The impact of live rock harvesting on abundance, substrate composition and reef topography along the Coral Coast, Islands

By

Make Liku Movono

A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science

School of Marine Studies Faculty of Island and Oceans The University of the South Pacific

December, 2007 Dedication

This is for my Normie and to God Almighty!

Declaration of Originality

I Make Liku Movono declare that this thesis is my own work and that, to the best of my knowledge, it contains no material previously published or substantially overlapping with material submitted for the award of any other degree at any institution, except where due acknowledgement is made in the text.

Make Liku Movono Date

The current research was conducted under mine and other co-supervisors and I am certain that this is the sole work of Ms Make Liku Movono.

i ACKNOWLEDGEMENTS

First and Foremost, I would like to thank my God Almighty for bringing me through these challenging times and has never failed me! In addition to this, acknowledging the financial assistance by the Institute of Applied Science at the

University of the South Pacific with which this project would not have been possible. A big “vinaka vakalevu” to Professor William Aalbersberg for giving me an opportunity to work on a challenging and vital issue. To the communities, whom without their concern, this study would not have been initiated. A very big

“vinaka vakalevu” to Dr James Reynolds, who was with me from “scratch” till the very end, justifying every detail of the work.

Heartfelt thanks goes to the communities of Namada, Namatakula, Vatukarasa,

Votua and Malevu for their hospitality in hosting me while I was doing my field work. To Alena, Bola, Kini, Jolame, the boys in Votua and Namatakula for assisting me in the field. Also the IAS boys- Ron V, Ron S and Rusi for assistance in field work. I know this would not have been possible if it weren’t for their tremendous help.

To James Comely for helping me with the editing and taking me through the stages. Also would like to thank Dr Clare Morrison for going through my work and great advice. Not forgetting Cherie of Marine Aquarium Council and Priti

Singh.

ii Lastly I would like to thank the Warbler House occupants, Hilda, Nuns and Clare for the great support. My wonderful friend Salote “Dudlz” Waqairatu for just being a great . This is goes the same for Lewa, for always being supportive in every way. My parents, bu and baby sitters for looking after Normie when I had to work late nights. Finally to my Normie for being just a source of joy! And to all those who I forgot to mention but have been there in one way or the other.

iii Abbreviations

CA Coralline Algae CAMP Council Collection Area Management Plan CCA Crustose Coralline Algae CCC Coral Cay Conservation CITES Convention on International Trade in Endangered Species CV Coefficient of variation DOM Dissolved Organic Matter EAM Epithilic Algal Matrix EPS Endangered Protected Species FLMMA Fiji Locally Managed Marine Areas FMAC Fiji Marine Aquarium Council FSPI Foundation for the Peoples the South Pacific International H Harvested Reefs IAS Institute of Applied Science ICM Integrated Coastal Management IMA International Marine Life Alliance MA Management Authority MAC Marine Aquarium Council NBSAP National Biodiversity Strategic Action Plan NDF Non Detriment Finding NH Non Harvested Reefs MOTA Marine Ornamental Traders Association MPA Marine Protected Areas SC Scientific Council WSI Walt Smith International WWF World Wildlife Fund

iv ABSTRACT

The lucrative live rock trade, of which Fiji is the major exporter, has raised concerns on sustainability and ecological impacts. This study is the first to quantify the ecological impacts of live rock removal. The abundance of seven fish families (Chaetodontidae, Blennidae, Gobidae, Pomacanthidae, Pinuipedidae,

Pomacentridae and Synodontidae), reef substrate composition and topography were compared between four harvested and four non-harvested reefs along the

Coral Coast, Fiji. Belt transect method was used for fish counts, point intercept method for substrate composition and a graduated rod was used to take depths for profiling. The abundance of Chaetodontidae, Blennidae, Pomacanthidae and

Synodontidae was significantly higher in the non harvested reefs while

Pinuipedidae were significantly more abundant in the harvested reefs. There were significantly more coralline algae and live coral in the non-harvested reefs and higher algae in the harvested reefs. The harvested reefs were on average significantly deeper compared to the non-harvested reefs. There was a significant variation in Coefficient of Variation (CV) between the four harvested reefs and non-harvested reefs. The observed differences in fish abundance, substrate composition and depth between harvested and non harvested reefs are indications of the adverse impact of live rock removal on reef flats. This study provides scientific evidence of the impact of live rock trade on reef ecology which will help government with decisions on the future of the trade in Fiji. We recommend short term measures including sustainable collection method

v guidelines along with long term goals to gradually phase out harvesting within five years by introducing cultured rocks as an alternative source of income.

vi INTRODUCTION ...... 1 CHAPTER 1: LITERATURE REVIEW...... 4 1.1 History of the trade ...... 4 1.1.1 Marine Aquarium Trade World-Wide...... 4 1.1.2 Marine Aquarium Trade in the Pacific Region...... 6 1.1.3 Aquarium trade in Fiji...... 7 1.2 Convention on International Trade in Endangered Species (CITES) ...... 9 1.2.1 Non Detriment Findings (NDF) ...... 11 1.2.2 Management...... 12 1.4 Previous Studies on Live Rock ...... 16 1.4.1 International ...... 17 1.4.2 National ...... 18 1.5 Coral Reef Communities...... 22 1.5.1 Benthic microflora, periphyton and plant associations...... 23 1.5.2 The periphiton communitiy/ live rock communitiy...... 24 1.6 Importance of live rock ...... 25 1.6.1 Calcification...... 25 1.6.2 Biogeochemical cycle ...... 26 1.6.3 Photosynthesis ...... 26 1.6.4 Habitat and food source...... 27 1.7 Disturbance on coral reef communities ...... 28 1.7.1 Reef in coral reef communities...... 30 1.8 Indicator Fish species...... 31 1.8.1 Chaetodonids (Butterflyfish)...... 32 1.8.2 Blennidae (Rockskippers) ...... 33 1.8.3 Pomacanthidae (Marine Angelfishes) ...... 34 1.8.4 The Synodontidae (Lizardfishes)...... 35 1.8.5 (Gobies)...... 36 1.8.7 Pinguipedidae (Sandperches)...... 37 CHAPTER 2: STUDY AREA ...... 39 2.1 The Coral Coast...... 40 2.1.2 Natural Habitats ...... 42 2.2 Environmental Issues ...... 44 2.2.1 Live Rock Harvesting ...... 44 2.2.2 Over Fishing ...... 45 2.2.3 Deterioration of Coastal Water Quality ...... 45 2.2.4 Logging...... 45 2.2.5 Coastal Erosion...... 46 2.2.6 Pollution...... 46 2.2.7 Overgrowth of Algae...... 46 2.2.8 Flooding...... 46 CHAPTER 3: METHODS ...... 48 3.1 Approach and Assumptions ...... 48 3.2 Reefs Selected as Study Units Sites...... 48 3.1.1 Votua Reef ...... 49 3.1.2 Silivaiyata Reef...... 50 3.1.3 Vatuolalai Reef ...... 51 3.1.4 Namatakula Reef ...... 51 3.1.5 Namada Reef ...... 52 3.1.6 Oria Reef ...... 52 3.1.7 Navoto Reef...... 53 3.1.8 Malevu Reef...... 53 3.3 Differences amongst reefs ...... 56 3.4 Indicators Selected for Live Rock Harvest Effects...... 56

vii 3.5 Methods Used for Sampling...... 57 3.6 Data Analysis ...... 60 3.6.1 Fish data Analysis...... 60 3.6.2 Substrate data analysis...... 62 3.6.3 Depth profiles ...... 64 CHAPTER 4: RESULTS...... 67 4.1 Fish Abundance ...... 67 4.1.1 Butterflyfish ...... 67 4.1.2: Blennie fish ...... 69 4.1.3: Angelfish ...... 71 4.1.4 Lizardfish ...... 73 4.1.5: Sandperch fish ...... 75 4.1.6: Damselfish ...... 77 4.1.7: Gobie fish...... 79 4.1.9: Summary of Fish Abundance...... 84 4.2 Substrate Composition...... 84 4.2.1 Harvested Reefs ...... 85 4.2.1.1 Malevu Reef ...... 85 4.2.1.2 Namada Reef ...... 85 4.2.1.3 Navoto Reef...... 86 4.2.1.4 Oria Reef...... 86 4.2.2 Analysis results between the four harvested reefs ...... 86 4.2.3 Non-harvested reefs...... 87 4.2.3.1 Namatakula Reef ...... 87 4.2.3.2 Silivaiyata Reef ...... 87 4.2.3.3 Votua Reef...... 87 4.2.3.4 Vatuolalai Reef...... 88 4.2.4 Analysis between the four non-harvested reefs ...... 88 4.2.5 Comparison between the four harvested reefs benthic composition and the four non- harvested reef ...... 89 4.2.6 Summary of substrate composition...... 90 4.3 Depth Profiles ...... 91 4.3.1 Non-harvested reefs...... 91 4.3.1.1 Namatakula depth profile...... 91 4.3.1.2 Votua depth profile ...... 92 4.3.1.3 Silivaiyata depth profile...... 93 4.3.1.4 Vatuolalai depth profile ...... 94 4.3.2 Analysis of the four non-harvested reefs depth profiles ANOVA...... 95 4.3.3 Harvested reefs...... 95 4.3.3.1 Oria Reef...... 95 4.3.3.2 Namada Reef ...... 96 4.3.3.3 Navoto Reef...... 97 4.3.3.4 Malevu Reef ...... 98 4.3.4 Analysis of the four harvested reefs depth profiles (ANOVA) ...... 99 4.3.5 Average depth profiles of the four harvested and four non-harvested reefs...... 99 4.3.6 Average coefficient of variation of the four harvested and four non-harvested reefs ...100 4.3.7 Summary of the depth profiles...... 102 CHAPTER 5: DISCUSSION ...... 104 5.1 General comments...... 104 5.2 Fish Abundance ...... 105 5.2.1 Fish abundance in the non-harvested (control reefs)...... 106 5.2.1.1 Food and habitat...... 106 5.2.1.2 Physical feature of individual reefs ...... 107 5.2.2 Fish composition in the non-harvested reefs...... 108 5.2.3 Fish abundance in the harvested reefs ...... 110

viii 5.2.3.1 Reduction in Fish Abundance as a Response to live rock harvest...... 111 5.2.3.1.1 Food limitation...... 111 5.2.3.1.1.0 Angelfish and Butterflyfish ...... 111 5.2.3.1.1.1 Blennies...... 112 5.2.3.1.1.2 Lizardfish ...... 112 5.2.3.1.2 Intensity of harvesting...... 113 5.2.3.1.3 Disturbance during survey ...... 114 5.2.3.1.4 Effect of depth...... 115 5.2.3.1.5 Malevu...... 116 5.2.4.0 Increase of fish abundance in response to live rock harvest ...... 117 5.2.4.1.0 Sandperch ...... 117 5.2.5.0 Fish that do not show any significant difference in abundance ...... 118 5.2.5.1.0 Gobies and Damselfish ...... 118 Damselfish ...... 118 Gobies ...... 119 5.2.6 Fish composition in the harvested reefs...... 120 5.3 Effects on benthic community...... 122 5.3.1 Comparison of the substrate composition in the four non-harvested reefs...... 123 5.3.2 Substrate composition in the four harvested reefs, responsive to live rock harvest.....126 5.3.1.0 Macro Algae and turf Algae...... 126 5.3.1.2 Crustose Coralline Algae (CCA)...... 128 5.3.1.3 Live Coral...... 129 5.3.1.5 Soft corals and others ...... 131 5.3.2.0 Abiotic factors...... 131 5.4 The effect of live rock on the reef morphology and depth...... 132 CHAPTER 6: CONCLUSION AND RECOMMENDATIONS ...... 133 REFERENCE...... 137 APPENDIX I ...... 162 APPENDIX II ...... 163 APPENDIX III...... 164 APPENDIX IV ...... 169

List of Figures List of Figures ...... page Figure 3.0: Map of the Coral Coast, Fiji with the study sites ...... 56 Figure 3.1: Sampling design on a reef ...... 59 Figure 3.1.1: Unit of sample...... 59 Figure 4.1.1: Butterflyfish abundance ...... 67 Figure 4.1.2: Blennie fish abundance...... 69 Figure 4.1.3: Angelfish abundance ...... 71 Figure 4.1.4: Lizardfish abundance...... 73 Figure 4.1.5: Sandperch fish abundance ...... 75 Figure 4.1.6: Damselfish abundance ...... 77 Figure 4.1.7: Gobie fish abundance...... 79 Figure 4.1.8: The Bray-Curtis dissimilarity dendogram ...... 81 Figure 4.2: Percentage substrate composition...... 84 Figure 4.3.1: Namatakula reef depth profile...... 89 Figure 4.3.2: Votua reef depth profile...... 90 Figure 4.3.3: Silivaiyata reef depth profile...... 91 Figure 4.3.4: Vatuolalai reef depth profile ...... 92 Figure 4.3.5: Oria reef depth profile ...... 93

ix Figure 4.3.6: Namada reef depth profile ...... 94 Figure 4.3.7: Navoto reef depth profile...... 95 Figure 4.3.1.1: Malevu reef depth profile ...... 96 Figure 5.0: Mean depth profiles of the 4 harvested and 4 non-harvested reefs .97 Figure 6.0: Coefficient of variation of the depth profiles of the four harvested and non-harvested reefs...... 98

List of Tables Table 4.1.1: Butterflyfish Frequency ...... 68 Table 4.1.2: Blennie fish Frequency...... 70 Table 4.1.3: Angelfish Frequency ...... 72 Table 4.1.4: Lizardfish Frequency...... 74 Table 4.1.5: Sandperch fish Frequency ...... 76 Table 4.1.6: Damselfish fish Frequency...... 78 Table 4.1.7: Gobie fish Frequency...... 80 Table 4.1.8: Bray-Curtis dissimilarity index ...... 82 Table 5.0: Comparison of percentage substrate composition (Z-test)...... 84

x INTRODUCTION

Live rock is dead coral rock (calcium carbonate material) that contains encrusting organisms such as Coralline Algae, other Algae, and epibenthic invertebrates (Delbeek and Sprung, 1994). It is used as partially-living substrate in creating relief or seascape in aquaria. The live part of the rock refers to the

Coralline Algae covering the surface and any fauna or flora living on or within

(Lovell and Timuri, 1999). The Algae and the bacteria components remove organic waste products such as ammonia and phosphate and act as a buffer maintaining the pH. Live rock serves as a biofiltering device, controlling the mineral cycle such as nitrogen by nitrification and denitrification processes (Falls et al., 2003). Live rock also acts as an ecological foundation in the aquaria, providing food and habitat. These are reasons for the increasing demand of the product (Parks et al.,

2003).

The live rock trade, a part of the marine aquarium industry, has stirred a lot of interest locally and on a worldwide scale. This is a result of people’s preference to have an aquarium that resembles a real coral reef system (Falls et al., 2003). Fiji is a major exporter of live rock; alongside Indonesia, it supplies 95% of live rock to the United States of America (US) (Falls et al., 2003). The amount of rock exported from Fiji has increased to approximately 1400 tonnes since live rock harvest began in 1994 (Isimeli, 2006).

The increasing demand for live rock has generated a lot of income to companies and local residents. Income to local residents comes from the access to

1 live rock on their fishing grounds used and employment for live rock harvest. The economic importance of live rock to local residents is therefore a valid one.

Concerns from environmental organizations have led to the banning of live rock harvest from the wild in several US Entities in 1997. The Gulf of Mexico, the

South Atlantic Exclusive Economic Zone (EEZ), the Caribbean EEZ, Puerto Rico,

U.S Virgin Islands, North Carolina, Western Pacific, California, Hawaii, and Guam are some of the states and territories that have banned harvesting from the wild.

Shortly after the bans, live rock export from Fiji grew five-fold within the years 1996-

1998 (Falls et al., 2003). This increase also coincided with the establishment of the

Walt Smith International (WSI), Fiji’s largest aquarium company, in the country.

According to the Marine Aquarium Council (MAC) (2003), large-scale removal of the rock can destroy habitat for fish and marine invertebrates. This would lead to decrease in reef abundance that relies on these for food. The coral population in reef flat lagoons (because the harvesting of the rocks also includes coral) is reduced which can result in erosion. This could imply a loss in reef rugosity or topographical diversity. Studies by leading Luckhurst and Luckhurst

(1978) have shown how loss in rugosity leads to lowered species richness. Other scientists, according to Lovell (2002), speculate that the removal of rock leaves shallow pools, which increases habitat relief and the amount of intertidal pond water, a beneficial effect. Microhabitats are important for sheltering fishes and other organisms from desiccation and predation. Whether the good consequences outweigh the destructive impacts is yet to be determined.

2 Determining whether or not live rock harvest affects the abundance of fish and substrate composition is the main goal of this research project. The reefs situated along the Coral Coast on the southwestern side of Viti Levu, Fiji, constitute the study area. This study is based on the assumption that substrate composition and fish abundance on the reef flats, where live rock harvest occurs, are responsive to the harvest and that these changes can be detected despite natural environmental variation. In the pursuit of this goal several objectives will be accomplished:

1. Compare fish abundance on reefs with a history of live rock harvest

(harvested or H reefs) to reefs with no history of live rock harvest (non-harvested or

NH reefs), to determine if a relationship exists.

2. Compare substrate composition on harvested and non-harvested reefs to determine if a relationship exists.

3. To compare the depth profiles on harvested reefs and non-harvested reefs to determine if a relationship exists.

3 CHAPTER 1: LITERATURE REVIEW

1.1 History of the trade

The following section discusses the historical literature of the live rock trade as a part of the World-wide trade to the establishment in the local market.

1.1.1 Marine Aquarium Trade World-Wide

Prior to 1986, the keeping of marine ornamentals was restricted to public aquaria and aquarium hobbyists in Europe. In Northern America publication of advances in husbandry techniques fueled the popularity of the mini-reef aquaria; these are 15 to 100 gallons in volume and house tropical marine fish, plants and invertebrates. This rise in the popularity of the mini-reef is considered to be the major factor responsible for expansion in the aquarium trade (Delbeek, 2001).

Rapid expansion in the trade has occurred since the 1980s, with massive increases in the trade of tropical marine fish and invertebrates; for example, the global trade in corals increased from 20, 000 kg/yr in 1985 to 400,000 kg/yr in 1995

(Green and Shirley,1999). In 1986, TRAFFIC (US), the American branch of the

World Wildlife Fund that tracks international trade in endangered plants and , estimated that there were 10 million marine aquarium hobbyists. The fastest-growing segment of the industry was the mini-reef an estimated amount spent by the North American hobbyists in 1999 for the mini-reef was some US$240 million. The global gross value of the aquarium trade in 2003 was estimated to be

US$350-530 million, that involved 1.5-2 million people. This increasing trend in the

4 trade was due to a desire of people to have aquaria in their homes (Wabnitz et al.,

2003). The other factor that has enhanced this fascination is by reef related entertainment such as the movie Finding Nemo. The trade, therefore, is largely driven by market demands.

Live rock is used in the aquarium systems because live rock is aesthetically pleasing; provides vital substrate for the settlement and recruitment of benthic organisms; acts as a natural biofilter that serves as habitat for nitrifying bacteria, protozoans ,foramineferas and Algae (Falls et al., 2003).

The demand for live rock steadily increases because of its attractive color and ecological and biofiltration values. Green and Shirley (1999) reported that there was thought to be more than 50 million kgs of live rock maintained within the US aquaria in 1999. The high demand for live rock in the worldwide market led to increases in harvesting using various destructive harvesting methods. Prior to

1997, the US was harvesting wild live rock with aid of destructive chemicals, explosives and crowbars that chip the rock into small pieces. However, a ban was placed in the Gulf of Mexico, South Atlantic and Florida State waters in 1997, due to deterioration coral reef conditions (Falls et al., 2003).

The closure of wild live rock harvest from the US waters in mid 1990 stimulated other suppliers like Fiji and Indonesia to increase exports. Fiji for example increased the exports, fivefold within a year in 1994 when it first started.

Since the 1990s the US has been the major importer of the worlds live rock market, importing about 95% of the live rock traded within the world wide marine aquarium

5 industry (Parks et al., 2003). It has been estimated that more than the reported value is imported into the US market because it is generally not reported separately from other Sceleractinian coral imports like coral rock (Bruckner, 2001). The total value of US live rock sales during the period 1992-2000 was estimated at $14 million, representing a volume of 2.5 million kg. According to Wabnitz (2003), the annual trade of live rock is about 3.9 million pieces or about 2.1 million kg. Fiji is currently the primary source of live rock to the States.

1.1.2 Marine Aquarium Trade in the Pacific Region

Fiji dominates the marine aquarium industry within the Pacific with a market share of approximately 75 percent of all trade; annual export earnings of US$19 million for the year 2001 and over 1000 individuals currently employed. Regional estimates indicate that over 150 species of aquarium fish are traded by the industry with an estimated annual number of over 400,000 individuals exported, with Fiji alone averaging 260,000 individual fish exported annually. Over 50 species of hard and soft coral are exported within the region with annual estimates indicating between 120,000 and 200,000 individuals exported. Annual live rock exports for the region are estimated at 700 million kg for 2003 with 95 percent of this originating from Fiji (Eco-Consultants Pacific, 2004).

Pacific live rock typically has a minimum of 80 percent coverage of Coralline

Algae and is considered by the North American industry to be the best quality available. Live rock is or has been exported from the majority of Pacific Island nations at one time or another. However, the export of live rock is economically

6 dependent on large volumes being shipped and therefore the industry is constrained by access to large airfreight space and regular market connections. Fiji is the region’s largest supply of live rock with the Kingdom of Tonga the next largest exporter. Several Pacific nations (e.g. Palau, Federal States of Micronesia (FSM)) have banned the removal of live rock from their reefs. It is estimated that over 14 million kg of live rock was exported from the Pacific between 1992 and 2000 and live rock exports from Fiji and Tonga alone have doubled each consecutive year from 1992-1997. In 2004, Fiji supplied 1.36 million pieces/0.92 million kg of live rock to the overseas market which was more than half of the world live rock market (Lal and Cerelala, 2005). The local mass harvesting of the live rocks for export markets caused a decline in the market price of live rock with which other countries could not compete.

