Coasts and Estuaries: The Future

By Eric Wolanski, John W. Day and Michael Elliott

Coasts and Estuaries: The Future provides valuable information on how we can protect and maintain natural ecological structures while also allowing estuaries to deliver services that produce societal goods and benefits. These issues are addressed through chapters detailing case studies from estuaries and coastal waters worldwide, presenting a full range of natural variability and human pressures. Following this, a series of chapters written by scientific leaders worldwide synthesizes the problems and offers solutions for specific issues graded within the framework of the socio-economic-environmental mosaic. These include fisheries, climate change, coastal megacities, evolving human-nature interactions, remediation measures, and integrated coastal management.

The problems faced by half of the world living near coasts are truly a worldwide challenge as well as an opportunity for scientists to study commonalities and differences and provide solutions. This book is centered around the proposed DAPSI(W)R(M) framework, where drivers of basic human needs requires activities that each produce pressures. The pressures are mechanisms of state change on the natural system and Impacts on societal welfare (including well-being). These problems then require responses, which are the solutions relating to governance, socio-economic and cultural measures (Scharin et al 2016).

• Covers estuaries and coastal seas worldwide, integrating their commonality, differences and solutions for sustainability
• Includes global case studies from leading worldwide contributors, with accompanying boxes highlighting a synopsis about a particular estuary and coastal sea, making all information easy to find
• Presents full color images to aid the reader in a better understanding of details of each case study
• Provides a multi-disciplinary approach, linking biology, physics, climate and social sciences

• Language: English
• Publisher: Elsevier Science
• Release date: Jan 24, 2019
• ISBN: 9780128140048

Book preview

Coasts and Estuaries

The Future

First Edition

Eric Wolanski

John W. Day

Michael Elliott

Ramesh Ramachandran

Table of Contents

Cover image

Title page

Copyright

Dedication

Contributors

About the Editors

Preface: Why This Book?

Chapter 1: A Synthesis: What Is the Future for Coasts, Estuaries, Deltas and Other Transitional Habitats in 2050 and Beyond?

Abstract

1 Introduction

2 Setting the Scene: The DAPSI(W)R(M) Framework

3 Current Status of Estuarine and Coastal Ecosystems

4 Quantifying Changes: The Need to Accommodate Moving Baselines

5 Changes to Stressors: The Input of Physical, Chemical, and Biological Pollutants and the Extraction of Biological Resources

6 Additional Future Threats and Challenges

7 Tools and Approaches for the Management of New Changes

8 Changes to Stressors: Responses to Increasing Coastal Populations, Their Environment, and Infrastructure

9 Sustainable Solutions

10 Conclusions

Section A: Estuaries

Chapter 2: An Assessment of Saltwater Intrusion in the Changjiang (Yangtze) River Estuary, China

Abstract

Acknowledgment

1 Introduction

2 Data Sources and Observation

3 Discussions

4 Future Scenarios

5 The Way Forward

Chapter 3: Río de la Plata: A Neotropical Estuarine System

Abstract

1 General Introduction

2 Major Anthropogenic Driving Forces at RDLP

3 Minor Drivers: Industry, Urbanization, and Tourism

4 The Future of the RdlP Estuary

Chapter 4: Estuaries and Coastal Zones in the Northern Persian Gulf (Iran)

Abstract

1 Geology and Geomorphology of the Persian Gulf

2 Climatic Conditions and Recent Changes

3 Hydrology and Circulation in the Persian Gulf

4 Biodiversity of the Iranian Coastal Waters of the Persian Gulf

5 Anthropogenic Stresses in the Northern Persian Gulf

6 The Future Changes to the Persian Gulf

Chapter 5: Protecting Water Quality in Urban Estuaries: Australian Case Studies

Abstract

1 Introduction

2 Case Study Examples

3 Considerations and Summary

Chapter 6: Management of Megafauna in Estuaries and Coastal Waters: Moreton Bay as a Case Study

Abstract

Acknowledgments

1 Introduction

2 Moreton Bay: A Megafauna Case Study

3 Moreton Bay—Physical Characteristics

4 Moreton Bay Megafauna

5 Protective Measures for Moreton Bay Megafauna

6 The Future

Chapter 7: Peel-Harvey Estuary, Western Australia

Abstract

Acknowledgments

1 Overview

2 The Peel-Harvey System

3 Historical Socio-Ecological Developments

4 Estuary Responses Over Recent Decades

5 Current Socio-Ecological Characteristics

6 Looking Forward

7 Concluding Remarks

Section B: Deltas

Chapter 8: Arctic Deltas and Estuaries: A Canadian Perspective

Abstract

Acknowledgments

1 Introduction

2 Environmental Forcing

3 Arctic Estuaries and Deltas

4 Discussion

5 Conclusions

Chapter 9: Delta Winners and Losers in the Anthropocene

Abstract

Acknowledgments

1 Introduction

2 A Framework for Understanding the Development, Functioning, and Sustainability of Deltas and the Role of Energetic Forcing Events in the Functioning of Deltas

3 Perspectives on Delta Sustainability

4 Impact of Climate Change and Resource Scarcity on Deltas

5 Classification of Delta Types in Relationship to Sustainability

6 Delta Winners and Losers—Sustainability of Individual Deltas

7 Sustainability of Individual Deltas

8 Asian Deltas

9 European and African Deltas

10 American Deltas

11 Ranking Sustainability

12 Conclusions

Chapter 10: Mississippi Delta Restoration and Protection: Shifting Baselines, Diminishing Resilience, and Growing Nonsustainability

Abstract

Acknowledgments

1 Introduction

2 Development of the Delta

3 Deterioration of the Delta

4 Global Change Constraints on Coastal Protection and Restoration

5 Coastal Protection and Restoration

6 Coastal Protection and Restoration in a Climate-Challenged, Energy-Scarce Future

7 Moving Forward on Coastal Protection

8 Shifting Baselines and Diminishing Resilience

9 Comprehensive Planning—The Importance of Global Change

Chapter 11: Integrated Management of the Ganges Delta, India

Abstract

1 Introduction

2 Upstream Effects

3 Coastal Effects

4 Conclusions

Annex 1

Chapter 12: The Indus Delta—Catchment, River, Coast, and People

Abstract

1 Origin of the River

2 Geomorphology and Hydrology

3 Upstream, Large, Manmade Structures

4 Catchment Areas

5 River Indus Delta Ecosystem

6 In the Last 50 Years

7 The Delta Faces Climate Change (Variability in Arabian Sea Monsoon)

8 Saving the Delta and Its People

9 Fishers and Fishery From the Delta

10 Dependence on the River

11 What to Save First? What Will Work—Political Will or Management Strategy?

12 Stakeholders—Coming Together

Chapter 13: A Brief Overview of Ecological Degradation of the Nile Delta: What We Can Learn

Abstract

Acknowledgments

1 Introduction

2 What We Can Learn?

Chapter 14: Status and Sustainability of Mediterranean Deltas: The Case of the Ebro, Rhône, and Po Deltas and Venice Lagoon

Abstract

1 Introduction

2 The Ebro Delta

3 The Rhône Delta

4 The Po Delta and Venice Lagoon

5 Discussion

6 Summary and Conclusions

Section C: Wetlands, Lagoons and Catchments

Chapter 15: Coastal Lagoons: Environmental Variability, Ecosystem Complexity, and Goods and Services Uniformity

