Klaus 2012 Reef Fish Thesis

Home , Inimicus filamentosus, Lethrinus mahsena

Habitat specific fish pattern of coral reef fish assemblages around Chumbe Island, Zanzibar

Presented by Melanie Klaus

Presented to the University of Bremen, Faculty for Biology & Chemistry

1st supervisor : Dr. Hauke Reuter, ZMT Bremen 2nd supervisor : Dr. Christopher A. Muhando, IMS Zanzibar

Bremen, August 2012 Abstract

Seagrass beds and coral reefs are important habitats for tropical fish. These habitats are connected with each other due to several processes, e.g. biologial processes from fish assemblages. These fish assemblages were influenced by behavioural pattern or temporal pattern. Information about these fish assemblages is needed for the sustainable management of marine protected areas. Within the scope of this master’s thesis stationary point count observations were done of coral reef fish assemblages in a coral reef and a seagrass bed. The field work was carried out around Chumbe Island (Zanzibar) from December 2011 until February 2012. The aims were to determine the fish community composition in East African tropical waters, especially in a coral reef and in a seagrass bed. The influence of temporal pattern was surveyed during 16 different samplings. These temporal pattern were lunar cycles (neap and spring), tidal amplitudes (high and low) and a diel cycle (day and twilight). The twilight samplings were done during sunrise and sunset. Species of special interest were determined, which were important for the ecosystem, interesting for commercial fisheries or had a high species diversity. 75 species were analysed for significant differences in their habitat use in terms of abundance and in terms of biomass. In total 168 species out of 42 different families were identified. Out of this 139 species belonging to 36 families were counted during the samplings. The fish community composition differed between the two habitats. 72 species were only seen in the coral reef and 14 were only observed in the seagrass bed. 53 species were counted in both habitats. Also different times influenced the fish community composition in both habitats. 63 species were seen during daytime and twilight. 19 species were only counted during daytime and 20 were only observed during twilight. There was also a difference in the fish community composition between sunrise and sunset. Five species were only counted during sunrise and twelve only during sunset. The fish community composition was significantly different between the two habitats, e.g. Acanthurus leucosternon, Chlorurus sordidus, and Plectroglyphidodon lacrymatus indicated significant differences in their habitat use. The fish community composition was influenced in both habitats by temporal pattern. The lunar cycle had in both habitats the least influence. The diel cycle influenced twelve species in both habitats, e.g. Thalassoma hebraicum and Sphyraena flavicauda. Most of the species showed a significantly higher habitat use at daytime. The tidal amplitudes had the biggest influence on the habitat use. 13 species revealed a significantly higher habitat use during high tide. It was concluded that the habitat use of coral reef fish assemblages is influenced by temporal pattern with different importance. Contents

List of ﬁgures 1

List of tables 4

1. Introduction 6 1.1. Habitat use of coral reef ﬁsh assemblages around Zanzibar ...... 6 1.2. Interest in habitat use in terms of management of marine protected areas (MPAs) 7 1.3. Scope and research questions ...... 8 1.4. Criteria for species of special interest ...... 8

2. Material and Methods 10 2.1. Study site ...... 10 2.2. Habitat characterization and environmental parameters ...... 10 2.3. Fish observation method ...... 13 2.4. Sampling design ...... 14 2.5. Calculation of biomass ...... 17 2.6. Statistical analysis ...... 17

3. Results 18 3.1. Fish community composition in East African tropical waters, e.g. Chumbe Island 18 3.2. Analysis in terms of abundance ...... 21 3.2.1. Comparison of different habitat types during high tide in a neap cycle . . 21 3.2.2. Comparison of different habitat types during high tide in a spring cycle . 23 3.2.3. Comparison of different cycles during high tide in the coral reef . . . . . 25 3.2.4. Comparison of different cycles during high tide in the seagrass bed . . . 27 3.2.5. Comparison of different habitat types during low tide in a neap cycle . . . 28 3.2.6. Comparison of different habitat types during low tide in a spring cycle . . 30 3.2.7. Comparison of different cycles during low tide in the coral reef ...... 32 3.2.8. Comparison of different cycles during low tide in the seagrass bed . . . . 34 3.2.9. Comparison of different tides in a neap cycle in the coral reef ...... 36 3.2.10. Comparison of different tides in a spring cycle in the coral reef ...... 38 3.2.11. Comparison of different tides in a neap cycle in the seagrass bed . . . . 40 3.2.12. Comparison of different tides in a spring cycle in the seagrass bed . . . 42 3.2.13. Comparison of different habitat types during sunset in a neap cycle . . . 44 3.2.14. Comparison of different times in a neap cycle in the coral reef ...... 46 3.2.15. Comparison of different times in a neap cycle in the seagrass bed . . . . 48 3.2.16. Comparison of different habitat types during sunset in a spring cycle . . 50 3.2.17. Comparison of different times in a spring cycle in the coral reef . . . . . 52 3.2.18. Comparison of different times in a spring cycle in the seagrass bed . . . 54 3.2.19. Comparison of different habitat types during sunrise in a neap cycle . . . 56 3.2.20. Comparison of different habitat types during sunrise in a spring cycle . . 58 3.3. Analysis in terms of biomass ...... 60 3.3.1. Comparison of different habitat types during high tide in a neap cycle . . 60 3.3.2. Comparison of different habitat types during high tide in a spring cycle . 62 3.3.3. Comparison of different cycles during high tide in the coral reef . . . . . 64 3.3.4. Comparison of different cycles during high tide in the seagrass bed . . . 66 3.3.5. Comparison of different habitat types during low tide in a neap cycle . . . 68 3.3.6. Comparison of different habitat types during low tide in a spring cycle . . 70 3.3.7. Comparison of different cycles during low tide in the coral reef ...... 72 3.3.8. Comparison of different cycles during low tide in the seagrass bed . . . . 74 3.3.9. Comparison of different tides in a neap cycle in the coral reef ...... 76 3.3.10. Comparison of different tides in a spring cycle in the coral reef ...... 78 3.3.11. Comparison of different tides in a neap cycle in the seagrass bed . . . . 80 3.3.12. Comparison of different tides in a spring cycle in the seagrass bed . . . 82 3.3.13. Comparison of different habitat types during sunset in a neap cycle . . . 84 3.3.14. Comparison of different times in a neap cycle in the coral reef ...... 86 3.3.15. Comparison of different times in a neap cycle in the seagrass bed . . . . 88 3.3.16. Comparison of different habitat types during sunset in a spring cycle . . 90 3.3.17. Comparison of different times in a spring cycle in the coral reef . . . . . 92 3.3.18. Comparison of different times in a spring cycle in the seagrass bed . . . 94 3.3.19. Comparison of different habitat types during sunrise in a neap cycle . . . 96 3.3.20. Comparison of different habitat types during sunrise in a spring cycle . . 98

4. Discussion 101 4.1. Fish community composition in East African tropical waters ...... 101 4.2. Comparison of the ﬁsh community composition in the coral reef and seagrass bed and the inﬂuence of lunar cycles, tidal amplitudes or diel cycle on this composition ...... 101 4.3. Difference between the analysis in terms of abundance and biomass ...... 104 4.4. Discussion of bias ...... 104 4.5. Conclusions ...... 105 4.6. Outlook ...... 106

List of abbreviations 107

References 108

Acknowledgements 111

A. Abundance boxplots 112

B. Biomass boxplots 138 List of Figures

2.1. Overview of Unguja (Zanzibar) ...... 10 2.2. Sampling area on the southwestern site of Chumbe ...... 11 2.3. Mean percentage cover of different substrate types in both coral reef transects . 12 2.4. Mean percentage cover of different substrate types in both seagrass transects . 12 2.5. Overview of sampling quadrats in each habitat ...... 13 2.6. Schematic ﬁgure of the sampling design ...... 14 3.1. Distinctions in means of abundance for SI for CRHN vs SBHN ...... 22 3.2. Distinctions in means of abundance for SI for CRHS vs SBHS ...... 24 3.3. Distinctions in means of abundance for SI for CRHN vs CRHS ...... 26 3.4. Distinctions in means of abundance for SI for CRLN vs SBLN ...... 30 3.5. Distinctions in means of abundance for SI for CRLS vs SBLS ...... 32 3.6. Distinctions in means of abundance for SI for CRLN vs CRLS ...... 34 3.7. Distinctions in means of abundance for SI for SBLN vs SBLS ...... 36 3.8. Distinctions in means of abundance for SI for CRHN vs CRLN ...... 38 3.9. Distinctions in means of abundance for SI for CRHS vs CRLS ...... 40 3.10.Distinctions in means of abundance for SI for SBHN vs SBLN ...... 42 3.11.Distinctions in means of abundance for SI for SBHS vs SBLS ...... 44 3.12.Distinctions in means of abundance for SI for CRSSN vs SBSSN ...... 46 3.13.Distinctions in means of abundance for SI for CRSSN vs CRLN ...... 48 3.14.Distinctions in means of abundance for SI for SBSSN vs SBLN ...... 50 3.15.Distinctions in means of abundance for SI for CRSSS vs SBSSS ...... 52 3.16.Distinctions in means of abundance for SI for CRSSS vs CRHS ...... 54 3.17.Distinctions in means of abundance for SI for SBSSS vs SBHS ...... 56 3.18.Distinctions in means of abundance for SI for CRSRN vs SBSRN ...... 58 3.19.Distinctions in means of abundance for SI for CRSRS vs SBSRS ...... 60 3.20.Distinctions in means of biomass for SI for CRHN vs SBHN ...... 62 3.21.Distinctions in means of biomass for SI for CRHS vs SBHS ...... 64 3.22.Distinctions in means of biomass for SI for CRHN vs CRHS ...... 66 3.23.Distinctions in means of biomass for SI for SBHN vs SBHS ...... 68 3.24.Distinctions in means of biomass for SI for CRLN vs SBLN ...... 70 3.25.Distinctions in means of biomass for SI for CRLS vs SBLS ...... 72 3.26.Distinctions in means of biomass for SI for CRLN vs CRLS ...... 74 3.27.Distinctions in means of biomass for SI for SBLN vs SBLS ...... 76 3.28.Distinctions in means of biomass for SI for CRHN vs CRLN ...... 78 3.29.Distinctions in means of biomass for SI for CRHS vs CRLS ...... 80 3.30.Distinctions in means of biomass for SI for SBHN vs SBLN ...... 82 3.31.Distinctions in means of biomass for SI for SBHS vs SBLS ...... 84 3.32.Distinctions in means of biomass for SI for CRSSN vs SBSSN ...... 86 3.33.Distinctions in means of biomass for SI for CRSSN vs CRLN ...... 88 3.34.Distinctions in means of biomass for SI for SBSSN vs SBLN ...... 90

