Garth Cripps Feasibility study on the protection and management of the Barren Isles ecosystem, Madagascar 309A/B Aberdeen Studios, 22-24 Highbury Grove, London N5 2EA, UK. [email protected] Tel: +44 (0)20 7359 1287 Fax: +44 (0)800 066 4032 © WWF 2011 . Copyright in this publication and in all text, data and images contained herein, except as otherwise indicated, rests with WWF. Keywords: Barren Isles, coral reefs, feasibility study, Madagascar, marine protected area. Acknowledgements: Financial support for this study was provided by WWF and the Natural Museum of Geneva through the: "Réseau interdisciplinaire pour une gestion durable de la biodiversité marine: diagnostic environnemental et social autour des tortues marines dans le sud-ouest de l’Océan Indien." Recommended citation: Cripps, G. 2010. Feasibility study on the protection and management of the Barren Isles ecosystem, Madagascar. Blue Ventures Conservation Report (2009), for WWF and the "Réseau interdisciplinaire pour une gestion durable de la biodiversité marine: diagnostic environnemental et social autour des tortues marines dans le sud-ouest de l’Océan Indien ". 272 pp Table of Contents List of figures ............................................................................................................................................................7 List of tables .............................................................................................................................................................9 Abbreviations and Acronyms .................................................................................................................................12 Glossary..................................................................................................................................................................14 Summary.......................................................................................................................................................15 1. Introduction ..........................................................................................................................................20 1.1 Existing data ...............................................................................................................................................21 2. Natural habitats and biodiversity ...........................................................................................................23 2.1 Summary ....................................................................................................................................................23 2.2 Oceanography ............................................................................................................................................24 2.3 Overview of the Barren Isles and associated habitats...............................................................................25 2.4 Coral Reefs .................................................................................................................................................28 2.4.1 Geomorphology....................................................................................................................................................28 2.4.1.1 The outer slope and submerged barrier reef........................................................................................30 2.4.1.2 The outer bank......................................................................................................................................30 2.4.1.3 The internal slope .................................................................................................................................31 2.4.2 Benthic communities............................................................................................................................................32 2.4.2.1 Hard coral (Scleractinia) diversity...................................................................................................................34 2.4.2.2 Benthic composition.......................................................................................................................................36 2.4.3 Reef fish communities ...............................................................................................................................................42 2.4.3.1 Reef fish diversity ...........................................................................................................................................42 2.4.3.2 Reef fish biomass and abundance..................................................................................................................46 2.4.4 Condition of coral reefs ........................................................................................................................................53 2.5 Seagrass beds.............................................................................................................................................61 2.6 Mangrove forests and coastal wetlands ....................................................................................................61 2.7 Littoral vegetation......................................................................................................................................67 2.7.1 Sand dunes ...........................................................................................................................................................67 2.7.2 Western dry forest ...............................................................................................................................................68 2.7.3 Grassland-wooded grassland mosaic ...................................................................................................................68 2.7.4 Island vegetation ..................................................................................................................................................68 2.8 Species of high conservation value............................................................................................................69 2.8.1 Ray-finned fishes ..................................................................................................................................................69 2.8.2 Sharks and rays.....................................................................................................................................................70 2.8.3 Coelacanth ( Latimeria chalumnae ) ......................................................................................................................71 2.8.4 Marine turtles.......................................................................................................................................................71 2.8.5 Cetaceans .............................................................................................................................................................73 2.8.6 Avifauna................................................................................................................................................................74 2.8.7 IUCN Red Listed species .......................................................................................................................................75 3. Socio-economic context.........................................................................................................................76 3.1 Summary ....................................................................................................................................................76 3.2 Introduction ...............................................................................................................................................78 3.3 Socio-economic environment of the general population..........................................................................78 3.3.1 Administration......................................................................................................................................................78 3.3.2 Population ............................................................................................................................................................79 3.3.3 Occupations..........................................................................................................................................................81 3.3.4 Social infrastructure .............................................................................................................................................81 3.3.4.1 Education........................................................................................................................................................82 3.3.4.2 Health .............................................................................................................................................................82 3.3.4.3 Transport and access ......................................................................................................................................83 3.3.5 Food security ........................................................................................................................................................84 3.3.6 Development priorities.........................................................................................................................................85 3.4 Socio-economic environment of the Barren