Abstract

Acknowledgments

1 Introduction

2 Coastal Lagoons: Definition and Distribution

3 Lagoon Functioning and Environmental Variability

4 Lagoon Biota and Ecology

5 The Lagoon Paradox

6 Influence of Coastal Lagoons on the Adjacent Sea

7 Ecosystem Services Provided by Coastal Lagoons: Actual Status and Perspectives

8 The Future of Coastal Lagoons: Main Pressures and Impacts on the Lagoon Systems

9 Outstanding Future Threats: Eutrophication

10 Final Remarks

Chapter 16: The Everglades: At the Forefront of Transition

Abstract

Acknowledgments

1 Introduction

2 The Geological Setting

3 The Eco-Hydrological Setting

4 The Eco-Economic Setting

5 Transition Awareness

Chapter 17: Population Growth, Nutrient Enrichment, and Science-Based Policy in the Chesapeake Bay Watershed

Abstract

Dedication and Acknowledgments

1 Introduction

2 Description of the Watershed and Its Estuary

3 Nutrient Enrichment in the Chesapeake

4 The PR Case as a Driver of Chesapeake Bay Policy

5 The State of the Bay: What Was Accomplished Since 2020 Report Was Published, and What Is to be Expected in 2020 and Beyond?

Chapter 18: The Senegal and Pangani Rivers: Examples of Over-Used River Systems Within Water-Stressed Environments in Africa

Abstract

1 Introduction

2 The Senegal River Basin

3 The Pangani River Basin

4 Conclusion

Chapter 19: Damming the Mekong: Impacts in Vietnam and Solutions

Abstract

Acknowledgments

1 Introduction

2 Hydropower Dam Network in the Mekong River Basin

3 The Vietnamese Mekong Delta

4 Dam Impacts on the Mekong Delta in Vietnam

5 The Conceptual Solutions

6 Conclusion

Section D: Enclosed, Semi-enclosed, and Open Coasts

Chapter 20: Baltic Sea: A Recovering Future From Decades of Eutrophication

Abstract

Acknowledgments

1 Introduction

2 Eutrophication

3 Food Production

4 Nutrient Loading Pressures

5 Eutrophication Status

6 Eutrophication Impact on Human Welfare

7 Responses to Counteract and Manage Eutrophication

8 Future Outlook in Eutrophication Development

9 New Innovations Toward Sustainable Baltic Sea Future

Chapter 21: The Black Sea—The Past, Present, and Future Status

Abstract

Acknowledgments

1 Introduction

2 Geographic Setting and Coastal Geomorphology

3 Ecological State and Health of the Sea

4 Fisheries

5 Pollution (Marine Litter)

6 Recommendations and Conclusions

Chapter 22: Ecosystem Functioning and Sustainable Management in Coastal Systems With High Freshwater Input in the Southern Gulf of Mexico and Yucatan Peninsula

Abstract

1 Introduction

2 The High River Discharge Zone and the Grijalva-Usumacinta Delta

3 Laguna De Terminos

4 Yucatan Groundwater Coastal Karstic Ecosystems—Environmental Risk and Management Opportunities

5 Management Perspectives for the Yucatan Peninsula and Southern Gulf of Mexico

Section E: Restoration of Estuaries

Chapter 23: Restoration of Estuaries and Bays in Japan—What’s Been Done So Far, and Future Perspectives

Abstract

Acknowledgments

1 Introduction

2 Restoration and Related Activities Performed to Date

3 Future Perspective

Chapter 24: Challenges of Restoring Polluted Industrialized Muddy NW European Estuaries

Abstract

Acknowledgments

1 Introduction

2 Estuary Management

3 Future Sea-Level Impacts

4 Future Costs

5 Degraded Major Estuaries of NW Europe and Their Restoration

6 Generic Sediment Management Systems

7 Cleansing of Mud in Contaminated Industrialized Estuaries

8 Conclusions

Chapter 25: Can Bivalve Habitat Restoration Improve Degraded Estuaries?

Abstract

1 Introduction: Bivalves—The Forgotten Habitat Builders

2 What Are Bivalve Habitats?

3 Ecosystem Services

4 Historic Extent and Fisheries

5 Global Decline of Bivalve Habitats

6 Restoration

7 The Future of Bivalve Habitat Restoration

8 Conclusion

Section F: Coral Reefs

Chapter 26: Successful Management of Coral Reef-Watershed Networks

Abstract

1 Introduction: Importance of Land-Sea Interactions

2 Major Contributors to Watershed Discharges

3 Contents of Watershed Discharges

4 The Key Role of Coastal Oceanography

5 Case Histories

6 Remediation Measures

7 Continuing Efforts

8 A Synthesis: Success and Failures of Different Approaches

9 Major Socioeconomic-Cultural Lessons Learned

10 The Future: Climate Change Issues

11 Evaluation of Mitigation: Metrics of Success

12 Conclusions

Chapter 27: Challenges and Opportunities in the Management of Coral Islands of Lakshadweep, India

Abstract

Acknowledgements

1 Introduction

2 SWOT Analysis

3 Challenges

4 Interventions and Opportunities

5 Integrated Island Management Plan

6 Conclusions

Chapter 28: The Future of the Great Barrier Reef: The Water Quality Imperative

Abstract

Acknowledgment

1 Introduction—The State of the Great Barrier Reef

2 Terrestrial Pollution and Sources

3 Stressors and the Impacts

4 The Current Water Quality Management Response and Progress

5 The Future Based on Current Management Regime

6 What Would Success Look Like?

7 What Could Be Done to Improve Governance and Management?

8 A Way Forward

Section G: Over-Arching Topics

Chapter 29: Estuarine Ecohydrology Modeling: What Works and Within What Limits?

Abstract

1 Introduction: The Need for Models

2 Models of Physical Processes

3 Models of Nutrient Sequestration by Fine Sediment

4 Estuarine Ecohydrology Models

5 A Synthesis

Chapter 30: Hypersalinity: Global Distribution, Causes, and Present and Future Effects on the Biota of Estuaries and Lagoons

Abstract

Acknowledgments

1 Introduction

2 Meta-analysis of Hypersaline Estuaries, Lagoons and Coastal Embayments

3 Laguna Madre

4 Lake St Lucia

5 Coorong

6 Stokes, Hamersley and Culham Inlets

7 Summary

Chapter 31: Alien Species Invasion: Case Study of the Black Sea

Abstract

1 Introduction

2 Alien Species Invasion of the Black Sea

3 Gradients of Temperature and Salinity as Ecological Barriers

4 Large-Scale Currents and Alien Species

5 Trends of Invasion of Alien Species

6 Invasive Corridors of the Black Sea Basin

7 Invasions of Alien Species in the Black Sea—The Future

Chapter 32: Coastal Fisheries: The Past, Present, and Possible Futures

Abstract

Acknowledgments

1 Introduction

2 Coastal Fisheries as a Key Component of Global Fisheries

3 Regional and Temporal Difference in Coastal Fisheries

4 Large-Scale Industrial Versus Small-Scale Artisanal and Recreational Fisheries

5 A Neglected Sector: Subsistence Fisheries

6 Fishing Down and Other Ecosystem Impacts of Coastal Fisheries

7 Coastal Fisheries and Climate Change

8 The Governance of Coastal Fisheries

Chapter 33: Temperate Estuaries: Their Ecology Under Future Environmental Changes

