SCUBA-Diver Impacts and Management Strategies for Subtropical Marine Protected Areas
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Please do not remove this page SCUBA-diver impacts and management strategies for subtropical marine protected areas Hammerton, Zan https://researchportal.scu.edu.au/discovery/delivery/61SCU_INST:ResearchRepository/1266958040002368?l#1367465550002368 Hammerton, Z. (2014). SCUBA-diver impacts and management strategies for subtropical marine protected areas [Southern Cross University]. https://researchportal.scu.edu.au/discovery/fulldisplay/alma991012820955902368/61SCU_INST:Research Repository Southern Cross University Research Portal: https://researchportal.scu.edu.au/discovery/search?vid=61SCU_INST:ResearchRepository [email protected] Open Downloaded On 2021/10/02 09:32:36 +1000 Please do not remove this page SCUBA-Diver Impacts and Management Strategies for Subtropical Marine Protected Areas. ZAN HAMMERTON Bachelor of Applied Science (Marine Science and Management) (Honours) A thesis submitted to the School of Environment, Science and Engineering in fulfilment of the requirements for the Degree of Doctor of Philosophy SOUTHERN CROSS UNIVERSITY September 2014 DECLARATION I certify that the work presented in this thesis is, to the best of my knowledge and belief, original, except as acknowledged in the text, and that the material has not been submitted, either in whole or in part, for a degree at this or any other university. I acknowledge that I have read and understood the University's rules, requirements, procedures and policy relating to my higher degree research award and to my thesis. I certify that I have complied with the rules, requirements, procedures and policy of the University. Print Name: Zan Hammerton Signature:………………………………………… Date: ……………………………………………… ii ABSTRACT The impacts of SCUBA-divers on tropical reefs have been widely studied. However, there have been few studies evaluating the effects of SCUBA diving on subtropical reefs. Subtropical reefs are ecotonal habitats that support unique biodiversity and attract all levels of SCUBA-divers. Repetitive contact by divers or their equipment is a principal mechanism for chronic impact on benthic life forms. Six hundred recreational SCUBA-divers were observed for this study, in two subtropical marine parks in northern New South Wales, Australia. In the first stage of this study a combination of in-water observational research and post- dive questionnaires were used to determine the variables that contributed most significantly to the number of contacts divers made with the benthos. Multiple linear regression analysis was used to identify the variables that correlate with the frequency of diver contacts with reef biota. Of the 17 variables tested, nine were found to be significant contributors to increased diver contacts. These were the number of days since a diver’s last dive, certification location, awareness and understanding of marine park zoning, dive site selection, the use of photographic equipment, total dives to date and diving depth. The next stage focused on comparing the severity of visible acute impacts made by 400 recreational SCUBA-divers at six subtropical dive sites. These data were statistically modelled to determine which types of diver contact create the most severe impact, and the taxa and habitat types that are most at risk of severe forms of diver impact. Diver fins contributed most medium and high-level impact with reef biota. Corals were the most sensitive benthic taxon to contact damage. Habitat complexity was found to influence the severity of impact. These results suggest that improving diver trim, buoyancy and propulsion techniques, and awareness of their actual contact and the need to care, especially in coral-rich trench-type habitats, are priorities. Awareness and subsequent behaviour can potentially be modified by pre-dive information and in-water reinforcement of the need to avoid contact. Two levels of intervention over and above the standard dive briefing were tested to determine effectiveness in reducing SCUBA-diver contact: 1) pre-dive briefing with specific reference to minimising benthic contact; and 2) direct underwater intervention at the time of first contact. Both intervention levels significantly reduced the subsequent number of contacts made by divers. In-water intervention was most effective, but may be unwarranted in low-risk habitats or with low- iii risk divers. The dive brief approach is an extension of existing health and safety practices. The final stage tested the effectiveness of Low Impact Diver (LID) training on 61 certified SCUBA-divers, to assess if specific education and training could provide divers with the skill-base to avoid or reduce contact with the reef. Students completed a single pre-training dive, in which a set of