Evaluating Benefits of Mangroves on Fish Pond Production and Protection in Ajuy, Panay Island, the Philippines Natalie Jaworska September 2010 A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science and the Diploma of Imperial College London. 1 Success will be had on the day my grandchildren walk with me through these habitats, understanding their importance, appreciating their diversity, and captivated by their magic (Primavera, J. H. 2005) 2 DECLARATION OF OWN WORK I declare that this thesis (insert full title) …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… is entirely my own work and that where material could be construed as the work of others, it is fully cited and referenced, and/or with appropriate acknowledgement given. Signature …………………………………………………….. Name of student …………………………………………….. (please print) Name of Supervisor …………………………………………. 3 Contents 1.0 Introduction ............................................................................................................................. 10 1.1 Aims and Objectives ........................................................................................................... 11 1.1.1 Aims .............................................................................................................................. 11 1.1.2 Objectives ..................................................................................................................... 12 1.1.3 Hypotheses .................................................................................................................... 12 1.2 Thesis Structure Overview ................................................................................................. 12 2.0 Background ............................................................................................................................. 13 2.1 Mangroves ........................................................................................................................... 13 2.1.1 Mangroves and Ecosystem Services ............................................................................. 13 2.1.2 Mangroves in the Philippines ........................................................................................ 14 2.2 Aquaculture ......................................................................................................................... 16 2.2.1 History ........................................................................................................................... 16 2.2.2 Management .................................................................................................................. 17 2.2.3 Pests .............................................................................................................................. 18 2.2.4 Impacts .......................................................................................................................... 20 2.2.5 The Future of Aquaculture ............................................................................................ 23 2.3 Reviews of Mangrove Benefits for Aquaculture .............................................................. 24 2.3.1 Waste Water Treatment ................................................................................................ 24 2.3.2 Nutrient Inputs .............................................................................................................. 25 2.3.3 Protection ...................................................................................................................... 25 2.4 Law ....................................................................................................................................... 27 2.4.1 Legislation Shortfalls .................................................................................................... 27 2.4.2 Mangrove Replanting and Rehabilitation ..................................................................... 28 2.5 Mangrove Structure ............................................................................................................ 30 2.6 Project Variables ................................................................................................................. 31 2.7 Study Area ........................................................................................................................... 31 3.0 Methods .................................................................................................................................... 32 3.1 Data Collection .................................................................................................................... 32 3.2 Research Assistants and Logistics ..................................................................................... 33 3.3 Social Research .................................................................................................................... 33 3.3.1 Pilot Study ..................................................................................................................... 33 3.3.2 Questionnaire Interviews .............................................................................................. 33 3.4 Mangrove Surveys .............................................................................................................. 35 4 3.5 Mangrove Calculations ....................................................................................................... 37 3.6 Data Analysis ....................................................................................................................... 38 4.0 Results ...................................................................................................................................... 39 4.1 Production ........................................................................................................................... 39 4.1.1 Anderson Darling Test in Minitab ................................................................................ 40 4.1.2 Pearson‟s Parametric Correlation Analysis in Minitab ................................................. 40 4.1.3 Response and Explanatory Variable Interactions ......................................................... 40 4.1.4 Production Analysis in R .............................................................................................. 41 4.2 Protection ............................................................................................................................. 46 4.2.1 Protection Analysis in R with Response Variable: Frequency of Dike Breaching ....... 46 4.2.2 Protection Analysis in R with Response Variable: Time Since Last Dike Breaching .. 47 4.3 Additional Analyses ............................................................................................................ 48 5.0 Discussion................................................................................................................................. 50 5.1 Production ........................................................................................................................... 50 5.1.1 Mangrove Area ............................................................................................................. 50 5.1.2 Pond Management......................................................................................................... 52 5.1.3 Additional Production Considerations .......................................................................... 54 5.1.3.1 Production and Fry Source ............................................................................................ 54 5.1.3.2 Production and Additional Recruitment........................................................................ 55 5.1.3.3 Production and Pond Water Source .............................................................................. 56 5.2 Protection ............................................................................................................................. 57 5.2.1 Dike Breach Frequency and Time Since Last Breaching ............................................. 57 5.3 Additional Mangrove Benefits ........................................................................................... 60 5.4 Additional Notes .................................................................................................................. 61 5.5 Strengths and Limitations .................................................................................................. 61 5.5.1 Strengths ....................................................................................................................... 61 5.5.2 Limitations .................................................................................................................... 61 5.5.2.1 Mangrove Surveys ........................................................................................................ 61 5.5.2.2 Interview Surveys ......................................................................................................... 62 5.6 Future Recommendations .................................................................................................. 64 5.7 Conclusion ........................................................................................................................... 67 6.0 References ...............................................................................................................................