Abstract

1 Introduction

2 The Response of Estuarine Ecological Components to Climate Change

3 Final Discussion and Conclusions

Chapter 34: Plastic Pollution in the Coastal Environment: Current Challenges and Future Solutions

Abstract

1 Plastic Pollution in the Marine Environment: An Emerging Contaminant of Global Concern

2 Sources and Methods of Dispersal of Microplastic Pollution in the Coastal and Marine Environment

3 Loss of Virgin Microplastics During Manufacture or Transport

4 Microplastics From Households—Fibers and Microbeads

5 Breakdown of Large Plastics

6 Microplastic Pollution in the Coastal and Marine Environment

7 Governance Challenges and Current Approaches

8 A Circular Economy Approach for Marine Plastic Pollution

9 Reducing Marine Plastic Pollution: Case Studies

10 Case Study 1: Banning Microbeads in Personal Care and Cleaning Products

11 Case Study 2: EPR

12 Behavioral Change—Littering and Plastic Pollution

13 Conclusion

Chapter 35: Changing Hydrology: A UK Perspective

Abstract

1 Introduction

2 Sensitivity of UK Estuaries to River Flows

3 Past Trends and Future Projections for Hydrology

4 Potential Impacts to Estuaries From Changing Hydrology

5 Summary

Section H: Management of Change

Chapter 36: Global Change Impacts on the Future of Coastal Systems: Perverse Interactions Among Climate Change, Ecosystem Degradation, Energy Scarcity, and Population

Abstract

1 Introduction

2 Global Climate Change: Past Trends, Future Predictions, and System Impacts

3 Coastal Wetland Response to Temperature and Accelerated SLR

4 The Impacts of Changes in Freshwater Input on Coastal Ecosystems

5 Tropical Cyclones

6 Extreme Weather Events

7 Energy Scarcity and Coastal Adaptation and Restoration

8 Coastal Environmental Degradation as a Societal Energy Sink

9 Ecological Engineering and Ecohydrology—System Functioning as a Basis for Sustainable Management of Coastal Systems

10 Conclusions: Ecosystem Goods and Services and Cost of Energy

Chapter 37: Human-Nature Relations in Flux: Two Decades of Research in Coastal and Ocean Management

Abstract

1 Preamble: Aim and Overview

2 Human-Nature Relations: Why COM?

3 Stakeholder Identification and Conflict Resolution: The Example of Sweden

4 National Coastal and Ocean Strategies: The Example of Germany

5 Natural Calamities and Coastal Hazards

6 Climate Change: The Example of Indonesia

7 Coastal and Ocean Typologies: An Analytical Instrument and Planning Tool

8 Summary and Conclusion

Chapter 38: Megacities and the Coast: Global Context and Scope for Transformation

Abstract

Acknowledgments

1 Introduction

2 Locating Coastal Megacities

3 Challenges in Defining Coastal Megacities

4 Risk, Vulnerability, and Resilience in Coastal Megacities

5 Conclusions: Urban Transitions, Urban Futures

Chapter 39: Arctic Coastal Systems: Evaluating the DAPSI(W)R(M) Framework

Abstract

1 Introduction

2 The Arctic Coastal Margin and Its Social-Ecological System

3 The Complexity of Ecosystem Management

4 The Possible Futures of Arctic Coastal Environmental Management

5 Conclusion

Index

Copyright

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Dedication

We dedicate this book to our grandchildren: Oliver, Grace, and Harry Wolanski; Olly, Dylan, and Mycah Elliott; and Daisy and Sunny Day; and to Ramachandran’s children Gowtham and Niveda Ramesh; we hope that they will enjoy healthy estuaries and coastal waters by 2050 and beyond and we hope that these will remain healthy to entrust to their children.

Contributors

Numbers in parentheses indicate the pages on which the authors’ contributions begin.

Waqar Ahmed     (213), National Institute of Oceanography, Karachi, Pakistan

A. Bauer-Civiello     (595), College of Science and Engineering, James Cook University, Townsville, QLD, Australia

C. Benham     (595), College of Science and Engineering, James Cook University, Townsville, QLD, Australia

K. Berry     (595), College of Science and Engineering, James Cook University, Townsville, QLD, Australia

Morris Bidjerano     (293), School of Public Policy and Administration, Walden University, Greenville, SC, United States

Sophie Blackburn     (661), Department of Geography, King’s College London, London, United Kingdom

Erik Bonsdorff     (343), Åbo Akademi University, Turku, Finland

J. Brodie     (477), ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia

Nguyen Ba Cao     (321), Vietnam Academy of Water Resources, Hanoi, Vietnam

Zhongyuan Chen     (31, 233), State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, People’s Republic of China

Peter Clift     (213), Louisiana State University, Baton Rouge, LA, United States

Craig Colten     (167), Department of Geography and Anthropology, Louisiana State University, Baton Rouge, LA, United States

K. Critchell

(595), College of Science and Engineering, James Cook University, Townsville

Marine Spatial Ecology Lab, University of Queensland, Brisbane, QLD, Australia

N.D. Cutts     (577), Institute of Estuarine and Coastal Studies, University of Hull, Hull, United Kingdom

Christopher F. D’Elia     (293), College of the Coast and Environment, Louisiana State University, Baton Rouge, LA, United States

A.P. Dale     (477), The Cairns Institute, James Cook University, Cairns, QLD, Australia

Moslem Daliri     (57), Department of Fisheries, Faculty of Marine and Atmospheric Sciences and Technologies, University of Hormozgan, Bandar Abbas, Iran

Steve E. Davis     (277), Everglades Foundation, Palmetto Bay, FL, United States

John W. Day     (1, 149, 167, 237, 377, 621), Department of Oceanography and Coastal Sciences, College of the Coast and Environment, Louisiana State University, Baton Rouge, LA, United States

J. Day     (477), ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia

T. Debasis     (461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Omar Defeo     (45), UNDECIMAR, Faculty of Sciences, University of the Republic, Montevideo, Uruguay

Mustafa Dihkan     (363), Department of Geomatics, Faculty of Engineering, Karadeniz Technical University, Çamburnu, Trabzon

Salif Diop     (311), Cheikh Anta Diop University, Dakar-Fann, Senegal

Sabine R. Dittmann     (523), College of Science & Engineering, Flinders University, Adelaide, SA, Australia

Tom Dreschel     (277), Everglades Systems Assessment Section, South Florida Water Management District, West Palm Beach, FL, United States

J.-P. Ducrotoy     (577), Institute of Estuarine and Coastal Studies, University of Hull, Hull, United Kingdom

Ryan J.K. Dunn     (69), Ocean Science & Technology, RPS, Gold Coast, QLD, Australia

L. Eagle     (595), College of Business, Law and Governance, James Cook University, Townsville, QLD, Australia

Michael Elliott     (1, 577), Institute of Estuarine and Coastal Studies, University of Hull, Hull, United Kingdom

Muzaffer Feyzioğlu     (363), Department of Marine Science and Technology, Faculty of Marine Sciences, Karadeniz Technical University, Çamburnu, Trabzon

Donald L. Forbes

(123), Geological Survey of Canada, Natural Resources Canada, Bedford Institute of Oceanography, Dartmouth, NS, Canada

