Long-Term Monitoring of Coral Reefs of the Main Hawaiian Islands Final Report 2009 NOAA Coral Reef Conservation Program State of Hawai’i Monitoring Report NA06NOS4260113 10/01/2006 - 09/30/2010 William Walsh, Russell Sparks, Camille Barnett, Courtney Couch, Stephen Cotton, Darla White, Kristy Stone, Eric Conklin Department of Land & Natural Resources December 2010 2 Contents SUMMARY OF FINDINGS .....................................................................................................9 CONTRIBUTORS ................................................................................................................ 14 OBJECTIVES ....................................................................................................................... 15 O’AHU SURVEYS ............................................................................................................... 16 Benthic Survey Methods ...................................................................................................... 17 Fixed Photo-Transects ......................................................................................................... 17 Benthic Assessments ........................................................................................................... 17 Fish Survey Methods ............................................................................................................ 18 Results ................................................................................................................................. 19 Benthic Surveys ................................................................................................................... 20 Fish Surveys ........................................................................................................................ 25 MAUI SURVEYS .................................................................................................................. 20 Benthic Survey Methods ...................................................................................................... 30 Benthic Survey Results ........................................................................................................ 31 Fish Survey Methods ............................................................................................................ 36 Resource Fish Surveys ........................................................................................................ 36 ‘Integrated’ Fish Surveys ...................................................................................................... 37 HAFA Surveys ......................................................................................................................38 Data Analysis ....................................................................................................................... 39 Fish Survey Results ............................................................................................................. 39 Resource Fish and Integrated Surveys ................................................................................ 39 HAFA Surveys ......................................................................................................................44 Kahekili Herbivore FMA Baseline Assessment ..................................................................... 46 Citizen Science - Kahekili Herbivore Enhancement Area (HEA) Surveys ............................. 50 Volunteer Herbivore Grazing Survey and Results ............................................................... 51 Herbivore Behavior Survey and Results ............................................................................... 54 Introduced Species .............................................................................................................. 56 Coral Disease – ‘Āhihi Outbreak .......................................................................................... 60 NOAA DZ Surveys ............................................................................................................... 61 Internships and Community Education Programs ................................................................. 61 Partnerships ......................................................................................................................... 61 HAWAI’I ISLAND SURVEYS ............................................................................................... 63 Benthic Monitoring Methods ................................................................................................. 63 3 Results ................................................................................................................................. 63 Octocoral Distribution ........................................................................................................... 64 Coral Disease.......................................................................................................................67 Methodology ........................................................................................................................67 Field Surveys .......................................................................................................................67 Colony Assessment.............................................................................................................. 67 Caculations and Analyses .................................................................................................... 67 Results ................................................................................................................................. 68 Coral disease by size class .................................................................................................. 68 Coral community structure.................................................................................................... 69 Diseases in Hawai’i .............................................................................................................. 69 Disease distribution and prevelance ..................................................................................... 70 Spatial patterns .................................................................................................................... 73 Temporal comparisons ......................................................................................................... 74 Temperature data ................................................................................................................. 76 Fish Surveys - Methodology ................................................................................................. 78 Shallow water resource fish surveys .................................................................................... 80 Adult yellow tang surveys ..................................................................................................... 81 Depth stratified random surveys ........................................................................................... 81 Retrospective surveys .......................................................................................................... 82 Fish Surveys Results-West Hawai’i ...................................................................................... 83 Introduced Species – Ta’ape ................................................................................................ 86 Roi .......................................................................................................................................87 Pufferfish Die-Off .................................................................................................................. 90 Roi Impacts .......................................................................................................................... 91 Aquarium Species ................................................................................................................ 93 Fish Replenishment Areas (FRAs) ....................................................................................... 96 Aquarium Species of Special Concern ............................................................................... 103 Aquarium Species Open vs. FRA Trend Analysis ............................................................... 104 Aquarium Species Population and Catch Analysis ............................................................. 111 Gill Net Management .......................................................................................................... 113 Invertebrates – Crown-of-Thorns ........................................................................................ 115 Urchins ............................................................................................................................... 116 East Hawai’i Fish Survey Results ....................................................................................... 116 4 Figures Figure 1. O’ahu integrated (co-located fish and benthic) survey sites ................................... 16 Figure 2. Diagram of ‘integrated’ fish survey transect configuration ...................................... 19 Figure 3. Mean percent cover of sand by protection status at all integrated monitoring sites around O’ahu ................................................................................................ 21 Figure 4. Mean percent cover of non-sand substrata by protection status at all integrated monitoring sites around