1 3.35.Distinctions in means of biomass for SI for CRSSS vs SBSSS ...... 92 3.36.Distinctions in means of biomass for SI for CRSSS vs CRHS ...... 94 3.37.Distinctions in means of biomass for SI for SBSSS vs SBHS ...... 96 3.38.Distinctions in means of biomass for SI for CRSRN vs SBSRN ...... 98 3.39.Distinctions in means of biomass for SI for CRSRS vs SBSRS ...... 100 A.1. Boxplots in terms of abundance for CRHNvsSBHN 1 ...... 112 A.2. Boxplots in terms of abundance for CRHNvsSBHN 2 ...... 113 A.3. Boxplots in terms of abundance for CRHSvsSBHS 1 ...... 114 A.4. Boxplots in terms of abundance for CRHSvsSBHS 2 ...... 115 A.5. Boxplots in terms of abundance for CRHNvsCRHS ...... 115 A.6. Boxplots in terms of abundance for CRLNvsSBLN 1 ...... 116 A.7. Boxplots in terms of abundance for CRLNvsSBLN 2 ...... 117 A.8. Boxplots in terms of abundance for CRLSvsSBLS 1 ...... 118 A.9. Boxplots in terms of abundance for CRLSvsSBLS 2 ...... 119 A.10.Boxplots in terms of abundance for CRLNvsCRLS 1 ...... 120 A.11.Boxplots in terms of abundance for CRLNvsCRLS 2 ...... 121 A.12.Boxplots in terms of abundance for CRLNvsCRLS 3 ...... 122 A.13.Boxplots in terms of abundance for SBLNvsSBLS ...... 122 A.14.Boxplots in terms of abundance for CRHNvsCRLN ...... 123 A.15.Boxplots in terms of abundance for CRHSvsCRLS 1 ...... 124 A.16.Boxplots in terms of abundance for CRHSvsCRLS 2 ...... 125 A.17.Boxplots in terms of abundance for SBHNvsSBLN ...... 125 A.18.Boxplots in terms of abundance for SBHSvsSBLS ...... 126 A.19.Boxplots in terms of abundance for CRSSNvsSBSSN 1 ...... 127 A.20.Boxplots in terms of abundance for CRSSNvsSBSSN 2 ...... 128 A.21.Boxplots in terms of abundance for CRSSNvsCRLN ...... 129 A.22.Boxplots in terms of abundance for SBSSNvsSBLN ...... 130 A.23.Boxplots in terms of abundance for CRSSSvsSBSSS 1 ...... 131 A.24.Boxplots in terms of abundance for CRSSSvsSBSSS 2 ...... 132 A.25.Boxplots in terms of abundance for CRSSSvsSBSSS 3 ...... 133 A.26.Boxplots in terms of abundance for CRSSSvsCRHS ...... 133 A.27.Boxplots in terms of abundance for SBSSSvsSBHS ...... 134 A.28.Boxplots in terms of abundance for CRSRNvsSBSRN ...... 135 A.29.Boxplots in terms of abundance for CRSRSvsSBSRS 1 ...... 136 A.30.Boxplots in terms of abundance for CRSRSvsSBSRS 2 ...... 137 B.1. Boxplots in terms of biomass for CRHNvsSBHN ...... 138 B.2. Boxplots in terms of biomass for CRHSvsSBHS 1 ...... 139 B.3. Boxplots in terms of biomass for CRHSvsSBHS 2 ...... 140 B.4. Boxplots in terms of biomass for CRHNvsCRHS ...... 141 B.5. Boxplots in terms of biomass for SBHNvsSBHS ...... 141 B.6. Boxplots in terms of biomass for CRLNvsSBLN 1 ...... 142 B.7. Boxplots in terms of biomass for CRLNvsSBLN 2 ...... 143

2 B.8. Boxplots in terms of biomass for CRLSvsSBLS ...... 144 B.9. Boxplots in terms of biomass for CRLNvsCRLS 1 ...... 145 B.10.Boxplots in terms of biomass for CRLNvsCRLS 2 ...... 146 B.11.Boxplots in terms of biomass for SBLNvsSBLS ...... 147 B.12.Boxplots in terms of biomass for CRHNvsCRLN ...... 148 B.13.Boxplots in terms of biomass for CRHSvsCRLS 1 ...... 149 B.14.Boxplots in terms of biomass for CRHSvsCRLS 2 ...... 150 B.15.Boxplots in terms of biomass for SBHNvsSBLN ...... 151 B.16.Boxplots in terms of biomass for SBHSvsSBLS ...... 152 B.17.Boxplots in terms of biomass for CRSSNvsSBSSN 1 ...... 153 B.18.Boxplots in terms of biomass for CRSSNvsSBSSN 2 ...... 154 B.19.Boxplots in terms of biomass for CRSSNvsCRLN 1 ...... 155 B.20.Boxplots in terms of biomass for CRSSNvsCRLN 2 ...... 156 B.21.Boxplots in terms of biomass for SBSSNvsSBLN ...... 157 B.22.Boxplots in terms of biomass for CRSSSvsSBSSS 1 ...... 158 B.23.Boxplots in terms of biomass for CRSSSvsSBSSS 2 ...... 159 B.24.Boxplots in terms of biomass for CRSSSvsSBSSS 3 ...... 160 B.25.Boxplots in terms of biomass for CRSSSvsCRHS 1 ...... 161 B.26.Boxplots in terms of biomass for CRSSSvsCRHS 2 ...... 162 B.27.Boxplots in terms of biomass for SBSSSvsSBHS 1 ...... 163 B.28.Boxplots in terms of biomass for SBSSSvsSBHS 2 ...... 164 B.29.Boxplots in terms of biomass for CRSRNvsSBSRN 1 ...... 165 B.30.Boxplots in terms of biomass for CRSRNvsSBSRN 2 ...... 166 B.31.Boxplots in terms of biomass for CRSRSvsSBSRS 1 ...... 167 B.32.Boxplots in terms of biomass for CRSRSvsSBSRS 2 ...... 168

3 List of Tables

2.1. Categorization of the twilight samples ...... 15 2.2. Summary of the analysed samples ...... 16 2.3. Summary of the different analysed pairs ...... 16 3.1. Overview of all species ...... 18 3.2. Overview for analysis of abundance for CRHN vs SBHN ...... 21 3.3. Overview for analysis of abundance for CRHS vs SBHS ...... 23 3.4. Overview for analysis of abundance for CRHN vs CRHS ...... 25 3.5. Overview for analysis of abundance for SBHN vs SBHS ...... 27 3.6. Overview for analysis of abundance for CRLN vs SBLN ...... 28 3.7. Overview for analysis of abundance for CRLS vs SBLS ...... 30 3.8. Overview for analysis of abundance for CRLN vs CRLS ...... 32 3.9. Overview for analysis of abundance for SBLN vs SBLS ...... 34 3.10.Overview for analysis of abundance for CRHN vs CRLN ...... 36 3.11.Overview for analysis of abundance for CRHS vs CRLS ...... 38 3.12.Overview for analysis of abundance for SBHN vs SBLN ...... 40 3.13.Overview for analysis of abundance for SBHS vs SBLS ...... 42 3.14.Overview for analysis of abundance for CRSSN vs SBSSN ...... 44 3.15.Overview for analysis of abundance for CRSSN vs CRLN ...... 46 3.16.Overview for analysis of abundance for SBSSN vs SBLN ...... 48 3.17.Overview for analysis of abundance for CRSSS vs SBSSS ...... 50 3.18.Overview for analysis of abundance for CRSSS vs CRHS ...... 52 3.19.Overview for analysis of abundance for SBSSS vs SBHS ...... 54 3.20.Overview for analysis of abundance for CRSRN vs SBSRN ...... 56 3.21.Overview for analysis of abundance for CRSRS vs SBSRS ...... 58 3.22.Overview for analysis of biomass for CRHN vs SBHN ...... 60 3.23.Overview for analysis of biomass for CRHS vs SBHS ...... 62 3.24.Overview for analysis of biomass for CRHN vs CRHS ...... 64 3.25.Overview for analysis of biomass for SBHN vs SBHS ...... 66 3.26.Overview for analysis of biomass for CRLN vs SBLN ...... 68 3.27.Overview for analysis of biomass for CRLS vs SBLS ...... 70 3.28.Overview for analysis of biomass for CRLN vs CRLS ...... 72 3.29.Overview for analysis of biomass for SBLN vs SBLS ...... 74 3.30.Overview for analysis of biomass for CRHN vs CRLN ...... 76 3.31.Overview for analysis of biomass for CRHS vs CRLS ...... 78 3.32.Overview for analysis of biomass for SBHN vs SBLN ...... 80 3.33.Overview for analysis of biomass for SBHS vs SBLS ...... 82 3.34.Overview for analysis of biomass for CRSSN vs SBSSN ...... 84 3.35.Overview for analysis of biomass for CRSSN vs CRLN ...... 86 3.36.Overview for analysis of biomass for SBSSN vs SBLN ...... 88 3.37.Overview for analysis of biomass for CRSSS vs SBSSS ...... 90

4 3.38.Overview for analysis of biomass for CRSSS vs CRHS ...... 92 3.39.Overview for analysis of biomass for SBSSS vs SBHS ...... 94 3.40.Overview for analysis of biomass for CRSRN vs SBSRN ...... 96 3.41.Overview for analysis of biomass for CRSRS vs SBSRS ...... 98

5 1. Introduction

Seagrass beds and coral reefs are important habitats for tropical fish. These fish use these habitats for feeding, shelter or nursery purposes [Beck et al., 2001]. Habitats are connected to each other due to several processes, which can be physical, biological and chemical. Fish play an important role in this processes because they migrate from one habitat to the other [Nagelkerken et al., 2008]. These migrations are influenced by different factors, e.g. tidal amplitude or daylight, and can have high variations in their dura- tions. Other studies observed a different behaviour of coral reef fish between day and night [Nagelkerken et al., 2008] and only a few studies worked with the interlinkage between a seagrass bed and a coral reef [Dorenbosch et al., 2006].