Department of Geography, Memorial University of Newfoundland, St. John’s, NL

Department of Earth Sciences, Dalhousie University, Halifax, NS, Canada

A. Franco     (577), Institute of Estuarine and Coastal Studies, University of Hull, Hull, United Kingdom

D. Ganguly     (187), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Javier García-Alonso     (45), Departament of Ecology, CURE, University of the Republic, Maldonado, Uruguay

Chris L. Gillies

(427), The Nature Conservancy, Carlton, VIC

James Cook University, Townsville, QLD, Australia

Liviu Giosan     (149, 213), Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States

Bernhard Glaeser

(641), Freie Universität

German Society for Human Ecology (DGH), Berlin, Germany

Yimnang Golbuu     (445), Palau International Coral Reef Center, Koror, Palau

A. Grech     (477), ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia

Abdulaziz Güneroğlu     (363), Department of Marine Ecology, Faculty of Marine Sciences, Karadeniz Technical University, Çamburnu, Trabzon

C.S. Hallett     (103), Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Perth, WA, Australia

M. Hamann     (595), College of Science and Engineering, James Cook University, Townsville, QLD, Australia

Boze Hancock     (427), The Nature Conservancy, Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, United States

G. Hariharan     (461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Anna-Stiina Heiskanen     (343), Finnish Environment Institute, Helsinki, Finland

K. Hennig     (103), Department of Water and Environmental Regulation, Perth, WA, Australia

Claudia Teutli Hernández     (377), Center for Research and Advanced Studies of the National Polytechnic Institute, Merida Campus, Mexico

Jorge A. Herrera-Silveira     (377), Center for Research and Advanced Studies of the National Polytechnic Institute, Merida Campus, Mexico

M.R. Hipsey     (103), Aquatic Ecodynamics, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia

Steeg D. Hoeksema

(523), Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch

Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, Western Australia, Australia

Jianyin Huang

(69), Natural and Built Environments Research Centre, School of Natural and Built Environments

Future Industries Institute, University of South Australia, Adelaide, SA, Australia

P. Huang     (103), Aquatic Ecodynamics, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia

Austin Humphries

(427), Department of Fisheries, Animal and Veterinary Science, University of Rhode Island, Kingston

Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, United States

K. Hussey     (595), Centre for Policy Futures, Faculty of Humanities and Social Sciences, The University of Queensland, St Lucia, QLD, Australia

Carles Ibáñez     (237), Aquatic Ecosystems Program, IRTA, San Carles de la Rapita, Catalonia, Spain

Asif Inam     (213), National Institute of Oceanography, Karachi, Pakistan

Marko Joas     (343), Åbo Akademi University, Turku, Finland

Ehsan Kamrani     (57), Department of Fisheries, Faculty of Marine and Atmospheric Sciences and Technologies, University of Hormozgan, Bandar Abbas, Iran

Coura Kane     (311), Cheikh Anta Diop University, Dakar-Fann, Senegal

G. Paul Kemp     (149, 167, 377), Department of Oceanography and Coastal Sciences, College of the Coast and Environment, Louisiana State University, Baton Rouge, LA, United States

Samina Kidwai     (213), National Institute of Oceanography, Karachi, Pakistan

K.L. Kilminster     (103), Department of Water and Environmental Regulation, Perth, WA, Australia

Brian A. King     (69), Ocean Science & Technology, RPS, Gold Coast, QLD, Australia

R. Kirby     (413), Ravensrodd Consultants Ltd., Liverpool, United Kingdom

Cheikh Tidiane Koulibaly

(311), Cheikh Anta Diop University, Dakar-Fann, Senegal

University of Ibadan, Ibadan, Nigeria

Ahana Lakshmi     (187), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Janet M. Lanyon     (87), School of Biological Sciences, The University of Queensland, St. Lucia, QLD, Australia

Ana L. Lara-Domínguez     (377), Institutue of Ecology, Veracruz, Mexico

Diego Lercari     (45), UNDECIMAR, Faculty of Sciences, University of the Republic, Montevideo, Uruguay, Montevideo, Uruguay

Matt J. Lewis     (611), School of Ocean Sciences, Marine Centre Wales, Bangor University, Menai Bridge, United Kingdom

Maotian Li

(31), State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, People’s Republic of China

Institute of Eco-Chongming Shanghai, China

S. Little     (577), School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottinghamshire, United Kingdom

Amy Lauren Lovecraft     (671), Center for Arctic Policy Studies, University of Alaska Fairbanks, Fairbanks, AK, United States

Concepción Marcos     (253), Department of Ecology and Hydrology, Regional Campus of International Excellence Mare Nostrum, University of Murcia, Murcia, Spain

César Marques     (661), National School of Statistical Science—Brazilian Institute of Geography and Statistics (ENCE/IBGE), Rio de Janeiro, Brazil

Osamu Matsuda     (401), Graduate School of Biosphere Sciences, Hiroshima University, Higashihiroshima, Japan

K. Mazik     (577), Institute of Estuarine and Coastal Studies, University of Hull, Hull, United Kingdom

John F. Meeder     (277), Sea Level Solutions Center and Southeast Environmental Research Center, Florida International University, Miami, FL, United States

Chanda L. Meek     (671), Department of Political Science, University of Alaska Fairbanks, Fairbanks, AK, United States

Ian Michael McLeod     (427), TropWATER, Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Townsville, QLD, Australia

T. Morrison     (477), ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia

R. Muruganandam     (461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Alice Newton

(253), NILU-IMPACT, Kjeller, Norway

CIMA-Centre for Marine and Environmental Research, Gambelas Campus, University of Algarve, Faro, Portugal

Nguyen Huu Nhan     (321), Vietnam Academy of Water Resources, Hanoi, Vietnam

Awa Niang     (311), Cheikh Anta Diop University, Dakar-Fann, Senegal

Sara Morales Ojeda     (377), Center for Research and Advanced Studies of the National Polytechnic Institute, Merida Campus, Mexico

Maria-Lourdes D. Palomares     (569), Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada

Daniel Pauly     (569), Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada

Mark Pelling     (661), Department of Geography, King’s College London, London, United Kingdom

Angel Pérez-Ruzafa     (253), Department of Ecology and Hydrology, Regional Campus of International Excellence Mare Nostrum, University of Murcia, Murcia, Spain

Isabel M. Pérez-Ruzafa     (253), Department of Plant Biology I, Complutense University of Madrid, Madrid, Spain

Didier Pont     (237), Institute of Hydrobiology and Aquatic Ecosystem Management (IHG), University of Natural Resources and Life Sciences, Vienna, Austria

Ian C. Potter

(523), Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute

School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia

B. Pressey     (477), ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia

R. Purvaja     (187, 461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

R. Raghuraman     (461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Ramesh Ramachandran     (1, 149, 187, 461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Robert H. Richmond     (445), Kewalo Marine Laboratory, University of Hawaii at Manoa, Honolulu, HI, United States

T. Ridgway     (595), Global Change Institute, The University of Queensland, St Lucia, QLD, Australia

R.S. Robin     (187), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Peter E. Robins     (611), School of Ocean Sciences, Marine Centre Wales, Bangor University, Menai Bridge, United Kingdom

Pablo L. Ruiz     (277), South Florida Caribbean Network, National Park Service, Palmetto Bay, FL, United States

John M. Rybczyk     (621), Department of Environmental Science, Western Washington University, Bellingham, WA, United States

Bonthu S.R.     (187), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Osman Samsun     (363), Faculty of Fisheries, Sinop University, Sinop, Turkey

