Prepared in cooperation with the State of HawaiHawai‘i‘i Department of Health DevelopmentDevelopment ofof InvertebrateInvertebrate CommunityCommunity IndexesIndexes ofof StreamStream QualityQuality forfor thethe IslandsIslands Ofof MauiMaui andand O‘ahu,O‘ahu, Hawai‘iHawai‘i Scientific Investigations Report 2012–5055 U.S. Department of the Interior U.S. Geological Survey COVER: Waterfall at one of the valleys of East Wailua Iki Stream near Wailua, east Maui, Hawaiÿi. (Photograph by Adam G. Johnson, U.S. Geological Survey) Development of Invertebrate Community Indexes of Stream Quality for the Islands of Maui and Oÿahu, Hawaiÿi By Reuben H. Wolff Prepared in cooperation with the State of Hawaiÿi Department of Health Scientific Investigations Report 2012–5055 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2012 This report and any updates to it are available online at: http://pubs.usgs.gov/sir/2012/5055/ For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Wolff, R.H., 2012, Development of invertebrate community indexes of stream quality for the islands of Maui and O‘ahu, Hawai‘i: U.S. Geological Survey Scientific Investigations Report 2012-5055, 191 p. iii Contents Abstract ..........................................................................................................................1 Introduction .....................................................................................................................1 Acknowledgments ...................................................................................................3 Macroinvertebrates in Hawaiian Streams .......................................................................3 Description of Study Areas .............................................................................................4 East Maui ................................................................................................................7 West Maui ...............................................................................................................7 Oÿahu ......................................................................................................................7 Stream Diversions and Instream Flow Studies........................................................7 Historical Land Use ...............................................................................................15 Recent History ...............................................................................................17 Data-Collection and Analysis Methods .........................................................................17 Selection of Sampling Sites ...................................................................................17 Determination of Habitat Characteristics ...............................................................18 Geographic Information System (GIS) ..................................................................18 Collection of Invertebrate Samples .......................................................................18 Qualitative Benthic Macroinvertebrate Sampling ...........................................18 Quantitative Benthic Macroinvertebrate Sampling .........................................18 Handling of Native Species ............................................................................21 Laboratory Methods ..............................................................................................21 Quality Control .......................................................................................................21 Laboratory Methods .......................................................................................21 Re-sort of Samples .................................................................................21 Replicate Sampling ........................................................................................21 Repeat Sampling ............................................................................................21 Additional Biological Surveys ................................................................................22 Snorkel Surveys .............................................................................................22 Damselflies .....................................................................................................22 Evaluation of Re-sort, Replicate, and Repeat Samples ...............................................22 Benthic Macroinvertebrate Community Structure in Maui and Oÿahu Streams ............23 Native Macroinvertebrates.....................................................................................23 Nonnative Macroinvertebrates...............................................................................25 Insects ............................................................................................................25 Trichoptera ..............................................................................................25 Chironomidae ..........................................................................................27 Empididae ...............................................................................................28 Decapods .......................................................................................................28 Cryptogenic Macroinvertebrates ...........................................................................29 Mollusks .........................................................................................................29 Native Fish ............................................................................................................30 Nonnative Fish ......................................................................................................34 Poeciliidae ......................................................................................................34 iv Development of Community Indexes ............................................................................35 Maui Metrics and Index Development ...................................................................36 Evaluation with the Preliminary–Hawaiian Benthic Index of Biotic Integrity ...36 Maui P–HBIBI Scores .............................................................................38 Total Macroinvertebrate Abundance Metric .....................................38 Taxonmic Richness Metric ...............................................................38 Relative Abundance of Insecta Metric .............................................38 Abundance of Nonnative or Cryptogenic Mollusks Metric ...............39 Abundance of Amphipoda Metric .....................................................44 ÿÖpae Presence/Absence Metric .....................................................44 Crayfish Presence/Absence Metric ..................................................45 Final P–HBIBI Score ........................................................................45 New Maui Metrics and Index ..........................................................................46 Maui Reference “Least Disturbed” Site Selection ...................................46 Total Macroinvertebrate Abundance Metric (Revised) ............................46 Relative Abundance of Insecta Metric (Revised) ....................................46 Ratio of the Nonnative Trichoptera and Diptera ......................................51 Native Macroinvertebrate Presence/Absence .........................................51 Final Index Score ....................................................................................51 Oÿahu Metrics and Index Refinement ....................................................................56 Evaluation with the Preliminary–Hawaiian Benthic Index of Biotic Integrity ........................................................................56 Oÿahu WSA P–HBIBI Scores ..................................................................56 Total Macroinvertebrate Abundance Metric .....................................56 Taxonomic Richness Metric .............................................................56 Relative Abundance of Insecta Metric .............................................56 Abundance of Nonnative or Cryptogenic Mollusks Metric ...............57 Abundance of Amphipoda Metric .....................................................57 ÿÖpae Presence/Absence Metric .....................................................57 Crayfish Presence/Absence Metric ..................................................57 Final P–HBIBI Score ........................................................................57 Refined Oÿahu Metrics and Index ...................................................................61 Oÿahu