The Conservation, Sustainable Use and Management of Mangrove Habitats in Oman Zakiya Musallam Mohammed Al-Afifi PhD University of York Environment and Geography September 2018 Abstract Mangroves are significant contributors to human wellbeing in many tropical and sub- tropical coastal communities and deliver a wide range of provisioning, regulating, cultural and supporting ecosystem services. Worldwide, the value of these services has been researched, but not in Oman. I explore the role of mangrove ecosystems in Oman dominated by Avicennia marina and the value of their services based on perceptions of locals, key utilisers of the ecosystem. I also examine temporal and spatial change in mangrove cover and identify the drivers of environmental change affecting these ecosystems. Perceptions were captured using self-completed questionnaires, aerial extent was estimated from aerial photgraphs and secondary fisheries data were used to evaluate the support of Omani fisheries by mangroves. Carbon sequestration was estimated through a combination of field sampling and reported allometric equations and the service of storm buffering evaluated using data from windroses and mangrove extent. For cultural services assessment, mapping and semi-structured interviews with locals were used. I found that Oman‘s mangroves are mainly threatened by cyclonic events, both intense marine wave action and flash flooding from the landward side, as well as urbanisation, leading to coastal squeeze with implications for sea-level rise. While mangroves do not appear to highly support commercial fisheries in Oman, they do support ecologically important ecosystem engineers and essential prey for higher tropic levels (including commercially important species). Estimated values of carbon stock ranged from 59.90 to 133.05 t/ha, much lower values for A. marina inhabiting more favourable environmental conditions in other parts of the world. Cultural services were highly appreciated by locals, reflecting the influence of both Arabic and Islamic identity in Omani society. Intrinsic, instrumental and relational values of nature were all highlighted by locals. An Ecosystem Based Management approach is advocated for the conservation and sustainable use of mangroves in Oman. ii List of Contents Abstract………………………...…………………...…………………………… ii List of Contents……………………………………….…………………………. iii List of Tables…………..………………………………………..…..…........…... vii List of Figures………………………………………...…………………………. ix List of Appendices…………………………………………………………....…. xiv Acknowledgements………………………………………….……….……….…. xv Declaration……….…………………………………………….…………....…... xvi Dedication…………..……………………………………………..…….....……. xvii Chapter 1 Introduction……………………………………….…………... 1 1.1. Ecosystems and human well-being……………….…... 2 1.2. Biological and physico-chemical characteristics of mangrove ecosystems…………………...…..………… 3 1.3. Environmental factors influencing mangroves………... 4 1.4. Valuable services and benefits of mangroves………… 6 1.4.1. Provisioning services………….……………. 6 1.4.2. Regulating services……………………….…. 7 1.4.3. Cultural services…….……………………….. 8 1.4.4. Supporting services………………………….. 8 1.4.5. The role of mangroves in the support of neighbouring ecosystems…………..……….. 8 1.5. Ecological indicators as measures of service flow……. 9 1.6. Towards successful management of mangroves……… 12 1.6.1. Conservation: a valuable management option …………………………………………. 12 1.6.2. Restoring the present for the future….…… 13 1.7. Mangrove Ecosystems in the Middle East: the Omani Experience …………………...…………………..…… 15 1.8. Thesis aim and objectives………….………………….. 17 1.9. Thesis contents………………………………………... 19 Chapter 2 Contrasting patterns of long-term change in mangrove area at coastal sites in Oman: the role of environmental and anthropogenic drivers………………………….……………… 21 2.1. Introduction……………………..…………..………… 21 2.2. Methodology………………………………………….. 23 2.2.1. Study sites………………….……………... 23 2.2.1.1. Cyclone-affected sites……………………. 23 2.2.1.1.1. Al-Qurum Nature Reserve….....………….. 23 2.2.1.1.2. Qurayyat…………….…………………..... 24 2.2.1.2. ―Control‖ sites: not cyclone-affected…...... 24 2.2.1.2.1. Harmul……………………………………. 24 2.2.1.2.2. Mahout……………………………………. 24 2.2.2. Spatial changes of mangroves…………... 25 iii 2.3. Results………………………………………………… 27 2.3.1. Changes in spatial extent of mangroves… 27 2.3.2. Cyclones and storminess at the different sites.............................................................. 29 2.3.3. Effects of urbanisation……….………….. 34 2.3.4. Sea-Level Rise (SLR)…………………….. 39 2.4. Discussion……………………………..……………… 41 2.4.1. Changes in spatial extent of mangroves… 41 2.4.2. Cyclones and storminess at the different sites……………………………………….. 42 2.4.2.1. Cyclone Gonu…………………...……….. 42 2.4.2.2. Cyclone Phet………………………….….. 