1.1.3 Aquarium trade in Fiji

The aquarium trade began in Fiji in 1984 with the export of ornamental fish only. The live coral trade started in 1992 and the live rock trade started in 1994

(Singh, 2005).

In 1997, there was a concern by the cabinet ministers of the government regarding the adverse impact of the live coral trade, particularly on fish stocks. This was due to the tripling of the amount harvested within that year. Customs department was asked to monitor live coral exports. The Fiji Trade and Investment

Board (FTIB) withdrew all concession licenses until a proper study on the impact of the trade on marine life was conducted by the Department of Environment. As

7 a result, a provisional EIA report on the extraction of coral reef products for marine aquarium and curio trade was produced in June 1999 by Edward Lovell and

Manasa Timuri of the Fisheries Department.

The coalition government in 1999 agreed to form a subcommittee responsible for the various entities; Environment, Fijian Affairs, Fisheries and

Justice to consider implications of the impacts of coral and live fish and the consideration of banning the trade. The work of the committee was disrupted by the events of the 2000 coup.

In 2001 the government (SDL), decided to follow up on the issue of coral harvest after concerns raised by the tourism sector. The cabinet decided on a

“consideration for moratorium on coral/ live rock harvesting” unless a thorough study was carried out and presented to Government.

International Marine Life Alliance (IMA) was contracted to carry out the study. The study came to a pause in 2002 due a collapse in the Global IMA organization. The work resumed in 2004 and was completed in 2006 after pauses in the study. During the duration of the IMA study, the Department of Fisheries developed guidelines, which were initiated in 1983 (Lovell and Timuri, 1999) to manage the trade, this was implemented in 2005. An outcome of the policy made was not to increase the number of exporters operating in Fiji amongst other guidelines.

At the 46th Standing Committee (SC46) meeting in Geneva 2002, Fiji voluntarily proposed to reduce the trade by 50% of the level of trade that happened

8 in 2001. A quota system for live Hard Corals and live rock was implemented in

2003. The quota established in 2003 and endorsed again in 2004 was based on arbitrary figures. The arbitrary quota for live rock is half of the 2003 quota which is

1.4 million kg. In 2005, about 97% of this quota was used and for half of the year

2006, about 58% of this yearly quota has been used. The existing quota is an interim precautionary measure to ensure that the extraction from the wild for the aquarium trade is within the reasonable limits whilst a quota based on scientific data is under development.

1.2 Convention on International Trade in Endangered Species (CITES)

Fiji became a party to CITES in 1997. Countries that have joined CITES agree to be bound by the convention known as parties. There are 169 parties including the US and UK who are the main importers of live rock. Since the countries are bound by the convention, live rock exported must comply with CITES regulations. Even though CITES legally binds the parties, parties have to implement the convention through national legislation since CITES does not take place of national law. Fiji therefore, enacted the Endangered Protected Species Act

(EPS Act) in December 2002 followed by the gazettal of the EPS regulation in

2003.

The EPS Act legislates that export of species listed in the Convention will be allowed only if such export is not detrimental to the survival of the species in the wild. This measure is known as Non Detriment Finding (NDF). Species that are covered by CITES for the aquarium trades are live rock and live Hard Corals only.

9 Live coral and live rock belongs to Appendix II of the CITES listing. The species covered by CITES are listed in three Appendices, according to the degree of protection required. Appendix II includes all species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival.

Under the EPS Act the Fiji Islands CITES Management Authority (MA) and

Fiji Islands CITES Scientific Council (SC) was established. The Scientific council is required to advice the Management Authority on the effects of trade and on the status of the species. The functions of the Council and the Authority are stated in the Act.

The Fiji CITES MA consists of:

The Permanent Secretary (CEO) responsible for Environment as the chairperson;

The Director of Environment;

The Director of the National Trust of Fiji;

3 Government public officers (Ministry of Agriculture, the Ministry of

Fisheries and Forests and the Fijian Affairs Board to nominate one each);

2 members to represent the non-governmental organizations dealing with the protection and conservation of the environment;

10 2 members nominated by the body that represents those involved in the trade, sale, possession, exportation or importation of species mentioned in section 3 of the Act.

The Fiji CITES SC consists of the:

the Conservator Forest as the chairperson;

the Director of Fisheries;

the Director of Environment;

the Director of Research of the Agricultural Division;

the Director of Animal Health and Production;

an academic nominated by the Ministry of Education;

a representative of the non-governmental organization responsible for the conservation of the Environment.

1.2.1 Non Detriment Findings (NDF)

In July 2004, a workshop was convened by TRAFFIC and Environment

Australia and funded by the British High Commission to bring together key stakeholders to develop the NDF framework. The Director of Reef Check, Marine

Aquarium Council and representative of the CITES Animals Committee as well as representatives from the Fiji government and NGO’s were present.

11 It is the responsibility of the national government to ensure the implementation of the NDF framework. The NDF framework developed in the workshop incorporates elements such as environmental dynamics, traditional social structure and national and local economies. Coral, live rock, fish and socio economic groups were formed to develop scientific and socio economic requirements for NDF findings.

NDF framework links with Fiji Locally Managed Marine Areas (FLMMA),

National Biodiversity Strategic Action Plan (NBSAP) and resource inventories by

Department of Fisheries. The NDF framework serves as a useful model for management of Fijis marine wildlife, providing the framework for monitoring extraction and regulating trade in species which may not be listed in the CITES appendices but are of conservation concern to Fiji (Parry-Jones, 2004).

Unfortunately the NDF framework remains undefined though the workshop was an attempt to implement criteria.

Recommendations from the proposed NDF framework, working groups were set up to provide a strategy for implementation and a Quota Review Group was established to coordinate the implementation. These included resource based inventories, socio-economic studies and robust ecological studies.

1.2.2 Management

The aquarium trade is managed by the Fiji Fisheries Department in accordance with the Fisheries Act and by the Department of Environment in accordance with the Endangered and Protected Species Act (EPS).

12 The Fisheries Department issues fishing licenses to harvesters and monitors shipments according to national quotas for each commodity. Fisheries also chair the Fiji Marine Aquarium Council (FMAC) which includes traders, government and non-government representatives. This group meets regularly to discuss issues of concern. Exporters are also encouraged to comply with guidelines which were developed in consultation with all stakeholders involved in the trade. The

Department of Environment issues export permits and management decisions are made by the CITES scientific and management authorities with regards to sustainability of the trade.

In addition, a lot of collaborative work is carried out with NGO’s like Marine

Aquarium Council (MAC), World Wildlife Fund (WWF), Foundation for the South

Pacific People (FSPI), University bodies like the Institute of Applied Science (IAS) and industries, to enhance the management and viability of the trade. Ideas are shared to build a sustainable and credible aquarium trade.

The other existing group is the Marine Ornamental Traders Association

(MOTA) that meets every month. MOTA is made up of four industry members

(traders). Concerns and issues regarding CITES requirements and constraints that the industries face are highlighted in meetings.

1.3 Live rock trade in Fiji

There are currently 4 companies operating in 25 customary owned coastal waters (I qoliqoli), around Viti Levu and the islands off the Western Division of Fiji.

Of these, Walt Smith International (WSI), Oceans 2000, Waterlife Exporters and

13 REL are the major exporters of live rock. There are about 1000 people employed by the aquarium trade in Fiji, and more than half are employed by the live rock industry. WSI is the largest live rock exporter, supplying more than 50% of rocks from Fiji and employing about 500 people. The total amount of live rock exported from Fiji in 2005-August 2006 was 2.2 million kg valued in FJ$12 million. However the number of rocks harvested from the reef flats is much more than the export figures because there is an estimated 50% rejection rate of rocks (MAC, 2003).

The live rock harvesters are villagers contracted by an exporter paying the local entity for harvesting permission. Local members of the I qoliqoli harvest live rock on the basis of a supply contract or by indigenous Fijians employed directly by the exporters. Supply contracts are usually informal arrangements where exporters provide a licensed collector a purchase order. The license holder represents the team who is trained in the removal of the reef rock. The quantity of rock required is specified daily. It is purchased by the kilogram from the collectors minus any material that is rejected as unsuitable as only a good Coralline Algae cover is accepted. A group of villagers would make about 4 trips daily and collect about

1500 pieces/1016 kg on average per day depending on the demand.

Collection of live rock on fringing reef flat is removed from around the edges of the reef patches within the shallow lagoon water or along the outer algal flat. At other places such as barrier reef lagoons, the rocks are collected from lagoons where they have been deposited. The removal strategy depends on the nature of the reef flat where both abundance and ease of extraction are considered.

14 The process involves the removal of blocks of rock with a diameter on the order of 10-20cm. The rock is chosen on the basis of the presence of the pink to dark purple Coralline Algae on its surface or within its cavities (this is known as collectable live rock). The rock is removed using iron bars, by breaking it from the reef; it is stockpiled and then loaded on a bamboo bilibili raft for transport ashore.

Not all rocks are taken ashore as some of the rocks with low Coralline Algae cover or poor coloration (light purple in color or not according to demand) are rejected by the collectors on site. This occurs in cases where there is a thick growth of the algal species of Sargassum covering the rock, which only allows collectable rock to be recognized after it has been broken off and removed from the reef. The rocks which have about 70% coloration which is maroon or deep purple are chosen onsite and taken to warehouse for further assessments and curing.

Once removed from the reef flat, there are two strategies in preparation for trans-shipment. One is the cleaning of the rock in the near-shore shallow water and the weighing and packaging of the material on the beach for direct shipment to the airport. The other is to collect the rock with some cleaning on-site and transport it to a holding facility where further cleaning occurs and a process called curing is employed. Cured rock is material which has been placed in a holding facility where it is kept moist by a fine spray of seawater. The objective is to keep the Coralline

Algae alive while the less hardy organisms die and are washed from the rock by the water spray. The cured product is considered of a much higher quality as it is less likely to foul the aquarium system. Rock, which is shipped from Fiji directly from the

15 beach, will have to be cleaned or cured to some degree before it enters the aquaria of retail customers (Lovell and Timuri, 1999; Lovell, 2001).

The labor force for live rock collection is drawn from a number of families who alternate in the work force, these are trained personnel. Villagers receive an average price of about FJ$0.80 for a kg of live rock. This price is controlled by the exporters, which the local resource owners regard as high. However the price on the overseas market depends on freight charges which could come to about US$5 per kg. This however takes into account the freight charges and transportation costs. The exporters often target the maximum amount of live rock they can ship because freight permits costs drop with volume but increase with quantity (Lal and

Cerelala, 2005).

Apart from the income earned by collectors where they can earn up to about

FJ$21,771 per annum, the resource owners is paid for the customary rights and goodwill gestures. For example Walt Smith International paid chiefs FJ$2000 for an annual permit for their fishing grounds and the use of their divers (Lal and Cerelala,

2005). It should be noted these are published figures, and this raises question whether harvesters really earn this much and there is considerable evidence for much higher “goodwill” payments.

1.4 Previous Studies on Live Rock

The next sections discuss previous research that has been conducted regarding live rock.

16 1.4.1 International

When live rock was banned in the US territories, there had been no proper research done on live rock. There had been concerns however on effects in general of the harvest on decline in fish abundance, increased coastal erosion, removal of fish habitat and reduction in reef structure (Ehringer and Webb, 1993).

The sensible alternative was to look into aquaculture of live rock. Therefore non-Fiji studies which related to live rock harvest have been aquaculture oriented.

Initial study of live rock centered on the recruitment of benthic organism to the rock that was monitored for the gradual attachment of organisms over time.

The density of the fish and organism depends on how big the farm is- the bigger the scale, the more the organisms. Ehringer and Webb (1993) completed the first U.S research, “Assessment of Live Rock Harvesting in Tampa Bay”. They reasoned that as the rocks are placed in water, growth of organisms undergo succession stages much like growth on any other pioneer substrate. This assumption was supported by an assessment of live bottom communities in Tampa Bay

(Derrenbacker and Lewis, 1985). Depending on environmental conditions such as salinity, temperature and turbidity, a variety of life forms would be expected on the rocks contingent upon where the rocks were placed within the bay, and during which successional stage they were removed. Comparisons were made between live rock and artificial reefs.

Mook (1980) stated that more species would be found on the rock near the mouth of an estuary than in the upper region estuary because of variance in

17 salinity, with consideration also being given to stability of other parameters.

Estevez (1985) stated the same factors were true for Tampa Bay.

Dean and Hurd (1980) found four sessile organisms on the rock: barnacles, hydroids, and mussels. Estevez (1985) listed the following groups of invertebrates for Tampa Bay: seafans, sea whips, hydroids, anemones, tunicates, bryozoans and Hard Corals. Santos and Simon (1980) showed great seasonal variation in species abundance and diversity of organism in Tampa Bay with the least colonization occurring in the months from September through February.

Therefore the seasonal timing for the placement of rocks may be of great importance.

However, according to The Gulf of Mexico Fishery Management Council reports in 1994, the collection of live rock from the Gulf of Mexico coastal waters resulted in the removal of the equivalent of two patch reefs each year (Falls et al.,

2003)

1.4.2 National

In Fiji most studies are unpublished and have focused on the effects of live rock harvest. An assessment of the live coral and rock extraction fishery at

Muaivuso I qoliqoli was conducted in 2000 (Sauni et al., 2003); these results showed significant differences in habitat health between reef biotope in live rock and live coral harvested and non-harvested sites. There were no significant differences in fish abundance between the two sites. The study however did not separate live rock from live coral removal impacts specifically. Coral is different

18 from live rock thus; the impacts of removal are not the same. There was also lack of understanding of the history of collection in the study site. The study remains unpublished.

In the pilot study Sykes (2001) conducted an environmental impact on harvesting live coral and live rock for the aquarium trade. This was a report commissioned by the Fiji Hotel Association, and the result of a short survey, regarded as a “snapshot” of the current state of reef health in the pilot study. The study recommended a larger monitoring program to give reliable scientific data on the exact effects of live rock extraction.

International Marine Alliance (IMA), in 2002, began a project to quantify the extent of live rock harvest and impact to the resources, with the intent to develop recommendations that would ensure that harvest is sustainable. After a lapse of 2 years, in 2004 the study was followed up and completed. Results on the analysis of live rock mining in Fiji indicated that some 270 hectares of reef have been used for live rock mining since 1992, at the rate of around 30 hectares of new reef currently being targeted for live rock mining each year. The study indicates that live rock harvest is detrimental and unsustainable. However, there has been a lot of criticism of the study, mainly regarding the lack of scientific replicable method used. (Why,

2004)

Wesson (2003) conducted a study as part of a thesis with the University of

Newcastle, the impacts and management of the marine ornamental trade of live rock in Fiji. Two different harvesting regimes at 4 harvested sites were compared to

19 1 control site. Results were confounded for the effect of live rock harvest but suggested that there were significant differences in substrate components between the control and the harvested site due to the two different techniques employed in harvesting.

The University has had students conducting post graduate work on live rock:

Fiu (2003) conducted her master’s (MSc) degree on the “Impact of live rock harvest on benthic assemblages on the reef flat”. There have been no conclusive results from this study as it continues to date. Kaur (2005) conducted a one year (2003-

2004) MSc on “Aquacultured live rock- hastening the process of colonization of artificial substrate". The results obtained from this experiment described the spatial and seasonal variations in the recruitment pattern of the crustose Coralline Algae.

Habitat comparison regarding growth of corallines; at which site and during which month the recruitment of Coralline Algae was the highest. The Crustose coralline recruits on the settlement plates were not mature enough and did not show morphological characteristics, so the genus of the Crustose Algae could not be determined. As part of a post graduate course Movono (2004) conducted a study on “The impact of the live rock trade on indicator fish species (Chaetodonidae and

Blennidae)”, a pilot study at USP, March-May 2004, which provided background for this research .

In response to the growing international concern on the destructiveness of coral harvesting in exporting countries, WWF-South Pacific took an active interest in the local aquarium trade, in Malomalo village. This was one area in which live- rock had been harvested since the early 1990s. In 2003, WWF embarked on a

20 CAMP certification project with MAC as this was seen as an appropriate mechanism for establishing and supporting the sustainable collection of aquarium products. Prior to this was socio-economic and biological monitoring of the

Malomalo collection area to provide information before actual certification. This was also in conjunction with the Locally Managed Marine Area (LMMA) in declaring

“tabu” no extraction areas (Susau et al, 2003)

The Marine Aquarium Council (MAC), in collaboration with the University of the South Pacific and consultants, has developed methods of monitoring live rock harvest in 2004. This has led to resource assessments on several of the harvested sites in Kalokolevu and Vatukarasa in 2005 (MAC, 2005). The Institute of Applied

Science (IAS) also conducted monitoring following the developments of monitoring methods in 2004 and 2005 on the impacts of live rock harvest. However the experimental design of the IAS monitoring did not take into account the effects of fishing and the history of live rock harvest at the sites (Reynolds et al, 2005).

Lal and Cerelala, (2005) conducted a study for SPREP and Foundation for the South Pacific People Initiative (FSPI) on the financial and economic analysis of wild harvest and cultured live coral and live rock in Fiji. They found out that it is possible to replace wild harvest with cultured rock after several years of gradually phasing out wild harvest live rock.

A considerable amount of work has been done on live rock, however the question that fails to be answered and a concern by the communities (Owen, 2003) is the ecological impacts. The ecological role of live rock has to be understood to

21 realize the extent of the impact of harvesting on village livelihood regarding fish and invertebrates which are important to the subsistence and artesinal fishery.

1.5 Coral Reef Communities

Coral reefs are the second most diverse ecosystem in the world and have been the model for some of the most important work in ecology (Hodgson, 1998).

They are renown for their diversity, not only in terms of species but also particularly because of the occurrence of representatives of most extant phyla. They are an economically valuable food source and their chemical compounds have pharmaceutical importance. Coral reefs control sediment transport processes, protect coastlines from erosion, help create sheltered harbors, and facilitates the development of shallow basins with associated mangrove and sea grass communities (Wood, 1999). They support a diverse range of flora and fauna as the primary productivity on coral reefs is amongst the highest in the marine communities (McClanahan et al., 2000).

In the Pacific, coral reefs are regarded of high importance. People rely on the reefs for their daily living, food, money and other traditional and medicinal uses

(Vuki et al., 2000). In Fiji, coral reefs are an important part of the Fijian identity as each indigenous tribal unit is allocated a fishing ground (I qoliqoli) or a reef where they can fish. Every tribal unit also has a fish as a totem signifying the intimate connection of mankind to their fishes/nature.

However, with an increasing population and modernization, anthropogenic disturbances have deteriorated the coral reefs. Pollution, elevated nutrient levels,

22 overfishing, coral and live rock harvesting are examples of such disturbances

(Thaman et al., 2002). An understanding of the coral reef ecology is needed to have a holistic idea of the extent of damage caused by such disturbance.

In this scenario, the impact of live rock harvesting can only be understood if live rock is understood and all its components including the role in the coral reef community. The live rock community is part of the benthic microflora, periphyton and plant association in the coral reef community. The Coralline Algae, being the main component of live rock (60- 80%) needs to be reviewed carefully.

1.5.1 Benthic microflora, periphyton and plant associations

The plant benthic communities and the bottom micro flora are responsible for more than half the total autotrophic production and of heterotrophic metabolism in coral-reef ecosystem (Clayton and King, 1990). The plant benthic communities have been described by Sorokin (1993) into three categories and their respective microbial associations. The microphytobenthos of soft sediments are represented by bacteria in soft sediments (soft Sands) and by bacteria in the detrital sediments.

The periphyton overgrowth of the solid surfaces and Rubble (which live rock is a part of) is associated with the periphiton bacteria. The thallophyte seaweeds/seagrasses are associated with the bacteria symbiotic to benthic animals such as sponges (Sorokin, 1993).

23 1.5.2 The periphiton communitiy/ live rock communitiy

The periphiton community which is the live rock community has been described by Sorokin (1993) in detail. The periphiton turfs, which are about 2-5cm in thickness, are vast surfaces of pourus lime reef rocks (Rubble) that is densely overgrown with Algae. They are structured like microhabitats or micro-bieonoses, which unite the autotrophic and heterotrophic components in one mucoid structure

(Sorokin, 1993).

The components contained are different types of bacteria and Algae, ciliates and Foraminiferans as well as other microbenthic animals. The microflora in the periphiton communities contains attached or chain forming bacteria. The single celled bacteria are numerous being attached to the surfaces of Algae with the aid of their stalk.

The plant communities of the periphiton turfs Algae include small thalloms of macrophytes, crustose Coralline Algae, filamentous and attached micro Algae. A significant part of the benthic plant communities of coral reef biomass is represented by crustose Corallinaceae. Corallines are able to inhabit poor light conditions such as caverns which are an advantage of the red Algae over other

Algae making them more diverse and abundance. The brown and green macroalgal species are well represented. The filamentous Algae include the green

Algae and cynobacteria.

24 The microbenthic heterotropihic part of the periphiton communities include ciliates represented by Vorticella, benthic Hypotricha, small Nematods and

Foraminifera

1.6 Importance of live rock

The role of live rock in the periphyton community has been well established, however the following paragraphs relates the vital role played in physical,bio chemical and ecological processes .