Swati Mohan Sappal     (187), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Francesco Scarton     (237), SELC Societá Cooperativa, Venezia, Italy

Peter Scheren     (311), WWF Regional Office for Africa, Nairobi, Kenya

Nickolai Shalovenkov     (547), The Centre for Ecological Studies, Russia

Moslem Sharifinia     (57), Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), Gulf of Oman and Indian Ocean Research Center, Marine Biology Division, Chabahar, Iran

Austin J. Shelton, III     (445), Center for Island Sustainability and Sea Grant Program, University of Guam, Mangilao, Guam

Fred H. Sklar     (277), Everglades Systems Assessment Section, South Florida Water Management District, West Palm Beach, FL, United States

Mary Divya Suganya     (187), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

James Syvitski     (149), Community Surface Dynamics Modeling System, University of Colorado, Boulder, CO, United States

Syed Mohsin Tabrez     (213), National Institute of Oceanography, Karachi, Pakistan

Peter R. Teasdale

(69), Natural and Built Environments Research Centre, School of Natural and Built Environments

Future Industries Institute, University of South Australia, Adelaide, SA, Australia

Tiffany G. Troxler     (277), Sea Level Solutions Center and Southeast Environmental Research Center, Florida International University, Miami, FL, United States

James R. Tweedley

(523), Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute

School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia

F.J. Valesini     (103), Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Perth, WA, Australia

Nathan J. Waltham     (69), Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), Division of Tropical Environments and Societies, James Cook University, Douglas, QLD, Australia

A. Wenger     (477), School of Earth and Environmental Sciences, University of Queensland, St. Lucia, QLD, Australia

Timothy B. Wheeler     (293), Bay Journal, Seven Valleys, PA, United States

Alan K. Whitfield     (523), South African Institute for Aquatic Biodiversity, Grahamstown, South Africa

M. Wilkinson     (577), Institute of Life and Earth Sciences, Heriot-Watt University, Edinburgh, United Kingdom

Kim Withers     (523), Department of Life Sciences, Texas A&M University, Corpus Christi, TX, United States

Eric Wolanski     (1, 503), TropWATER and College of Marine & Environmental Sciences, James Cook University and Australian Institute of Marine Science, Townsville, QLD, Australia

Tetsuo Yanagi     (401), International EMECS Center, Kobe, Japan

Alejandro Yáñez-Arancibia     (377), Institutue of Ecology, Veracruz, Mexico

S. Yogeswari     (461), National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

Jing Zhang     (213), State Key Laboratory in Estuarine and Coastal Research, Shanghai, China

Philine S.E. zu Ermgassen     (427), School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom

About the Editors

Professor Eric Wolanski

Eric Wolanski is an estuarine oceanographer and ecohydrologist at James Cook University and the Australian Institute of Marine Science. His research interests range from the oceanography of coral reefs, mangroves, and muddy estuaries to the interaction between physical and biological processes determining ecosystem health in tropical waters. He has over 400 scientific publications, including 12 books, and technical reports. Eric is a fellow of the Australian Academy of Technological Sciences and Engineering, the Institution of Engineers Australia (ret.), and l’Académie Royale des Sciences d’Outre-Mer. He was awarded a Doctorate Honoris Causa by the catholic University of Louvain, another Doctorate Honoris Causa by the University of Hull, a Queensland Information Technology and Telecommunications Award for Excellence, and a Lifetime Achievement Award by the Estuarine & Coastal Sciences Association. Eric is an Editor-in-Chief of Wetlands Ecology and Management, Treatise on Estuarine and Coastal Science, the Honorary Editor of Estuarine, Coastal and Shelf Science, and a member of the editorial board of four other journals. He is also a member of the Scientific and Policy Committee of Japan's EMECS (focusing on the Seto Inland Sea) and the European Union DANUBIUS-PP Scientific and Technical Advisory Board, which is a pan-European distributed research infrastructure dedicated to interdisciplinary studies of large river–sea systems throughout Europe.

Professor John Day

John Day is distinguished professor emeritus in the Department of Oceanography and Coastal Sciences at Louisiana State University. He has over 400 publications focusing on the ecology and management of coastal and wetland ecosystems, with emphasis on the Mississippi delta, as well as, among many, coastal ecosystems in Mexico and the impacts of climate change on wetlands in Venice Lagoon and in the Po, Rhone, and Ebro deltas in the Mediterranean. John is the coeditor of 14 books including Estuarine Ecology, Ecological Modeling in Theory and Practice, The Ecology of the Barataria Basin, An Estuarine Profile, Ecology of Coastal Ecosystems in the Southern Mexico: The Terminos Lagoon Region, Ecosystem Based Management of the Gulf of Mexico, America’s Most Sustainable Cities and Regions—Surviving the 21st Century Megatrends. John served as chair of the Science and Engineering Special Team on restoration of the Mississippi delta, on the Scientific Steering Committee of the Future Earth Coasts program, and a National Research Council panel on urban sustainability.

Professor Michael Elliott

Michael Elliott is the professor of Estuarine and Coastal Sciences at the University of Hull, United Kingdom. He is a marine biologist with a wide experience and interests and his teaching, research, advisory, and consultancy work includes estuarine and marine ecology, policy, governance, and management. Mike has published widely, coauthoring/coediting 18 books/proceedings and > 270 scientific publications. This includes coauthoring The Estuarine Ecosystem: Ecology, Threats and Management, Ecology of Marine Sediments: Science to Management, and Estuarine Ecohydrology: An Introduction’ and as a volume editor and contributor to the Treatise on Estuarine & Coastal Science. He has advised on many environmental matters for academia, industry, government, and statutory bodies worldwide. Mike is a past-President of the international Estuarine & Coastal Sciences Association (ECSA) and is an Editor-in-Chief of the international journal Estuarine, Coastal & Shelf Science; he has been adjunct professor and held research positions at Murdoch University (Perth), Klaipeda University (Lithuania), the University of Palermo (Italy), and the South African Institute for Aquatic Biodiversity, Grahamstown. He was awarded Laureate of the Honorary Winberg Medal of the Russian Hydrobiological Academic Society in 2014.

Professor Ramesh Ramachandran

Ramesh Ramachandran is director of the National Centre for Sustainable Coastal Management at the Ministry of Environment, Forest and Climate Change, Government of India. His expertise includes coastal/marine biogeochemistry, conservation of coastal/marine biodiversity, and Integrated Coastal Zone Management. He has over 135 research publications and over 100 technical reports. Among the several awards Professor Ramesh has received are the University Grants Commission UGC-Swami Pranavananda Saraswathi Award in Environmental Sciences and Ecology for the Year 2007 (awarded in February 2010). He was the chair of the Scientific Steering Committee of LOICZ (currently renamed as Future Earth Coasts), member of the Scientific Steering Committee of the Monsoon Asia Integrated Regional Study, chairman of the International Working Group on Coastal Systems on the Role of Science in International Waters Projects of UNEP-GEF, as well as being affiliated with the Bay of Bengal Large Marine Ecosystem Programme of the FAO. He is currently the chair of the Global Partnership in Nutrient Management (GPNM) of UNEP.

Preface: Why This Book?