tasks were completed which could be used as a baseline for comparison with a similar post-training dive. Regardless of an individual diver’s certification, or experience level, LID training was shown to significantly reduce contact with the benthos during subsequent dives. Due to the international scope of the SCUBA-diving industry and diver impacts being a global issue, the multi-faceted research outcomes presented within this thesis may be applied to many other tropical and subtropical diving locations. Applying management strategies that reduce diver contacts will ultimately enhance the experience for divers, provide greater protection to benthic taxa and aid in the development of SCUBA diving becoming more ecologically sustainable. iv ACKNOWLEDGEMENTS This thesis is a product of field research conducted at Julian Rocks in Cape Byron Marine Park and Solitary Islands Marine Park both located in northern New South Wales, Australia. It was conducted through the Marine Ecology Research Centre; the National Marine Science Centre and the School of Environment, Science and Engineering, Southern Cross University, Lismore New South Wales Australia. Firstly, many thanks to my principle supervisor, Dr Daniel Bucher for on-going guidance, support, sound boarding of ideas/issues and valuable thesis feedback. Huge thanks also to my partner, family and friends for their on-going love, support and patience. I dedicate this thesis to my mother who passed away suddenly in 2006 and my father who passed away in 2013. Thanks also to Dr Stephen Smith (co-supervisor) for thesis feedback and suggestions. I would also like to thank Dr Andrew Carroll and Dr Steven Dalton for assistance with in situ diver observations at Solitary Islands Marine Park and Dr Mateus Baronio for assisting with in situ diver observations during the low impact diver (LID) course training sessions at Julian Rocks. Thanks also to Byron Bay Dive Centre, Byron Bay and Jetty Dive, Coffs Harbour, for supporting the research being conducted, by providing me with access to their customers. This research was funded through Cape Byron Marine Park Authority, Southern Cross University, and the New South Wales Catchment Management Authority. v TABLE OF CONTENTS DECLARATION…………………………………………………………………….…..ii ABSTRACT.…………………..……………………………………………………......iii ACKNOWLEDGEMENTS………...……………………………………………………v TABLE OF CONTENTS.………….…………………………………………………...vi LIST OF FIGURES….....……………………………………………………………….ix LIST OF TABLES….………………………………………………………………….xii LIST OF ABBREVIATIONS……………………………………...………………….xiv CHAPTER 1: GENERAL INTRODUCTION…………............................................15 1.1 RELATIONSHIP OF THE RESEARCHER TO THE FIELD……………...…17 1.2 BACKGROUND – RECREATIONAL SCUBA DIVING…………………….18 1.3 DIVER IMPACT ON TROPICAL BENTHOS………………………………..18 1.4 SUBTROPICAL REEFS AND THEIR IMPORTANCE ………………….21 1.5 DIVER IMPACTS ON SUBTROPICAL AND TEMPERATE REEF ECOLOGY……………………………………………………………………..23 1.6 CURRENT MANAGEMENT STRATEGIES ………………………….26 1.6.1 Carrying Capacity Approach (CCA) ………………………………….26 1.6.2 Limits of Acceptable Change (LAC) ………………………………….27 1.6.3 Percentile Approach ………………………………………………….28 1.7 ALTERNATIVE STRATEGIES TO LIMITING DIVER IMPACTS...……....29 1.7.1 Dive Marshals ………………………………………………….29 1.7.2 Diver Education ………………………………………………….30 1.7.3 Dive Site Rating System ………………………………………….31 1.8 THE AUSTRALIAN DIVING INDUSTRY ………………………………….31 1.9 SCUBA DIVING AS ECOTOURISM ………………………………….32 1.8.1 Eco Certification – Australia ………………………………………….34 1.10 THESIS AIMS …………………………………………………………………36 CHAPTER 2: GENERAL METHODS ………………………………………….39 2.1 STUDY LOCATIONS ………………………………………………….39 2.2 DIVING SITES ………………………………………………………….39 2.2.1 Cape Byron Marine Park ………………………………………….39 2.2.2 Solitary Islands Marine Park ………………………………………….42 2.3 PARTICIPANT SELECTION ………………………………………….46 2.3.1 Ethics Statement ………………………...……………………………..47 2.4 IN-WATER SURVEY AND QUESTIONNAIRE METHODS ………….47 2.4.1 Pilot Study …………………………...………………………………...47 2.4.2 Data Collection ………………………………...………………………48 2.4.3 Definition of Categories for Type of Impact ………………………….50 vi CHAPTER 3: DETERMINING THE DRIVERS OF SCUBA-DIVER CONTACTS USING LOG LINEAR REGRESSION AND MIXED MODEL ………………….52 3.1 ABSTRACT ………………………………………………………………….52 3.2 INTRODUCTION ....………………………………………………………….52 3.3 METHODS .………………………………………………………………….55 3.3.1 Ethics Statement .……..………………………………………………55 3.3.2 Data Collection ……………………………...…………………….....55 3.3.3 Statistical Analysis ..……………………………..………………….56 3.4 RESULTS ...………………………………………………………………….58 3.4.1 Variables Contributing to Diver Contacts ……………………….…...58 3.4.2 Actual Versus Perceived Number of Contacts …….…………….…….64 3.5 DISCUSSION.....…..…..……………………………………………………….66 3.6 CONCLUSION……...…………………………………………………………71 CHAPTER 4: MODELLING RISKS TO HABITAT FROM SCUBA-DIVER CONTACTS – SUBTROPICAL