1.6.1 Calcification

Coral reefs are structures formed by calcium carbonate extracted from the sea almost exclusively by living organisms, a process called calcification. The primary roles of corallines are calcification and association with the periphiton community (Sorokins, 1993). They are important organisms on coral reefs as cementers and builders of carbonate material (Keats et al., 1997). Coralline Algae mount and cement the reefs constructions in the most stressed zones producing bulks of hard calcareous material (Adey and Vassar, 1975). In the process of photosynthesis, the Coralline Algae fix carbon for physiology and for the calcification processes (Borowitzka, 1983). The calcium is deposited in the cell walls of the Algae in the form of calcium carbonate, which is not used by the Algae but is reef building (Death and Fabricius, 2001).

The algal ridge on the reef crest is an area where the coralline is particularly important in constructing reef framework (Vroom et al., 2006). This algal ridge

25 require high and persistent wave action to form, so are best developed on the wind- ward reefs in areas where there little change in wind direction (Keats et al., 1997).

These ridges are one of the main reef structures that help prevent coastal erosion.

This area and the outer reef flat are where the live rock is being harvested.

1.6.2 Biogeochemical cycle

One of the main features of the periphiton communities which are vital to the functioning of the coral ecosystem is the microbial degradation of organic matter.

The nitrogen fixing bacteria and denitrifying bacteria regulate the nitrogen cycle which is supplied by oceanic waters and rivers (Segar, 1998). These provide a positive balance of nutrients and organic matter in marine environment during bacterial interaction with surrounding ocean (Sorokin, 1993). This is also one of the main reasons live rock is harvested to promote ecological balance in the aquaria.

Sorokin (1993) further states that the periphiton microflora being a site of microbial degradation in coral reefs, could have a global importance for the turnover of

Dissolved Organic Matter (DOM) contained in oceanic waters.

1.6.3 Photosynthesis

About 40-80% of primary productions in the coral reef ecosystem come from benthic plant associations (Borowitzka, 1983). Experiments by Sorokin (1993) also show that the periphiton communities are amongst the most active metabolizing compartments of a reef system. In the process of photosynthesis, the Coralline

Algae takes in carbon as CO2 and gives off oxygen, an essential to animal life in the marine ecosystem.

26 1.6.4 Habitat and food source

Coralline Algae are a source of primary food production for herbivorous grazers such as blennids and scarids (Addey and Vassar, 1975). Harmelin-Vivien et al. (1989) have shown that periphiton turfs are one of the main sources of feeding for herbivorous invertebrates and fish. The periphiton Algae are grazed by numerous surgeon fish, Scarids, Chaetodons, as well as by , shrimps,

Gastropods and Urchins (Sorokin, 1993). The Epithilic algal matrix (EAM) is also a part of periphiton community of which 10% to 78% is detritus, serving as major food source for many fish species (Wilson, et al, 2003). Sorokin (1993) also states that the high biomass and production of epithilic algal and bacterial turfs provide quick restoration of food sources for these important groups of reef animals.

Some Coralline Algae develop thick crusts, which provide microhabitats for many invertebrates, (which is also part of live rock) such as Urchins, Chitons and

Limpets. On a community level this is important for fishes which rely on the invertebrates as a food source.

The chemicals produced by the Coralline Algae promote the settlement of the larvae of herbivorous invertebrates such as abalone (Daume et al., 1999). This also benefits the coralline since the herbivore removes the epiphytes, which could smother the crusts and reduce available light. At the community level, the presence of invertebrates associated with corallines can generate patchiness in the survival of young stages of dominant seaweeds. The sloughing of the epithelial

27 layer of some coralline has anti-fouling effects, which also enhances herbivore recruitment (Keats et al., 1997).

1.7 Disturbance on coral reef communities

The combined forces of nature like storms, cyclone, tsunami, Crown of

Thorns (COT) outbreaks along with human intervention all appear to be bad for coral reefs (Bellwood et al., 2004). Disturbances may have a range of effects including the loss, fragmentation and/or degradation of preferred habitat, which may affect fish species in different ways (Lewis, 1997). The physical attributes of the reefs, whether perturbed by man or naturally is influential in the fish abundance and species composition on each reef. The impacts of physical disturbances are generally much greater than those of biological disturbances, highlighting the importance of topographic complexity and live coral cover in supporting reef fishes. These factors could ultimately affect fish behavior and alter fish composition of a reef.

Several studies have established how fish and substrate have been responsive to disturbance on coral reef communities. These are naturally induced disturbances as well as anthropogenic ones. Hoegh-Guldberg (1999) and Moran (1986) have described the effect of coral bleaching and Acanthester planci outbreak causing a widespread loss of live coral cover and algal proliferation. Pratchett et al. (2004), have indicated how sub lethal bleaching affected the physiology of butterflyfish, but not immediate abundance suggesting this would lead to declines in future population. Rogers (1990) discusses how coral reefs and organisms are sensitive to sedimentation. A combination of

28 disease, pollution and overfishing are implicated as the most likely cause of coral reef degradation (McClanahan et al., 2001). Furthermore, during severe tropical storms and direct physical perturbation, there is an immediate reduction in both live coral cover and complexity of reef framework (Lewis, 1997). Gratwicke and

Speight (2005) stated that habitat complexity is important for species. The effects of coral mining in the Maldives have been investigated in several studies. The biological and physical impacts of coral mining on reefs in Malé Atoll, Maldives were investigated by Brown and Dunne (1988). They reported that live coral cover on reefs subject to coral mining was very low compared to unmined reefs.

Response to reef associated fish to coral mining was reported by Shepherd et al.

(1992) and Brown et al. (1990). They have shown that there were two principal effects of coral mining on reef fish communities, which were, the loss of live coral correlated to loss in fish abundance and the reduction in rugosity which have been reported to reduce species richness.

A few researches have been conducted to investigate into the relationship of the benthic communities and fish association. Pranovi et al. (1998) have looked into how anthropogenic perturbations have reduced the benthic population and have temporarily changed the environments biotic and Abiotic features. In Robert and Ormond (1987) investigations of habitat cover and reef fish species of the , they correlated the substrate diversity to species richness. Most studies have correlated fish abundance and richness to coral cover (Bell and Galzin 1984, Chabanet et al.1997, Garpe and Ohman 2003).

Ault and Johnson (1998) have shown a correlation of fish composition and

29 richness to the substrate in a contiguous reef type, this however is not applicable to patch reef types.

1.7.1 Reef Fishes in coral reef communities

Coral reefs which cover only 0.09% of the ocean are the habitat of approximately a quarter of all fish species (Sale, 1980)). Fishes are the most conspicuous, diverse and well studied groups of organisms that are closely associated with coral reefs. For the large part, they are dependent on coral reef communities for vital resources such as food, shelter and living space, the requisites for survival and reproduction (Jones and Syms, 1998). Some fishes may be associated with biotic features of the habitat such as corals or sponges, while others are more associated with the topographical complexity of the reef, occupying caves, holes or crevices (McCormick, 1994). The abundance of individual species and the structural and functional community should, thus, be very sensitive to disturbance-induced changes in habitat structure (Gratwicke and Speight, 2005).

There have been several studies dealing with factors affecting fish populations. Factors that influence the distribution pattern and community structure of inshore fishes are difference in physical factors between habitats

(Blaber and Blaber, 1980), difference in structural heterogeneity and thus shelter from predation between habitats (Heck and Orth, 1980), difference in food availability and productivity between habitats (Odum and Herald, 1975) and water clarity (Blaber and Blaber, 1980). Reef fish species vary from small population that may be associated with a single coral species to those that may be found almost everywhere (Munday et al., 1997) According to Vazquez and

30 Simberloff (2002), the theory is that the susceptibility to disturbance may largely be determined by where most fish lie, between the extremes of specialization and versatility. This implies that specialized environments which cater for only specialist feeders, when disturbed will affect certain species that rely on that. However environments that provide food source for various versatile feeders, when disturbed will affect more range of species. The live rock community could in this case be affected by the disturbance because it provides a wide range of foods and habitat for fishes from detritus to Algae.

To understand the impacts of habitat-disturbance on fishes we need to understand not only the specific habitat requirements of the fish, but the ways in which the different disturbance affect the biological and physical structure of the substratum (Wilson et al., 2006).

1.8 Indicator Fish species

The concept of using certain key species as indicators of ecological condition is now well established (Crosby and Reese, 1996). For an indicator species, an extensive knowledge of the ecology, behavior of the fish is vital

(Schiemer, 2000).

The seven families used as indicators for this study will be briefly described.

Chaetodonids (Butterflyfish), Blennidae (Rockskippers), Pomacanthidae (Angelfsh),

Synodontidae (Lizardfishes), Gobiidae (Goby), Pomacentridae (Damselfish) and

Pinguipedidae (Sandperches) are appropriate indicators of the impact of the live rock harvest because of their intimate relationship with live rock (periphyton)

31 community. These chosen fishes are common reef fish which can be found on the reef flats all year round.

1.8.1 Chaetodonids (Butterflyfish)

Fishes of the family Chaetodonidae, the Butterflyfishes, are found in all tropical seas of the world (Reese, 1996). There are 114 Species in 10 Genera with

90 of the Species in the genus Chaetodon. Butterflyfishes are characterized as diurnally active, brightly colored inhabitants of coral reefs (Michael and Woodward,

1994). They belong to three feeding groups: corallivores, benthic omnivores and planktivores (Pratchett et al., 2006).

Reese (1996) recommended that the corallivores Chaetodon as being a good indicator of coral reef health because of the direct dependence of food on the coral. However for live rock studies omnivorous Chaetodon are also chosen because they feed on the benthic invertebrates and Algae associated with the live rock

Chaetodons are territorial fishes in which males are usually the defensive ones. There is an associative mating pair bond formation based on size.

Butterflyfish are dusk spawners on evenings and full moon. Chaetodon pairs show a very high degree of site fidelity with the same individuals being found on the same territories for seven to eight years. Their life span is 10 to 12 years depending on the species. Predation is minimal on adults but occurs on larval stages. Their striking colors make them ideal for observations in the field. Hence, all these

32 characteristics make them ideal candidates for indicator species of ecological conditions on coral reefs. (Reese, 1996)

1.8.2 Blennidae (Rockskippers)

Blennids are a member of fishes of the family Blennidae that was formerly placed in the family Gobiidae. All of the fish are elongated, generally bottom dwelling fish with long anal and dorsal fins and prominent eyes (Thresher, 1980).

They are cryptic and largely territorial fish (Sale, 1980). Due to their behavior, feeding habits and habitat, Blennies make a good indicator the impact live rock removal.

Blennies are one of those reef fishes that are strongly site attached living in holes and burrows on the reef (Lowe-McConnell, 1987). Reasons for this behavior includes defense for space, food, mates, spawning sites and offspring. They are mainly herbivorous and depend largely on Algae for food (Townsend and Tibbets,

2000). Some researchers (Wilson, 2001) have stated that classifying blennies as a herbivore is often misleading and more specifically regard Blennies as Epithilic

Algal Matrix (EAM) feeders. This is largely due to the investigation of their stomach contents in which mixtures of detritus, Algae and inverts was found (Wilson, 2002).

The presence and absence of their microhabitats influence the distribution of

Blennies as previously studied by Townsend and Tibbets (2000).

33 These fishes are vigorously territorial (Thresher, 1980). Each of these fish defends an area of about 1.5- 2sq meters chasing off other fishes. Periodically

Blennies patrol their territory moving from one high point to another. If the fishes are carefully approached carefully, despite being cryptic, one can see about 6-7

Blennies on one microhabitat (Lowe-McConnell, 1987). On high tide, each fish would defend a single preferred hole. For these reasons Blennidae would make an appropriate indicator species.

1.8.3 Pomacanthidae (Marine Angelfishes)

Marine Angelfish are a type of perciform fish of the family Pomacanthidae.

They are found on shallow reefs in the tropical Atlantic, Indian, and mostly western

Pacific Ocean. The family contains seven Genera and approximately 86 Species

(Alevizon, 1994).

With their vibrant colours and deep, laterally compressed bodies, marine angelfishes are some of the more conspicuous residents of the reef. They most closely resemble the Butterflyfishes, a related family of similarly reef fish. Marine

Angelfish are distinguished from Butterflyfish by the presence of strong preopercle spines (part of the gill covers) in the former (Debelius et al., 2003).

While the majority adapt easily to captive life, some are specialist feeders which are difficult to maintain. Feeding habits can be strictly defined by genus, with

Genicanthus species feeding on zooplankton and Centropyge preferring filamentous Algae. Other species focus on sessile benthic invertebrates; sponges, tunicates, bryozoans, and hydroids are staples (Michael, 2004).

34 They are diurnal animals, hiding amongst the nooks and crevices of the reef by night. Some species are solitary in nature and form highly territorial mated pairs; others form harems with a single male dominant over several females (Allen et al.,

1998).

Due to their physical, feeding and behavioral characteristics, Angelfish are ideal indicators for live rock harvest.

1.8.4 The Synodontidae (Lizardfishes)

The Synodontidae or Lizardfish Family has 40 species, of which 31 are of the genus Synodus, five of these reside in the eastern Tropical Pacific (Randall et al., 1997).

The Lizardfishes have slender cylindrical bodies, pointed “lizard-like" heads with large mouths that have many rows of fine teeth (Nelson, 1994). They are sedimentary bottom dwellers found sitting motionless, perched on their pectoral fins, or buried in the Sand with one exposed, waiting to ambush unsuspecting prey. They are voracious predators feeding primarily on small fishes, krill, squid, and shrimp. Observations of Lizardfish in the aquarium show that surface area is more important than water volume because most of their time is spent resting on the bottom of the aquarium (Scott, 2005).

Although Lizardfish are not as conspicuous as Butterflyfishes and

Angelfishes, their reliance on bottom substrate would make them ideal candidate for live rock harvest indicator. The theory is that live rock removal cause’s

35 disturbance to substrate; hence bottom dwelling fish would be good indicators of the impact.

1.8.5 Gobiidae (Gobies)

The gobies form the family Gobiidae, which is one of the largest families of fish, with more than 2,000 species in more than 200 genera. Most are relatively small, typically less than 10 cm (4 in) in length (Delbeek & Sprung, 1994)) they are of great significance as prey species for commercially important fish like cod.

Several gobies are also of interest as aquarium fish, such as the bumblebee gobies of the genus Brachygobius. Goby fish is not exploited by humans for food due to their small size.

Gobies occupy coral reefs where Sand and Rubble are interspersed because they feed on Sand-dwelling micro-invertebrates, epilithic algal mats and

Algae, and use crevices to hide from predators. They have a limited home range and short life cycle (Hernaman and Munday, 2005). A study by Steele and

Forrester (2005) showed that Gobies were largely dependent on crevices for protection from predators. Thus the theory that live rock provides the crevices for the goby fish suggests that gobies will be impacted to some extent by the removal of live rock. Due to the limited home range and reliance for live rock, Goby fish would possibly make a good indicator for live rock removal.

1.8.6 Pomacentridae (Damselfish)

36 The family Pomacentridae comprises 321 species (Allen, 2001). The average size of such Damselfish is around 3 inches (8 centimeters) (Delbeek &

Sprung, 1994). They are all marine fishes, however, a couple of species are regularly found in the lower stretches of rivers in pure freshwater, and usually have bright colours (Alevizon, 1994).

Some species of Damselfish are hardy species and are able to tolerate a wide range of harsh environmental conditions. Others such as the white-spotted damselfish are not as hardy. The diet of Damselfish is wide-ranged, from small fish to Algae depending on the genus. Some are considered benthic carnivores of small invertebrates and fishes. The diet of other Damselfishes can include small crustaceans, plankton, and Algae. Behaviorally they are territorial and haremic

(Alevizon, 1994).

1.8.7 Pinguipedidae (Sandperches)

The family Pinguipedidae includes six genera, about 50 of which are marine species and one freshwater species (Alevizon, 1994).

Sandperch are bottom-dwelling carnivores and rely on small fishes and invertebrates. They inhabit open Sand and Rubble bottoms. They consume invertebrates such as bristle worms, small mantis shrimps and xanthid crabs.

Small Sandperches have been known to eat feather duster worms and Christmas tree worms. Larger individuals may consume small bivalves, anemone crabs, cleaner shrimp, anemone shrimp, pistol shrimp, small boxer shrimp, juvenile brittlestars, serpent stars and small fishes (Scott, 2005)

37 They can be aggressive toward other bottom-dwelling predators, especially those with a similar body shape (e.g. gobies). Aggression is also likely to occur between Sandperches of different species (Randall, 1997).

Their reliance on food and Sandy bottom makes Sandperches an ideal indicator for live rock harvest.

38 CHAPTER 2: STUDY AREA

Fiji is located in the Southwest Pacific Ocean at latitude of 150 –200 south and longitude 1770 west to 1740 east. It is a vast archipelago centered on two relatively shallow geological features, the Fiji Platform and the Lau Ridge.

Geologically, the area lies on the Indo-Pacific plate close to the boundary with the Pacific plate, in an area of relatively complex geology and fracturing. The two largest islands of Viti Levu and Vanua Levu, together with a large number of smaller ones, lie on the relatively shallow Fiji Platform. The country is made up of approximately 844 volcanic islands and is dominated by the Viti Levu and Vanua

Levu platforms which account for 87% of the total land area. Fringing, barrier and nearshore reefs surround most of Viti Levu, with the largest continuous fringing reef along its southern shore (Vuki et al, 2000).

Figure 1: Map of the Fiji Islands

39 (http://www.nationsonline.org/oneworld/map/google_map_Suva.htm. 12/07/2007, 2.06pm)

2.1 The Coral Coast

The Coral Coast is situated on the southwestern coast of Viti Levu and is the longest chain of fringing reefs in Fiji. The well-developed fringing reefs of the

Coral Coast extend almost unbroken for 63 km and have a seaward extension of

500 to 1000 meters. These fringing reefs protect the mangrove-fringed bays and pocketed Sandy beaches. This coastal environment has been subject to rapid

Figure 2: The map of Viti Levu showing the Coral Coast situated on South Western side of the island

40 (http://www.nationsonline.org/oneworld/map/google_map_Suva.htm. 12/07/2007, 2.06pm ) changes during storm surges. Recurrent cyclones usually come from the North

West direction.

The Coral Coast encompasses the coastal areas of the Nadroga-Navosa provinces from the village of Namatakula through to the Fijian Hotel at

Rukurukulevu village (Thaman et al., 2002). Sigatoka town is the main commercial centre for coastal and inland residents in the area. Inland residents live mainly along the Sigatoka River that is about 80 km long. Sigatoka’s population in 1996 was 7,862 increasing by 5.1% since 1986 (Fiji Bureau of

Statistics, 1998). The town also houses the provincial government, hospital and several primary and secondary schools.

The Coral Coast has a number of physical characteristics which includes a mild climate, a variety of natural habitats, and a number of interesting natural and cultural features.

2.1.1 Climate

Air temperature is relatively consistent due to the ocean temperature ranging from a low of 18oC during the coolest months (July-August) to a high of

32oC during the warmest months (January and February). Rainfall is highly variable and mainly orographic often falling in heavy, brief local showers. In addition, Fiji experiences a distinct wet season (November to April) and a dry season. Annual rainfall for the area is expected to be between 2000 and 3000 mm. The predominant winds are the trade winds from the east to southeast,

41 which are generally light to moderate in strength. Tropical cyclones which occur from November to April can cause high winds and have caused widespread damage in the area in the past (Pitman et al., 2001).

Storm surges which are temporary elevation in sea level rise caused either by very low or the piling up of water against a coast driven by strong winds (both associated with cyclones), occur on the Coral

Coast. The most recent was in early 2001 after Paula resulting in winds attaining speeds up to 90knots. This resulted in flooding and damage of coastal areas due to a .

2.1.2 Natural Habitats

The well-developed fringing reefs of the Coral Coast extend almost unbroken for 63 km and have a seaward extension of 500 to 1000 meters. The only major gap is at the mouth of the Sigatoka River. Where creeks descend from the hills the reef is broken by passages of 100 to 300 meters across. The fringing reef has a shallow tidally submerged platform, usually called a reef flat, which is interspersed with moats and channels. Beyond the platform is a consolidated reef crest. The shallow lagoon-like nature of the reef flat allows for snorkeling at high tide. Morton and Raj (1980) have described the reefs at Cuvu,

Korolevu, Namatakula, Komave and Malevu in detail.

White carbonate Sand beaches back the reefs. The unconsolidated sediments making up the beaches are a mix of terrigenous, calcareous and other shallow water marine sediments. Active Sand transport is mainly to the west along the Coral Coast carried by longshore drift (Pitman et al .2001).

42 At the mouth of the Sigatoka River and other river mouths along the coral coast, terrigenous Sands have built up into high dunes.

Along the Coral Coast the lagoon is fairly narrow with the 200-meter isobath being only about 1 km offshore. Average depth of the lagoon is around 2 meters making it suitable for swimming, snorkeling, and fishing. Bathymetric surveys conducted by SOPAC indicate that the passages can attain depths of around 200m that drop at around 800 meters offshore (Manoa, 2006). Water temperature is always above 20oC with summer maximum around 30oC. Tides are semi-diurnal with neap tides having a mean range of 0.9m and spring tides

1.9m (Ryland, 1981).

Marine water quality is associated with terrestrial and anthropogenic sources, where elevated nutrient levels occur around these areas. Studies by

USP conducted in the lagoon offshore from the Outrigger Resort indicate that nutrient levels often are higher than acceptable limits and faecal coliform levels at times may exceed acceptable levels after heavy rains, especially at the mouths of creeks and near shore waters (Mosley and Aalbersberg, 2003).

