SUCCESSION AND BIODIVERSITY OF AN ARTIFICIAL REEF MARINE PROTECTED AREA: A COMPARISON OF FISH ASSEMBLAGES ON PROTECTED AND UNPROTECTED HABITATS A thesis submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE in ENVIRONMENTAL STUDIES by KEVIN J. KOLMOS June 2007 at THE GRADUATE SCHOOL OF THE COLLEGE OF CHARLESTON Approved by: _______________________________________ Glenn F. Ulrich _______________________________________ Robert M. Martore _______________________________________ David Owens _______________________________________ Melvin Bell ACKNOWLEDGEMENTS This project was completed with the help of many individuals over the past two years. I would like to thank Glenn Ulrich for his guidance and wealth of knowledge he imparted during my research. He was an excellent primary advisor and a true friend. He taught me many things about the marine world with this project as well as working on the COASTSPAN and the Adult Red Drum projects. I would also like to thank my committee members: Dave Owens, Mel Bell, and Bob Martore who introduced me to the world of artificial reefs which was a major deciding factor in enrolling in the Environmental Studies program at the College of Charleston. The project was greatly enhanced by the insight and observations of my committee. I would like to give a special thanks to Martin Jones for taking so much time to help me with the statistical analyses with this thesis. His assistance was invaluable. I also had a great experience working with Bryan Frazier, Carrie Hendrix, and Jon Richardson. My time with this project was memorable with the cruises and sampling trips we conducted together from taking pictures with Bryan’s fish, to pulling hooks out of Carrie’s finger, to arguing with Jon whether something was a scamp or gag in the UW videos. We made some awesome memories. The artificial reef group was a great help in conducting underwater SCUBA surveys as well as diver observations. Thanks to Bob Martore, Daryl Stubbs, Ian Moody and Ryan Yaden; even though I had to pay Daryl a nickel for every fish he helped me ii identify in the videos. I would also like to thank Paul Tucker and Rob Dunlap for captaining the R/V Silver Crescent. Financial support was provided in part by the South Atlantic Fishery Management Council Inshore Fisheries Section and the Artificial Reef Program at the South Carolina Department of Natural Resources through a non-work study. The funding provided by these groups was genuinely appreciated. I would like to give a final thanks to my family and friends. My mother, father, and sister have always been supportive in my quest for knowledge and understanding in the marine biology realm. They encouraged me to succeed in obtaining my dreams. Even while being five states away, their love and support was greatly felt during times of adversity as well as triumph. They helped me more than they know. Also to my friends that I have grown with and experienced hand in hand the struggles and successes of the graduate school life. I can only hope I give as much support to those that have helped me. iii Table of Contents TITLE AND APPROVAL PAGE…………………………………………………………i ACKNOWLEDGEMENTS……………………………………………………………….ii TABLE OF CONTENTS…………………………………………………………………iv LIST OF FIGURES……………………………………………………………………….v LIST OF TABLES …………………………………………………………………..viii ABSTRACT……………………………………………………………………………...ix INTRODUCTION………………………………………………………………………...1 MATERIALS AND METHODS…………………………………………………………8 RESULTS………………………………………………………………………………..16 DISCUSSION……………………………………………………………………………26 CONCLUSION…………………………………………………………………………..42 LITERATURE CITED…………………………………………………………………..44 FIGURES………………………………………………………………………………...51 TABLES…………………………………………………………………………………70 APPENDIX………………………………………………………………………………75 iv List of Figures Figure Page 1: An artificial reef unit used by the SCDNR and deployed at Area 53. This picture was taken six months after units were deployed off the coast of Charleston, SC. Photo by R.M. Martore……………………………………….51 2: Nylon dart tags used in marking and identifying individual fish. Tags are color-coded for visual reference according to respective reef orientation and also contain unique identification numbers as well as contact numbers if found……………………………………………………….52 3: Gray triggerfish tagged on the left side of the body. Tags were inserted past the pterigiophores to ensure a solid holding position………………………53 4: Fluctuations in individual site abundance based on the four identified species: C. striata, B. capriscus, M. phenax, and M. microlepsis.