COOK ISLANDS MARINE PARK Coral reef survey of Aitutaki, Manuae, Mitiaro, Takutea, and Atiu in the southern Cook Islands Graham McDonald Teina Rongo Jacqueline Evans Kelvin Passfield Jessica Cramp Mareike Sudek Ben Tautu Graham McDonald Teariki Charles Rongo Barbara Hanchard 0 2013 COOK ISLANDS MARINE PARK Coral reef survey of Aitutaki, Manuae, Mitiaro, Takutea, and Atiu in the southern Cook Islands This research was a collaboration between the Office of the Prime Minister of the Cook Islands (Climate Change Division), Te Ipukarea Society, Oceans 5, Waitt Institute, Pacific Islands Conservation Initiative, Cook Islands National Environment Service, Secretariat of the Pacific Community, European Union, and the Global Climate Change Alliance. 1 How to cite this report: Rongo, T.*, Evans, J., Passfield, K., Cramp, J., Sudek, M., Tautu, B., McDonald, G., Rongo, T.C., & B. Hanchard. 2013. Cook Islands Marine Park: coral reef survey of Aitutaki, Manuae, Mitiaro, Takutea, and Atiu in the southern Cook Islands. Government of the Cook Islands. 64 p. *Corresponding author: Office of the Prime Minister, Private Bag, Avarua, Rarotonga, Cook Islands; [email protected]. 2 TABLE OF CONTENTS EXECUTIVE SUMMARY.................................................................................................................................................... 4 1. INTRODUCTION............................................................................................................................................. 5 1.1. PRIMARY OBJECTIVES ............................................................................................................ 8 1.2. EXPEDITION TEAM ................................................................................................................... 8 1.3. MATERIALS AND METHODS..................................................................................................... 9 1.3.1. Sites ........................................................................................................................... 9 1.3.2. Transect deployment ................................................................................................. 9 1.3.3. Biological surveys ...................................................................................................... 9 1.3.3.1. Coral communities................................................................................... 9 1.3.3.2. Coral colony size..................................................................................... 9 1.3.3.3. Macro-invertebrates & fish....................................................................... 10 1.3.3.4. Biological diversity................................................................................... 10 1.3.4. Data analysis.............................................................................................................. 10 1.3.4.1. Percent cover calculations....................................................................... 10 1.3.4.2. Colony size calculation............................................................................ 11 1.3.4.3. Average density....................................................................................... 11 1.3.4.4. Species diversity...................................................................................... 11 1.3.4.5. Statistical analysis................................................................................... 11 2. PROFILE AND RESULTS BY ISLAND.......................................................................................................... 12 2.1. AITUTAKI...................................................................................................................................... 12 2.1.1. Site characteristics..................................................................................................... 12 2.1.2. Benthic communities.................................................................................................. 13 2.1.3. Macro-invertebrate communities................................................................................ 13 2.1.4. Discussion.................................................................................................................. 14 2.2. MANUAE....................................................................................................................................... 18 2.2.1. Site characteristics..................................................................................................... 18 2.2.2. Benthic communities.................................................................................................. 19 2.2.3. Macro-invertebrate communities............................................................................... 22 2.2.4. Fish communities....................................................................................................... 23 2.2.5. Discussion.................................................................................................................. 25 2.3. MITIARO....................................................................................................................................... 28 2.3.1. Site characteristics..................................................................................................... 28 2.3.2. Benthic communities.................................................................................................. 29 2.3.3. Macro-invertebrate communities................................................................................ 31 2.3.4. Fish communities....................................................................................................... 32 2.3.5. Discussion.................................................................................................................. 33 2.4. TAKUTEA..................................................................................................................................... 34 2.4.1. Site characteristics..................................................................................................... 34 2.4.2. Benthic communities.................................................................................................. 35 2.4.3. Macro-invertebrate communities................................................................................ 37 2.4.4. Fish communities....................................................................................................... 38 2.4.5. Discussion.................................................................................................................. 39 2.5. ATIU.............................................................................................................................................. 40 2.5.1. Site characteristics..................................................................................................... 40 2.5.2. Benthic communities.................................................................................................. 41 2.5.3. Macro-invertebrate communities................................................................................ 44 2.5.4. Fish communities....................................................................................................... 46 2.5.5. Discussion.................................................................................................................. 47 3. OVERALL COMPARISON.............................................................................................................................. 48 3.1. BENTHIC COMMUNITIES........................................................................................................... 48 3.2. MACRO-INVERTEBRATE COMMUNITIES................................................................................ 53 3.3. FISH COMMUNITIES................................................................................................................... 54 4. SUMMARY...................................................................................................................................................... 56 5. ACKNOWLEDGEMENTS............................................................................................................................... 58 LITERATURE CITED.......................................................................................................................................................... 59 APPENDICES..................................................................................................................................................................... 60 3 EXECUTIVE SUMMARY From 28 July – 9 August 2013, a research team consisting of individuals from the Office of the Prime Minister of the Cook Islands, Te Ipukarea Society, Oceans 5, Pacific Islands Conservation Initiative, Cook Islands National Environment Service, and local volunteers travelled aboard the vessel Plan B of the Waitt Institute to conduct a rapid marine assessment of the fore reefs of the islands of Aitutaki, Manuae, Mitiaro, Takutea, and Atiu in the southern Cook Islands –– for the purpose of assessing the health of coral reefs within the proposed Cook Islands Marine Park. The results of this assessment showed that coral communities on the fore reefs of Manuae, Mitiaro, Takutea, and Atiu were relatively healthy with good coverage of hard corals. Indicators of healthy reefs on these islands also included the dominance and high abundance of the coral-associated fish family Pomacentrids,