Eric Wolanski; John Day; Michael Elliott; Ramesh Ramachandran

Coastal ecosystems are at the nexus of the Anthropocene, with enormous environmental issues, and inhabited by nearly half of the human population. These coastal systems and the surrounding human societies form coastal social-ecological systems that increasingly face enormous environmental issues from multiple pressures, which threaten their ecological and economical sustainability. The pressures are derived from hazards which then become risks where they impact the society and where, in some cases, human responses exacerbate the risks. There is only one big idea in managing these systems—how to maintain and protect the natural ecological structure and functioning and yet at the same time allow them to deliver ecosystem services which produce societal goods and benefits. The pressures include basically all human activities within the river catchments such as changes to land use and hydrology in the river catchment, and directly on coastal ecosystems from land claim, coastal sand mining, harbor dredging, pollution and eutrophication, overexploitation such as overfishing and extraction of groundwater, gas and petroleum extraction. In addition, coastal zones are impacted by climate change—this is not just the ‘usual’ culprits of sea level rise, ocean acidification, and increased temperature but also, just as important, changes in the rainfall-runoff of the river catchments, stronger coastal storms, and the changes to species distributions, including the influx of invasive species.

The problems faced by half of the humanity worldwide living near coasts are truly a worldwide challenge as well as an opportunity for science to study commonality and differences and provide solutions. During the five decades of monitoring the degradation of estuaries and coastal waters in the 20th century, coastal scientists studied the problems and issues arising along the coasts worldwide. Now, in the 21st century, the scientists need to use their science to help find solutions to these problems through science-informed management and innovation. The issues to solve are complex because they involve large areas, many users, and sociopolitical-environmental mosaics.

This book provides a typology of the human interaction with estuaries and coastal waters worldwide as a comprehensive description of what works and what does not work for estuaries and coastal waters worldwide and what remediation measures are possible and likely to succeed within limits. This is the first time that such a worldwide approach to estuarine and coastal sustainability has been initiated.

Thus the book addresses these real-life issues in order to learn from each other, by having a series of chapters written by the leading local experts detailing case studies from estuaries and coastal waters worldwide in the full range of natural variability and human pressures. The study sites are located in all the continents, except for the Antarctic, and several oceanic islands. This is followed by a series of chapters written by scientific leaders worldwide synthesizing the problems and offering solutions for specific issues graded within the framework of the socioeconomic-environmental mosaic. These include coastal fisheries, climate change, biophysical limits and energy costs, coastal megacities, evolving human-nature interactions, remediation measures for a number of worldwide issues such as mud and metal legacy as well as plastic pollution, integrated coastal management, and international water conflicts affecting estuaries, deltas, and coastal waters.

We wish to thank Jaclyn Truesdell and Lindsay Lawrence at Elsevier for their help in producing this book.

Chapter 1

A Synthesis: What Is the Future for Coasts, Estuaries, Deltas and Other Transitional Habitats in 2050 and Beyond?

Michael Elliott⁎; John W. Day†; Ramesh Ramachandran‡; Eric Wolanski§    * Institute of Estuarine and Coastal Studies, University of Hull, Hull, United Kingdom

† Department of Oceanography and Coastal Sciences, College of the Coast and Environment, Louisiana State University, Baton Rouge, LA, United States

‡ National Centre for Sustainable Coastal Management, Ministry of Environment, Forest and Climate Change, Government of India, Anna University Campus, Chennai, India

§ TropWATER and College of Marine & Environmental Sciences, James Cook University and Australian Institute of Marine Science, Townsville, QLD, Australia

Abstract

We synthesized the results of many case studies from experts worldwide on the state of the environment, sustainability, and the likely future of estuaries, lagoons, semienclosed seas, and coastal ecosystems. There is a high natural variability in these ecosystems and in their responses to historical human pressures within their catchments, the river, and the estuary, and the potential for sustainability depends on many variables including population growth, the culture, historical changes, and the involvement of the communities. The problems faced by half of the global population living near coasts are truly worldwide challenges and they give us the opportunity to study commonalities and differences and to provide solutions. Fundamental to addressing these challenges is an understanding of the biophysical constraints especially along the catchment-river-estuary ecosystem continuum. We emphasize that there is a need to better manage all these areas to ensure that we can maintain natural ecological structure and functioning while also allowing these systems to deliver services that produce societal goods and benefits, both now and in the future. By investigating the problems, we can offer solutions for specific issues graded within the framework of the socioeconomic and environmental mosaic. These challenges include fisheries, climate change, growing resource scarcity, coastal megacities, a growing population and an increaisng urbanisation and industrialisation of the coast, evolving human-nature interactions, remediation measures, and the willingness to adopt governance at the catchment scale. In these case studies, the DAPSI(W)R(M) problem-solving framework usefully allows us to assess risks and potentials for an effective response which have to be based on the use of good science. To be effective, this framework must be accompanied by the so-called 10-tenets of sustainable management, which include the ecological, economic, technological, societal, administrative, legislative, political, ethical/moral, cultural, and communication aspects. Stakeholder involvement therefore becomes central to successful management of the coasts and estuaries in accommodating changes over the coming century.

Keywords

Human population; Urban development; Degradation; Sustainability; Restoration; Recovery; Use of science; Catchment-river-estuary ecosystem

1 Introduction

Estuaries, deltas, coastal lagoons, and fjords are transitional waters and contain ecosystems between riverine and coastal marine ecosystems. They are sites of important connectivity and intense gradients that make them among the world’s most productive ecosystems. The coastal and transitional areas considered here are only a small fraction of the marine and brackish areas worldwide (~ 5%) but produce approximately half of the global fish catch per year (Palomares and Pauly, 2019). Although up to half of this catch is from small-scale fisheries (artisanal, subsistence, and recreational), it gains less attention worldwide than the larger-scale and open ocean industrial fisheries. At the same time, they develop ecological communities with an important diversity and complex mechanisms of self-regulation (Pérez-Ruzafa et al., 2019) and they provide significant ecosystem services and societal goods and benefits (Van den Belt and Costanza, 2011; Wolanski and Elliott, 2015). These and associated coastal ecosystems, including the open coast, enclosed and semi-enclosed seas, and special systems such as polar and coral environments, will be subject to change in the coming decades, and those changes will have to be either managed or accommodated by society.

Coastal and transitional ecosystems have been, are being, and will continue to be adversely affected by global climate change in many ways. These changes include increasing temperatures and sea levels, either reduced, increased, or at least subject to more erratic rainfall and freshwater discharges, especially in temperate areas, and the likelihood of more frequent or more severe droughts and storms (Day and Rybczyk, 2019). The changes to biogeographical regimes are likely with the movement of organism distributions toward higher latitudes. Higher sea levels, perhaps up to 1.5 m higher in the next century, will both increase saline intrusion and water levels into transitional areas, thereby changing vegetation and foodweb structure and perhaps causing loss of wetlands that have been important in producing ecosystem services and delivering societal goods and benefits. Growing resource scarcity, especially of energy, will limit our ability to handle these evolving problems effectively (Day et al., 2016, 2018; Wiegman et al., 2017; Day and Rybczyk, 2019).

In addition to climate changes, coastal and transitional ecosystems are increasingly subject to other types of environmental degradation, not least from increased industrialization, urbanization (urban development), and agricultural and aquacultural expansion. There is an increasing occurrence of non-native species with more vectors and migration routes becoming available; for example, the loss of polar ice may open up migration routes. There is increasing habitat loss and fragmentation not the least of which is because of land use changes for perhaps short-term economic gain but with long-term environmental and societal consequences; for example, the loss of mangroves for shrimp ponds ultimately reduces the resilience of coasts to hazards and storm events (Elliott et al., 2015, 2016; Day and Rybczyk, 2019). Because of this, there is the need for a holistic approach which incorporates the catchment-river-estuary continuum of ecosystems as well as the adjacent coastal and marine areas.