1.1. Habitat use of coral reef ﬁsh assemblages around Zanzibar

Bergman et al. (2000) investigated “the inﬂuence of habitat on the distribution and abundance of Pomacentrus sulfureus on coral reefs in Zanzibar”. The densities of juvenile and adult Po- macentrus sulfureus were measured in relation to habitat structure and composition. Bergman and co-workers compared two measurements of habitat structure which were rugosity and percent cover of branching structure. The distribution of Pomacentrus sulfureus had an uneven pattern around Zanzibar. The analysis showed that the distribution of juveniles was related to the branching structure. The rugosity had no inﬂuence on the distribution of juveniles or adults. Pomacentrus sulfureus showed an ontogenetic shift in habitat use [Bergman et al., 2000].

Bergman and co-workers (2001) surveyed the influence of algal farming on fish distributions in two shallow lagoons in Zanzibar. 101 fish species of 31 different families were counted. Al- gal farming had an effect on abundance, species richness, trophic identity and fish community composition of the interfaced fish. The influence of algal farming was different in both lagoons. The suggestion was made that this is an effect of farming intensity and characteristics of the substrate [Bergman et al., 2001].

Dorenbosch did several studies about habitat use in Zanzibar. In 2004, Dorenbosch and co-workers investigated homing and tidal movements of juvenile snappers from the family Lut- janidae between shallow-water nursery habitats. Daily tidal movements of tagged juveniles of Lutjanus fulviﬂamma and Lutjanus ehrenbergii were observed between two habitats. These two habitats were a subtidal channel and shallow tidal notches in a marine bay. One quarter of tagged juveniles showed a clear movement between the habitats in perpendicular orientation to tidal currents. Some juveniles indicated homing, but the majority moved to avoid predation pressure [Dorenbosch et al., 2004].

In 2005, Dorenbosch and co-workers surveyed “the contribution of Indo-Paciﬁc seagrass beds and mangroves to ﬁsh density and diversity on adjacent coral reefs”. The value of neighbouring habitats to coral reefs should be estimated. These neighbouring habitats were supposed

6 to act as nursery habitats. The density distribution patterns of juveniles and adults of 76 species were investigated. It was assumed that seagrass beds and coral reefs were the most important habitats for juvenile ﬁsh. Ontogenetic migrations occurred between seagrass beds and coral reefs and the presence of a seagrass bed had a positive inﬂuence on the densities of adults on adjacent coral reefs [Dorenbosch et al., 2005a].

Also in 2005, Dorenbosch and co-workers determined a distribution of coral reef ﬁsh along a 60 metres coral reef – seagrass bed gradient in Chwaka Bay, Zanzibar. The 48 observed species were classiﬁed in four categories according to their habitat use and frequency. The gradient showed that there was a habitat segregation between species and life stages and indicated an edge effect [Dorenbosch et al., 2005b].

In 2006 Dorenbosch and co-workers examined how fish assemblages in East African seagrass beds were influenced by surrounding landscapes. A comparison was made between bay and reef seagrasses using underwater visual census surveys. No differences occurred in total fish density or total species richness but at species level significantly higher densities for the two seagrass bed types were observed [Dorenbosch et al., 2006].

Lokrantz and co-workers surveyed in 2010 “the impact of artisanal fisheries on key functional groups and the potential vulnerability of coral reefs” on five sites on the western coast of Zanzibar. Fishing is supposed to have a major influence for the health of a coral reef. When herbivores were reduced, the coral reef could shift to a macroalgal stage. In this study was examined the fishing pressure on three functional groups of herbivores. Fishing pressure was negatively correlated with fish biomass, abundance, diversity and species richness and al- tered the demographic structure of fish populations. Fishing pressure is supposed to enhance unsolicited ecosystem shifts [Lokrantz et al., 2010].

Lugendo and co-workers investigated in 2007 the fish community composition in a nonestuarine embayment in Zanzibar. The fish were caught with a seine net from three different habitats during eleven months. 150 fish species were identified. These species belonged to 55 families. The highest means of biomass were recorded in the mangrove creek. A high species overlap was measured for neighbouring habitats [Lugendo et al., 2007].

1.2. Interest in habitat use in terms of management of marine protected areas (MPAs)

The interest in habitat connectivity of coral reef ﬁsh has raised with management and development of marine protected areas [Roberts, 1997]. These protected areas are assumed to have a positive effect on neighbouring habitats [Roberts, 1997].

The deﬁning and understanding of the mosaic of habitats and their connection between an ecosystem is one of the critical parameters for optimizing the size and space of MPAs

7 [Almany et al., 2002, Friedlander et al., 2007]. Integrated approaches were used for the deﬁn- ing of biologically relevant boundaries of MPAs [Friedlander et al., 2007]. These coupled distribution of habitats and species with geographical information systems (GIS) [Friedlander et al., 2007].

The ﬁrst step in assessing the effectiveness of marine protected areas is the deﬁnition of species habitat utilization patterns [Friedlander et al., 2007]. Mumby did this in 2006 and con- verted the data of habitat use of different species into a series of algorithms for use in natural resource management. Conservations strategies should maintain connected corridors and encourage the natural migration of species among habitats [Mumby, 2006].

1.3. Scope and research questions

The aim of this Master’s thesis is to get an overview of the fish and families occurring in East African tropical waters with the fieldwork carried out around Chumbe Island. Also their habitat use of a seagrass bed and a coral reef is of interest for this thesis. Addition- ally the temporal patterns behind this habitat use were investigated. These temporal pattern are different tides at day (low & high tide), different lunar cycles (neap & spring) and different times (twilight & day). A particular aspect is the habitat use of species of special interest. The last surveyed aspect is the influence of the analysed parameter (abundance & biomass) on the fish community composition. The following questions were answered in this thesis:

1. What is the ﬁsh community composition in East African tropical waters surveyed at Chumbe Island, Zanzibar?

2. Is this composition different for the two habitat types (coral reef & seagrass bed)?

3. How is the ﬁsh community composition inﬂuenced by lunar cycles (neap-/spring-cycles), tidal amplitudes (low-/ high tide), and/ or diel cycle (day/ twilight)?

4. How is the habitat use for species of special interest (SI)?

5. Is the ﬁsh community composition different for abundance and biomass?

1.4. Criteria for species of special interest

The species of special interest were chosen because of different criteria:

1. Different trophic levels: Herbivores play an important role for healthiness of coral reefs, e.g. acanthurids, scarids and siganids. Also omnivores, corallivores and piscivores are included to see differences between trophic levels, e.g. labrids, chaetodontids and sphyraenids.

2. Commercial value for ﬁsheries: Haemulids, lethrinids, lutjanids, mullids, scarids and siganids are supposed to have a commercial value for ﬁsheries [Dorenbosch et al., 2005a].

8 3. High species diversity: The two families with the highest species diversity were also included. These were the labrids and pomacentrids.

9 2. Material and Methods

2.1. Study site

This study was carried out at Chumbe Island (6° 17’ S, 39° 10’ E), which is a small island approximately 10 km southwest from Unguja. Unguja is the main island of the Zanzibar archipelago, which is off the coast of Tanzania in the western Indian Ocean (ﬁgure 2.1).

Figure 2.1: (a) Overview of Unguja (Zanzibar) and the mainland of Tanzania with its capitol Daressalam (b) overview of Chumbe Island, the white-banded polygon is the Chumbe Island Coral Park (MPA), Google Earth (07/16/2012).

Chumbe Island was an uninhabitated and pristine island before the Chumbe Island Coral Park Ltd. (CHICOP) was established in 1991 to preserve the environment and the coral garden with its biodiversity. An ecohotel was built on the island, where at maximum 14 tourists are allowed to stay on the island. Rainwater, solar energy and compost-toilets were used on the island, so no release of wastewaters occurred into the ocean. A no take-area was established around the western site of the island in 1992, which became a UN Protected Area in 1994. The no take-area is observed and controlled by rangers of Chumbe Island, but sometimes illegal ﬁsheries occur. The eastern site, which is not protected, is exploited by artisanal ﬁsheries [www.chumbeisland.com, 2012].

2.2. Habitat characterization and environmental parameters

The ﬁeld work took place in a seagrass bed and coral reef on the southwestern site of Chumbe (ﬁgure 2.2).

10 In each habitat type (seagrass bed and coral reef) two 50 m transect lines (red lines in ﬁgure 2.2) were laid.

Figure 2.2: Sampling area on the southwestern site of Chumbe. The red lines are 50 m transect lines. The red lines with the green colour were laid in the seagrass bed, the red lines with the blue colour were laid in the coral reef, Google Earth (12/15/2011).