Mangroves at present are located adjacent to only a few villages to the east of Sigatoka town. The mangroves patches occur in the villages of

Vatuolailai, Tagaqe, Vatukarasa, and Korotogo. Reports from Thaman et al.,

(2002) indicated the presence of mangroves previously in the villages of

Namatakula, Navola, Komave and Malevu. To the west of Sigatoka town, the mangrove patches are more extensive and occur adjacent to the villages of

Yadua, Naevuevu, and Rukurukulevu.

43 The natural features of the Coral Coast have been a major tourism attraction. Tourism contributes 35-40% of GDP annually, making it the largest export earner. The Coral Coast is the third highest tourism destination in Fiji with an occupancy level of 68% per night following Nadi (72.5%) and the Mamanuca groups (70%) (Smith & Zographou, 2006). The high level of occupancy reflects the increased number of large hotels and smaller tourism operators spreading out along the coast. This consequently has led to the increased the population along the Coral Coast because of employment opportunities offered by the industry. This rapid economic and population growth adversely affects the environment. The Coral Coast therefore is faced with an array of environmental issues.

2.2 Environmental Issues

One major issue the Coral Coast is facing is the deterioration of the coral reef ecosystem. A range of anthropogenic activities such as over fishing, destructive fishing methods, sedimentation, eutrophication, live rock harvesting and pollution has contributed to this situation. This has been a major concern from the communities along the Coral Coast (Thaman et al., 2002). Natural occurrences has also made significant contribution towards agitating even further the decline of reef health, by means of outbreaks of the coral eating Crown of

Thorns starfish (Acanthaster planci), coral bleaching events and storm damages.

2.2.1 Live Rock Harvesting

Live rock harvesting for the aquarium trade occur along the three villages of the studied area; Vatukarasa, Malevu and Namada. Live rock is removed from

44 the reef as blocks 15-35 cm in diameter usually by iron bars. Collectors gather from areas predetermined by the customary chief. Impacts of coral harvesting includes breakage of non-target species, potential destruction of coral population, potential alteration of reef topography and conflicts with tourism operators.

2.2.2 Over Fishing

Decline of coral cover and fish abundance have been observed by the villages over the past years. The use of destructive fishing methods such as derris sp., dynamite fishing, undersized nets and over fishing has been the contributing factor to the decline in fish abundance (Thaman et al., 2002).

2.2.3 Deterioration of Coastal Water Quality

Deteriorating water quality is often blamed on the nearby hotels disposing of their solid waste and sewage waste into the ocean. However, the continued dependence of most of the villages on pit toilets and septic tanks out of which sewage waste may leach during heavy rains and the location of pig pens close to the ocean in many of the villages probably also contributes to sewage pollution in the coastal waters (Mosley and Aalbersberg, 2003; Pareti, 2006)

2.2.4 Logging

Logging is still carried out upriver of Komave, Navola and Votua villages and on the slopes above Tagaqe and Namada. The logging is primarily pine and is thought to be a major cause of soil erosion. A logging concession area,

Navutulevu, is active in the Coral Coast area. In 1997, 3,608 m3 of timber was harvested from the area.

45 2.2.5 Coastal Erosion

All villages except along the Coral Coast have indicated that coastal erosion was a major problem especially during storm surge (Thaman et al.,

2002). These storm surges damage existing seawalls, wash away houses, and cause extensive erosion of shoreline.

2.2.6 Pollution

The disposal of rubbish in the village and on the coast occurs in all villages. This is mainly plastics, tin cans, and other non-biodegradable solid waste. Due to there being no formal rubbish collection villagers often dispose of rubbish along the coastline assuming that the ocean will remove it. Siltation from small streams is also a problem in Namatakula, Komave, Navola, Tagaqe,

Vatukarasa and Korotogo especially during heavy rain. Votua and Votualailai communities also mentioned that the disposal of rubbish from nearby hotels and sewage disposal from the Votua Housing settlement via a small stream are a major cause of pollution in their coastal waters.

2.2.7 Overgrowth of Algae

The overgrowth of Algae, especially Sargassum species, is mentioned to be a problem in all villages (Thaman et al., 2002). The excessive growth of Algae smothers coral and is thought to be due to elevated nutrients in the waters, siltation and to higher ocean temperatures (Mosley & Aalbersberg, 2003).

2.2.8 Flooding

In two villages, Votualailai and Korotogo, the construction of the Queens

Highway has contributed to the floodings in the villages (Thaman, 2002). In

46 Korotogo the road is higher than the village and inappropriately constructed culverts lead to flooding in the village during heavy rain.

2.3 Problem Solving Efforts

The communities themselves have raised concerns on the deterioration of their resources. In response, government, NGOs, universities and various other organizations have come in to try and help them solve these problems. Projects such as waste management, Locally Managed Marine Areas (LMMA) and

Integrated Coastal Management (ICM) have been implemented and have been ongoing in the communities. UK based NGO, Coral Cay Conservation (CCC) has done baseline surveys all along the Coral Coast for the communities which provided some background data for this study. The procedures to solve problems used have been a “bottom up” approach. This involves communities identifying the problems and attaining help from organizations and stakeholders involved. The organizations along side the communities work together to find sound management practices.

47 CHAPTER 3: METHODS

3.1 Approach and Assumptions

A control-impact design was used to estimate the effect of live rock harvest. The study was initiated after harvesting, therefore the assumption is that there were no differences amongst reefs selected for study prior to the onset of live rock harvesting (i.e their natural abundances were similar). All reefs were selected to have similar geology/ecology.

A reef was regarded as a study unit. The magnitude of the effect was estimated by comparing reef fish abundance, substrate composition and depth profile between e among reefs that have been harvested and not harvested.

Reefs subjected to harvesting are considered “treatment” study units, reefs never harvested are not true controls but regarded as “reference” study units for comparison in this study. Statistical testing for the effects of live rock harvest was made using the null hypothesis or no difference (Ho). If there was no difference, the Ho was accepted. However, if a difference was detected the Ho was rejected and the alternate hypothesis (HA) of a significant difference was accepted.

3.2 Reefs Selected as Study Units Sites

The reefs were selected based on preliminary surveys by Movono (2004) and Coral Cay Conservation surveys during 2004. The GIS images that were produced by CCC were analysed for Coralline Algae, Sargassum, Hard Coral, and Rubble distribution and cover along the Coral Coast. Abundance of these substrate components were categorized based on colour intensity derived from the satellite images and were categorized as low, medium-low, medium,

48 medium-high and high coverage. This provided background information of the study sites which is explained in detail below. The previous and current surveys both showed that tabu areas, protected from fishing and areas open to fishing could have confounding effects on live rock harvest. If live rock harvest occurred in an area subsequently declared an MPA, fish protection had a confounding effect by inflating fish numbers without regard to live rock harvest. If live rock harvest occurred in areas open to fishing edible fish species, the effect of live rock harvest was confounded by decreasing numbers of edible fish with regard to live rock harvest. Therefore reefs selected as study units did not have tabu areas and were open to fishing. Also, families of non-edible fish, not targeted by fishing, were used as indicators. Four reefs were selected as reference study units (never harvested for live rock, NH); Votua, Silivaiyata, Vatuolalai and

Namatakula (Fig 3.0).

The GIS images and tools from Google Earth were used to calculate the areas of the eight reef units studied. These are included in the detailed descriptions of the eight reefs below.

3.1.1 Votua Reef

The beach comprises mostly of pebbles with an intertidal zone of abundant and substantial beach rock. The reef area is the largest compared to the three other non-harvested reefs, at 609km2. There is a lagoon with a shallow reef crest which is exposed at low tide. Currents are very strong during rising and ebbing tide especially on the reef flat adjacent to channels. A sewage flows into the stream by the village, which outflows into the beach front. There are piggeries

49 located near the stream. Apart from the villages, there is a government housing authority scheme community (Votua housing) which has 60 houses situated approximately 1 km inland. A baseline survey by CCC showed a low Coralline

Algae cover, medium brown Algae, low bed rock, low live Hard Coral, medium- high Rubble and a medium to high Sargassum sp. coverage.

There have been marine conservation measures here as Votua is one of the Fiji Locally Managed Marine Areas (FLMMA) sites. A Marine Protected Area

(MPA) is situated on the reef flat adjacent to the village. There is also an ecotourism dive shop (Mike’s Divers).

3.1.2 Silivaiyata Reef

This is a shallow reef with many gaps due to the patchy coral growth. The spaces therefore provides for water in the reef walls. The area studied on

Silivaiyata reef comprises about a third of the whole reef flat, an area of 0.114 km2 making the area the smallest of the four non-harvested reefs. The reef is adjacent to the channel; hence there are strong underwater currents during ebbing and flooding tides. The study site is located adjacent to an MPA. There is wastewater outfall nearby which flows onto the reef flats. A restaurant and a backpacker’s lodge is situated in front of the beach followed by the Silivaiyata

Reef. When study was undertaken, there was ongoing construction for the development of a resort adjacent to the lodge. A baseline survey by CCC showed naturally low Coralline Algae, medium brown Algae cover, low bed rock, low live Hard Coral cover, medium-high Rubble cover and a medium to high

Sargassum sp. coverage.

50 3.1.3 Vatuolalai Reef

This reef features a calcareous Sandy beach. The study area on this reef flat is approximately 0.290km2. The reef is shallow and gradually deepens.

Corals are in patchy distribution and the reef crest is not well developed. The site is adjacent to an MPA. There is an outfall outlet from the hotel and the village that flows into the beachfront. Adjacent to Vatuolalai Village is Naviti Resort which provides employment to the local community. CCC surveys show medium-low Coralline Algae, medium brown Algae, medium-low bedrock, medium-low live coral, medium Rubble cover and a low Sargassum sp. cover.

3.1.4 Namatakula Reef

The Namatakula Reef flat is an extensive one featuring a Sandy (granite) beach. The intertidal reef flat features a seagrass community. The area of the reef is approximately 0.312km2, the second largest of the four non-harvested reefs. The middle reef has much bed rock which leads to a shallow reef crest.

The shallow reef crest is exposed during low tide while the lagoon is submerged.

There is a channel in front of the village. The MPA is on the opposite side of the channel. A little stream from the village leads to the main beach. A resort is situated on either side of the village. To the west of the village is the

Beachhouse Resort and to the east the newly developed Mango Bay Resort.

CCC baseline surveys showed medium-low Coralline Algae cover, brown

Algae is medium-low, medium bed rock, medium-low live Hard Coral cover, medium Rubble and medium to low Sargassum sp. coverage.

51 The four reefs selected as treatment study units or reference reefs have a history of live rock harvest. The reefs are Vunisese Reef (Namada), Oria Reef,

Navoto Reef and Natarawau reef (Malevu).

3.1.5 Namada Reef

The reef flat is extensive; however the collection study site is on the right hand side of the reef adjacent to a bay. The area studied is 0.145km2 which is a third of the entire reef. The reef flat is shallow and exposed during low tide.

There are rocks, Rubble and pebbles on the beach. Currents are strong due to the passage/bay.

There is an eight-year history of live rock harvesting on the reef flat which is currently on-going. Live rock is usually harvested daily for 3 weeks, stops for a week and then rotates after a month.

A river flows into the bay. Logging also occurs inland up the river. There is much evidence of extensive coastal erosion. The nearby village and resort is

Namada Village and Tambua Sand Resort. There is a 3 year MPA site adjacent to the harvesting sites and marine parks. Marine parks are part of an ecotourism project involving the villagers as tour guides for tourist snorkeling activities.

CCC surveys show that there was a medium-low Coralline Algae, medium-high brown Algae cover, medium bedrock cover, medium-low Hard

Coral cover, medium Rubble cover, and medium to high Sargassum sp. cover.

3.1.6 Oria Reef

This shallow fringing reef is populated by Diadema urchins, Echinometra.

There is a white calcareous beach featuring beach rocks. The reef area is

52 approximately 0.347km2 .The current is very strong owing to the adjacent Sovi

Bay. The reef has been extensively harvested for the past 8 years. Harvesting occurs all over the reef flat. There was evidence of Derris sp. fish poisoning.

Apart from the village, the nearby Indian community comes here for fishing. The reef is right in front of a resort development site. CCC survey showed low

Coralline Algae cover, high brown Algae cover, low bed rock cover, low live coral cover, medium Rubble cover, medium-high and a high Sargassum sp. cover.

3.1.7 Navoto Reef

This is a large reef flat exposed at low tide, featuring a pebbly beach.

The reef covers an area of 0.625km2, the largest of the eight reefs studied. The reef crest is shallow and wide. Currents are strong when wind is strong. There has been extensive harvesting occurring for the past 7-8 years all over the reef.

The reef is adjacent to the Sovi Bay therefore exposed to run off. There is a small backpacker’s facility behind the reef.

CCC survey showed a low Coralline Algae cover, medium-high brown

Algae cover, medium-low bedrock cover, low live coral cover, medium-high

Rubble cover and a medium-high Sargassum sp. cover.

3.1.8 Malevu Reef

The reef features a pebbly granitic beach, covering an area of about

0.607km2. This reef system has a relatively deep lagoon. The left side was surveyed immediately adjacent to the village. This side of the reef was relatively patchy and contained gaps. As part of a coral restoration project, a Japanese

53 NGO called OISCA have placed coral racks in the lagoon. The reefs have a live rock harvesting history of five years since starting in 1992. This stopped and resumed for a year in 2003 and then stopped.

The reef is at the front of Malevu village and adjacent to this is Tubakula beach resort. Hotels and resorts share the same reef including Outrigger Resort and Vaka Viti Resort. The reefs are exposed to an outfall from the village and hotels.

CCC surveys showed that there is medium-low Coralline Algae, medium- low brown Algae cover, medium bedrock cover, low Hard Coral cover, medium

Rubble cover, low Sargassum sp. cover.

54 Figure 3: Coral Coast maps study area with the eight reefs near the seven villages. The harvested reefs (H) are by Malevu, Vatukarasa and Namada Villages. The non-harvested reefs are by Vatuolalai, Votua and Namatakula villages

55 3.3 Differences amongst reefs

The closer the proximity of the reefs is to each other, the more similar they would be. The harvested reefs are closer to each other in terms of their general reef structure. However the reference reefs could not be situated adjacent to the harvested sites due to the history of intensive harvesting along the Coral Coast on the west of Sigatoka up to the first reference reef which was Vatuolalai (where harvesting had been opposed by the communities) (Fig 3.0). The control sites vary in that some feature a more calcareous Sandy beach, whilst, others have a more terrigenious beach. They differ in the sizes of the lagoon and the area of the reefs flat, t-test on size of the areas between the four harvested and non- harvested reef do not show any statistical difference (t-test: p=0.43, t- critical=2.44). However, the areas are not different from each other in terms of geological history as they are all part of the same fringing reef system. A major difference of Malevu Reef from the rest of the reefs is the coral restoration project. This coral restoration is a program set up by a Japanese NGO called

OISCA. This involves coral racks being placed in the lagoon to restore the coral population.

3.4 Indicators Selected for Live Rock Harvest Effects

The indicators chosen for the study were based on preliminary sampling by Movono (2004), MAC (2004) and CCC in 2004 indicating that invertebrates were too patchy and low in density to have statistical reliability. The indicators chosen were non-edible or low priority edible fish families: Chaetodonidae

(Butterflyfish), Blennidae (Blennies), Gobiidae (Gobies), Pomacanthidae

56 (Angelfish), Pinguipedidae (Sandperches), Pomacentridae (Damsel fishes) and

Synodontidae (Lizard fishes).

The Reef Check life-form category was used for indicators of substrate composition (Appendix ii). The only modification made to suit indicator for live rock was that Coralline Algae was prioritized over Macro Algae. This means that if there was Macro Algae on the surface but Coralline Algae beneath, would be recorded as Coralline Algae. This modification was made after consultation with harvesters who indicated that live rock was harvested based on Coralline Algae cover. Collectable live rock was consolidated material, with more than 50-70% coralline cover, beneath Sargassum sp. In this study, the collectable live rock was categorized under Coralline Algae. If Macro Algae was on Rubble or Sand- this would be categorized as Macro Algae. The categories used were: Coralline

Algae, Hard Coral, Soft coral, Algae (macro Algae, turf Algae and Algae assemblage), Sponges, Abiotic (Sand, Rubble and rocks) and Others

(zooanthids inverts etc).

Working with the assumption that live rock harvest will change depth, depth profiles were taken of each reef to determine if such an effect could be detected.

3.5 Methods Used for Sampling

Three sites were selected at each of the eight reefs. At each site, two 100 m transects, end to end and 10 m apart were laid perpendicular to the beach to cover the reef crest and back reef area. Each 100 m transect was divided into

57 four 20 m segments with 5m in between the segments. In total, this equates to twenty four 20 m segments in each of the eight reefs.

Fig 3.1 test 1

100m

20m

Fig 3.1.1 Shows the four 20m segments in one hundred meter transects with 5m intervals in between the segments

58 A belt transect technique was used to count fish in all twenty-four 20 m segments at each reef. The belt-transect technique involved a snorkeler swimming through a 20 x 5 m segment and counting individual fish of the seven indicator families. There were three Reef Check trained personnel that provided assistance in the surveying of fish. The substrate composition was categorized using a modified Reef Check point intercept method, where the substrate type was recorded at meter intervals along each segment (Appendix 1).

Depth was measured to the nearest 1 cm using a graduated rod every meter along the segments at every site on the reefs. The start and stop times of each segment were taken to standardize depth profile to chart datum. GPS points were also taken at the beginning and end of each transect (Appendix iii).

Each of the eight reefs was visited once. The surveys were conducted at a time when good weather and tide were suitable and personnel were available.

Initially four sites were chosen when the first two reefs were surveyed (Oria and

Namatakula); this was later reduced to three sites when surveying other 6 reefs.

It was found that 3 sites represented a better coverage for all the reefs and there were two zones distinct which were prevalent amongst all the reefs. For analysis purposes only the three sites which were common to all the eight reefs were used.

59 The four sites on Oria Reef were surveyed during 1st -6th of May 2005.

The four sites on Namatakula Reef were surveyed during 20th -22nd of June

2005. The three sites each on the Namada, Navoto and Malevu Reefs were surveyed on the 30th November-1st December, 2005 respectively. The remaining three control reefs (Votua, Vatuolalai and Silivaiyata Reef) were surveyed from the 21st -23rd of March, 2006.

3.6 Data Analysis

A 20m segment was the unit of analysis for the fish and substrate data.

3.6.1 Fish data Analysis

The frequency of each fish family on each reef was tallied and tabulated.

Fish individuals from the 24 segments on each eight reefs were counted and categorized into respective groups from 0-9, 10-19 and so forth. For comparison purposes, since 2 of the eight reefs (Oria and Namatakula reefs) had 32 segments compared to the 24 from the other reefs, the mean number of fish counts was used. A frequency table was synthesized for each family in the eight reefs and graphed . A frequency graph of each of the seven fish family was constructed using SPSS version 10.5

The fish data were analyzed using a chi-squared test., Chi-square is calculated by finding the difference between each observed and theoretical frequency for each possible outcome, squaring them, dividing each by the theoretical frequency, and taking the sum of the results:

Where:

60 Oi = an observed frequency;

Ei = an expected (theoretical) frequency, asserted by the Ho.

Pearson's chi-square is used to assess two types of comparison: tests of goodness of fit and tests of independence (Mendenhal, 1991). A test of goodness of fit establishes whether or not an observed frequency distribution differs from a theoretical distribution. A test of independence assesses whether paired observations on two variables, expressed in a contingency table, are independent of each other. Chi-square test was used to analyze the difference in abundance of each of the seven fish familiies between the four harvested reefs and four non-harvested reefs using SPSS Version 10.5. A significant chi- squared value indicates a significant difference in the fish abundance between harvesting and non-harvested reefs. A chi-squared test was also used to compare the abundance of each fish families within the four harvested reefs. A significant chi-squared value indicates a significant difference amongst the four harvesting reefs. The same statistical analysis was done for the four non- harvested reefs.

The next step was to apply two analytical procedures to the data on the distributions of the seven key families first an index of association (the Bray

Curtis dissimilarity measure) (Legendre and Legendre,1998) was used to establish the degree of similarity of the species compositions (families present and abundances of each) at the eight different reefs. Each reef was compared to each of the remaining seven and given a rating, ranging from 0.0 for complete similarity (all attributes with identical values) to 1.0 for complete dissimilarity (no

61 attributes in common) (Fig. 4.1.8 and Table 4.1.8)(Legendre and

Legendre,1998).

3.6.2 Substrate data analysis

All substrate data from each of the 24 segments on the eight studied reefs were entered into EXCEL, Windows XP and grouped using the pivot table. The percentage substrate in each of the eight reefs was calculated and graphed

(Figure 4.2). The substrate composition was analyzed using a chi-squared test on the total composition of the four harvested and four non-harvested reefs. A significant chi-squared value indicates a significant difference in the substrate composition between the harvested and non-harvested reefs. Chi-squared test was also used to compare differences within the four harvested reefs. A significant chi-squared value indicates a significant difference within in the four reef types. The same analysis was conducted within the four non-harvested reefs.

The Z-test is a statistical test used in inference which determines if the difference between a sample mean and the population mean is large enough to be statistically significant. In order for the Z-test to be reliable, certain conditions must be met. The most important is that since the Z-test uses the population mean and population standard deviation, these must be known. The sample must be a simple random sample of the population. If the sample came from a different sampling method, a different formula must be used. It must also be known that the population varies normally (i.e., the sampling distribution of the probabilities of possible values fits a standard normal curve). If it is not known

62 that the population varies normally, it suffices to have a sufficiently large sample, generally agreed to be (Table 5).

# cases such as standardized testing in which the entire population is known. In cases where it is impossible to measure every member of a population it is more realistic to use a t-test, which uses the standard error obtained from the sample along with the t-distribution (Sheskin, 2003).

