IUCN Rue Mauverney 28 CH-1196 Gland Switzerland Tel: + 41 22 999 0000 Fax: + 41 22 999 0015 iucn/redlist iucnredlist Madagas Car aNd the I NdIaN OCea N Isla Nds the IUCN red list of threatened species tM the stat Us aNd dIstr IBUt ION OF Freshwater BIOdIvers Ity IN Madagas Car aNd the I NdIaN OCea N Isla Nds h Otsp Ot Edited by Laura Máiz-Tomé, Catherine Sayer and William Darwall IUCN Freshwater Biodiversity Unit, Global Species Programme the stat Us aNd dIstr IBUt ION OF Freshwater BIOdIvers Ity IN Madagas Car a Nd the I NdIaN OCea N Isla Nds h Otsp OtTHE STATUS AND DISTRIBUTION OF FRESHw ATER BIODIv ERSITy IN MADAg ASc AR AND THE INDIAN Oc EAN ISl ANDS HOTSp OT Edited by Laura Máiz-Tomé, Catherine Sayer and William Darwall IUCN Freshwater Biodiversity Unit, Global Species Programmeii The designation of geographical entities in this book, and the presentation of the material, do not imply the expression of any opinion whatsoever on the part of IUCN concerning the legal status of any country, territory, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The views expressed in this publication do not necessarily reflect those of IUCN, or other participating organisations. This publication has been made possible by funding from The Critical Ecosystem Partnership Fund. Published by: IUCN Cambridge, UK in collaboration with IUCN Gland, Switzerland Copyright: © 2018 IUCN, International Union for Conservation of Nature and Natural ResourcesReproduction of this publication for educational or other non-commercial purposes is authorised without prior written permission from the copyright holder provided the source is fully acknowledged.Reproduction of this publication for resale or other commercial purposes is prohibited without prior written permission of the copyright holder. Citation: Máiz-Tomé, L., Sayer, C. and Darwall, W. (eds) (2018). The status and distribution of freshwater biodiversityin Madagascar and the Indian Ocean islands hotspot. Gland, Switzerland: IUCN. viii+128pp. ISBN: 978-2-8317-1881-1 (print version)978-2-8317-1882-8 (PDF) DOI: 10.2305/IUCN.CH.2018.RA.1.en Cover photo: Malagasya antongilensis. © Rob Schell Photography All the photographs used in this publication remain the property of the original copyright holder (see individual captions for details). Photographs should not be reproduced or used in other contexts without written permission from the copyright holder. Layout by: NatureBureau naturebureau.co.uk/ Printed by: Langham Press Ltd The text of this book is printed on Cocoon FSC 50% Recycled Silk 115 gsm. Available from: IUCN (International Union for Conservation of Nature)Global Species ProgrammeRue Mauverney 281196 GlandSwitzerlandTel +41 22 999 0000Fax +41 22 999 0002iucn/resources/publications iucn/theme/species/our-work/freshwater-biodiversity If you have any questions regarding the data and outputs presented in this report, please contact the IUCN Freshwater Biodiversity Unit (Freshwater.Biodiversityiucn).iii Contents Acknowledgements .v Executive summary .vi Chapter 1 Madagascar and the Indian Ocean islands biodiversity hotspot .1 1.1 Situation analysis .11.1.1 The value of freshwater wetlands and their biodiversity .11.1.2 Main threats to freshwater species .1 1.2 Objectives of this study .2 1.3 Project components.3 1.4 Freshwater species as indicators .3 1.5 Madagascar freshwater ecoregions .3 1.6 References .3 Chapter 2 Red List assessment methodology .7 2.1 Selection of priority taxa .72.1.1 Fishes .72.1.2 Molluscs .72.1.3 Aquatic plants .82.1.4 Odonata .82.1.5 Decapods (crabs, crayfishes and shrimps) .8 2.2 Data collection and quality control .8 2.3 Species mapping .8 2.4 Assessment of species threatened status .9 2.5 References .10 PART 1 SPECIES OF IMPORTANCE FOR CONSERVATION Chapter 3 The status and distribution of freshwater fishes .13 3.1 Overview of the ichthyofauna of Madagascar and the Indian Ocean islands hotspot .13 3.2 Patterns of overall species richness .14 3.3 Conservation status .173.3.1 Threatened species .173.3.2 Data Deficient species .193.3.3 Red List Index .19 3.4 Main threats .20 3.5 Conservation recommendations .23 3.6 Research actions .24 3.7 Species in the spotlight .24 3.8 References .25 Annex 3.1 Red List status of freshwater fishes .27 Chapter 4 The status and distribution of freshwater molluscs .29 4.1 Overview of freshwater molluscs of Madagascar and the Indian Ocean