The benthic substrate was categorized with a point sampling in a transect swim for a general habitat characterization. This method was used for both transects. The sampling was done for 40 metres of every line, from zero to 19.5 metres and from 30 m to 49.5 metres. A fishing weight is needed for this method. The weight falls down every 0.5 metre of the transect. The substrate, which had the first contact with the fishing weight, is written down on an underwater slate. Also pH and salinity were measured during each sampling phase (neap/ spring cycle). The mean density of the seagrass was counted once in each quadrat on both transect lines with a 50 cm*50 cm quadrat made of PVC-sticks. Additionally the length of ten seagrass plants per quadrat were measured (with one of the extra transect lines).

The results of the point sampling are shown in ﬁgure 2.3 for the coral reef transects and in ﬁgure 2.4 for the seagrass bed transects. The main components of the substrate were sand and rubble, but hard corals were only minimal less abundant. Also rock had an abundance of nearly 20 percent. Macroalgae, turf algae, sponges, recently killed corals and others were only less abundant. The main component of the substrate in the seagrass bed was seagrass, macroalgae (Sar- gassum spp.) and rocks were only less abundant. The seagrass was dominated by Thalasso- dendron cilliatum with a mean density of 144 shoots per 0.25 m2 ± 30.8 shoots per 0.25 m2. The seagrass plants had a mean length of 37.92 cm with a standard deviation of 10 cm.

11 1% 1% 1% 1% 1%

18%

26%

RC SD RB HC TA MA SP RKC OT 26%

26%

Figure 2.3: Mean percentage cover of different substrate types in both coral reef transects. RC = rock, SD = sand, RB = rubble, HC = hard coral, TA = turf algae, MA = macroalgae, SP = sponge, RKC = recently killed coral, OT = others (e.g. Millepora).

1% 1%

SG MA RC

98%

Figure 2.4: Mean percentage cover of different substrate types in both seagrass transects. SG = seagrass, MA = macroalgae, RC = rock.

The tidal range during neap cycles was 1.2 m and during spring cycles 3.9 m. The water temperature in the coral reef ranged between 27.8°C and 34.7°C and in the seagrass bed from 27.7°C to 30.2°C. The salinity in the coral reef was between 37.0 and 40.0 in neap cycles and between 37.0 and 38.3 in spring cycles. The salinity in the seagrass bed ranged in neap cycles from 36.7 to 39.3 and in spring cycles from 36.5 to 39.0. The pH-value in the coral reef varied in neap cycles

12 between 8.14 and 8.29 and in spring cycles between 8.22 and 8.26. The pH-value ranged in the seagrass bed from 8.21 to 8.31 in neap cycles and from 8.22 to 8.29 in spring cycles.

2.3. Fish observation method

Two methods were tested for the observation of the coral reef fish assemblages. The first one was the visual census survey after English et al. (1997). For this, three tapes of 50 m length were used to lay 50 m transects. The three transects had a distance of ten metres to each other [English et al., 1997]. The observer swum two and a half metres above the transect and observed a width of five metres to minimize disturbances of fish communities. The second method was a stationary point count after two other studies [Polunin and Roberts, 1993, Watson and Quinn, 1997]. In this method defined quadrats were observed by one observer for ten minutes. In the first eight minutes the observer stayed in one edge of the quadrat and counts fish entering the quadrat. In the last two minutes the observer swum through the quadrat and searched for sedentary and hiding species. At every 50 m transect line three quadrats were layed with an additional line (figure 2.5).

Figure 2.5: Overview of six sampling quadrats in each habitat (seagrass bed = green, coral reef (blue)). The transition zone in between consists of sandy bottom, Google Earth (12/15/2011).

The quadrats had a size of five times five metres each. According to Dorenbosch (2006), the size should be chosen in dependence of the visibility. Measurements of the visibility showed a maximum visibility of ten metres under good conditions, but normally it was less than ten metres. These quadrats were laid from zero to five metres, from 25 to 30 m and from 45 to

13 50 m on each of the four transect lines. Both observation methods started four minutes after laying the transect line to permit fish to get back to their normal behaviour. I used for the collection of my data the stationary point count method after a test of both methods because the disturbances were less. The observations were carried out by two observers. The samplings during low tide were done with snorkeling, the samplings during high tide were carried out with SCUBA diving. Before the start of data collection both observers trained fish identification and size estimation until the results were accurate and the same. The size estimation was trained with PVC sticks representing all size classes [English et al., 1997]. The fish were counted on an underwater slate with their abundance and their estimated size. For this, eight size classes were used with 5 cm each from 0 to 40 cm. Underwater pictures were taken of the observed fish in the area for the fish identification. Then the pictures were compared mainly with Froese and Pauly (2012), but also additional literature was used [Lieske and Myers, 1999, Allen, 2009, Randall et al., 1997, Debelius, 1996]. In addition, video recording and taking pictures with GoPro Hero cameras were used to reduce the bias of the point count method. Also the light intensity and temperature were measured during these samplings with a HOBO-Logger (HOBO Pendant Temperature/Light Data Logger 64K– UA–002–64, accuracy: temperature ±0.53°C from 0° to 50°C). Analysis of the videos showed that identification and size estimation could not be done properly. Additionally the number of fish differed between the point count and the video data. During the video sampling less fish could be counted. Thus this method was discarded and used only as a source for additional information about the fish community composition.

2.4. Sampling design

The observation of reef ﬁsh assemblages were carried out during spring and neap lunar cycles from December 2011 until February 2012. The sampling design is shown in ﬁgure 2.6. In total 76 samples were collected.

Figure 2.6: Schematic ﬁgure of the sampling design. At least three replicates were done for each habitat type and the different combinations.

14 The observations were done for both habitat types with at least three replicates. The samples are marked with a code. The first abbreviation was for the habitat type (CR for coral reef, SB for seagrass bed), the second shortcut was for the time and the tide (H for high tide at day, L for low tide at day, SR for sunrise and SS for sunset), the third abbreviation stood for the lunar cycle (N for neap cycle and S for spring cycle), and the digits indicate the date on which the sample was taken. The fish were observed during daytime for low and high tide. The point counts for daytime were done between 9 am and 4:30 pm to count only day-active fishes. The daytime observations were started two hours before the low or high tide time as stated in a tidal calendar. Also observations were carried out during sunrise and sunset. These were done for sunrise from 5:30 am until 7:30 am, and point counts for sunset between 5:30 pm and 7:30 pm, which means one hour before sunrise or sunset and one hour after it. The categorization of these twilight samplings to the different tidal categories is summarized in table 2.1.

Table 2.1: Categorization of the twilight samples to different tides. Intermediate = between high and low tide, incoming water = sampling before high tide, outgoing water = sampling before low tide

Sampling Low Tide High Tide Sampling time Categorization of tide CRSRN 0102 03:30 6:34 – 7:24 Intermediate (incoming water) SBSRN 0102 03:30 6:34 – 7:24 Intermediate (incoming water) CRSRS 0702 10:10 6:39 – 7:24 Intermediate (outgoing water) SBSRS 0702 10:10 6:39 – 7:24 Intermediate (outgoing water) CRSSS 1101 17:38 17:47 – 18:49 High SBSSS 1201 18:14 17:28 – 18:15 High CRSSS 2712 18:00 17:31 – 18:15 High CRSSN 0301 17:14 17:22 – 18:15 Low SBSSN 0401 18:47 17:53 – 18:48 Low CRSSN 1601 14:38 17:25 – 18:01 Intermediate (incoming water) SBSSN 1601 14:38 18:03 – 18:28 Intermediate (incoming water)

This categorization showed that the sunrise samplings can only be compared with each other for a difference in the habitat type. The sunset samplings of spring could be analysed together with data of daytime samplings during high spring tide. Only the sunset sampling during neap cycles from the third and fourth of January could be used for a comparison with daytime samplings during low neap tide. The different samples, which were used for the analysis, were shown in table 2.2. These different samples were used for a comparison for differences in abundance and biomass of the counted ﬁsh for the two different habitat types, for the two different tidal levels, for the two different lunar cycles, and for differences between daytime samples and twilight samples with the same tide (table 2.3). During this analysis 75 species were analysed in terms of abundance and biomass. Only species were analysed with more than ﬁve individuals in total in the 16 analysed samplings. Only species with a total biomass of more than 400g/25m2 were used in the analysis in terms

15 Table 2.2: Summary of the samples which will be analysed in this thesis

CRHN1901 SBHN1901 CRLN1302 SBLN1302 CRSRN0102 SBSRN0102 CRSSN0301 SBSSN0401 CRHS2301 SBHS2301 CRLS2512 SBLS2612 CRSRS0702 SBSRS0702 CRSSS1101 SBSSS1201

Table 2.3: Summary of the different pairs which were analysed in the different comparisons.

Comparison between different habitat types cycles tides times CRHNvsSBHN CRHNvsCRHS CRHNvsCRLN CRSSNvsCRLN CRHSvsSBHS CRLNvsCRLS CRHSvsCRLS CRSSSvsCRHS CRLNvsSBLN SBHNvsSBHS SBHNvsSBLN SBSSNvsSBLN CRLSvsSBLS SBLNvsSBLS SBHSvsSBLS SBSSSvsSBHS CRSRNvsSBSRN – – – CRSRSvsSBSRS – – – CRSSNvsSBSSN – – – CRSSSvsSBSSS – – –

16 of biomass. This biomass was calculated out of all 16 samplings.

2.5. Calculation of biomass

The biomass was calculated with the following formulas from Froese and Pauly (2012):

b 1. Wi = a ∗ Li P 2. Biq = Wi/numberi

The first formula was the length-weight-equation. A and b were species-specific coefficients, which were taken for each species from FishBase [Froese and Pauly, 2012]. For species with no data available, means were calculated from the coefficients of all other counted species of each family or similar species. Wi is the weight of species i, and Li the length of species i which was estimated during the observations. The biomass of species i per quadrat q is

Biq. It is calculated with the sum of the weight of all size classes of species i in one quadrat divided by the number of species i counted in one quadrat. The biomass was calculated in g per 25 m2.

