Towards an understanding of mangrove diversity in Australia Ian David Cresswell B Sc (Hons) Murdoch University This thesis is presented for the degree of Doctor of Philosophy Murdoch University, 2012 21 December 2012 An internationally significant mangrove fringe in an open embayment (with spits at the headlands), Mitchell Plateau, WA Nationally significant mangrove tidal creeks behind mangrove fringed tidal flats and tidal creeks partially protected by a limestone barrier, Cape Keraudren, WA A regionally significant mangrove lined tidal creek complex and tidal flats leeward of a limestone barrier, Port Hedland, WA Dedication This work is dedicated to my mother Rose Lilian Cresswell (14 March 1921 – 18 May 2010) whose unwavering belief in me and support is the bedrock upon which everything else is built. Declaration I declare that this thesis is my own account of my research and contains as its main content work which has not previously been submitted for a degree at any tertiary education institution. Ian David Cresswell Contents Contents ............................................................................................................................................ i Figures ............................................................................................................................................ iv Tables ............................................................................................................................................. v Appendices ....................................................................................................................................... v Acknowledgements ......................................................................................................................... vi Abstract........................................................................................................................................... vii Abbreviations ................................................................................................................................... ix Scale Terminology ............................................................................................................................ ix Salinity Terminology ........................................................................................................................ ix Glossary ............................................................................................................................................ x Chapter 1: Introduction and aims ....................................................................................... 1 1.1 Background .......................................................................................................................... 1 1.2 Aim of thesis ........................................................................................................................ 9 1.3 Thesis structure .................................................................................................................11 Chapter 2: Literature review ............................................................................................. 13 2.1 Introduction .......................................................................................................................13 2.2 Methods ............................................................................................................................13 2.2.1 Literature review of Australian geology, physiography, climate and oceanography ....................................................................................................................13 2.2.2 Literature review of Australian coastal systems .....................................................14 2.2.3 Literature review of mangrove ecology ..................................................................14 2.2.4 Literature review of international and national mangrove management and conservation laws and policies ..........................................................................................14 2.3 Results and Discussion ......................................................................................................15 2.3.1 Geology of Australia ................................................................................................15 2.3.2 Physiography of Australia .......................................................................................19 2.3.3 Climate of Australia .................................................................................................23 2.3.4 Oceanography of Australia .....................................................................................27 2.3.5 Coastal systems .......................................................................................................28 2.3.6 Mangrove ecology ...................................................................................................31 2.3.7 Previous studies of the distribution of Australian mangroves ................................35 2.3.8 International policy instruments .............................................................................42 2.3.9 National and State policies and laws ......................................................................43 2.4 Conclusion .........................................................................................................................50 Chapter 3: Processes of coastal evolution and development of mangrove habitats ........... 53 3.1 Introduction .......................................................................................................................53 | i 3.2 Methods ............................................................................................................................ 53 3.3 Results ............................................................................................................................... 55 3.4 Discussion .......................................................................................................................... 85 Chapter 4: The physical framework of the Australian coast and mangrove habitats .......... 97 4.1 Introduction ...................................................................................................................... 97 4.2 Methods .......................................................................................................................... 100 4.3 Results ............................................................................................................................. 104 4.3.1 Coastal geological setting ..................................................................................... 104 4.3.2 Coastal physiographic setting ............................................................................... 108 4.3.3 Coastal climate setting.......................................................................................... 108 4.3.4 Coastal oceanographic setting .............................................................................. 110 4.3.1 Australian coastal sectors and the development of mangrove habitats across Australia .......................................................................................................................... 114 4.3.5 Description of the coastal sectors around Australia ............................................ 117 4.4 Discussion ........................................................................................................................ 137 Chapter 5: Influences of continental gradients in tide, climate and habitat heterogeneity on Australia’s mangrove ecosystems ......................................................................................... 141 5.1 Introduction .................................................................................................................... 141 5.2 Methods .......................................................................................................................... 142 5.3 Results ............................................................................................................................. 145 5.3.1 The distribution of mangroves along the Australia coast in relationship to latitude ............................................................................................................................ 145 5.3.2 Mangrove structure and form .............................................................................. 148 5.3.3 The suites/arrays of mangrove habitats that occur across Australia ................... 162 5.4 Discussion ........................................................................................................................ 165 5.5 Conclusions ..................................................................................................................... 167 Chapter 6: Developing a framework for mangrove conservation in Australia .................. 171 6.1 Introduction .................................................................................................................... 171 6.2 Methods .......................................................................................................................... 173 6.3 Results ............................................................................................................................. 174 6.3.1 The need for a national mangrove conservation strategy ................................... 174 6.3.2 The objectives of a national mangrove