46 2.4.3. Effects of variable precipitation on mangroves in Oman………………………. 47 2.4.4. Urbanisation………………….………….. 48 2.4.5. Sea-level rise (SLR)………….…………… 50 2.5. Conclusion…………………………………….……… 52 Chapter 3 Local perceptions of mangrove ecosystem services in Oman… 54 3.1. Introduction………….………………………………... 54 3.2. Methodology………………………………...………... 55 3.3. Results………………………..……………………….. 58 3.3.1. Socio-economic characteristics of respondents…………………………………… 58 3.3.2. Respondent opinions and attitudes towards nature in general and towards mangrove habitats in particular…………………….. 61 3.3.2.1. Public awareness of mangrove habitats and benefits…………………………………… 61 3.3.2.2. Perceptions of changes to estuarine trees (mangroves)…………………………...…. 62 3.3.2.3. Public perceptions towards natural benefits …………………………………………… 63 3.3.3. Significance of ecosystem services provided by mangroves…………………… 64 3.3.4. Activities at the sites……………………… 67 3.4. Discussion…………………………………………….. 69 3.4.1. Overview………………………………….. 69 3.4.2. Socio-economic characteristics of respondents …………………………………. 69 3.4.3. Respondent opinion and attitudes towards nature in general and mangrove habitats in particular……………………………… 70 3.4.3.1. Public awareness of mangrove habitats and benefits………………………..………….. 70 iv 3.4.3.2. Perceptions of mangrove change……….... 71 3.4.3.3. Public perception of natural benefits of mangroves………………………………… 72 3.4.5. Activities at the sites……………………… 75 3.5. Some reflections on the study………………………… 76 3.6. Conclusions…………………………………………… 77 Chapter 4 An initial assessment of the role and value of Omani mangroves for fisheries………………………………………. 80 4.1. Introduction…………………….…………………….. 80 4.2. Methodology…………………………………………. 85 4.3. Results………………………………………………… 87 4.3.1. Overview………………………………….. 87 4.3.2. Species mangrove-association…………… 88 4.3.3. Commercial value of mangrove-associated species……………………………………. 89 4.3.4. Commercial mangrove-associated species in Oman……………………………….….. 89 4.4. Discussion……………..……………………………… 93 4.4.1. Overview…………………………..……… 93 4.4.2. Species mangrove-association…………… 94 4.4.2. Commercial value of mangrove-associated species………………………………..…… 97 4.4.3. Commercial mangrove-associated species in Oman…………………………………... 103 4.5. Conclusion……………………………………………. 104 Chapter 5 How important are carbon sequestration and storm buffering services at Al-Qurum mangroves, Oman?................................. 106 5.1. Introduction…………………………………….…….. 106 5.2. Methodology……………………………………..…… 111 5.2.1. Study area……………………….……….. 111 5.2.2. Quantification of AGB and carbon…….… 112 5.2.3. Storm buffering potential………………… 115 5.3. Results………………………………………………… 115 5.3.1. H and DBH ranges of Avicennia marina… 115 5.3.2. AGB estimates and carbon stock in Avicennia marina………………………… 118 5.3.3. Protective role of mangroves against waves and storminess……………………. 120 5.4. Discussion……………………………..……………… 125 5.4.1. Estimation of AGB and carbon stock……. 125 5.4.1.1. H and DBH ranges of Avicennia marina… 125 5.4.1.2. AGB estimates and carbon stock in Avicennia marina………………………… 126 5.4.2. Defensive role of mangroves against v winds, waves and storminess ……….......... 128 5.5. Conclusion……………………….…………………… 130 Chapter 6 Cultural services in Qurayyat: assessing and mapping the local experience………………………………………………. 132 6.1. Introduction……………………………………...…… 132 6.2. Methodology…………………………………………. 135 6.3. Results…………………………...……………………. 139 6.3.1. Socio-economic characteristics of respondents…………………………………… 139 6.3.2. Frequency of visits……………….………. 141 6.3.3. Identification, understanding and mapping of cultural services……………………….. 141 6.3.4. Individual preferences for landscapes…… 149 6.3.5. Disservices of mangroves……………..….. 154 6.3.6. Perceptions of site management…………. 158 6.4. Discussion…………………………………………….. 160 6.4.1. Socio-economic characteristics of respondents ………………………………. 161 6.4.2. Frequency of visits………………………... 161 6.4.3. Identifying, understanding and mapping cultural services………………………….. 161 6.4.4. Individual preferences for landscapes…… 163 6.4.5. Disservices of mangroves………………… 164 6.4.6. Perceptions of site management………….. 166 6.5. Conclusion…………………………………………….. 167 Chapter 7 General discussion and conclusions…………..……………… 168 7.1. Thesis summary and key findings……………………. 168 7.2. Management approaches towards mangroves at the study sites……………………………………………... 171 7.3. Can management approaches perform better?............... 174 7.4. Recommendations and suggestions for further work... 181 Appendices……………………………………………………………………… 175 Abbreviations…………………………………………………………………… 229 References…………………………………………………..…………………… 231 vi List of Tables Table 1.1. The most commonly used indicators to monitor the flow of ecosystem services. Obtained from Wood et al. (2010), Egoh et al. (2012) and Plieninger et al.