The test requires the following to be known:

 andard deviation of the population)

 )+

 x (the mean of the sample)

 n (the size of the sample)

First calculate the standard error (SE) of the mean:

The formula for calculating the z score for the Z-test is as follows:

Finally, the z score is compared to a Z table, a table which contains the percent of area under the normal curve between the mean and the z score.

Using this table will indicate whether the calculated z score is within the realm of chance or if the z score is so different from the mean that the sample mean is unlikely to have happened by chance.

63 A z-test was used to indicate which substrate composition was causing the significant difference in the composition of the harvested and non-harvested reefs. A significant z value indicates a significant difference in substrate composition (Table 5).

3.6.3 Depth profiles

Several formulas/steps were used which were synthesized by (Reynolds and Movono, 2006) to create depth profiles from raw data.

Step 1

The first step was the estimated time (Et) of measurement that was taken between the start and stop times of the surveying of each segment.

The formula (Et) = ((Q/84)*(1550-1510)) +1510

Meaning that each measurement (Q) is divided by the largest sequence number to get a proportion; the proportion is multiplied times the result of subtract the start time from the stop time, then adding the start time. This formula assumes that each measurement was taken at regular time intervals between the start and stop times.

Step 2

TPlt= Et-low tide

This is the number of minutes that have passed since low tide (TPlt). The time of low tide is subtracted from the estimated time of measurement.

Step 3

Xtp = TPlt/ (hightide-low tide time)

64 This is the proportion of time that has passed between low tide time and high tide time. The number of minutes passed since low tide is divided by the difference between time of high tide and time of low tide.

Step 4

Depth (cm) = depth measured x Xtp

This is the estimated depth as if it were taken exactly at low tide. Because the depth is taken at some tide level that is higher than low tide, the depth measurement is too high by the proportion of time that has passed since low tide.

The estimated depth at low tide is calculated by multiplying the depth measurement by the proportion of time passed since low tide.

Step 5

Distance (m)

This is the distance in meters to each measurement point from the first measurement point assuming each transect is end to end. There is also allowance for spaces between segments in a transect and between the ends of transects. This will be the X axis of a scatter plot with connecting lines. This is the depth at low tide, but with a negative sign in front for graphing purposes.

Step 6

(Depth (cm)) x –ve= Depth final (cm)

This will be the Y axis of a scatter plot for graphing purposes.

There were three depth profiles on each reef that represented each site on the reef (150m perpendicular from shore). The three profiles were averaged to

65 get the mean depth profile of each reef and Coefficient of Variation (CV) was calculated.

In probability theory and statistics, the coefficient of variation (CV) is a measure of dispersion of a probability distribution. It is defined as the ratio of the standard deviation to the mean :

The CV of the four harvested reefs and the four non-harvested reefs were calculated and plotted. A t-test of the mean depth profiles and CV profiles of the four harvested and non-harvest reefs was conducted. A significant p value will indicate a significant difference in the depth profiles and CV of the four harvested and the four non-harvested reefs. A single factor analysis of variance (ANOVA) using EXCEL in Windows XP was performed on the four harvested reefs depth data to ascertain whether there were significant differences in the depth profiles of the four reefs. This was also performed on the depth data of the four non- harvested reefs.

66 CHAPTER 4: RESULTS

4.1 Fish Abundance

4.1.1 Butterflyfish

There were significantly more Butterflyfishes recorded in the four non- harvested reefs compared to the four harvested reefs, (X2= 12.8, p=0.002, df= 2,

Fig. 4.1.1, table 4.1.1).

KEY Harvested reefs

Non-harveste reefs

Represents one count, every stroke on circle is another count

Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS

Fig 4.1.1: Butterflyfish abundance in the segments within the eight reefs

67 Table 4.1.1: Butterflyfish frequency in four harvested and four non- harvested reefs on the Coral Coast

Harvested reefs frequency Non-harvested reefs frequency

Numbers Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

/100sqm

0 18 19 8 21 10 2 10 14

1-9 6 4 16 11 19 20 14 10

10-19 132

Mean 0.38 0.29 1.50 0.88 3.53 3.92 1.33 0.71

median 1 2.5 3 1 observations 24 24 24 32 32 24 24 24

Within the non-harvested reefs, there were more Butterflyfishes recorded in Namatakula and Votua than Silivaiyata and Vatuolalai (Fig. 4.1.1). A comparison of Butterflyfish abundance between the four non-harvested reefs was not significant (X2=16.952, p= 0.009, df=6).

The lowest counts on harvested reefs were observed in Namada and

Navoto Reefs. A higher number of Butterflyfish (8 counts) were observed in one of the segments in Oria Reef compared to the other segments in which mostly none was found. The greatest mean number of Butterflyfish recorded within the four harvested reefs was on Malevu Reef, (X2=20.18, p<0.001, df=3).

68 4.1.2: Blennie fish

Blennie fish individuals are significantly more abundant in the four non- harvested reefs compared to the four harvested reefs (X2=86.5, p<0.001, df=3; fig 4.1.2, table 4.1.2).

KEY Harvested reefs

Non- harvested reefs

Represents one count, every stroke on circle is another count

Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS

Fig 4.1.2: Blennie fish abundance in the segment within the eight reefs

69 Table 4.1.2: Blennie fish frequency in four harvested and four non-

harvested reefs on the Coral Coast

Harvested reefs Non-harvested reefs

Number/100sq Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai m

0 17 19 9 28 8 5 10 4

1-9 7414410171413

10-19 11 122 7

20-29 2

Mean 1.25 1.08 2.21 0.16 9.25 3.29 0.96 6.25 median 1.5 7.5 2.5 1 4 observations 24 24 24 32 32 24 24 24

The greatest mean number of Blennies was observed on Namatakula

Reef. Votua and Vatuolalai Reefs had relatively high Blennie counts while those

observed on Silivaiyata Reef were significantly lower than the other three non-

harvested reefs (X2=26.96, p<0.001, df=6).

Blennies were rarely observed in three of the harvested reefs, which were

(Namada, Navoto and Oria) while the lowest number of blennies was observed

on Oria Reef. Malevu Reef was an exception to the trend, and had more Blenny

individuals than the other three harvested reefs (X2=19.4, p=0.004, df=6).

70 4.1.3: Angelfish

Angelfish counts observed in the eight studied reefs were low overall.

However due to the higher individuals recorded in Namatakula and Votua,

Angelfish abundance was significantly higher in non-harvested reefs (X2=33.95, p<0.001, df=2, Fig 4.1.3, table 4.1.3).

KEY Harvested reefs

Non- harvested reefs

Represents one count, every stroke on circle is another count

Fig

Fig 4.03: Angelfish abundance in the segments within the

Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS

Fig 4.1.3: Angelfish abundance in the segments along the eight studied reefs

71 Table 4.1.3: Angelfish frequency table in four harvested and four non-

harvested reefs on the Coral Coast

Harvested reefs Non-harvested reefs

Number/100sqm Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

0 23 23 22 32 1 15 22 23

1-9 1120279 2 1

10-19 00004 0 0 0 mean 0.08 0.04 0.13 0 5.16 1.71 0.08 0.04 median 4.5 observations 24 24 24 32 32 24 24 24

Comparisons within the non-harvested reefs showed Namatakula Reef to

have the greatest mean number of observed Angelfish counts. There were also

high Angelfish numbers observed on Votua, but low counts on Silivaiyata and

Vatuolalai. A chi-squared test comparison confirmed the significant difference in

Angelfish abundance within the non-harvested reefs (X2=57.99, p< 0.00, df=61).

The Angelfish abundance in the four harvested reefs was either very low

or absent. A chi-squared test comparison of the four harvested reefs showed no

significant difference in the Angelfish counts between the four reefs (X2=2.6,

p=0.457, df=3).

72 4.1.4 Lizardfish

Lizardfish counts were low amongst the eight reefs. However, Lizardfish abundance was significantly higher in the non-harvested reefs (X2=16.47, p=

0.001, df= 2, Fig 4.1.4, table 4.1.4).

KEY Harvested reefs

Non- harvested reefs

Represents one count, every stroke on circle is another count

Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS

Fig 4.1.4: Lizardfish abundance in the segments within the eight reefs

73 Table 4.1.4: Lizardfish frequency table in four harvested and four non-

harvested reefs on the Coral Coast

Harvested reefs Non-harvested reefs

Number/100s Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai qm

0 14 23 19 32 8 16 19 19

1-9 10 1 5 24 7 5 5

10-19 1 mean 0.88 0.04 0.63 0.00 1.28 1.67 0.25 0.38 median 1 observations 24 24 24 32 32 24 24 24

Within the non-harvested reefs, Votua Reef had the greatest mean

number of lizardfish, although there were a few segments with no fish records,

(X2=28.16, p<0.001, df=6) . The observation of Lizard fish individuals on

Namatakula Reef was low with some segments having no fish. Lizard fish

individuals were rarely observed in the two non-harvested reefs (Silivaiyata and

Vatuolalai). The differences within the four non-harvested reefs were significant.

There was significance variation in Lizardfish abundance within the four

harvested reefs (X2=21.42, p<0.001, df=3). There were no Lizardfish individuals

observed on Oria Reef while there was one Lizardfish individual recorded on

Navoto Reef. Lizardfish counts recorded on Malevu Reef and Namada Reef was

observed to be higher compared to the other two harvested reefs.

74 4.1.5: Sandperch fish

Sandperch fish was observed in low numbers throughout the eight reefs.

However there were significantly more Sandperch observed in the harvested reefs (X2=11.28, p=0.004, df=2,Fig 4.1.5, table 4.1.5).

KEY Harvested reefs

Non- harvested reefs

Represents one count, every stroke on circle is another count

Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS Fig 4.1.5: Sandperch abundance in the segments within the eight reefs

75 Table 4.1.5: Sandperch frequency table in four harvested and four non-

harvested reefs on the Coral Coast

Harvested reefs Non-harvested reefs

Number/100s Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai qm

0 11 17 16 18 10 9 9 8

1-9 12 7 8 12 22 15 15 16

10-19 12 mean 2.04 0.58 1.54 1.53 1.19 2.04 0.79 0.96 median 1111 observations 24 24 24 32 32 24 24 24

The four non-harvested reefs had low counts of Sandperch fish

abundance and there was no significant difference in the Sandperch fish

abundance between the four non-harvested reefs (X2=8.47, p=0.037, df=3).

The greatest Sandperch mean numbers were observed on Votua Reef while

Vatuolalai on the other hand the lowest.

Comparisons within the four harvested reefs show that the greatest mean

numbers of Sandperch individuals were observed on Namada and Oria Reefs.

However the variation of Sandperch abundance between the reefs was not

significant (X2=5.87, p=0.438, df=6). On Oria Reef Sandperch abundance was

higher in two of the segments whilst low or no records of individuals was found

on the rest of the segments. This trend of distribution was prevalent amongst the

three other harvested reefs.

76 4.1.6: Damselfish

The observed Damselfish abundance was high throughout the eight reefs.

There was no significant difference in the observed Damselfish abundance in the four harvested and non-harvested reefs (X2=13.7, p=0.246, df=11, Fig.4.1.6,

Table 4.1.6).

KEY Harvested reefs

Non harvested reefs

Represents one count, every stroke on circle is another count

Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS

Fig 4.1.6: Damselfish abundance in the segments within the eight reefs

77 Table 4.1.6: Damselfish frequency table in four harvested and four non-

harvested reefs on the Coral Coast

Harvested reefs Non-harvested reefs

Number/100s Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai qm

0 5

1-9 1125

10-19 16446 6 4 2

20-29 10 5 9 10 11 4 9 3

30-39 8876115 2 3

40-49 12124 3 2 1

50-59 3 2 135

60-69 11 3

70-79 111

80-89 11 2 3

90-99 11

>100 12 mean 30.25 32.00 29.67 23.72 27.75 22.21 35.17 50.26 median 29.5 30 25 23 27.5 20 24.5 50 observations 24 24 24 32 32 24 24 24

There was significant variation in the observed Damselfish abundance

between the four non-harvested reefs(X2=65.5, p<0.001, df=30). Votua Reef

had a record of low mean Damselfish counts, compared to the other three non-

harvested reefs (Namatakula, Silivaiyata and Vatuolalai). The greatest mean

number of Damselfish was recorded in Vatuolalai Reef.

There was no marked difference in the observed damselfish counts within

the harvested reefs (X2=36.43, p=0.194, df=30).

78 4.1.7: Gobie fish

In general, the recorded Goby fish abundance throughout the eight reefs was low. There was no significant difference in Gobie fish abundance between harvested and non-harvested reefs (X2= 4.85, p=0.08, df=2, table 4.1.7).

KEY Harvested reefs

Non- harvested reefs

Represents one count, every stroke on circle is another count Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai

REEFS

Fig 4.1.7: Gobie fish abundance in the segments within the eight reefs

79 Table 4.1.7: Gobie fish frequency table in four harvested and four non- harvested reefs on the Coral Coast

Harvested reefs Non-harvested reefs

Number/100sq Namada Navoto Malevu Oria Namatakula Votua Silivaiyata Vatuolalai m

0 23 16 9 29 13 9 15 17

1-9 1 8 14 3 29 13 9 7

10-19 12

Mean 0.04 0.67 2.42 0.09 1.09 2.33 0.79 0.54

Median 1.5 1 1

Observations 24 24 24 32 32 24 24 24

The greatest mean number of Goby fish individuals was observed in

Votua Reef when compared to the other three reefs. There was significant variation in the recorded Goby fish abundance between the four non-harvested reefs (X2= 26.4, p<0.001, df=6).

Malevu had the highest records of mean Goby fish individuals. The other three harvested reefs had very low goby fish counts observed. There was significant variation in the Goby fish abundance between the four harvested reefs(X2=29.19, p<0.001, df=6).

4.1.8 The fish community composition of the four harvested and four non- harvested reefs

The Bray-Curtis dendogram for the reef fish community composition (Fig

4.18) for the eight studied reefs illustrated that the composition of the seven fish families in the four harvested reefs were more similar to each than other than the

80 composition in the four non-harvested reefs. The low dissimilarity index value between the harvested reefs (<10.8%) with respect to the non-harvested reefs (>

20%) suggests that there were similar fish compositions on the harvested reefs.

However all the non-harvested reefs were dissimilar in composition from each other (> 20%).

81 Figure 4.1.8: The Bray-Curtis dissimilarity dendogram showing the degree of similarity of the fish families composition (presence and abundance of each) at the eight different reefs. A value of 0 for complete similarity to 1 for complete dissimilarity. (Harvested reefs= Malevu, Navoto, Namada Oria; Non-harvested reefs= Silivaiyata, Votua, Vatuolalai, Namatakula)

82 Table 4.1.8: The Bray- Curtis dissimilarity index for fish on four harvested and four non-harvested reefs on the Coral Coast

Reefs Malevu Namada Navoto Oria (H) Silivaiyata Votua Vatuolalai Namatakula

(H) (H) (H) (NH) (NH) (NH) (NH)

Malevu

Namada 0.0799

Navoto 0.1086 0.0705.

Oria 0.1069 0.0606 0.0583

Silivaiyata 0.1499 0.1452 0.0930 0.1176

Votua 0.1909 0.2509 0.3068 0.2905 0.3312

Vatuolalai 0.3109 0.3133 0.2834 0.3082 0.2145 0.4344

Namatakula 0.2849 0.3154 0.3074 0.3121 0.2323 0.3005 0.282

Malevu Reef fish community composition was more similar to Namada

Reef composition compared to the other two harvested reefs (Navoto and Oria).

The three harvested reefs, Namada, Navoto and Oria were all similar in fish composition with low dissimilarity values (<7%). However, the harvested reefs were dissimilar to all the non-harvested reefs except for Silivaiyata Reef.

Silivaiyata Reef was most similar in fish composition to Navoto Reef (9%).

Silivaiyata Reef fish composition, was more similar to the harvested reefs with low values of dissimilarity ranging from (9%-14%) compared to the other non-harvested reefs (>21%). Votua Reef fish composition, when compared to the three non-harvested reefs had a high degree of dissimilarity (>20%) but relatively similar to Malevu Reef (19%). All the other non-harvest reefs were dissimilar to each other with high dissimilarity indices exceeding 21%.

83 4.1.9: Summary of Fish Abundance

The abundance of four of the fish families was significantly higher in the non-harvested sites compared to the harvested sites. The families include

Chaetodonidae (Butterfly fish), Blennidae (Blennies), Pomacanthidae (Angel fish) and Synodontidae (Lizardfishes). The Pinguipedidae (Sandperches) however were found to be significantly more abundant in the harvested reefs compared to the non-harvested. No significant difference in the frequency of occurrence between the harvested and non-harvested reefs was observed in two families:

Pomacentridae (Damsel fishes) and Gobiidae (Gobies).

The dissimilarity index shows that the four harvested reefs fish composition are more similar to each other compared to the four non-harvested reefs. In the non-harvested reefs, although communities are dissimilar in composition to the harvested reefs, they are also dissimilar to each other.

4.2 Substrate Composition

The percentage composition of benthos in the harvested and non- harvested reefs were composed of Abiotic variables (47%) (Sand, Rubble and

Rocks) and biotic variables (53%). The biotic variables include Coralline Algae, live corals and other minor components like zooanthids. The percentage substrate composition within the eight studied reefs is presented in Figure 4.2.

84 Substrate composition in the 4 harvested (H) and the 4 non-harvested reefs (NH)

100%

90%

80%

70%

60%

50%

percentage 40%

30%

20%

10%

0% H-Malevu H-Namada H-Navoto H-Oria reef N-Namatakula N-Silivaiyata N-Votua N-Vatuolalai Reefs Abiotic Algae Coralline algae Live hard coral Others Soft coral Sponges

Fig 4.2: Percentage substrate composition of the four harvested reef (left) and the four non-harvested reefs (right)

4.2.1 Harvested Reefs

4.2.1.1 Malevu Reef

A large component of Malevu Reef was composed of Abiotic factors

which consisted of Sand, Rubble and Rock (49.7%). The other major

components were Algae (20.9%) then live Hard Coral (19.7%). Coralline Algae

percentage composition was relatively low (7.0%), whilst the minor components

were soft coral (2.1%) and sponges (0.5%).

4.2.1.2 Namada Reef

85 Namada Reef was dominated by Abiotic factors (39.2%) and Algae

(36.7%). About a fifth of the composition was Coralline Algae (21.9%). The minor components of the reef were live Hard Coral (1.9%) along with sponges and other invertebrates (0.3%).

4.2.1.3 Navoto Reef

The Abiotic factors (48.1%) and Algae (35.1%) dominated Navoto Reef substrate composition. Coralline Algae and Live Coral comprised less than a tenth of the percentage composition (7.8% and 7.0% respectively). The minor components which made up the rest of the substrate composition were soft corals 1.3%, sponges (0.6%) and others (0.1%).

4.2.1.4 Oria Reef

More than 80% of the recorded substrate composition of Oria Reef was composed of Abiotic factors and Algae, 40.1% and 42.5% respectively. About a tenth of the percentage composition was Coralline Algae (11.36%). Four percent was composed of live coral and the minor components were soft corals (0.1%), sponges (0.2%) and others (1.3%).

4.2.2 Analysis results between the four harvested reefs

There were significant differences in the substrates composition between the four harvested reefs (X2 = 531.498, df = 18, p<0.001). The greatest percentage of live coral and soft coral components was recorded on Malevu reef

(21.9%) compared to the other three harvested reefs (<10%). The other three harvested reefs were found to have more Algae (>35%) in their substrate composition compared to the Malevu reef (20.9%). Namada reef had the greatest

86 Coralline Algae composition in its substrate (21.9%) compared to the other three harvested reef (<8%) substrate composition. All the reefs had a record of high

Abiotic factors and Algae in general.

4.2.3 Non-harvested reefs

4.2.3.1 Namatakula Reef

Coralline Algae dominated the recorded substrate composition on

Namatakula reef with 45.4%. This was followed by Algae (31.3%) and Abiotic factors (17.2%). Live Hard Corals comprised of 5.7% of the observed substrate composition. The minor components observed which were sponges (0.3%) and other components (0.15%), constituted less then 1% of the Namatakula reef substrate.

4.2.3.2 Silivaiyata Reef

The substrate composition recorded on Silivaiyata Reef was dominated by

Abiotic factors (58.9%). This was followed by Algae, 19.6%. Live Hard Corals recorded on the reef were 13.2% of the total substrate composition. The recorded percentage Coralline Algae was about 8% of the substrate composition.

Less then 1% of the observed substrate composition were the sponges and others categories.

4.2.3.3 Votua Reef

The recorded substrate composition in Votua Reef was dominated by

Abiotic factors (43.70%). This was then followed by Algae coverage of 27.34% and Coralline Algae consisting 19.31% of the substrata. Live coral cover

87 comprised 9.5% of the substrate and the minor components (sponges, and others) making up 0.4%.

4.2.3.4 Vatuolalai Reef

The substrate composition of Vatuolalai Reef was dominated by Abiotic factors, 73.27%. Algae cover was 13.01% of the total substrate composition and live Hard Coral made up 11.36%. The other components which made up less than 2.5% of the substrate composition were Coralline Algae (0.71%), soft coral

(0.71%), sponges (0.41%) and others (0.51%). Soft coral was only found on

Vatuolalai compared to the other three non-harvested reefs.

4.2.4 Analysis between the four non-harvested reefs

There were significant differences in the substrate composition of the four non-harvested reefs (X2= 1257.526, df =18, p= 0.001). Namatakula had a record of the greatest Coralline Algae (45.4%) composition in its substrate compared to the other three non-harvested reefs (>19.5%). However, the Coralline Algae composition in the other three reefs was variable, ranging from 19.3% at Votua reef to 0.7% at Vatuolalai reef. Live Coral cover within the four non-harvested reefs range from 13.2% at Silivaiyata reef to 5.7% of the substrata at Namatakula reef. Algae cover ranged from 31.3% at Namatakula reef to 13.0% at Vatuolalai reef. The greatest percentage of Abiotic factors was in the substrate of Vatuolalai reef (73.27%) and the lowest was at Namatakula reef which composed 17.2% of its substrate.