………………54 5: 5a: Centropristis striata length frequency distribution between fished and unfished sites during the three time intervals……………………………………55 v 5b: Centropristis striata trend lines for corresponding fished and unfished locations during the three time intervals…………………………..56 6a: 6a: Centropristis striata length frequency distribution for each individual site……………………………………………………………………57 6b: This illustration shows the C. striata trend lines for individual sites during the three time intervals…………………………………………………..58 7: Centropristis striata mean lengths are compared between fished and unfished locations. This graph illustrates the length frequency distributions and shows how unfished locations have a steady increase in mean length throughout the experiment and into future sampling trips………………………………………………………………………………59 8: Centropristis striata mean lengths between all the sites………………………...60 9: 9a: Length frequency distribution for B. capriscus comparing fished and unfished locations……………………………………………………………….61 9b: Balistis capriscus length frequency distribution trend lines illustrate the responses to fishing pressure on fished and unfished populations………………………………………………………………………62 vi 10: Balistes capriscus mean lengths are compared between fished and unfished locations……………………………………………………………………….63 11: Balistes capriscus mean lengths are compared between each individual site……………………………………………………………………………..64 12: 12a: Box plot for C. striata on growth/day between fished and unfished locations………………………………………………………………………..65 12b: Box plot for B. capriscus on growth/day between fished and unfished locations………………………………………………………………………..66 13: The equation for growth (mm) per day was determined using all recaptured C. striata……………………………………………………………67 14: The growth(mm) per day was calculated between fished and unfished locations for C. striata populations…………………………………………….68 15: The overall growth (mm) per day was calculated for B. capriscus populations……………………………………………………………………..69 vii List of Tables Page Table 1: Species present on Area 53 site …………………………………………71 Table 2: Species present on adjacent natural reefs………………………………..72 Table 3: Top six recaptured species data………………………………………….73 Table 4: Values for C. striata site population estimates…………………………74 viii ABSTRACT SUCCESSION AND BIODIVERSITY OF AN ARTIFICIAL REEF MARINE PROTECTED AREA: A COMPARISON OF FISH ASSEMBLAGES ON PROTECTED AND UNPROTECTED HABITATS A thesis submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE in ENVIRONMENTAL STUDIES by KEVIN J. KOLMOS June 2007 at THE GRADUATE SCHOOL OF THE COLLEGE OF CHARLESTON The goal of the proposed research was to document the succession and characteristics of finfish communities on four artificial reef systems established at a depth of 33 m off the South Carolina coast. The location of the reefs has not been disclosed to the public allowing them to function as Marine Protected Areas (MPAs) and as an experiment to examine the dynamics of fish recruitment and responses to protection and exploitation. Two of the sites were randomly selected for intensive fish removals to simulate conditions in open-access fishing habitats leaving the remaining reef sites unfished, functioning as fully protected MPAs. The species diversity, size composition and abundance of recreationally and commercially exploited finfish species were compared on the protected and harvested sites through analysis of recapture data and video SCUBA surveys from both fished and unfished sites. Abundance of pooled Centropristis striata, Balistes capriscus, Mycteroperca phenax, and Mycteroperca microlepsis on protected sites were significantly greater than fished sites. Protected sites also had significantly larger C. striata and B. capriscus. Unfished reefs had greater biomass than exploited reefs; increasing the potential reproductive output and larval spillover of protected artificial reef systems. Locations that have a paucity of hard bottom habitat such as the South Atlantic Bight (SAB) would benefit from the establishment of a network of MPAs on artificially created hard bottom habitat. Artificial reef MPAs are a viable management strategy for the SAB to protect and enhance populations of commercial and recreationally important finfish species. ix Introduction Declining fish populations and overexploited fish stocks have stimulated the search for new and more effective management of the fishing industry. Nearly 70% of the world’s fished stocks are listed as “fully fished, overfished, depleted, or recovering”, prompting fishermen and scientists to investigate alternative management options to protect these natural resources (World Resources Institute, 1996). One avenue of conservation management that could lead to the restoration of depleted stocks involves marine reserves that protect reef sites where fish live, feed, spawn, and find shelter (Roberts, 1995; Halpern & Warner, 2002, 2003; Clark, 1996; Boersma & Parrish, 1999; Lauck et al.,