2.6. Statistical analysis

The statistical analysis for the different pairs was done in two steps. The first step was an analysis of variance (Fisher’s F-test). When there is a significant difference between the variances, an additional analysis of the means can have a false result [Crawley, 2005]. This test is appropriate for comparing variances of two samples, but is also highly sensitive to outliers [Crawley, 2007]. Boxplots of all species with significant differences were created (appendix A + B). These boxplots gave an information about possible outliers between two samplings.

The second step was an analysis of the means. The data are count data. For this, the errors are not normally distributed, because they cannot be negative. These features led to a Gen- eralized Linear Model (GLM). GLMs were used for all comparisons between two samplings (table 2.3) [Crawley, 2007]. There is the problem of spatial pseudoreplication for the samples from the same habitat, because they are all collected from the same quadrats [Crawley, 2007]. This problem only occurred for species, which are living in these quadrats, e.g. Amphiprion allardi. All species with a high non-signiﬁcant p-value of one were under special investigation for spatial pseudoreplication. They were excluded from the discussion, when they indicated these p-values in the analysis in terms of abundance and biomass.

17 3. Results

3.1. Fish community composition in East African tropical waters, e.g. Chumbe Island

The ﬁsh community composition at Chumbe Island consisted of 178 species belonging to 42 different families (table 3.1). Out of this 168 species were identiﬁed up to species level.

Table 3.1: Overview of all species seen in the area with information about their feeding type, observed habitat and observed time (day/twilight). Indicator a and/or b behind species name = species is analysed for abundance (a) and/or biomass (b). Count = species is counted during observations. FT = Feeding type, COR = corallivore, H = herbivore, INV = invertebrates, OMNI = omnivore, P = planktivore, PIS = piscivore, Pis/Inv = only fish & invertebrates, NK = Not known. CR = coral reef, SB = seagrass bed. D = day, SR = sunrise, SS = sunset, TW = twilight (counted in both sunrise & sunset). The information about feeding type was taken from Froese and Pauly (2012) no. family species count FT habitat day/ twilight 1 Acanthuridae Acanthurus leucosternon a,b yes H CR/SB D/TW 2 Acanthurus lineatus – OMNI – – 3 Acanthurus mata – P – – 4 Acanthurus nigricauda – NK – – 5 Acanthurus nigrofuscus a,b yes H CR/SB D/TW 6 Acanthurus triostegus yes H SB SR 7 Ctenochaetus binotatus a,b yes OMNI CR/SB D/TW 8 Ctenochaetus striatus a,b yes OMNI CR/SB D/TW 9 Ctenochaetus truncatus a,b yes NK CR D/TW 10 Naso brevirostris yes P CR D/TW 11 Naso hexacanthus yes OMNI CR SS 12 Naso lituratus yes H CR SR 13 Naso unicornis yes H CR D 14 Zebrasoma scopas a,b yes H CR/SB D/TW 15 Apogonidae Apogon sp yes NK SB D 16 Cheilodipterus macrodon yes PIS CR D 17 Cheilodipterus quinquelineatus yes PIS/Inv CR SS 18 Nectamia savayensis – INV – – 19 Atherinidae Atherinomorus lacunosus – INV – – 20 Aulostomidae Aulostomus chinensis yes PIS/Inv CR/SB D/SR 21 Balistidae Balistapus undulatus yes OMNI CR D 22 Melichthys indicus – OMNI – – 23 Sufflamen chrysopterum a,b yes INV CR D/TW 24 Belonidae Unid needlefish – NK – – 25 Blennidae unid blenny yes NK CR TW 26 Exallias brevis yes COR CR D 27 Meiacanthus mossambicus a,b yes NK CR/SB D/TW 28 Plagiotremus rhinorhynchus – PIS – – 29 Plagiotremus tapeinosoma – PIS – – 30 Carangidae Caranx melampygus – PIS/Inv – – 31 Scomberoides lysan a,b yes PIS/Inv SB SS 32 Trachinotus baillonii – PIS – – 33 Carcharhinidae Carcharhinus melanopterus – PIS/Inv – – 34 Chaetodontidae Chaetodon auriga a yes OMNI CR D/SS 35 Chaetodon falcula – INV – – 36 Chaetodon guttatissimus a,b yes OMNI CR/SB D/TW 37 Chaetodon kleinii a yes OMNI CR/SB D/SR 38 Chaetodon lunula yes OMNI SB SS 39 Chaetodon meyeri yes COR CR D 40 Chaetodon trifascialis a,b yes COR CR D/TW 41 Chaetodon trifasciatus a,b yes COR CR/SB D/TW 42 Chaetodon zanzibarensis yes COR CR D 43 Cirrhitidae Cirrhitichthys oxycephalus yes PIS/Inv CR SS 44 Paracirrhites forsteri – PIS/Inv – – 45 Dasyatidae Taeniura lymma b yes INV CR D/SS 46 Diodontidae Diodon liturosus b yes INV CR SR 47 Ephippidae Platax teira a,b yes NK CR D/SS 48 Fistulariidae Fistularia commersonii yes PIS/Inv CR/SB D/TW 49 Gobiidae Valenciennea strigata yes PIS/Inv CR D 50 Haemulidae Plectorhinchus flavomaculatus a,b yes PIS/Inv CR/SB D/TW 51 Plectorhinchus gaterinus – NK – –

18 52 Plectorhinchus schotaf – NK – – 53 Holocentridae Myripristis violacea yes P CR SS 54 Labridae Anampses caeruleopunctatus yes OMNI CR SS 55 Anampses meleagrides – NK – – 56 Anampses twistii a,b yes NK CR D/SR 57 Bodianus axillaris a,b yes INV CR D/TW 58 Cheilinus chlorourus b yes INV CR/SB D/SS 59 Cheilinus fasciatus yes INV CR SS 60 Cheilinus trilobatus a,b yes PIS/Inv CR/SB D/TW 61 Cheilio inermis a,b yes INV SB D/TW 62 Coris aygula – INV – – 63 Coris caudimacula yes INV CR/SB D 64 Coris formosa b yes INV CR/SB D/TW 65 Gomphosus caeruleus a,b yes INV CR/SB D/TW 66 Halichoeres hortulanus a,b yes INV CR/SB D/TW 67 Halichoeres nebulosus a yes NK SB D/TW 68 Hemigymnus fasciatus a,b yes INV CR D/TW 69 Hemigymnus melapterus b yes INV CR D/TW 70 Hologymnosus annulatus – PIS/Inv – – 71 Labrichthys unilineatus – COR – – 72 Labroides bicolor yes INV CR D/SS 73 Labroides dimidiatus a,b yes INV CR/SB D/TW 74 Novaculichthys taeniourus yes INV CR D 75 Pseudocheilinus hexataenia a,b yes INV CR/SB D/TW 76 Stethojulis bandanensis a,b yes INV CR/SB D/TW 77 Thalassoma amblycephalum a yes P CR/SB D/TW 78 Thalassoma hardwicke a,b yes PIS/Inv CR/SB D/TW 79 Thalassoma hebraicum a,b yes NK CR/SB D/TW 80 Thalassoma lunare yes INV CR/SB D 81 Lethrinidae Lethrinus harak a,b yes PIS/Inv CR/SB D 82 Lethrinus mahsena a,b yes PIS/Inv CR/SB D/TW 83 Lethrinus obsoletus a,b yes INV CR/SB D/SS 84 Monotaxis grandoculis yes INV CR SS 85 Lutjanidae Lutjanus bohar b yes PIS/Inv CR/SB D/TW 86 Lutjanus fulviﬂamma yes PIS/Inv CR/SB D/SS 87 Lutjanus monostigma – PIS/Inv – – 88 Macolor niger – PIS/Inv – – 89 Microdesmidae Ptereleotris sp a yes NK SB D/SS 90 Monacanthidae Amanses scopas a,b yes NK CR/SB D/TW 91 Cantherhines pardalis a,b yes INV CR/SB D/TW 92 Oxymonacanthus longirostris a yes COR CR D/TW 93 Mullidae Parupeneus cyclostomus a,b yes PIS/Inv CR D/SS 94 Parupeneus macronemus a,b yes OMNI CR/SB D/TW 95 Muraenidae Gymnothorax griseus – NK – – 96 Gymnothorax meleagris – PIS/Inv – – 97 Nemipteridae Scolopsis ghanam yes PIS/Inv CR D/SS 98 Ostraciidae Ostracion cubicus yes OMNI CR D 99 Ostracion meleagris yes OMNI CR D/SS 100 Pempheridae Pempheris vanicolensis – P – – 101 Pinguipedidae Parapercis hexophtalma a,b yes NK CR D/TW 102 Parapercis xanthozona a,b yes NK CR D/SS 103 Platycephalidae Papilloculiceps longiceps – NK – – 104 Plotosidae Plotosus lineatus a,b yes PIS/Inv SB TW 105 Pomacanthidae Centropyge multispinis a,b yes NK CR D/TW 106 Pomacanthus imperator – INV – – 107 Pomacanthus semicirculatus a,b yes OMNI CR D/TW 108 Pygoplites diacanthus b yes INV CR D/SS 109 Pomacentridae Abudefduf sexfasciatus a,b yes OMNI CR/SB D/SS 110 Abudefduf sordidus – OMNI – – 111 Abudefduf sparoides – OMNI – – 112 Abudefduf vaigiensis yes OMNI SB D/SR 113 Amblyglyphidodon leucogaster a,b yes OMNI CR/SB D/TW 114 Amphiprion akallopisos a yes NK CR/SB D/TW 115 Amphiprion allardi yes NK CR D/SS 116 Chromis atripectoralis a,b yes P CR/SB D/TW 117 Chromis dimidiata a,b yes NK CR D/TW 118 Chromis nigrura a yes NK CR D/TW 119 Chromis ternatensis yes NK CR D 120 Chromis viridis a,b yes H CR/SB D/TW 121 Chromis weberi a,b yes NK CR D/TW 122 Chrysiptera brownriggii yes OMNI SB D/SR 123 Chrysiptera unimaculata yes H SB D/SS 124 Dascyllus aruanus a yes OMNI CR D/SR 125 Dascyllus carneus – P – – 126 Dascyllus trimaculatus a yes OMNI CR D/TW 127 Neoglyphidodon melas a,b yes DET CR D/TW 128 Neopomacentrus azysron yes NK CR D/SS 129 Plectroglyphidodon dickii a,b yes OMNI CR D/TW 130 Plectroglyphidodon johnstonianus a yes OMNI CR D/SS