islands hotspot .29 4.2 Patterns of overall species richness .31 4.3 Conservation status .334.3.1 Threatened species .344.3.2 Data Deficient species .36 4.4 Main threats .36 4.5 Conservation recommendations .37 4.6 Research actions .39 4.7 Species in the spotlight .38 4.8 References .39 Annex 4.1 Red List status of freshwater molluscs .41 Chapter 5 The status and distribution of freshwater decapod crustaceans .42 5.1 Overview of freshwater decapods of Madagascar and the Indian Ocean islands hotspot .42 5.2 Patterns of overall species richness .425.2.1 Freshwater crabs .425.2.2 Freshwater crayfish .455.2.3 Freshwater shrimps .47 5.3 Conservation status .475.3.1 Threatened species .475.3.2 Data Deficient species .49 5.4 Main threats .51 5.5 Conservation recommendations .53 5.6 Research actions .54 5.7 Species in the spotlight .56 5.8 References .55 Annex 5.1 Red List Status of freshwater crabs .58 Annex 5.2 Red List Status of freshwater crayfish .58 Annex 5.3 Red List Status of freshwater shrimps.58 Chapter 6 The status and distribution of aquatic plants .59 6.1 Overview of aquatic plants of Madagascar.59 6.2 Patterns of overall species richness .60 6.3 Conservation status .616.3.1 Threatened species .636.3.2 Data Deficient species .64 6.4 Main threats .64 6.5 Conservation recommendations .68 6.6 Research actions .68 6.7 References .69iv Annex 6.1 Family name inconsistencies between the IUCN Red List website and the APG IV system relevant for the Madagascar aquatic plant dataset .71 Annex 6.2 Fern families that include aquatic species for Madagascar .71 Annex 6.3 Seed-plant families that comprise only aquatic species in Madagascar .71 Annex 6.4 Seed-plant families comprising aquatic and terrestrial species in Madagascar .72 Annex 6.5 Number of species in lentic habitats in Madagascar .72 Annex 6.6 Summary of Red List assessment results .72 Annex 6.7 Red List status of Madagascar aquatic plants .73 Chapter 7 The status and distribution of Odonata .75 7.1 Overview of the Odonata of Madagascar and the Indian Ocean islands hotspot .75 7.2 Patterns of overall species richness .76 7.3 Conservation status .787.3.1 Threatened species .787.3.2 Data Deficient species .79 7.4 Main threats .79 7.5 Conservation recommendations .83 7.6 Research actions .84 7.7 Species in the spotlight .84 7.8 References .85 Annex 7.1 Red List status of Odonata .87 Chapter 8 Synthesis for all taxa .89 8.1 Introduction .89 8.2 Freshwater biodiversity across Madagascar and theIndian Ocean islands hotspot .898.2.1 Patterns of species richness.898.2.2 Threatened species .918.2.3 Data Deficient species .91 8.3 Main threats .94 8.4 Conservation priorities and recommendations .958.4.1 Integrated River Basin Management (IRBM) .958.4.2 Securing environmental flows .958.4.3 Site protection .968.4.4 Environmental Impact Assessments .968.4.5 Enforcement of existing legislation andgovernment awareness.96 8.5 References .96 PART 2 SITES OF IMPORTANCE FOR FRESHWATER SPECIES Chapter 9 Freshwater Key Biodiversity Areas in Madagascar .98 9.1 Background .98 9.2 Methodology .999.2.1 KBA criteria and thresholds .999.2.2 Freshwater KBA delineation process .99 9.3 Results .1039.3.1 Freshwater KBA trigger species .1039.3.2 Freshwater KBAs overview .1039.3.3 Current levels of protection .1049.3.4 Newly delineated KBAs .104 9.4 Site champions .106 9.5 Summary and recommendations .106 9.6 Next steps .108 9.7 References .108 Annex 9.1 KBA trigger species .109 Annex 9.2 Site Champions Madagascar . 113 Annex 9.3 Summary of the KBA Criteria and Thresholds (IUCN 2016) . 114 Chapter 10 A critical sites network for freshwater biodiversity in Madagascar . 115 10.1 Introduction . 11510.1.1 Systematic conservation planning . 115 10.2 Methods . 11610.2.1 Marxan . 11610.2.2 Conservation features . 11610.2.3 Planning units . 11610.2.4 Connectivity . 11710.2.5 Locking in existing management units . 11710.2.6 Conservation features versus planning units . 11810.2.7 Conservation features targets . 11810.2.8 Marxan set up . 118 10.3 Results . 11810.3.1 Summary of scenarios run . 11810.3.2 Scenario C Optimal network consideringcurrent land use and potential management .122 10.4 Caveats.127 10.5 Conclusions .127 10.6 References .127v Acknowledgements Donor IUCN would like to thank the Critical Ecosystems Partnership Fund for providing the financial support for this project. In particular we are grateful for the s