88 4.2.5 Comparison between the four harvested reefs benthic composition and the four non-harvested reef

There was significant difference between the total percentage substrate composition of the four harvested reefs and the four non-harvested reefs (X2=

214.071, df = 6, p <0.001).

Substrate type Percentage Percentage Z value Critical Z value

composition composition

(Harvested) (N-Harvested)

Coralline Algae 11.96 20.4 13.78 2.58

Abiotic factors 43.95 45.9 2.5 2.58

Algae 34.46 23.5 16.98 2.58

Soft coral 0.84 0.2 10.78 2.58

Live Hard Coral 7.93 9.6 3.53 2.58

Sponges 0.38 .30 0.86 2.58

Others 0.47 0.2 3.13 2.58

Table 4.2.5: Comparisons of substrate composition of the four harvested and the four non-harvested reefs. There are significant differences (where

Z> critical Z) in Coralline Algae, Algal, Soft Coral, Live Hard Corals and others components. No significant differences in the Abiotic factors and sponges where Z< critical z.

89 There was significantly more Coralline Algae in the non-harvested reef compared to the harvested reef (Table 9). There was significantly more live coral cover in the non-harvested reefs compared to the harvested reefs (Table 9).

There was significantly more Algae (macro and turf Algae) in the harvested reefs in comparison to the non-harvested reefs (Table 9). There was significantly more

Soft Corals in the harvested reefs compared to the non-harvested reefs.

4.2.6 Summary of substrate composition

There was a significant difference in the percentage substrate compositions between the two reef types. The components in which there were significant differences were coralline Algae, live coral cover, Algal cover soft coral cover and other category (zooanthids, starfish, and urchins). The non- harvested reefs had more Live Coral cover and coralline cover compared to harvested reefs. Harvested reefs had more Algae cover, soft coral cover and others categories. There were no significant differences in the Abiotic factors between the two reef types.

There were significant differences in the substrate composition of the four non-harvested reefs. Namatakula had a record of the greatest Coralline Algae composition in its substrate compared to the other three non-harvested reefs.

However, the Coralline Algae composition in the other three reefs was variable.

Live coral cover within the four non-harvested reefs was consistent with not much variation in percentage composition. Algae cover was higher at Namatakula reef and lowest at Vatuolalai reef. The greatest percentage of Abiotic factors was in the substrate of Vatuolalai reef and the lowest was at Namatakula reef.

90 There were significant differences in the substrates composition between the four harvested). The greatest percentage of live coral and soft coral components was recorded on Malevu reef compared to the other three harvested reefs. The other three harvested reefs were found to have more Algae in their substrate composition compared to the Malevu reef. Namada reef had the greatest Coralline Algae composition in its substrate compared to the other three harvested reef substrate composition. All the reefs had a record of high Abiotic factors and Algae in general.

4.3 Depth Profiles

All distances from 0m at the beginning of the transect refers to distance from the shore which ends at 150m at the reef crest. All depth values refers to the chart datum depth, hence a –ve value is below chart datum and above is a

+ve value. Chart datum is the height reference surface used in hydrography - depths depicted on navigation charts are below chart datum and drying heights are above it. This is the level to which both tidal levels and water depths are reduced. This level is that of the predicted lowest astronomical tide (LAT).

4.3.1 Non-harvested reefs

4.3.1.1 Namatakula depth profile

Ten meters offshore (from the beach), which is the starting point of the transect,, the reef deepens (till -40cm at 40 m) while it goes out (Fig 4.3.1). The reef then gradually becomes shallow towards the reef crest from 50 m onwards and peaking at the reef crest depth which is about 160 m from the beach. There

91 is generally a lot of variation due to the hollow structure at the beginning of the profile then the gradual shallow reef towards the reef crest.

Namatakula depth profile

10

0 0 50 100 150 200 -10

-20

-30

vertical depth (cm) -40

-50 distance (m) from shore

Figure 4.3.4: Mean depth profile of Namatakula Reef with a mean depth of-18.49, SE=0.99 and CV=68.8

4.3.1.2 Votua depth profile

This reef is generally deep with variations in the structure (Fig 4.3.2). At the beginning of the transect, it is deep becoming shallower from 20-80 m, before entering a deep pool from 80-100 m then gradually becoming shallow again at the reef crest (150 m) onwards.

92 Votua depth profile

0 -10 0 50 100 150 200 -20 -30 -40 -50 -60 -70 vertical depth(cm) -80 -90 distance(m) from shore

Figure 4.3.5: Mean depth profile of Votua Reef with a mean depth of -52.13, SE=0.84, CV=20.8

4.3.1.3 Silivaiyata depth profile

The general reef structure is deeper at the beginning of the transect becoming shallow further offshore (Fig 4.3.3). The shallow depth prevails throughout the reef flat with variations and deep peaks persisting. The deepest peak of -45cm is at 130 m towards the reef crest.

93 Silivaiyata depth profile

0 0 50 100 150 200 -10

-20

-30

-40

vertical depth (cm) -50

-60 distance(m) from shore

Figure 4.3.6: Mean depth profile on Silivaiyata Reef with and average depth of -30.49cm, SE=0.44, CV=18

4.3.1.4 Vatuolalai depth profile

This is a generally shallow reef flat, with outcrops of Bommies at 30 m in to the transect (Fig 4.3.4). The deepest part of the reef is around 60 m into the transect. It is shallower from 90 m onwards towards the reefs crest.

94 Vatuolalai depth profile

100

80 60 40

20 0 vertical depth(cm) -20 050100150200

-40 distance(m) from shore

Figure 4.3.7: Mean depth profile of Vatuolalai Reef with a mean depth =- 18.58cm, SE=0.73, CV=50.6

4.3.2 Analysis of the four non-harvested reefs depth profiles ANOVA

There was significant variation in the depth profiles of the four non- harvested reefs (ANOVA, F=2.61 , p<0.001). There is a significant difference in the coefficient of variations of the four non-harvested (ANOVA, F=2.61, P<0.001)

4.3.3 Harvested reefs

4.3.3.1 Oria Reef

The general reef structure of is shallow with beach rocks at 60m from the beginning of transect becoming deeper from 100m onwards towards the reef crest (Fig 4.3.5). There is not much variation in the general reef structure but existing variations is mostly at reef crest, above and below.

95 Oria depth profile

0 0 50 100 150 200 -5

-10

-15

vertical depth (cm) -20

-25 distance(m) from shore

Figure 4.3.8: Mean depth profile of Oria Reef with a mean depth=17.20cm, SE=0.15, CV=11.79

4.3.3.2 Namada Reef

The general structure of the reef is it is shallow at the beginning with sharp peaks at about 70 m before deepening then finally becoming shallower towards the reef crest (Fig 4.3.6). There is however a lot of variation caused by the crevices at the reef crest.

96 Namada depth profile

0 0 50 100 150 200 -5

-10

-15

-20

vertical depth (cm) -25

-30 distance (m) from shore

Figure 4.3.9: The mean depth profile of Namada Reef with a mean depth=17.52cm, SE=0.43, CV=31.75

4.3.3.3 Navoto Reef

There are a lot of top and bottom peaks throughout the entire reef due to crevices on the reef flat (Fig 4.3.7). A noticeable deep slope is at 100-150 meter, and then the reef is the shallowest at the reef crest. There is a lot of variation throughout the profile of the entire reef and there is not a definite trend to the reef morphology.

97 Navoto depth profile

0 -10 0 50 100 150 200 -20 -30 -40 -50 -60 vertical depth (cm) -70 -80 distance(m) from shore

Figure 4.3.10: Mean depth profile of Navoto Reef with a mean depth =-39.17cm, SE=0.96, CV=31.73

4.3.3.4 Malevu Reef

There is generally a lot of variation on the Malevu bathymetric profile (Fig 4.3.8).

Generally there are a few deep pools on Malevu Reef, particularly from 70-100 m then again from 120-150 m. Although shallower at the reef crest, variation is still relatively considerable.

98 Malevu depth profile

0 -10 0 50 100 150 200 -20 -30 -40 -50 -60 -70

vertical distance (cm)-80 -90 distance (m) from shore

Figure 4.3.11: Mean depth profile Malevu Reef with a mean depth = 51.08cm, SE=1.2, CV=31.06

4.3.4 Analysis of the four harvested reefs depth profiles (ANOVA)

There was significant variation in the depth profiles of the four harvested reefs (ANOVA, F=2.61, p<0.001). There is also a significant difference in the coefficient of variations of the four harvested (ANOVA, F=2.61, P<0.001).

4.3.5 Average depth profiles of the four harvested and four non-harvested reefs

The harvested reefs were on average significantly deeper (30.9cm) than the non-harvested reefs (25.8 cm) (t-test: t-critical=1.97, p<0.02). The average depth profile of the non-harvested reefs shows a gradual trend in the general reef structure with a sharp peak at about 30 m (Fig 9a). In comparison, the harvested reefs show more hollow structures with larger peaks and drops in the general reef morphology (Fig 9b)

99 a)

Mean depth profile of non-harvested reefs

0 -5 0 50 100 150 200 -10 -15 -20 -25 -30 -35

vertical distance (cm) -40 -45 distance from shore (m)

b)

Mean depth profile of the harvested reefs

0 -5 0 50 100 150 200 -10 -15 -20 -25 -30 -35 vertical depth (cm) -40 -45 distance from shore (m)

Figure 9: a) Mean depth profile for the 4 NH reefs with a mean depth of -25.8 cm, S.E=0.334, n =168, b) Mean depth profile of the 4 harvested reefs with a mean depth of -30.9cm and S.E =0.4751, n=168.

4.3.6 Average coefficient of variation of the four harvested and four non- harvested reefs

100 The trend in the coefficient of variation of the harvested reefs illustrates great variation throughout the l reef (Fig. 10a). By contrast the non-harvested reefs show less variation compared to the harvested CV profile, however there is a sharp peak in variation at 160 m from the beginning of the transect (Fig. 10b).

There was a significant difference in the CV between the average depths of the four harvested and four non-harvested reefs (t-test: t critical=1.65, p=0.001).

Coefficient of variation (cv) of the four harvested reefs

0 -100 0 50 100 150 200 -200

(%) -300 cv -400 -500 -600 distance a)

Coefficient of variation (cv) of the four non- harvested reefs

20000

10000

0 (%) 0 50 100 150 200

cv -10000

-20000

-30000 distance b)

Figure 12: shows the coefficient of variation in the average depth of the a) harvested reefs CV=19.14 b) CV= 16

101 4.3.7 Summary of the depth profiles

The average depth profile of each of the four harvested reefs is deeper with greater variation occurring within each reef than within the non-harvested reefs. This is reflected by the coefficient of variation (CV) of each reef. The highest variation was of Navoto (CV=31.73), Malevu (CV=-31.06) and Namada

(CV= 31.75) with Oria reef having the least (CV=11.79). The deepest reef on average was Malevu reef with an average of 50.44 cm in depth. This is followed by Navoto reef with an average depth of 38.62 cm. Oria and Namada reefs had the same mean depths of 17.35 cm.

The average depth profile of each of the four non-harvested reefs is significantly shallower than the harvested reefs. The general structure and depths of the reefs are variable. There is also a significant difference in the coefficient of variations of the four non-harvested reefs. On average, Votua was the deepest reef (52.13cm) followed by Silivaiyata (30.4 cm), Namatakula reef

(18.49 cm) and shallowest was Vatuolalai (18.58 cm). The variation of the mean depth profiles reflected in CV within the four non-harvested reefs. Namatakula has the greatest CV of (68.8), and then Vatuolalai reef (50.6), Votua reef (20.8) followed by Silivaiyata reef (18.0).

There was a significant difference in the coefficient of variation between the two reef types (harvested and non-harvested), although the trends of variation are different. The harvested reefs show that there is a lot of variation in the profile towards the reef crest zones. In contrast, for the non-harvested reefs, the general structure of the reefs contributes to the variation. For example,

102 Votua has deeper lagoons and pools featured in the reef structure, whereas

Silivaiyata is a flatter reef with a lot of small channels observed on the reef.

103 CHAPTER 5: DISCUSSION

5.1 General comments

A major problem with environmental studies impact of this type is that their validity rests on the assumption that the control differs from the impacted sites in the intensity of the human activity under consideration (Underwood,1984;

Shepherd, 1992). Generally, this is difficult to achieve in practical situations.

Mining operations are likely to be localized on close or similar geographical locations; therefore, the ecological community would be similar. This makes it difficult to compare to the control reefs, whether- the similarity- is due to the harvesting or because of similar community types due to spatial variation. This study is based on the assumption that substrate composition and fish abundance are responsive to live rock harvest despite natural variations that exists. These assumptions have been dealt with in Chapter 2.

In this study, four of the seven fish families’ studies were found to be more abundant in the non- harvested reefs compared to the harvested reefs.

Sandperch however was found to be more abundant on the harvested reefs compared to the non-harvested. Three of the harvested reefs showed similar fish community composition compared to the non-harvested reefs. The non- harvested reefs showed very dissimilar fish community composition from each other. This indicates the various other components apart from live rock harvesting influencing the fish composition on each reef.

The response of benthic components in this study in the harvested reefs compared to the non-harvested reefs is an indication of live rock harvest. There

104 was significantly more live coral and Coralline Algae cover in the non-harvested reefs compared to the harvested reefs. The harvested reefs on the other hand have significantly more alga cover compared to that of the harvested reefs. The harvested reefs on average are deeper than the non-harvested reefs. There is also a significant difference in the CV of the depth profiles. This suggests that the natural variation occurring may be masking the variations caused by live rock harvesting.

5.2 Fish Abundance

The abundance of the four families (Butterflyfish, Blennie, Angelfish and

Lizard fish) were significantly lower in the harvested sites while Sandperch was significantly higher. Two of the studied fish families (Gobies and Damselfish) did not show any significant differences in abundance between the harvested and non-harvested reefs. The response of the fish families in the control reefs indicates factors other than live rock affecting the abundance. The fish families that were more abundant in the non-harvested reefs compared to that of the harvested reefs are considered to be negatively affected by live rock harvest. In contrast, the fishes that were more abundant in harvested reefs and responded positively to live rock harvest in this study were the Sandperch fish family. The two fish families that showed no response to live rock removal, are the ones which did on have any significant in abundances between the two reef types, which were Damselfishes and Gobies.

105 5.2.1 Fish abundance in the non-harvested (control reefs)

The factors affecting the abundance of fish in the control reefs are all the other factors apart from live rock harvest. These could be anthropogenic and natural variations which could affect the abundance of fish. Some contributing factors that could explain the higher fish abundance in the control reefs as compared to harvested reefs would be; food and habitat, and various physical features of the individual reefs. These would be natural features such as reef size or human perturbed disturbances such as seepage or other experienced on the various non-harvested reefs.

Butterflyfish, Blennies Angelfish and Lizardfish Abundance were significantly more abundant in the non- harvested site compared to the harvested sites. This indicates an overall effect of the live rock harvest on the two reef types. However results also show significant variations occurring within the harvested reefs as well as within the non-harvested reefs. This is an indication that there are differences occurring within each of the harvested reefs and non- harvested reefs.

5.2.1.1 Food and habitat

The live rock community includes fauna and flora associated with the periphiton communities which are corals, Coralline Algae and invertebrates.

These are sources of food and habitat for fish, hence the reliance of fish on the live rock community. This could be a probable reason as to why there was significantly more Butterflyfish, Angelfish, Lizard fish and Blennies abundant in the control compared to the non-harvested reefs. De Mazieres (2008) has also

106 suggested that the fish distribution along the Coral Coast is due to reliance on food.

5.2.1.2 Physical feature of individual reefs

There are significant differences in the Butterflyfish, Angelfish, Lizard and

Blennies abundance amongst the four non-harvested reefs as reflected by the results. In the natural environment, there are no two reefs that are similar in every aspect. They differ in size, general reef morphology, geology and various types of disturbances to which they are exposed to.

The significant chi-square value when comparing the fish abundance of the four non-harvested reefs shows the differences occurring in the four reefs.

There were more Butterflyfish, Angelfish, Lizardfish and Blennies observed on the two reefs of Namatakula and Votua compared to Silivaiyata and Vatuolalai.

The lowest counts of Butterflyfish, Angelfish, Lizardfish and Blennies were found on Silivaiyata and Vatuolalai reefs. Silivaiyata and Vatuolalai are smaller reefs which suggest a restriction of space on these reefs. The effect of space restriction has been investigated by Wilson (2001) stating that space regulates fish population. Pratchett and Berumen (2006) demonstrated the effect of small space on Butterflyfish behavior. Small spaces usually lead to aggression and competition, which often results in species being displaced. Wilson (2000) has shown that Blennies share the same shallow habitat and similar feeding behavior. This could result in overlap of habitat demand, making competition for holes more intense. In addition to the smaller sizes of reefs, the two reefs of

Silivaiyata and Vatuolalai, both have been affected by anthropogenic factors, like

107 resort development and dredging respectively. These developments could have also contributed to the lower abundance of fish found on these two reefs compared to Namatakula and Votua reefs. Another interesting factor that should be considered is the carrying capacity.. These two reefs have major resorts and villages situated on adjacent sides, thus the amount of villagers and tourist that use the reefs would be significant. This places pressure on small fishing grounds as well as affect the reef fish communities.

Votua and Namatakula Reefs, on the contrary are bigger reefs indicating more food and space suggesting foraging and lesser aggression. This could be a factor contributing to the higher fish abundance in these reefs compared to

Vatuolalai and Silivaiyata. In addition to this, the Resort nearby Votua village is a small scale- eco tourism dive shop- Mikes divers. Eco-tourists are usually more conscientious of the corals and marine environment. Namatakula reef also has a small backpacking Venture- the beach house, as compared to 4 star resorts on

Vatuolalai (Warrick and Naviti Resorts). This implies that in addition to

Namatakula and Votua reefs having larger reef sizes, the impact from tourism is less. There should be more investigations on impact of tourism and water quality, but this has also being discussed by Mosley and Aalbersberg (2003) as a contributing factor to the poor water quality.

5.2.2 Fish composition in the non-harvested reefs

The fish composition observed in the four non-harvested reefs are due to natural and anthropogenic factors besides live rock harvest. All of the non- harvested reefs show dissimilar fish composition from each other reef (> 21%).

108 The most robust reef with high abundance of all of the seven fish families studied was Votua Reef. Votua Reef is similar in fish composition to Malevu Reef in this respect (71%) similarity. Each of the three other non-harvested reefs has different fish composition mainly due to the different features which are unique to each reef.

Vatuolalai shows high dissimilarity index when compared to every other reef. Vatuolalai features a sandy beach which was previously dredged. There have been studies on the initial effect of dredging and have shown to affect species richness, abundance and diversity of benthic communities (Guerra

Garcia et al., 2003). However an investigation of the long term effect by Moulaert

(2005) indicated that there was stability in community structure. Thus the difference in fish communities here could be a consequence of the substrate modification after dredging. On the other hand, the Blennie and Sandperch numbers observed on this reef were high which could indicate favorable substrate for fish.

The Namatakula fish composition being dissimilar from all the other reefs is peculiar considering the area of the reef. The reef shows a high abundance of all the fish families except for Lizardfish. Considering the extensive reef area, a high abundance of all families studied is expected but not so for Lizardfish. This could either be due to divers not seeing the fish because of the adverse weather conditions during survey or the misidentification of the species. A study by Edgar et al. (2004) discussed how the belt transect method using under water visual census techniques tend to underestimate or overestimate fish size and numbers.

109 Further more they commented on the higher the inaccuracy when there were larger time intervals, months or weeks as in this study.

Silivaiyata Reef shows a more similar fish composition to the harvested reefs rather than the non-harvested could be due to several factors. The small size of the reef, the development site behind the reef and the sewage outlet which flows into the reef flats could account for the low fish abundance. The effect of sewage seepage into the coral reef ecosystem often leads to algal bloom which results in fish being deprived of oxygen leading to mortality

(Pastorok and Bilyard, 1985). However, the Coral Coast has high wave action and current, thus effects of seepage are not as drastic as to eutrophic conditions.

The development of the backpackers’ accommodation has resulted in a lot of sediment from construction materials ending up on the reef flats. Local community members have written a petition raising their concerns on the construction site detrimentally affecting the reefs (Bonito pers comm, Votua

Village, 2006). Sedimentation from the construction sites could have resulted in the smothering of corals and relocation of fish. However, further studies on the impact of the development sites need to be investigated and monitored.

5.2.3 Fish abundance in the harvested reefs

The following paragraphs discuss the factors affecting the reduction and increase in fish abundance as a response to live rock harvest.

110 5.2.3.1 Reduction in Fish Abundance as a Response to live rock harvest

The abundance of fish in the harvested reefs would probably be a response to limitation in food and habitat in addition to the various intensity of harvesting that has occurred over the 13 years prior to when the study was undertaken.

5.2.3.1.1 Food limitation

The Butterflyfish, Angelfish, Lizardfish and Blennies numbers found in the harvested reefs were significantly lower than the harvested reefs. Butterflyfish,

Angelfish and Blennies rely on benthic invertebrates, Algae and coral for food which are offered by the periphiton (live rock community). The decline in numbers in these three families in the four harvested reefs, suggests the decline of food and habitat resources due to live rock removal.