This synthesis, which is based largely on the chapters in this volume, aims to show that an eventual reduction in land and water resources, and perhaps increases in energy use in restoration and alleviation schemes, have long-term consequences (Day and Rybczyk, 2019). The loss of these resources and the increase in arid areas, the reduction in deltas and wetlands, and the loss of resilience and resistance to natural hazards may all exceed biophysical limits. Therefore, using a set of case studies covering a large geographical area (Fig. 1), in this chapter we focus on the need for a holistic approach to create sustainable management of the coastal areas. We emphasise that there is the need for a good and appropriate use of the best-available science linked to that management. Such science will help to indicate the causes and consequences of the problems as well as the solutions to them.

Fig. 1 Location map of the main study sites discussed in the text.

2 Setting the Scene: The DAPSI(W)R(M) Framework

All environments are affected by change, both natural and anthropogenic. To determine the causes and consequences of change, there is an increasing need for risk assessment and risk management frameworks that center on the human uses and abuses of the environment. One such framework originated as the DPSIR approach, but it more recently has been refined into DAPSI(W)R(M) (Drivers, Activities, Pressures, State change, Impacts (on human Welfare), Responses (using management Measures), (Patricio et al., 2016; Elliott et al., 2017). This relates to the acceptance that society has basic demands, termed Drivers, from the environment, such as the need for food, for shelter, well-being, and security, which require current Activities in an area. These activities in turn create Pressures in an area, which are termed endogenic managed pressures (for example, the need to go fishing for food and to build sea defenses for shelter and security as the mechanisms of change; again, for example, fishing involves scraping nets over the bed whereas building sea defenses may influence hydrographic processes and sediment-scouring in an area). The pressures are the mechanisms of both State change on the natural system (the loss of biota or the interference with normal hydrographic processes) and Impacts (on human Welfare). For example, the latter may be a loss of fish for human food or the reduced resilience of an area to storm events that results in the loss of human assets and livelihoods. The State changes and the Impacts on human Welfare then require Responses, which are management Measures to prevent the adverse effects. Hence the Responses should operate on the Drivers, Activities and Pressures.

The Responses (including management Measures) can fall within what has been termed the 10-tenets: that for the management to be successful and sustainable, our actions have to be ecologically sustainable, technologically feasible, economically viable, socially desirable/tolerable, legally permissible, administratively achievable, politically expedient, ethically defensible (morally correct), culturally inclusive, and effectively communicable (Barnard and Elliott, 2015). It is emphasized that whereas only one of these relates to ecological well-being, the remainder are all society-based. As noted earlier, growing pressures arising from climate change, resource scarcity, environmental degradation, and growing population will challenge the ability to manage these problems effectively.

The Endogenic Managed Pressures emanate from inside an area in which management can address both the causes and the consequences of the pressures (Elliott, 2011). For example, future demographic changes to estuaries and coastal areas will increase urbanization and industrialization, which are likely to result in pollution loadings, eutrophication, and the discharge of ballast water. In contrast, global climate change is regarded as an Exogenic Unmanaged Pressure, in which the cause emanates from outside the area of concern but the consequences have to be managed within an area. For example, sea-level rise is caused by global changes in greenhouse gases and by isostatic events, so either cause needs global action or it cannot be subject to any action to stop it, but the consequences sea-level rise, such as increased flooding and erosion, require actions (responses) inside the management area (Ducrotoy and Elliott, 2008).

The pressures mentioned earlier constitute hazards, both natural and anthropogenic, which, if they affect human assets and livelihoods, become risks (Cormier et al., 2013; Elliott et al., 2014) (Table 1). As shown by many of the contributions referenced here, to determine the future trajectories of change, it is important to use the best-available science to know what the areas are like now and what they were like in the past and to determine what hazards and risks were in the past, are occurring now, and will occur in the future. Hence the management of transitional and coastal areas becomes an exercise in risk assessment and management, that is, determining which risks are real and need to be addressed becomes the main challenge both now and with future developments. However, in considering the future for the coast and associated habitats, it is of note than the effects of a natural hazard can become much greater through human actions (see below), and biophysical constraints will result in increasing challenges to the ability to solve growing problems.

Table 1

Modified from Elliott, M., Cutts, N.D., Trono, A., 2014. A typology of marine and estuarine hazards and risks as vectors of change: a review for vulnerable coasts and their management. Ocean Coast Manag. 93, 88–99.

3 Current Status of Estuarine and Coastal Ecosystems

3.1 Estuaries

While many estuaries globally have changed throughout geological times and in many cases show their ephemeral nature, recent anthropogenic changes have received the most attention and indeed potentially indicate the trajectory of future changes (Duarte et al., 2015). As an example, Li and Chen (2019) show the value of a long-term dataset (e.g., half a century) for the changing hydrographical parameters in the Changjiang River estuary in China resulting from a combination of three hazards: water transfer projects, building of infrastructure (the Three-Gorges Dam), and sea-level rise. The increasing population in the catchment exacerbated the effects of each of these. By assessing the pattern between saline intrusion and river discharge levels, and calculating threshold values, they showed that fresh water will not be available each decade after 2040 during the annual low-flow periods. This emphasizes the need for early planning for management and remedial measures, possibly starting decades in advance.

In some cases, several adjacent estuaries are just components of a delta but they need to be considered as a single system. The so-called Delta of the rivers Rhine, Meuse, and Scheldt in the southwest part of the Netherlands is formed by the estuaries of these three rivers (Professor Patrick Meire, University of Antwerp, pers. comm.). In the last two millennia, human-induced changes have been greater than natural changes, especially with navigation and agriculture becoming the dominant drivers. However, the repercussions of such changes were then exposed due to the natural pressure of the storm surges of 1953 and 1976. The many lives lost following the first of these and the fears in the 1970s led to the so-called Delta plan in the Netherlands (Nienhuis and Smaal, 1994) and the Sigma plan in Flanders (Belgium). Excessive engineering of the estuaries, including closures and diversions, both increased public safety but at the same time led to unforeseen consequences such as changes to the water quality (stratification, anoxia, eutrophication) and ecological features (loss of commercial shellfish beds). This is now leading to further engineering and adaptive management and confirms the adage that once the systems begin to be engineered, then interventions have to continue, otherwise the systems revert to an unwanted state (for human uses). These estuaries are now central the European economic prosperity, through the ports of Antwerp and Rotterdam, and so their managers have to reconcile the natural functioning of the estuaries with the need for access by larger and larger vessels. Because of this, innovative engineering is aiming to work with nature-based solutions such as controlled inundation areas with reduced tides, managed retreat, adapted dredging, and dredging-disposal strategies to cope with human demands while ensuring natural functioning (Professor Patrick Meire, University of Antwerp, pers. comm.).