19 131 Plectroglyphidodon lacrymatus a,b yes OMNI CR/SB D/TW 132 Pomacentrus baenschi yes NK CR/SB D/SS 133 Pomacentrus caeruleus yes NK CR D/SS 134 Pomacentrus pavo a yes OMNI CR D/TW 135 Pomacentrus sulfureus yes NK CR D 136 Pomacentrus trichrourus yes NK CR/SB D/SS 137 Pomacentrus trilineatus a,b yes NK CR/SB D/TW 138 Scaridae Calotomus carolinus a,b yes H CR/SB D/TW 139 Cetoscarus bicolor yes H CR D 140 Chlorurus sordidus a,b yes H CR/SB D/TW 141 Chlorurus strongylocephalus b yes H CR D/SS 142 Hipposcarus harid b yes H CR SS 143 Leptoscarus vaigiensis a,b yes H SB D/SS 144 Scarus caudofasciatus a,b yes NK CR D/TW 145 Scarus frenatus a,b yes H CR/SB D/TW 146 Scarus ghobban a yes H CR/SB TW 147 Scarus niger a,b yes H CR D/TW 148 Scarus rubroviolaceus b yes H CR D/SS 149 Scarus scaber b yes H CR D 150 Scarus tricolor a,b yes H CR/SB D/TW 151 Scorpaenidae Dendrochirus zebra – NK – – 152 Inimicus filamentosus – NK – – 153 Parascorpaena mossambica yes NK SB D 154 Pterois volitans b yes PIS/Inv SB SR 155 Scorpaenopsis diabolus – NK – – 156 Serranidae Aethaloperca rogaa yes PIS/Inv CR D/SS 157 Anyperodon leucogrammicus a,b yes PIS/Inv CR D/SR 158 Cephalopholis argus yes PIS/Inv CR D/SS 159 Cephalopholis boenak a,b yes PIS/Inv CR D/TW 160 Cephalopholis leopardus yes INV CR SS 161 Epinephelus fasciatus yes PIS/Inv CR SR 162 Epinephelus ongus – NK – – 163 Grammistes sexlineatus yes PIS CR/SB D/SR 164 Plectropomus laevis – PIS/Inv – – 165 Plectropomus punctatus – PIS – – 166 Pseudanthias squamipinnis – P – – 167 Siganidae Siganus stellatus – H – – 168 Siganus sutor a,b yes H CR/SB D/TW 169 Sphyraenidae Sphyraena flavicauda a,b yes NK CR/SB D/TW 170 Syngnathidae Corythoichthys flavofasciatus yes NK CR/SB D/SS 171 Synodontidae Synodus variegatus yes PIS CR D/SS 172 Tetraodontidae Arothron hispidus – OMNI – – 173 Arothron mappa b yes OMNI CR SS 174 Arothron nigropunctatus yes OMNI CR D 175 Canthigaster bennetti a,b yes OMNI CR/SB D/TW 176 Canthigaster solandri a yes OMNI CR D/SS 177 Canthigaster valentini a,b yes OMNI CR/SB D/TW 178 Zanclidae Zanclus cornutus b yes INV CR D/TW

139 species were counted during all observations. These species belonged to 36 different families also including the families and species of special interest. The fish community composition was bigger in the coral reef than in the seagrass bed. 14 species could only be observed in the seagrass bed, e.g. some labrids, and some scor- paenids. 72 species were only seen in the coral reef, e.g. lots of pomacentrids, and also most of the serranids. 53 species were counted in both habitats, e.g. one haemulid, and most of labrids. The fish community composition was influenced by different times. 63 species could be counted during daytime and twilight samplings, e.g. lots of acanthurids. 19 species were only seen during daytime samplings, e.g. a few chaetodontids, and labrids. 20 species were only observed during all twilight samplings, five species only during sunrise samplings and twelve species only during sunset samplings. To these species belonged a few labrids, and acanthurids. Eight species were counted during daytime and sunrise samplings, e.g. a few serranids, and pomacentrids. 29 species were seen during daytime and sunset samplings, e.g. a few scarids, and pomacentrids. Species were taken into account for the analysis in terms of abundance when more than five

20 individuals were counted during all analysed samplings. This criterium reduced the amount of species for the analysis in terms of abundance to 75 species (indicated with an a in table 3.1). The criterium for the analysis in terms of biomass was a total biomass of at least 400 g per 25 m2 in all analysed samplings. This leaded also to a reduction in the amount of species to 75 (indicated with a b in table 3.1). 61 species were taken into account for both analyses.

3.2. Analysis in terms of abundance

3.2.1. Comparison of different habitat types during high tide in a neap cycle

The observation showed that 20 species were absent in both habitats during high tide in a neap cycle, e.g. Plectorhinchus ﬂavomaculatus, Scarus caudofasciatus, and Amblyglyphi- dodon leucogaster (table 3.2).

Table 3.2: Overview of the analysis of 75 species for the comparison between both habitat types during high tide in a neap cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRHN SBHN p-value no. family species mean sd var mean sd var F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 1 1 0 0 0 NA 0.0319 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus 1 1 1 0 0 0 NA 0.1340 4 Ctenochaetus striatus 3 2 7 <1 1 1 0.1443 0.0781 5 Ctenochaetus truncatus <1 <1 <1 0 0 0 NA 0.3560 6 Zebrasoma scopas 1 2 5 0 0 0 NA 0.2540 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 2 1 3 <1 <1 <1 0.0554 0.0871 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga <1 1 1 0 0 0 NA 0.3560 11 Chaetodon guttatissimus 1 1 1 <1 <1 <1 0.2026 0.2782 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 1 1 1 0 0 0 NA 0.0941 14 Chaetodon trifasciatus 2 <1 <1 <1 1 1 0.9447 0.0175 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii <1 <1 <1 0 0 0 NA 0.3560 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus 0 0 0 <1 <1 <1 NA 0.1340 20 Cheilio inermis 0 0 0 <1 <1 <1 NA 0.1680 21 Gomphosus caeruleus 2 1 2 0 0 0 NA 0.0105 22 Halichoeres hortulanus 1 1 1 0 0 0 NA 0.0591 23 Halichoeres nebulosus 0 0 0 <1 1 1 NA 0.3560 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.1682 25 Labroides dimidiatus 1 1 1 1 1 2 0.8844 0.6202 26 Pseudocheilinus hexataenia 1 2 5 0 0 0 NA 0.2540 27 Stethojulis bandanensis 3 2 8 5 9 84 0.0930 0.6580 28 Thalassoma amblycephalum 1 2 6 <1 <1 <1 0.0253 0.4630 29 Thalassoma hardwicke 0 0 0 <1 <1 <1 NA 0.1340 30 Thalassoma hebraicum 5 0 0 2 1 2 NA 0.0054 31 Lethrinidae Lethrinus harak <1 <1 <1 <1 1 1 0.2848 0.6700 32 Lethrinus mahsena 0 0 0 1 <1 <1 NA 0.0020 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 0 0 0 NA 0.3560 36 Cantherhines pardalis 0 0 0 1 1 2 NA 0.1470 37 Oxymonacanthus longirostris 2 5 25 0 0 0 NA 0.3560 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 1 1 1 <1 <1 <1 0.1535 0.1210

21 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 0 0 0 NA 0.1682 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 2 1 2 0 0 0 NA 0.0498 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos <1 <1 <1 0 0 0 NA 0.3560 48 Chromis atripectoralis <1 <1 <1 0 0 0 NA 0.3560 49 Chromis dimidiata <1 1 1 0 0 0 NA 0.3560 50 Chromis nigrura 1 2 4 0 0 0 NA 0.3560 51 Chromis viridis 3 6 42 5 11 121 0.4105 0.7370 52 Chromis weberi 14 22 521 0 0 0 NA 0.2510 53 Dascyllus aruanus <1 1 2 0 0 0 NA 0.3560 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.3560 55 Neoglyphidodon melas <1 <1 <1 0 0 0 NA 0.3560 56 Plectroglyphidodon dickii <1 1 1 0 0 0 NA 0.3560 57 Plectroglyphidodon johnstonianus 1 1 2 0 0 0 NA 0.2070 58 Plectroglyphidodon lacrymatus 3 1 2 0 0 0 NA 0.0046 59 Pomacentrus pavo 1 2 6 0 0 0 NA 0.3560 60 Pomacentrus trilineatus 2 1 3 1 1 3 0.9540 0.5890 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 4 4 18 4 5 27 0.7623 0.9440 63 Leptoscarus vaigiensis 0 0 0 1 1 1 NA 0.1340 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus <1 <1 <1 <1 <1 <1 1.0000 0.2070 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus <1 1 1 0 0 0 NA 0.3560 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.3560 71 Siganidae Siganus sutor 0 0 0 5 4 18 NA 0.0565 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 1 2 4 NA 0.3560 73 Tetraodontidae Canthigaster bennetti 1 1 3 0 0 0 NA 0.1682 74 Canthigaster solandri <1 <1 <1 0 0 0 NA 0.3560 75 Canthigaster valentini 4 1 2 1 <1 <1 0.4802 0.0150

31 species were present in the coral reef but absent in the seagrass bed. To this group of species belonged e.g. Acanthurus leucosternon, Gomphosus caeruleus, Centropyge multispinis, and Plectroglyphidodon lacrymatus. The means of abundance of these four species were signiﬁcantly higher in the coral reef than in the seagrass bed (ﬁgure 3.1).