5.2.3.1.1.0 Angelfish and Butterflyfish

Declines in live coral cover have direct effects across a fairly narrow range of species, with disproportionate impact on those fishes that rely on coral for food and habitat. Bozec et al. (2005) have correlated the increase in fish abundance with live coral cover and overall fish abundance. This could be a probable explanation to the abundance of Butterflyfish corallivores as they are specialist feeders. Some Angelfish are specialist invertebrate feeders, which inhabit the live rock community. Research by Hourigan et al. (1989) has found algae and sponges to be a major part of three angelfish species studied. Therefore the removal of live rock suggests the removal of invertebrates and algae, which may result in lowered food source and a subsequent decline in Angelfish abundance.

111 The Angelfish observations were relatively low throughout the Coral Coast with none observed on Oria Reef. The removal of live rock decreases food and habitat for the three fish families, thus they could be forced to relocate to some other part of the reef. The study suggests that live rock harvesting limits their abundance. The lack of food usually results in natural mortality or emigration.

5.2.3.1.1.1 Blennies

Blennies are small cryptic benthic dwellers and versatile feeders. They are generalist feeders and live off Algae, Coralline Algae, scrape on coral and detritus in the Sand. The low abundance of Blennies in the harvested reef could be an effect of the removal of food and habitat for Blennies. Szmant (2002) supports this study which correlates low coral cover to a decline in Blennies abundance. The density of Blennies according to Jones (1991) may be influenced by the abundance and distribution of micro-habitats because it has been suggested that microhabitats create different potentials for fish growth and survival. This is also supported in a study by Orlando-Bonaca and Lipej (2007) on the influence of depth and microhabitat in affecting fish abundance. Blennies are territorial fish that lay demersal eggs and are not good long distance swimmers (Thresher, 1980). Therefore, disturbances such as live rock harvest could also affect settlement and growth of Blennie eggs and thus contribute to lower numbers.

5.2.3.1.1.2 Lizardfish

Lizardfish are benthic solitary voracious predators. They are found to be densely populated in calcareous bottom substrate associated with the algal rim

112 (live rock zone). In this study lizard fish was observed to be significantly more abundant in the non-harvested reefs compared to harvested reefs. The short term effect of live rock harvesting implies that habitat and energy reserves could have been removed. Long term effects could have led to the decline in fish abundance, which would mean less fish as a food source for the lizard fish.

Lizard fish are piscivorous thus their reliance on juveniles of other fishes.

These fishes are reliant on herbivorous fishes such as blennies that ultimately rely on lgae and food source that live rock offers. Fish production according to,

Lowe-McConnell (1987) in the sea depends ultimately on primary production by

Algae at the base of food chain. Live rock harvest removes Coralline Algae and other Algae and invertebrates which provide food and habitat to fish which may have caused a decline in the Blennie fish, Butterflyfish, and Angelfish population.

This in turn may have lowered food source for predatory fishes like lizard fish.

5.2.3.1.2 Intensity of harvesting

The lowest counts of Butterflyfish, Angelfish and Blennies were observed on Oria and Navoto Reefs. Some of the factors contributing which have been well established that have led to decline in fish abundance are predation, coral bleaching and nutrient effects. The implications of live rock would be the effect of chronic disturbance caused by the long term harvesting on the reef community.

An area that has been perturbed extensively over a long period of time would implicate a drastic loss in energy reserves or food. A long term consequence of this is the survivorship and reproductive output, leading eventually to declines in population sizes (Jones and McCormick, 2002). This has also been supported in

113 a study by (Nicholas et al., 2006), specifically on the changes in the fish species diversity following a large scale coral depletion. They have shown that such disturbances have a broad impact across a wide range of different fishes and lead to marked reductions in species diversity. There were no Angelfish observed on Oria Reef, and low fish abundance in all the other fish families studied. This perhaps may have been due to the loss of food and habitat from removal of live rock for these fishes.

Townsend and Tibbets (2000) have identified that blennies tend to conform to micro-habitat like the reef rims (calcium carbonate platform cemented by Coralline Algae and robust coral which, in this study the place where most rocks are harvested from). The microhabitat could have been disturbed by the harvest causing a shift of these fish towards the healthier (non-harvested) part of the reef with more food.

5.2.3.1.3 Disturbance during survey

There were slightly more Butterflyfish found on Oria Reef compared to

Namada and Navoto. The Butterfly and Blenny fishes were found on one of the segment of the transects in Oria reef but rarely found on the other parts. The survey was conducted while there was live rock harvesting on the reef, thus the fish could have relocated to one area of the reef as in this case. Although

Butterflyfish and Blennies are site attached Lewis (1997) and Wilson et al.

(2006), have shown that small scale patchiness in disturbance and associated changes in resource availability will serve as a powerful force to promote migration of fishes among habitat or between adjacent reefs or even mortality of

114 fish. This is could have been the reason as to the observed low Butterflyfish and

Blennie fish abundance on Oria Reef.

5.2.3.1.4 Effect of depth

Another possible contributing factor to the abundance of fishes in the harvested reefs is the effect of depth on the fish larvae or food and habitat

(Srinivasan, 2003; Orlando-Bonaca & Lipej, 2005). Some fish larvae prefer shallow depths and some deeper depths to settle. Leis et al. (2002) showed some Pomacentrids and Gobies prefer deeper depths and Blennies preferring shallower depths to settle on. In this study the two families Gobiidae and

Pomacentridae did not show any significant difference in abundance observed in the harvested reefs and non-harvested reefs. A probable reason as two why they would also thrive in the harvested reefs could be the suitability of depth for larvae settlement. Another possible explanation is that some fish prefer deeper depths because of food and habitat. This has been shown by Bell (1983) in studying the effects of depth and fishing reserves on fish in the Mediterranean

Sea. In the study, it was suggested that depth influenced abundance of fish because of feeding requirements. Not all species of the two families mentioned prefer deeper reefs to settle as some prefer shallow waters. Blennies have shown preference for shallower depths in larvae settlement (Leis et al. 2002).

Macpherson (1994) has found that Blennie density and species numbers to be higher in shallow depths. This is also supported in a research conducted by

Topolski & Szedlmayer (2004) of how shallow depths were most suitable for

115 blennies. In the current study, blennies were found to be significantly more abundant in the non-harvested reefs which were on average significantly shallower than harvested reefs. Wilson et al. (2006) states that many reef fish require structural complexity at the time they settle from the plankton, a time when they are particularly susceptible to predation and competition. Therefore a reduction in complexity and increase in depth could reduce some fish species abundance. This is supported by the results of the low abundance in the four fish families (Angelfish, Butterflyfish, Blennies and Lizardfish). Some fish species that belong to the families of Damselfish on the other hand, thrive in deeper conditions, which will be discussed later.

5.2.3.1.5 Malevu

There were significant differences in fish family abundances when comparing amongst the harvested reefs. Malevu Reef had the greatest number of the Butterflyfish, Angelfish and Blennies compared to the other three reefs.

Two factors contributing to the variation are the low duration of harvesting (only a year of harvesting) and the existing coral farms on the reefs only found on

Malevu compared to the other harvested reefs. The reef had not been harvested for the previous 10 years until it was opened for harvesting four years ago for a year. Along with the coral farms, supplementing the diet and habitat for

Butterflyfish, recovery of the coral and fish population could have been enhanced. Coral restoration projects have been used recently to rehabilitate degraded coral reefs. Studies by Ohman et al. (1998), have also found how live coral was a preferred habitat for fish larvae settlement. Therefore coral racks

116 could have provided habitat for larvae settlement which could later contribute to increased fish abundance. There are arguments against the effectiveness of coral restoration because other vital factors which inhibit coral growth needs to be looked at in order for the coral projects prove effective.

5.2.4.0 Increase of fish abundance in response to live rock harvest

The fish family which showed a positive response, which is an increase in population in the harvested reefs compared to the non-harvested, will be discussed in the following paragraph.

5.2.4.1.0 Sandperch

The increased abundance of Sandperch in harvested sites could be an indication of the increased availability of sandy-bottom habitat exposed after the harvesting of live rock. Sandperch are sandy bottom dwellers and feed on invertebrates (crabs, shrimps, crustaceans) that inhabit Sandy bottoms. The removal of live rock creates a suitable habitat for Sandperch by offering exposed sandy bottom. Depczynski and Bellwood (2005) have also noted how cryptic fish abundance is mainly influenced by sand and rubble micro habitats. The higher numbers of Sandperch observed in the harvested reefs suggests the suitability of habitat and food availability. The size of Sandperch in the harvested reefs was notably smaller compared to that in the harvested reefs. However the size of fish was not recorded in this study, therefore little can be explained on the size. It is worth mentioning that the observed fish size was small in the harvested area, and according to Wilson et al. (2006) a reduction in food availability results in reduced growth rates although abundance is not severely affected.

117 5.2.5.0 Fish that do not show any significant difference in abundance

The fish families which seemed to be not affected by the live rock harvested, meaning the numbers were not significantly different in both the reef type studied will be discussed in the following paragraphs.

5.2.5.1.0 Gobies and Damselfish

The Gobies and Damselfishes did not show any significant variations between the harvested and non-harvested reef. There was high abundance of

Damselfish throughout the eight studied reefs. The observed Goby abundance on the other hand was variable throughout the eight reefs.

Damselfish

The Damselfish are a diverse and widespread family; there are obligate coral feeders, generalist feeders and herbivorous damselfish. Foster and Smith

(1997) have established that Damselfishes are hardy species which is why they are often used to break in or cycle a new environment for the aquarium. Their ability to tolerate harsh chemical and physical conditions proves them to be hardy. Most Damselfish species accept all types of food eagerly and are very disease resistant. Therefore they may readily adapt in a perturbed environment where harvesting takes place. This offers an explanation as to why they were not significantly affected by live rock harvest. A study on the Chromis atripectoralis, although obligate plankton feeders showed that declines in coral cover did not affect the abundance. They are often gregarious when crowded and their general compatibility with fishes and invertebrates is an advantage to survivorship.

118 However Damselfishes, become quite aggressive among themselves, and toward other fishes. Intra and inter-specific competition has deleterious effects on survivorship of fishes (McClanahan et al., 2000). Therefore, being highly competitive could be a reason for the high abundance of Damselfish in the non- harvested reef. Also some of the population may be producing offspring and some may be sinks—full of adults that are not able to reproduce (Roach, 2004).

This could account for the low population in some of the non-harvested reefs while plentiful in the other reefs. This may explain the significance in variation which is occurring within the four non-harvested reefs.

The abundance of Damselfish is also influenced by other factors apart from the live rock harvest. The results indicate that depth could be responsible for the structuring of fish assemblages including Damselfish. Bell (1984), pointed out that Chromis chromis, a diurnal planktivore, is more abundant at deeper sites. In this study, Damselfish were also just as abundant in the harvested reefs which were on average deeper than the non-harvested; depth could therefore be a major factor in the high abundance of the harvested reef as well. This is presumably because there is greater volume of water in which to feed (Bell &

Harmelin-Vivien 1983). Other studies that support water depth influencing the fish communities of many reefs are McGehee (1994); Lara & Gonzalez (1998);

Khalaf & Kochzius (2002).

Gobies

Gobies, according to Lowe-McConnell (1987), feed off corals and

Coralline Algae using their razor sharp teeth to bite and scrape off the substrate.

119 The rate and magnitude of declines in the abundance of fishes following coral depletion vary depending on the degree to which coral limits their abundance.

Munday et al. (1997) observed that coral dwelling gobies tend to saturate available habitats, such that their abundance is limited by the availability of suitable habitat. Macpherson (1994) showed in a study that Gobies did not have a particular depth preference. This could mean that, despite the depth differences between the harvested and non- harvested reefs, this did not affect

Gobie abundance. However, declines in the availability of habitat negatively affect their abundance.

This is may also explain the low abundance of Gobies throughout the reefs along the Coral Coast. However, their small size could be a factor which contributed to divers not identifying them and could be a probable cause of the low numbers observed throughout the studied reefs. Willis (2002) has discussed how underwater visual census tends to underestimate the abundance of cryptic fishes, due to their small size and cryptic behavior.

5.2.6 Fish composition in the harvested reefs

The Bray-Curtis dendogram (Fig 4.1.8) shows that the fish compositions in the harvested reefs are more similar to each other than the non-harvested reefs.

The diagram takes into account the abundance and fish families found in the studied reefs. The chi-test comparisons show that there were low abundances of

Butterflyfish, Angelfish, Blennies and Lizardfish in the harvested reefs. As discussed above, these are due to limitations in habitat, food and space.

120 Within the harvested reefs, some reefs have similar fish composition compared to the other reefs. For instance, Malevu Reef is dissimilar from the rest of the reefs because all the fish families studied were found in abundance on this reef despite being previously harvested. The fish composition in Malevu was most similar to Namada Reef because of the high abundance of Lizard fish,

Blennies and Sandperch observed on Namada Reef as well. Another factor which could affect the three fish families above is the adjacent MPA situated on

Namada and Malevu Reefs. An effect of the MPA providing healthier habitat could have led to the recovery of adjacent habitat which would increase fish abundance. Ashworth, and Ormond (2005) have indicated in a study of the how spill over effects increases the fish abundance in areas adjacent to no take zones in the Red Sea. Malevu and Namada Reefs have MPAs and Coral restoration projects which are management tools for increasing fish abundance. It should also be noted that there were also adjacent MPAs on Vatuolalai and Silivayaita which were non-harvested reefs. Fish counts however, were lower than

Namatakula and Votua reefs, where MPAs were not on the same reef flat.

Another most likely explanation is that for Namada and Malevu, only a section of the reef was harvested, about a third, compared to Navoto and Oria where the whole reef is harvested. The unharvested sections of the reef could support recovery of the harvested reef parts. This could explain why these two reefs have greater fish abundance than Oria and Navoto.

Navoto and Oria Reefs both had low records of all of the fish families. On these reefs, live rock harvesting occurs all over these reefs as opposed to the

121 harvesting on Namada and Malevu, where a part of the reefs is allocated for harvesting. This could be due to the fact that Oria and Navoto Reefs are not in close proximity to the villages like Namada and Malevu. When the villages are close by harvesters are more mindful of the amount they extract (pers. comm,

Orisi, 2005 (Vatukarasa)).

A major factor that was not considered in this study, neither in previous studies, is the effect of spatial and temporal differences on Fish communities.

Ault and Johnson, 1998 have indicated the lack of consideration on temporal and spatial effect on fish assemblages as this has been demonstrated in various studies previously. Since the surveys were conducted at various time (3 different times) this could have affected the fish abundance. However there need to be further studies on the effect of spatial and temporal effect on Fish communities.

5.3 Effects on benthic community

The substrate composition of the harvested reefs, being significantly different from the non-harvested reefs, suggests a direct impact of the harvesting on the benthos. Since live rock harvesting involves the actual removal of substrate (Rubble, Coral, Algae and invertebrates), the substrate composition of a reef is altered. The current study shows that there is significantly less Live

Coral and Coralline Algae cover and more Algae and Soft Coral in the harvested reefs compared to that in non-harvested reefs.

The action of the crow bar in physically removing the substrate from the reef leaves open spaces. The substrate that is being removed for live rock is composed of consolidated Rubble, Algae, Coralline Algae, inverts and in some

122 cases live coral. Therefore in certain areas when these are removed, an open space exposes Sand as well as fragmented Rubble. Not only does it have an effect on biotic factors, the physical structures of the reefs could be impacted.

The effect of the live rock harvest on the substrate compositions is demonstrated by the difference observed on the harvested reefs compared to the non-harvested. The substrate compositions of the non- harvested reefs will also be mentioned as these are all the other factors, apart from live rock harvesting which affecting substrate composition.

5.3.1 Comparison of the substrate composition in the four non-harvested reefs

The differences of substrate composition within the four harvested reefs are worth mentioning as there were factors other than live rock harvest affecting it. The results indicated that the two reefs, Namatakula and Votua were similar in the percentage substrate composition compared to Silivaiyata and Vatuolalai.

The reef substrate compositions of Namatakula and Votua were dominated by

Coralline Algae and Algae, with a lower Live Coral and Abiotic cover. In contrast the two reefs, Vatuolalai and Silivaiyata were largely composed of Abiotic factors which were Sand, Rubble and Rock, with some Live Coral and Algae. The Live

Coral cover was slightly higher in Vatuolalai and Silivaiyata reefs compared to

Namatakula and Votua. However there were considerable differences in the

Coralline Algae, Algae and Abiotic components between the Namatakula and

Votua compared to Silivaiyata and Vatuolalai.

The dominance of Coralline Algae and Algae with a low Coral Cover in

Namatakula and Votua reef could be an indication of areas which have been

123 exposed to high levels of disturbance. This does not necessarily mean that the reefs are devastated, because coralline dominated reefs are highly productive ecological communities and their growth and distribution are mainly attributed to hydrodynamics. In this study, hydrodynamics was not investigated, but would be useful for further studies. To support this, there was a lower Abiotic cover- which is an indication that the reefs are dominated by life forms as opposed to barren reefs. Therefore, it could be said that these reefs were in some successional stage as the life forms indicate productivity. Although the intertidal area was not surveyed as a part of the study, there were seagrass beds observed on the

Namatakula intertidal area (pers. Obs). This was also noted by De Marzieres,

2008 on the study of the spatial reef fish communities along the Coral Coast.

Corals on the other hand, is susceptible to environment degradation, thus the low coral cover could be an indication of poor water quality. Namatakula and Votua reefs are both exposed to seepage, terrestrial run offs, piggeries and fresh water in flow from nearby creek. These are the obvious factors which could be affecting the coral cover in the area. Macro Algae is also prevalent on these reefs and such is an indicator of elevated nutrients and reduced herbivore fish grazing. Previous studies have mentioned high levels of nutrients throughout the

Coral Coast.

Vatulalai and Silivaiyata reefs, compared to Namatakula and Votua reefs indicate less vibrancy in their benthic communities. The substrate compositions on these reefs are mostly dominated by Abiotic variables, which are Sand,

Rubble and Rock. Algae cover is low and coral is not much higher than the

124 other two reefs. It should be noted, that soft Coral was only found on Vatuolalai reef, compared to the other three reefs. Benayahu and Loya (1981) have shown that soft corals increase after a loss in coral cover. This could be a reason as to why there is soft Coral on Vatuolalai. Clearly, these reefs have been exposed to high level of disturbances. These are similar disturbances like poor water quality, human perturbations, developments of resorts and more. There is an outfall outlet from the hotel and the village that flows into the beachfront. Adjacent to

Vatuolalai Village is Naviti Resort, a four star resort which suggests more human activities and disturbance on the reef flat.

Another probable reason as to why the reefs were much more devastated than the other two reefs could be attributed to their sizes. Vatuolalai and

Silivaiyata reefs are much smaller in sizes compared to Namatakula and Votua.

A smaller reef size to human population ratio could result in over degradation of reefs due to more demand and pressure on the small reefs. This could also mean, that the chronic disturbances would not allow the communities to recover.

It should be noted that Vatuolalai was previously dredged, and this is an added disturbance to the benthic communities. Vatuolalai, from this study was observed to have the lowest Coralline Algae cover in its substrate compared to the other three reefs. Whether this is related to dredging or hydrodynamics alone needs to be investigated before further can be commented.

125 5.3.2 Substrate composition in the four harvested reefs, responsive to live rock harvest

Namada, Navoto and Oria reefs were clearly dominated by Algae. The three reefs of Namada, Navoto and Oria have been extensively harvested for the past 13 years. The intensity of the harvesting is the most probable cause of low live coral cover and Algae cover. Malevu reef was an exception with high live

Coral cover and lower Algae cover compared to the three other reefs.

5.3.1.0 Macro Algae and turf Algae

The harvested reefs had significantly higher algal (turf and Macro Algae) cover than the non-harvested reefs. Research by Szmants (2002), have shown how Macro Algae colonizes open spaces. This could be a reason as to why there is dominance of Algae on these reefs and significantly higher than the non- harvested reefs. The removal of rock could have left open spaces for Macro

Algae to colonize. Studies by Szmants, 2002, have also stated that water quality and nutrient level as major factor influencing Algae growth. It should be noted that there is elevated nutrient levels throughout the Coral Coast which have been mentioned by Mosley and Aalbersberg (2003). Other factors like over fishing of grazers and predators, sedimentation stress and terrestrial run off have also been well established as major factors affecting algal growth. However the water quality throughout the study area showed little variation (Aalbersberg &

Mosley, 2003), this parameter is assumed a non issue in delineating the impacts of live rock harvest. That there are significantly more Algae in the four harvested reefs could be an indication of the effect of live rock harvest. One probable

126 explanation is that the harvesting of the rocks could have affected the nutrient uptake, by turbulence created from alteration of the reef morphology by harvesting.

Morphology is important in a coral reef ecosystem because the nutrient recycling by the periphiton community (live rock) depends on the morphology of the reef surface to sustain the rapid influx of nutrients across the reef. Hearn et al., 2001 has demonstrated how roughness creates turbulence needed to mix the diffusive layer which allows the plants to take up the nutrients. The action of live rock harvest removes the substrate which could also mean unequal holes are created. This does not necessarily mean the roughness is lost because the crevices in some places are small, in other places bigger. The variation in holes produces different roughness; therefore there could be an unequal effect on the wave energy. In other wards, the harvest may cause great variation and thus turbulence. Turbulence is essential for nutrients uptake and balance hence, harvesting rocks may be a contributing factor to the nutrient imbalance. The harvesting could have been creating turbulence which may have led to more mixing and uptake by the plants, hence growth. There needs to be specific studies designed for the uptake of nutrients and turbulence on the harvested reefs to state more.

The role of live rock as a site of degradation or turn over for Dissolved

Organic Matter (DOM) should also be given consideration as an explanation to nutrient imbalance. Sorokin (1993) has commented on the role of the periphiton community and its importance in degradation or turnover of DOM of oceanic

127 waters. The site of microbial degradation (periphyton/live rock) community is removed when the rocks are harvested. Since bacteria are essential for the recycling of DOM in the ocean, the removal may lead to an influx of DOM which suggests an imbalance of nutrients in the ecosystem. The consequences of this occurring could be the result of dominance of Algae observed on the reef flats.

