HABITAT USE AND TROPHIC ECOLOGY OF THE INTRODUCED SNAPPER LUTJANUS KASMIRA AND NATIVE GOATFISHES IN HAWAI‘I A DISSERTATION SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI‘I IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN ZOOLOGY (Marine Biology) AUGUST 2011 By Brett D. Schumacher Dissertation Committee: Alan Friedlander, Chairperson Charles Birkeland Kim Holland William Walsh Jeffrey Drazen UMI Number: 3485487 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent on the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI 3485487 Copyright 2011 by ProQuest LLC. All rights reserved. This edition of the work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, MI 48106 - 1346 iii ACKNOWLEDGEMENTS I would like to gratefully acknowledge James Parrish for his loyal and longstanding support of my research as my original advisor and committee chair. I would also like to thank Alan Friedlander for taking over as chair after Dr. Parrish’s well- deserved retirement. I sincerely appreciate the suggestions and advice I received from my other committee members, Charles Birkeland, Curt Daehler, Jeff Drazen, Kim Holland and Bill Walsh. I am greatly indebted to Jeremy Claisse, Eric Conklin, Katie Howard, and Craig Musberger, dedicated research assistants who were willing to go into the field at all hours and in any kind of weather. Ken Longenecker and the hospitality of Lu Eldridge and Bernice Pauahi Bishop Museum were instrumental in providing training to identify invertebrate prey. I would also like to thank Greta Aeby, Wendy Bauckham, Ray Boland, Brent Carmen, Tim Clark, Ralph DeFelice, Tim Fitzgerald, Brian Greene, Chris Knickerbocker, Lucy Kida, Ross Langston, Sarah McTee, Amanda Meyer, Carl Meyer, Frank Parrish, Dave Pence, Paul Schumacher, Angela Sy, Dale Webber, Ivor Williams and Thierry Work for additional field, laboratory and intellectual support. The Hawai‘i Division of Aquatic Resources (HDAR) office in West Hawai‘i provided access to facilities and indispensible local knowledge of potential study sites. Institutional support and funding were provided by Sea Grant Hawai‘i, the Hawai‘i Cooperative Fishery Research Unit (US Geological Survey), the Western Pacific Regional Fishery Management Council, and the NOAA Coral Conservation Fund through the HDAR. The National Park Service Kaloko-Honokōhau National Historical Park also provided iv generous logistical support. Finally, I would like to thank my family and friends for their support throughout my nearly unending career as a student. v ABSTRACT There have been persistent concerns among the fishing community in Hawai‘i that the introduced snapper Lutjanus kasmira has caused declines in populations of native shallow-water fishery species. L. kasmira has purportedly caused these declines through predation on juveniles and/or competition with adults for food or shelter. Because goatfishes were commonly cited as having been adversely affected by the introduced snapper, the present investigation compared habitat use and trophic ecology of L. kasmira and three native species of goatfish (Mulloidichthys flavolineatus, M. vanicolensis and Parupeneus multifasciatus). Studies of small-scale habitat use indicated that L. kasmira can displace resting schools of M. vanicolensis farther from shelter. However, clear detrimental effects of this displacement have not been quantified, and any such effects would likely be limited to locations where these species co-occur at high densities. Acoustic telemetry and research fishing found that larger-scale habitat use patterns of L. kasmira and goatfishes would be unlikely to drive competition for food. Areas used by Mulloidichthys spp. for nocturnal feeding were generally deeper sandy habitats, while those used by L. kasmira were shallower and closer to the reef. P. multifasciatus always stayed relatively close to the reef but fed during the day. Fish were collected for dietary analysis off the south shore and Kane‘ohe Bay of O‘ahu, and off the west shore of the Island of Hawai‘i. Archived diet data from the Northwestern Hawaiian Islands and Puako Bay on the Island of Hawai‘i were also incorporated into dietary analyses. Although there was some similarity in types of prey consumed by L. kasmira and P. multifasciatus, there vi was no evidence that abundance of L. kasmira affected the diet or biological condition of P. multifasciatus or any other species in the study. Additionally, no fish (e.g. P. porphyreus, Zebrasoma flavescens) or invertebrate (Ranina ranina, Octopus cyanea) species that were important to local fisheries were identified in L. kasmira guts. Given the lack of evidence of strong ecological interactions between L. kasmira and other species in this study, fears that the introduced snapper has had a detrimental impact on commercially important native species in Hawai‘i appear to be unfounded. vii TABLE OF CONTENTS ACKNOWLEDGEMENTS…………………………………………………………….iii ABSTRACT……………………………………………………………………………....v LIST OF TABLES AND APPENDIX.………………………………………………....ix LIST OF FIGURES ........................................................................................................xii CHAPTER I: General Introduction…................................................................................1 Overview……………………………………..…..……….....…………………….1 Introduction and spread of L. kasmira………….………....………………………3 Rationale for present study…………………….………...……………………..…5 Selection of focal species……………………………..…………………………...8 Description of research…………………………………………………………..11 CHAPTER II: Spatial relationships between an introduced snapper and native goatfishes on Hawaiian reefs Abstract..................................................................................................................23 Introduction............................................................................................................24 Methods.................................................................................................................27 Results ...................................................................................................................29 Discussion..............................................................................................................32 CHAPTER III: Habitat use and movement patterns of native goatfishes and the introduced snapper Lutjanus kasmira Abstract..................................................................................................................43 viii Introduction............................................................................................................44 Methods..................................................................................................................46 Results....................................................................................................................52 Discussion..............................................................................................................64 Conclusions............................................................................................................70 CHAPTER IV: Diets of the introduced snapper Lutjanus kasmira and native fishes in Hawai‘i Abstract..................................................................................................................97 Introduction............................................................................................................98 Methods................................................................................................................104 Results..................................................................................................................115 Discussion............................................................................................................136 Conclusions……………………………………………………………….…….149 CHAPTER V: Summary and Conclusions.....................................................................221 LITERATURE CITED.................................................................................................227 ix LIST OF TABLES AND APPENDIX TABLE PAGE 1.1. Summary of introductions by Hawai‘i Division of Fish and Game………………...14 1.2. Introduction events of Lutjanus kasmira………….…………………………….…..14 1.3. First reported capture or sighting of Lutjanus kasmira…………………………...…15 1.4. Summary of previous diet studies...............................………………………….......16 2.1. Results of multi-factor ANOVA………………...………………………………......37 3.1. Summary of active tracking data……………………………………………………72 3.2. Summary of remote monitoring data………………………………………………..73 3.3. Summary of conventional tagging data……………………………………………..74 3.4. Fisher’s exact test of co-occurrence of species during research fishing…..……...…74 4.1. Number of fish specimens with gut contents………………………………………152 4.2. Size and trophic level of prey items……………………………………..…………153 4.3. ANCOVA of maximum prey size…..............………………...……………………153 4.4. Multiple comparisons of maximum prey size……………………………...………154 4.5. ANCOVA of maximum prey size by species.........…….…………….............……155 4.6. Size and trophic level of prey items from comparison sites…….…………………156 4.7. ANCOVA of maximum prey size from comparison