3,5

2,5

s 2 Acanthurus leucosternon n

a Chaetodon trifasciatus e 1,5 m

Gomphosus caeruleus f o 1 Thalassoma e

c amblycephalum n e r 0,5 Thalassoma hebraicum e f f i Lethrinus mahsena d 0 Plectroglyphidodon -0,5 lacrymatus

-1

-1,5 species of special interest

Figure 3.1: Distinctions in means of abundance for species of special interest with a signiﬁcant difference for both habitat types during high tide in a neap cycle. Positive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed.

Nine species were present in the seagrass bed, but absent in the coral reef. Lethrinus mahsena was one of this species and showed a signiﬁcant difference between its means of abundance. The mean of abundance of Lethrinus mahsena was signiﬁcantly higher in the seagrass bed

22 than in the coral reef. Chaetodon trifasciatus, Thalassoma hebraicum and Canthigaster valentini were present in both habitats and had a significant difference between their means of abundance. The mean of abundance of all three species was significantly higher in the coral reef than in the seagrass bed (figure 3.1). Thalassoma amblycephalum was also present in both habitats and showed a significant difference between its variances. The variance of Thalassoma amblycephalum was higher in the coral reef than in the seagrass bed (figure 3.1).

3.2.2. Comparison of different habitat types during high tide in a spring cycle

The observations indicated an absence of 19 species in both habitats during high tide in a spring cycle, e.g. Lethrinus harak, Chaetodon guttatissimus, and Zebrasoma scopas (table 3.3). All these three species were present during high tide in neap cycles.

Table 3.3: Overview of the analysis of 75 species for the comparison between both habitat types during high tide in a spring cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both sampling from four quadrats. CRHS SBHS statistics no. family species mean sd var mean sd var F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 1 1 <1 <1 <1 0.2848 0.6700 2 Acanthurus nigrofuscus 0 0 0 <1 <1 <1 NA 0.3560 3 Ctenochaetus binotatus <1 <1 <1 0 0 0 NA 0.1340 4 Ctenochaetus striatus 2 1 2 1 1 2 0.9430 0.8394 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus <1 <1 <1 <1 <1 <1 1.0000 1.0000 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 1 1 1 0 0 0 NA 0.0240 14 Chaetodon trifasciatus 2 1 1 0 0 0 NA 0.0117 15 Ephippidae Platax teira <1 <1 <1 0 0 0 NA 0.3560 16 Haemulidae Plectorhinchus flavomaculatus 0 0 0 <1 <1 <1 NA 0.1340 17 Labridae Anampses twistii <1 <1 <1 0 0 0 NA 0.3560 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus 0 0 0 <1 <1 <1 NA 0.1680 20 Cheilio inermis 0 0 0 <1 <1 <1 NA 0.3560 21 Gomphosus caeruleus 2 2 8 0.5 1 1 0.1054 0.2029 22 Halichoeres hortulanus 1 1 1 0 0 0 NA 0.0240 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.3560 25 Labroides dimidiatus 2 1 2 1 1 2 1.0000 0.3560 26 Pseudocheilinus hexataenia 1 2 5 <1 <1 <1 0.0291 0.3440 27 Stethojulis bandanensis 1 1 2 4 6 44 0.0356 0.4130 28 Thalassoma amblycephalum 1 2 4 0 0 0 NA 0.3560 29 Thalassoma hardwicke <1 <1 <1 <1 <1 <1 1.0000 1.0000 30 Thalassoma hebraicum 6 5 30 1 1 2 0.0588 0.1047 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 0 0 0 2 1 3 NA 0.0710 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 0 0 0 NA 0.3560 36 Cantherhines pardalis <1 <1 <1 0 0 0 NA 0.3560 37 Oxymonacanthus longirostris – – – – – – – – 38 Mullidae Parupeneus cyclostomus <1 <1 <1 0 0 0 NA 0.1340 39 Parupeneus macronemus 1 1 2 <1 <1 <1 0.1215 0.3560

23 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 0 0 0 NA 0.1340 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis <1 1 1 0 0 0 NA 0.3560 44 Pomacanthus semicirculatus <1 <1 <1 0 0 0 NA 0.1340 45 Pomacentridae Abudefduf sexfasciatus 0 0 0 <1 <1 <1 NA 0.3560 46 Amblyglyphidodon leucogaster <1 <1 <1 0 0 0 NA 0.1340 47 Amphiprion akallopisos <1 <1 <1 0 0 0 NA 0.3560 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata <1 1 1 0 0 0 NA 0.3560 50 Chromis nigrura 1 2 6 0 0 0 NA 0.3560 51 Chromis viridis <1 1 2 9 13 174 0.0049 0.2480 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus <1 1 1 0 0 0 NA 0.3560 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.3560 55 Neoglyphidodon melas <1 1 1 0 0 0 NA 0.3560 56 Plectroglyphidodon dickii – – – – – – – – 57 Plectroglyphidodon johnstonianus <1 1 1 0 0 0 NA 0.3560 58 Plectroglyphidodon lacrymatus 3 2 4 0 0 0 NA 0.0148 59 Pomacentrus pavo 1 2 4 0 0 0 NA 0.3560 60 Pomacentrus trilineatus 1 <1 <1 1 2 5 0.1144 0.5700 61 Scaridae Calotomus carolinus 0 0 0 <1 <1 <1 NA 0.1340 62 Chlorurus sordidus 5 4 19 1 1 2 0.1106 0.2113 63 Leptoscarus vaigiensis 0 0 0 <1 <1 <1 NA 0.1680 64 Scarus caudofasciatus 2 2 4 0 0 0 NA 0.0718 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.3560 66 Scarus ghobban – – – – – – – – 67 Scarus niger <1 1 1 0 0 0 NA 0.3560 68 Scarus tricolor 0 0 0 <1 1 2 NA 0.3560 69 Serranidae Anyperodon leucogrammicus <1 1 2 0 0 0 NA 0.3560 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.3560 71 Siganidae Siganus sutor 0 0 0 6 8 64 NA 0.1700 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 <1 1 1 NA 0.3560 73 Tetraodontidae Canthigaster bennetti 1 <1 <1 0 0 0 NA 0.0498 74 Canthigaster solandri <1 <1 <1 0 0 0 NA 0.3560 75 Canthigaster valentini 2 2 6 1 1 1 0.2891 0.3250

31 species were only present in the coral reef. Chaetodon trifascialis, Chaetodon trifasciatus, Halichoeres hortulanus, Plectroglyphidodon lacrymatus, and Canthigaster bennetti showed a signiﬁcantly higher mean of abundance in the coral reef while this group was absent in the seagrass bed (ﬁgure 3.2).

0 s Chaetodon trifascialis n

a Chaetodon trifasciatus e m

-2 Halichoeres hortulanus f o Pseudocheilinus e

c hexataenia n -4 e r Stethojulis bandanensis e f f i Chromis viridis d -6 Plectroglyphidodon lacrymatus -8

-10 species of special interest

Figure 3.2: Distinctions in means of abundance for species of special interest with a signiﬁcant difference for both habitat types during high tide in a spring cycle. Positive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed.

Eleven species were only present in the seagrass bed, but no species had a signiﬁcant difference in their means of abundance. Plectorhinchus ﬂavomaculatus, Cheilinus trilobatus and

24 Lethrinus mahsena were three species which could only be observed in the seagrass bed during high tide in spring cycles. Pseudocheilinus hexataenia, Stethojulis bandanensis and Chromis viridis were present in both habitats and showed a significant difference in their variances. The variance of Pseudocheili- nus hexataenia was significantly higher in the coral reef. For the two other species the variance was significantly higher in the seagrass bed. Two species showed a high non-significant p-value for their means of abundance. These were Thalassoma hardwicke and Meiacanthus mossambicus.

3.2.3. Comparison of different cycles during high tide in the coral reef

The observation showed that 21 species were absent during samplings in the coral reef during high tide in both cycles, e.g. Siganus sutor, Sphyraena ﬂavicauda, and Plectorhinchus ﬂavo- maculatus (table 3.4).