The trajectories of the change of estuaries and other transitional waters relate strongly to the features of the catchment, but also there are site-specific differences depending on the size of the estuary. For example, García-Alonso et al. (2019) studied the Río de la Plata, one of the largest estuaries in the world, and the second largest in South-America, with a catchment (of two main tributaries, the Paraná and the Uruguay Rivers) extending into five countries: Argentina, Bolivia, Brazil, Paraguay, and Uruguay. Its catchment has pressures from arable and pastoral agriculture and forestry as well as the infrastructure of hydroelectric dams, whereas the pressures in the de la Plata are from marine and river vessels, fisheries, and coastal urbanization, including tourism, and polluting discharges. Abstraction upstream for drinking water for Buenos Aires has changed the freshwater inputs, and hence the salinity balance, whereas downstream, the estuary supports cultural ecosystem services for recreation and tourism. These show that pressures equally affect neo-tropical areas and cross national boundaries. With increasing populations in these South American countries, it is expected that all of these pressures will increase.

In some areas, authorities have focused on increasing the resilience of the system in protecting the coastal and marine biodiversity, for example along the coastline of the Middle East and the northern Persian Gulf (Sharifinia et al., 2019). The Iranian coastal waters support internationally important habitats including coral reefs, mangrove forests, and seagrasses, with sandy beaches, rocky shores, and estuaries also being important. These, importantly, deliver ecological services and also support recreational, economic, and cultural activities and societal benefits. Despite this, the Persian Gulf is strongly affected by human activities, has suffered from the effects of conflicts and various human pressures even though the population density is not as high as in other areas. In contrast to many other areas, sea-level rise does not appear to be a high-priority concern given the abundance of unoccupied land and the ability to move infrastructure landward. Management here aims to increase the ability of the ecosystem to absorb natural and anthropogenic disturbances, but this area is continuing to experience potential risks because of geopolitical hazards (Table 1) with uncertain effects on the ecosystem. This area, especially the delta of the Tigris-Euphrates River, is also likely to be affected by growing water scarcity (Day et al., 2019a).

Urban estuaries, especially those in arid areas such as Australia, face severe problems of both water quality and quantity. Dunn et al. (2019), using examples from three cities in Australia, show the way in which the important provision of environmental, social, cultural, and economic ecosystem services in estuaries are often negatively affected by urbanization in the catchment and along the coast; they also show some practical and proven remediation measures. In these measures, stormwater management is a priority—for example, for new suburbs to divert their stormwater to ponds in public parks—whereas multi-solution plans cover water-sensitive urban design, removal of polluted sediment, restoration of vegetation along creeks and riverbanks, debris traps, and monitoring/research. They rightly put a high value on education and on actively canvasing the community for their views and their input to the solutions.

Although the understanding and management of estuaries has to acknowledge the bottom-up approach by looking after the hydrology, ecohydrology, and fundamental lower-level ecological processes (Wolanski and Elliott, 2015), it is often the charismatic megafauna that gets the attention of the public, the policy-makers, and the politicians. In a good news story, which is a rare occurrence for the world’s estuaries, Lanyon (2019) illustrates the success of preserving charismatic and iconic marine megafauna (turtles, dolphins, and dugongs, as well as migratory habitats for whales and shorebirds) in Moreton Bay, Australia, despite increasing estuarine urbanization. This is one of the few sites in the world where proactive management has succeeded in ensuring the survival of this high-profile and mobile marine wildlife next to a large city. This was made possible by integrating protection legislation that incorporates water quality and critical habitats protected by Marine Protected Areas (MPA), with regulating activities such as shipping, dredging, and fishing, and enforcing the legislation. Most areas worldwide have appropriate environmental protection legislation but this is not always successfully implemented and enforced. Monitoring also has to be used, as in Moreton Bay, to determine whether the management is effective and is leading to adaptive management. This is necessary, because although MPAs are effective at protecting the static features and seabed, they may be less effective for highly mobile species. In the case of the high-profile megafauna, the health of individuals and their populations similarly receives a large amount of attention and may be the end point of stressors further down the system (Lanyon, 2019).

The Moreton Bay success story contrasts with the disastrous evolution of the tidal flats along the coast of the Yellow Sea coastline in North and South Koreas and China; here the extent of the tidal flats has decreased by 50%–80% over the past 50 years because of land claim, and the decline continues at a rate of about 1.2% year-1 (Murray et al., 2012, 2014, 2015). As a result, the migratory waterbird populations that use the East Asian-Australasian Flyway, from Japan to Australia, are decreasing at a rate of about 5%–9% year-1 (MacKinnon et al., 2012; Clemens et al., 2016). As detailed by Fang (Box 1), efforts are underway in China to at least preserve some of the remaining tidal flats.

Box 1

China’s Mudflats

Qinhua Fang*,†    * Coastal and Ocean Management Institute, Xiamen University, Xiamen, China

† Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, China

There are few data published in China at the national scale about the country’s coastal mudflats. The total area of China’s coastal mudflats in the 1980s was 20,293 km² according to China Statistical Yearbook (1989). However, a more recent analysis indicated an area of 13,104 km² of China’s coastal natural wetlands (including tide zone/shallow beach, marine marshes/mangrove, estuarine water, estuarine delta, and lagoons) in 1978, 11,463 km² in 1990, 9108 km² in 2000, and 7890 km² in 2008 (Niu et al., 2012). Another similar study showed that the area of coastal natural wetland was 14,674.3 km² in 2000 and 14,318.5 km² in 2010 (Hou et al., 2016). There are thus wide discrepancies in the absolute estimates, but all studies point to a rapid loss of mudflats: for example, a 39.8% loss from 1978 after three decades of rapid coastal development in China (Niu et al., 2012). A historical satellite image analysis of the Yellow Sea coastal region (~ 4000 km coastline of China, North Korea, and South Korea) also shows that 65.3% (70.2% on China’s part) of tidal flats that existed in the 1950s had disappeared by the late 2000s (Murray et al., 2014). The rate of loss of China’s mudflats (wetlands) is decreasing in recent years; it was 13.4% from 2000 to 2008 (Niu et al., 2012; Murray et al., 2014).

This loss of coastal mudflats resulting from the sea enclosing and from land reclamation, coupled with other anthropogenic threats such as land-based pollution and climate-change effects, has led to ecosystem degradation at different scales, from local water quality degradation (Ma et al., 2017) to a regional decline of shorebirds migrating through the East Asian–Australasian Flyway (MacKinnon et al., 2012; Murray et al., 2015).

Coastal wetland administration in China was fragmented among several departments, which include Development and Reform, Oceanic Administration, Land Resources, Water Resources, Agriculture, Fisheries, Forestry, Tourism, Industry and Information, and Environmental Protection, etc., and each department has different priorities. However, a strong political will to protect coastal wetlands has been displayed in China in recent years. The Chinese central government has developed a national protection goal for wetlands, which lasts until 2020, including a series of polices such as the Wetland Protection and Restoration Plan in 2016, the 13th Five-Year National Wetland Protection Implementation Plan in 2017, Management Regulation on Coastline Protection and Use in 2016, and Guiding Opinions on Strengthening Coastal Wetland Management and Protection in 2016—as well as the reshuffling of the central government in 2018 to address ambitiously the problem of the fragmentation of wetland management.

With the efforts mentioned, it is believed that the coastal mudflats in China will likely enter a period of stabilization. However, a long process will be needed that depends on the continuous implementation of those good governmental policies and the support of the whole society.

References

Hou X., Xu X., Wu T., Li X. Change characteristics and scenario analysis of coastal wetlands in China. Wetland Sci. 2016;14(5):597–606 (in Chinese).

Ma D.Q., Zhang L., Fang Q., Jiang Y.,