Another obvious factor which could have contributed to the increased macroaglae growth in the harvested reefs is the close proximity of Sigatoka River compared to the non-harvested reefs. All the reefs studied however, are situated between small rivers and creeks thus are exposed to river inputs. Sigatoka River is part of a bigger hydrological basin, transporting more nutrients and pollutants- which may have led to increased Algae in the non- harvested reefs. There should be further investigations on the river input on to the reef and Oceanic flow.

The studied reefs lay east to the Sigatoka River, but Zann, 2002 shows that the

Global currents in the Southern Fiji basin flow south-westward, rendering further investigations.

5.3.1.2 Crustose Coralline Algae (CCA)

Historically, researchers thought that Crustose Coralline red Algae were slow-growing members of reef communities. Current observations show the opposite for some tropical species like the live rock corallines. Crustose Coralline red Algae can be among the first to colonize vacant-reef substrate, and dime- sized colonies can be seen within weeks of space becoming available (Vroom et al., 2006). This could explain why Coralline Algae is observed on the harvested reefs [Namada (21%)], but is not all collectable live rock. It should also be noted

128 that the rocks on Namada reef are harvested from the leeward side. A previous study by Villas Boas et al. (2005) have shown Coralline Algae to thrive on

Leeward side of the reef as compared to the windward side, which could be why there is more Coralline Algae on this part of the reef. There are still significantly more Coralline Algae in the non-harvested reefs compared to the harvest which suggests that the rocks could be removed at a rate too fast for Coralline Algae to recover, due to the chronic disturbance.

In many cases, the build-up of a reef system arises from a joint effort between Crustose Coralline red Algae and corals (Randall et al., 1997). From this study there is a negative correlation with Algae and coral cover in most sites and a positive correlation of Coral cover and Coralline Algae cover. Reefs which have been harvested for live rock have significantly low Coral cover and Coralline cover, and high Algae cover. Crustose Coralline red Algae produces a chemical that triggers settlement in coral and other invertebrate larvae, which creates a vital link between the Algae and coral communities (Vroom et al., 2006). This suggests that this relationship between coral and coralline algae is why there seems to be low cover of Coral and Coralline in the harvested reefs.

5.3.1.3 Live Coral

The low live coral cover in the harvested sites when compared to the non- harvested could be a result of inhibition of recruitment, apart from other factors such as poor water quality and environment degradation. Smith et al. (2006) have stated that over time the spaces which have been colonized by Algae inhibit coral recruitment. However, great consideration should be placed on the physical

129 disturbance caused by the removal of corals during live rock harvest and the harvesters stepping on the corals. This results in immediate reductions in live coral and complexity of reef framework.

Some coral species have more rapid recruitment, faster growth and lower mortality rate than others (Hughes and Connell, 1999). Larval recruitment in coral occurs soon after space is available if the space has not been colonized by

Algae. The recruitment rate of corals decrease as the amount of free space declines, this is probably due to preemption, shading by Algae. This could be a reason as to why there is preponderance of Algae and the low coral cover in the harvested reefs. Furthermore, disturbance causes an effect on the coral settlement and growth. Differential recruitment occurs after disturbance (Hughes and Connell, 1999) which results in changes in coral reef community composition. Some coral branches however, recover quickly from minor damage through passive tumbling and reattachment of vegetative fragments. Therefore even on the harvested reefs, there still is live coral, however the species found is mostly Staghorn coral which are fast growing species. This is supported by

Hughes and Jackson (1985) stating that some taxa grew faster than massive or encrusting species and increase the abundance by high rates of asexual fragmentation. This could be an explanation for Malevu Reef (coral restoration project site) having more live coral cover in comparison to the other three non- harvested reefs. The corals that are planted in the coral restoration project in

Malevu Reef belong mainly to the fast growing coral taxa. Despite the history of intensive harvesting 10 years ago and recently for a period of 18 months, coral

130 cover appears to be significantly more abundant in Malevu compared to the other harvested reefs. Whether this is a direct impact of the coral restoration project or the undamaged areas supporting recovery naturally or recruitment is favorable is not known.

5.3.1.5 Soft corals and others

The zooanthids, which fall under the “others” category, were more prevalent in the harvested reefs as well as soft Coral. It has been mentioned above how soft Corals tend to grow where there has following a degradation of

Coral. This may be a reason as to why there is more Soft Coral observed on the harvested reefs. The sea urchins, Diadema, in particular were more abundant in the harvested reefs. These are herbivorous-grazer urchins which mostly feed on the macro algal beds that are abundant in the harvested reefs. This offers an explanation for the abundance of the herbivorous invertebrates on the harvested reefs, suitable food and habitat.

5.3.2.0 Abiotic factors

Live rock harvesting could have attributed to the amount of Rubble in the harvested sites, but not significantly. It is not significant because the proportion of

Abiotic factors in the non-harvested reefs were not significantly different to those of the harvested reefs. Wave energy, wind stress and tidal surges are the main factors that influence the amount of Abiotic factors in the reefs along the Coral

Coast. There are channels separating the reefs along the Coral Coast which would also affect the currents on the reefs. According to Lowe-McConnell (1987), surge channels often have tidal waves with strong currents. This in effect would

131 re-mobilize considerable amount of Rubble and affect Sand accretion and erosion.

5.4 The effect of live rock on the reef morphology and depth

This study is a snap-shot of the general reef morphology. It is limited to descriptive qualitative analysis, the bathymetry, to describe the effects of live rock removal on depth. The profiles of the four harvested and non- harvested reefs show where the variations on the reef occur. The depth profiles indicate that in the harvested reefs, the variation is mostly around a 100m from the beach and back reef area. This coincides with the parts of the reefs where intensive harvesting takes place. The implication is that the holes created while removing the rocks is a probable cause of variation on the harvested reefs. This suggests that the removal of the rocks causes the variation on places where the rocks are removed. However, it cannot be verified whether the live rock significantly affects the depth because of the high variations that exists on each and every individual reef. This indicates that natural variation like the natural topography should not be ignored. This suggests that despite the variations caused by harvesting, the natural variation amongst the reefs is also prevalent. However, the bathymetry results, provides the topographical and morphological features of the reefs studied .

132 CHAPTER 6: CONCLUSION AND RECOMMENDATIONS

From the study conducted, it has been found that live rock harvesting may have significant effects on abundance in five of the seven families. The abundance of four of the fish families was significantly higher in the non- harvested sites: Chaetodonidae (Butterflyfish), Blennidae (Blennies),

Pomacanthidae (Angelfish) and Synodontidae (Lizardfishes). No significant difference in the frequency of occurrence between the harvested and non- harvested reefs was observed in the two families Pomacentridae (Damsel fishes) and Gobiidae (Gobies). On the other hand the families Pinguipedidae

(Sandperches) were more abundant in the harvested sites. The main factor influencing the abundance of fish was the availability of food, space and mates and the chronic disturbance caused by the harvesting of live rock.

The harvesting of live rock also may also have significantly affected the substrate composition in the direct removal of substrate in terms of altering the substrate compositions. The percentage composition of benthos in the harvested and non-harvested reefs was dominated by Abiotic variables (Sand, Rubble and rocks). There was no significant difference in the percentage composition of

Abiotic variables between the harvested and non-harvested sites. The biotic variables which were Coralline Algae, live corals and other minor components like zooanthids made up the rest of the of substrate composition in both the harvested and non-harvested reefs. There were significant differences in the biotic variables between the harvested and non-harvested reefs. There were significantly more Coralline Algae and Live Coral in the non-harvested reefs

133 compared to the harvested reefs. In contrast, there were significantly more Algae

(macro and turf Algae) and Soft Coral and others (invertebrates, zooanthids) in the harvested reefs in comparison to the non-harvested reefs.

Conclusions can be drawn from observations recorded when comparing within the four harvested reefs. Malevu and Namada reefs where harvesting was restricted to sections of the reef flat, comprised a higher fish abundance and more live coral/Coralline Algae cover compared to Oria and Navoto reefs in which the entire reefs were harvested. It can be concluded that recovery of fish population and benthic community is possible with restrictions on some areas of the reef for harvesting.

The significant variation of the depth profiles of the harvested reefs being more towards the reef crest maybe indicative of live rock harvesting effects..

However the significance of the variations in comparing the four non-harvested reefs also suggests natural effects. There was a significant variation in

Coefficient of Variation (CV) between the four harvested reefs and non-harvested reefs. The natural variation that exists could have masked the variation contributed by live rock harvest. Since there are significant differences occurring in all the reefs, it cannot be assumed that live rock harvest, substantially affects the reef topography.

The implication of this study would be towards the conservation of the live rock (periphiton) community which is the largest primary producers of the coral reefs. The study demonstrates the importance of the live rock community in terms of food and habitat which the fauna and flora of the coral reef community

134 rely on. Therefore the results would prove useful for decision making for the future of the trade, in terms of sustainability of natural resources.

At present the live rock harvest in Fiji has important economic benefits associated with it to the local communities. Combining these economic benefits with the probable and demonstrated ecological impacts, this study therefore recommends short and long term sustainable measures. The short term measures includes protocols from the Marine Aquarium Council Collection Area

Management Plan (CAMP) be followed. These are guidelines on sustainable collection methods agreed by NGOs, universities, government and exporters.

However this does not improve changes on the reef topography which can not be replaced in a short time. For a more quantitative analysis, accretion rate of tropical Coralline Algae and morphology over time should be monitored. This is because geological processes take a longer time than ecological processes to display a significant change. The amount of rocks that are harvested should be weighed on site so that the specific amounts of rocks removed are documented.

This will give a better idea of how much is actually removed before the best rocks are chosen and taken for curing. The sustainability of the trade could be answered when the amount removed is known and how much is actually left on the reef flats and the accretion rate of tropical Coralline Algae. Another recommendation is that less than a third of the reef flat should be allocated for harvesting must this take place due to economic or inevitable reasons.

135 The long term measures would be to gradually phase out harvesting within a five year period while introducing artificial cultured rocks. There is currently an ongoing joint project by Institute of Applied Science and Georgia Institute of

Technology on the cultured live rock experiment. The cultured rocks would be an alternative source of income for communities reducing the pressure of wild harvest. Quotas should be reduced according to phasing out of the wild harvest

(and focused on the cultured rocks provided there would be no CITES quotas for cultured rocks Communities should be more business orientated with assistance from government so that the industry is not monopolizing live rock harvest.

For further research, the impacts on a wider range of taxa and specific to species level should be conducted. Future studies should take into consideration size of fish as this reflects the energy reserve of the habitat. Studies on the spatial and temporal effects on the fish would be useful. Also oceanic studies and effects of the Sigatoka Basin hydrology and currents would be useful in understanding the ecology of reef communities along the Coral Coast.

A recommendation for a study on the phasing out of wild harvest and increasing cultured rocks should be carried out and documented. This could be replicated in other countries for the conservation of the natural resource, the coral reef community of which live rock is a part of.

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161 APPENDIX I

Reef Check Substrate Codes

ACRONYMN ABBREVIATION

HC HARD CORAL

CA CORALLINE ALGAE

SC SOFT CORAL

RCK ROCK

MA MACRO ALGAE

SP SPONGE

RKC RECENTLY KILLED CORAL

SD SAND

SI SILT/CLAY

RB RUBBLE

OT OTHERS

162 APPENDIX II

Table of similarities and differences between the harvested and non-harvested reefs

Harvested reefs Non-harvested reef Difference Similarity

Reef sizes Malevu 0.607 Namatakula 0.312 P=0.43

(area km2) Navoto 0.625 Votua 0.609 (non-significant)

Oria 0.347 Silivaiyata 0.114

Namada 0.145 Vatuolailai 0.157

Reef type Fringing reef Fringing reefs same

Geomorphology Same extensive Same extensive reef same

reef

Water quality Close proximity Close proximity similar

Proximity of Close close similar hotels/villages

Harvested for fish fishing fishing similar

Fish abundance ^ ` Significant

` differences

{|^

}

Fish abundance Gobies Damselfish Non-significant

Substrate + ~ Significant composition  differences

Average depths ~^ Significant

differences

CV € Non-significant

difference

163 APPENDIX III

Table of GPS points of the beginning and end of each transect on the eight reefs

 missing GPS points is due to mechanical fault of GPS during survey

Transects Latitudes Longitudes

Namatakula_1a_1 18°13'55.00"S 177°46'41.86"E

Namatakula_1a_2 18°13'58.03"S 177°46'40.33"E

Namatakula_1b_1 18°14'0.40"S 177°46'39.60"E

Namatakula_1b_2 18°14'2.82"S 177°46'38.24"E

Namatakula_2a_1 18°13'52.73"S 177°46'33.02"E

Namatakula_2a_2 18°13'55.87"S 177°46'31.42"E

Namatakula_2b_1 18°13'57.82"S 177°46'30.44"E

Namatakula_2b_2 18°14'1.31"S 177°46'28.79"E

Namatakula_3a_1 18°13'49.29"S 177°46'28.01"E

Namatakula_3a_2 18°13'52.63"S 177°46'26.45"E

Namatakula_3b_1 18°13'54.68"S 177°46'25.62"E

Namatakula_3b_2 18°13'57.71"S 177°46'24.32"E

Silivaiyata_1a_1 18°12'59.11"S 177°42'56.20"E

Silivaiyata_1a_2 18°13'2.10"S 177°42'54.62"E

Silivaiyata_2b_1 18°13'4.36"S 177°42'53.90"E

Silivaiyata_2b_2 18°13'8.29"S 177°42'52.36"E

Silivaiyata_2a_1 18°12'55.29"S 177°42'53.60"E

164 Silivaiyata_2a_2 18°12'58.23"S 177°42'51.98"E

Silivaiyata_2b_1 18°12'59.90"S 177°42'51.12"E

Silivaiyata_2b_2 18°13'3.25"S 177°42'50.00"E

Silivaiyata_3a_1 18°12'50.04"S 177°42'49.49"E

Silivaiyata_3a_2 18°12'53.17"S 177°42'48.01"E

Silivaiyata_3b_1 18°12'55.94"S 177°42'46.82"E

Silivaiyata_3b_2 18°12'59.16"S 177°42'45.26"E

Votua_1a_1 18°12'41.04"S 177°42'28.10"E

Votua_1a_2 18°12'44.38"S 177°42'27.51"E

Votua_1b_1 18°12'48.20"S 177°42'26.97"E

Votua_1b_2 18°12'51.69"S 177°42'26.02"E

Votua_2a_1 18°12'37.56"S 177°42'17.08"E

Votua_2a_2 18°12'40.75"S 177°42'15.66"E

Votua_2b_1 18°12'43.36"S 177°42'14.66"E

Votua_2b_2 18°12'46.73"S 177°42'13.57"E

Votua_3a_1 18°12'34.07"S 177°42'10.44"E

Votua_3a_2 18°12'37.21"S 177°42'9.02"E

Votua_3b_1 18°12'40.60"S 177°42'7.70"E

Votua_3b_2 18°12'43.88"S 177°42'6.64"E

Namada _1a_1 18°11'19.35"S 177°36'51.22"E

Namada _1a_2 18°11'21.72"S 177°36'51.86"E

Namada _1b_1 18°11'22.83"S 177°36'50.41"E

Namada _1b_2 18°11'26.50"S 177°36'50.43"E

165 Namada _2a_1 18°11'15.21"S 177°36'45.81"E

Namada _2a_2 18°11'18.41"S 177°36'45.69"E

Namada _2b_1 18°11'20.23"S 177°36'44.42"E

Namada _2b_2 18°11'22.44"S 177°36'45.12"E

Namada _3a_1 18°11'11.86"S 177°36'40.93"E

Namada _3a_2 18°11'15.52"S 177°36'40.88"E

Namada _3b_1 18°11'17.96"S 177°36'40.24"E

Namada _3b_2 18°11'21.78"S 177°36'40.54"E

Oria_1a_1 18°11'15.72"S 177°36'4.34"E

Oria_1a_2 18°11'18.16"S 177°36'4.55"E

Oria_1b_1 18°11'19.01"S 177°36'5.66"E

Oria_1b_2 18°11'21.61"S 177°36'5.80"E

Oria_2a_1 18°11'12.78"S 177°35'56.45"E

Oria_2a_2 18°11'14.63"S 177°35'54.96"E

Oria_2b_1 18°11'16.30"S 177°35'54.51"E

Oria_2b_2 18°11'18.98"S 177°35'55.39"E

Oria_3a_1 18°11'5.18"S 177°35'46.81"E

Oria_3a_2 18°11'7.86"S 177°35'45.78"E

Oria_3b_1 18°11'8.98"S 177°35'43.23"E

Oria_3b_2 18°11'11.38"S 177°35'42.01"E

Navoto_1a_1 18°11'1.43"S 177°34'59.70"E

Navoto_1a_2 18°11'3.36"S 177°35'1.06"E

Navoto_1b_1 18°11'6.38"S 177°35'2.39"E

166 Navoto_1b_2 18°11'9.28"S 177°35'3.38"E

Navoto_2a_1 18°11'2.26"S 177°34'43.53"E

Navoto_2a_2 18°11'5.69"S 177°34'44.22"E

Navoto_2b_1 18°11'7.46"S 177°34'45.65"E

Navoto_2b_2 18°11'10.55"S 177°34'43.78"E

Navoto_3a_1 18°10'58.98"S 177°34'29.73"E

Navoto_3a_2 18°11'1.33"S 177°34'28.63"E

Navoto_3b_1 18°11'3.20"S 177°34'29.53"E

Navoto_3b_2 18°11'5.09"S 177°34'27.36"E

Malevu_1a_1 18°10'57.77"S 177°33'52.07"E

Malevu_1a_2 18°11'1.05"S 177°33'53.11"E

Malevu_1b_1 18°11'4.50"S 177°33'54.36"E

Malevu_1b_2 18°11'5.95"S 177°33'55.63"E

Malevu_2a_1 18°10'56.59"S 177°33'41.39"E

Malevu_2a_2 18°10'58.75"S 177°33'41.04"E

Malevu_2b_1 18°11'1.45"S 177°33'38.84"E

Malevu_2b_2 18°11'3.58"S 177°33'37.63"E

Malevu_3a_1 18°10'56.10"S 177°33'32.17"E

Malevu_3a_2 18°10'58.54"S 177°33'30.26"E

Malevu_3b_1 18°11'0.37"S 177°33'30.03"E

Malevu_3b_2 18°11'3.66"S 177°33'29.52"E

Vatuolalai_1a_1 18°12'18.53"S 177°41'22.18"E

Vatuolalai_1a_2 18°12'22.27"S 177°41'22.17"E

167 Vatuolalai_1b_1 18°12'25.33"S 177°41'21.28"E

Vatuolalai_1b_2 18°12'28.60"S 177°41'22.03"E

Vatuolalai_2a_1 18°12'18.22"S 177°41'17.11"E

Vatuolalai_2a_2 18°12'21.55"S 177°41'15.92"E

Vatuolalai_2b_1 18°12'23.72"S 177°41'14.31"E

Vatuolalai_2b_2 18°12'25.56"S 177°41'12.26"E

Vatuolalai_3a_1 18°12'14.98"S 177°41'9.92"E

Vatuolalai_3a_2 18°12'17.86"S 177°41'8.23"E

Vatuolalai_3b_1 18°12'20.36"S 177°41'6.78"E

Vatuolalai_3b_2 18°12'24.19"S 177°41'5.97"E

168 APPENDIX IV

Substrate and fish abundance data

Percentage substrate composition on the harvested reefs

Substrate Malevu Namada Navoto Oria Composition composition (%) average

Abiotic 49.7 39.2 48.1 40.1 44.3

Algae 20.9 36.7 35.1 42.5 33.8

Coralline algae 7.0 21.9 7.8 11.4 12.0

Live hard coral 19.7 1.9 7.0 4.4 8.25

Others 0.1 0 0.1 1.3 0.37

Soft coral 2.1 0 1.3 0.1 0.88

Sponges 0.5 0.3 0.6 0.2 0.4

Total 100 100 100 100 100

Percentage substrate composition on non-harvested reefs

Substrate Namatakula Silivaiyata Votua Vatuolailai Composition composition average

Abiotic 17.2 58.9 43.7 73.3 48.2

Algae 31.3 19.6 27.3 13.0 22.8

Coralline algae 45.4 8.0 19.3 0.7 18.3

Live hard coral 5.7 13.2 9.5 11.4 9.9

Others 0.10 0 0.5 0.2

Soft coral 0 0.2 0.7 0.3

Sponges 0.30.3 0.4 0.3

Total 100 100 100 100 100

169 Fish data showing the chi-square test which confirms that the difference in family composition between the two types of reefs and the difference is significant.

LOG N RANK PERCENT 0.778151 1 0.184729 2.045323 5 3.417488 1.826075 3 2.062808 3.447313 7 86.23768 1.886491 4 2.37069 1.568202 2 1.139163 2.173186 6 4.587438 3.511616 100

LOG N RANK PERCENT 2.1959 4 3.456627 2.681241 6 10.56803 2.356026 5 4.997798 3.526856 7 74.06429 2.060698 2 2.531924 1.919078 1 1.827389 2.064458 3 2.553941 3.657247 100

PERCENT WHOLE NUMBERS CHI-SQUARE TAXON DIFF HARV NO HARV ANGEL 1 3 BLENNIE 3 11 BUTTERFLY 2 5 DAMSEL 86 74 GOBIES 2 2 LIZARD 1 2 SANDPRCH 5 3 Chi-square = 12.731 df = 6 P = 0.0475 significant

170 171