Table 3.4: Overview of the analysis of 75 species for the comparison between both cycles during high tide in the coral reef in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRHN CRHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 1 1 <1 1 1 0.7150 0.1708 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus 1 1 1 <1 <1 <1 0.2848 0.4680 4 Ctenochaetus striatus 3 2 7 2 1 2 0.4490 0.3720 5 Ctenochaetus truncatus <1 <1 <1 0 0 0 NA 0.3560 6 Zebrasoma scopas 1 2 5 0 0 0 NA 0.2540 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 2 1 3 <1 <1 <1 0.2923 0.2070 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga <1 1 1 0 0 0 NA 0.3560 11 Chaetodon guttatissimus 1 1 1 0 0 0 NA 0.1340 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 1 1 1 1 1 1 0.7150 0.7663 14 Chaetodon trifasciatus 2 <1 <1 2 1 1 0.6645 0.5504 15 Ephippidae Platax teira 0 0 0 <1 <1 <1 NA 0.3560 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii <1 <1 <1 <1 <1 <1 1.0000 1.0000 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus – – – – – – – – 20 Cheilio inermis – – – – – – – – 21 Gomphosus caeruleus 2 1 2 2 2 8 0.2878 1.0000 22 Halichoeres hortulanus 1 1 1 1 1 1 0.6850 1.0000 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 <1 <1 <1 0.3142 0.3903 25 Labroides dimidiatus 1 1 1 2 1 2 0.8844 0.6202 26 Pseudocheilinus hexataenia 1 2 5 1 2 5 1.0000 1.0000 27 Stethojulis bandanensis 3 2 8 1 1 2 0.2973 0.3302 28 Thalassoma amblycephalum 1 2 6 1 2 4 0.7228 0.8810 29 Thalassoma hardwicke 0 0 0 <1 <1 <1 NA 0.3560 30 Thalassoma hebraicum 5 0 0 6 5 30 NA 0.5522 31 Lethrinidae Lethrinus harak <1 <1 <1 0 0 0 1.0000 0.3560 32 Lethrinus mahsena – – – – – – – – 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 <1 <1 <1 1.0000 1.0000 36 Cantherhines pardalis 0 0 0 <1 <1 <1 NA 0.3560 37 Oxymonacanthus longirostris 2 5 25 0 0 0 NA 0.3560 38 Mullidae Parupeneus cyclostomus 0 0 0 <1 <1 <1 NA 0.1340 39 Parupeneus macronemus 1 1 1 1 1 2 0.8844 0.6202

25 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 <1 <1 <1 0.4282 0.6700 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 2 1 2 <1 1 1 0.4419 0.1682 44 Pomacanthus semicirculatus 0 0 0 <1 <1 <1 NA 0.1340 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster 0 0 0 <1 <1 <1 NA 0.1340 47 Amphiprion akallopisos <1 <1 <1 <1 <1 <1 1.0000 1.0000 48 Chromis atripectoralis <1 <1 <1 0 0 0 NA 0.3560 49 Chromis dimidiata <1 <1 <1 <1 <1 <1 1.0000 1.0000 50 Chromis nigrura 1 2 4 1 2 6 0.7228 0.8810 51 Chromis viridis 3 6 42 <1 1 2 0.0380 0.4820 52 Chromis weberi 14 22 521 0 0 0 NA 0.2510 53 Dascyllus aruanus <1 1 2 <1 1 1 0.5226 0.7910 54 Dascyllus trimaculatus <1 <1 <1 <1 <1 <1 1.0000 1.0000 55 Neoglyphidodon melas <1 <1 <1 <1 1 1 0.2848 0.6700 56 Plectroglyphidodon dickii <1 1 1 0 0 0 NA 0.3560 57 Plectroglyphidodon johnstonianus 1 1 2 <1 1 1 0.5836 0.5850 58 Plectroglyphidodon lacrymatus 3 1 2 3 2 4 0.6785 1.0000 59 Pomacentrus pavo 1 2 6 1 2 4 0.7228 0.8810 60 Pomacentrus trilineatus 2 1 3 1 <1 <1 0.2191 0.3560 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 4 4 18 5 4 19 0.9861 0.8164 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus 0 0 0 2 2 4 NA 0.0718 65 Scarus frenatus <1 <1 <1 <1 <1 <1 1.0000 0.2070 66 Scarus ghobban – – – – – – – – 67 Scarus niger 0 0 0 <1 1 1 NA 0.3560 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus <1 1 1 <1 1 2 0.5226 0.7910 70 Cephalopholis boenak <1 <1 <1 <1 <1 <1 1.0000 1.0000 71 Siganidae Siganus sutor – – – – – – – – 72 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 73 Tetraodontidae Canthigaster bennetti 1 1 3 1 <1 <1 0.1952 0.6480 74 Canthigaster solandri <1 <1 <1 <1 <1 <1 1.0000 1.0000 75 Canthigaster valentini 4 1 2 2 2 6 0.4237 0.3432

Nine species were only present in a neap cycle in the coral reef, e.g. Zebrasoma scopas, and Chaetodon guttatissimus. No one of these species showed a significant difference. Eight species were absent in a neap cycle in the coral reef, e.g. Scarus caudofasciatus, and Parupeneus cyclostomus. Also no species of this group showed a significant difference between variances or means of abundance. Only one species had a significant difference between its variances. This was Chromis viridis which was present in both cycles in the coral reef (figure 3.3).

2,5 2,5

2 2 s n a e 1,5 1,5 m

f o

c Chromis viridis n

e 1 r 1 e f f i d

0,5 0,5

0 0 species of special interest

Figure 3.3: Distinctions in mean of abundance for species of special interest with a signiﬁcant difference in both cycles during high tide in the coral reef. Positive values = higher mean abundance in the neap cycle, negative values = higher mean abundance in the spring cycle.

26 Eleven species showed high non-signiﬁcant p-values, e.g. four pomacentrids, Gompho- sus caeruleus, Halichoeres hortulanus, and Pseudocheilinus hexataenia.

3.2.4. Comparison of different cycles during high tide in the seagrass bed

43 species were absent during both cycles during high tide in the seagrass bed, e.g. Chaetodon trifascialis, Zebrasoma scopas, and most of pomacentrids, except for Abudefduf sexfasciatus, Chromis viridis, and Pomacentrus trilineatus (table 3.5).

Table 3.5: Overview of the analysis of 75 species for the comparison between the two cycles during high tide in the seagrass bed in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. SBHN SBHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 0 0 0 <1 <1 <1 NA 0.3560 2 Acanthurus nigrofuscus 0 0 0 <1 <1 <1 NA 0.3560 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus <1 1 1 1 1 2 0.4028 0.2530 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus <1 <1 <1 <1 <1 <1 0.3142 0.3900 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus <1 <1 <1 0 0 0 NA 0.3560 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis – – – – – – – – 14 Chaetodon trifasciatus <1 1 1 0 0 0 NA 0.3560 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0 0 0 <1 <1 <1 NA 0.1340 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus <1 <1 <1 <1 <1 <1 0.4282 0.6700 20 Cheilio inermis <1 <1 <1 <1 <1 <1 0.3142 0.3903 21 Gomphosus caeruleus 0 0 0 <1 1 1 NA 0.3560 22 Halichoeres hortulanus – – – – – – – – 23 Halichoeres nebulosus <1 1 1 0 0 0 NA 0.3560 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus 1 1 2 1 1 2 1.0000 1.0000 26 Pseudocheilinus hexataenia 0 0 0 <1 <1 <1 NA 0.3560 27 Stethojulis bandanensis 5 9 84 4 6 44 0.6059 0.8660 28 Thalassoma amblycephalum <1 <1 <1 0 0 0 NA 0.3560 29 Thalassoma hardwicke <1 <1 <1 <1 <1 <1 0.8187 0.5370 30 Thalassoma hebraicum 2 1 2 1 1 2 0.9251 0.4943 31 Lethrinidae Lethrinus harak <1 <1 <1 0 0 0 NA 0.3560 32 Lethrinus mahsena 1 <1 <1 2 1 3 0.0905 0.6202 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis 1 1 2 0 0 0 NA 0.1466 37 Oxymonacanthus longirostris – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus <1 <1 <1 <1 <1 <1 1.0000 1.0000 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus 0 0 0 <1 <1 <1 NA 0.3560 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos – – – – – – – – 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata – – – – – – – – 50 Chromis nigrura – – – – – – – – 51 Chromis viridis 5 11 121 9 13 174 0.7716 0.6780

27 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas – – – – – – – – 56 Plectroglyphidodon dickii – – – – – – – – 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus – – – – – – – – 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus 1 1 3 1 2 5 0.7244 0.7520 61 Scaridae Calotomus carolinus 0 0 0 <1 <1 <1 NA 0.1340 62 Chlorurus sordidus 4 5 27 1 1 2 0.0684 0.3534 63 Leptoscarus vaigiensis 1 1 1 <1 <1 <1 0.7656 0.7500 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.3560 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor 0 0 0 <1 1 2 NA 0.3560 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor 5 4 18 6 8 64 0.3238 0.7920 72 Sphyraenidae Sphyraena ﬂavicauda 1 2 4 <1 1 1 0.2848 0.6700 73 Tetraodontidae Canthigaster bennetti – – – – – – – – 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 1 <1 <1 1 1 1 0.6645 1.0000

Eight species were absent during high tide in the neap cycle, e.g. Plectorhinchus flavomaculatus, and Calotomus carolinus. But there was no significant difference for one of these species. Seven species were not counted in the sampling of the spring cycle, e.g. Chaetodon trifasciatus. But there was also no significant difference for the species of this group during these samplings. In total no species had a significant difference between the samplings in the two cycles during high tide in the seagrass bed. Labroides dimidiatus and Parupeneus macronemus had high non-significant p-values for their means of abundance.

3.2.5. Comparison of different habitat types during low tide in a neap cycle

The observations showed that 23 species were absent in both habitats during low tide in a neap cycle, e.g. Lethrinus harak, and Calotomus carolinus (table 3.6).

Table 3.6: Overview of the analysis of 75 species for the comparison between both habitat types during low tide in a neap cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variances and the means are also summarized. Sig- niﬁcant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRLN SBLN statictics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 1 2 0 0 0 NA 0.3560 2 Acanthurus nigrofuscus <1 1 1 0 0 0 NA 0.3560 3 Ctenochaetus binotatus 2 1 3 0 0 0 NA 0.0710 4 Ctenochaetus striatus 1 1 1 <1 <1 <1 0.1683 0.1901 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas 1 1 1 0 0 0 NA 0.1340 7 Balistidae Sufﬂamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 1 1 2 1 1 2 0.9251 0.4943 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus <1 <1 <1 0 0 0 NA 0.3560 12 Chaetodon kleinii <1 <1 <1 <1 <1 <1 1.0000 1.0000 13 Chaetodon trifascialis 1 1 3 0 0 0 NA 0.1340 14 Chaetodon trifasciatus 1 1 1 0 0 0 NA 0.0240

28 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus ﬂavomaculatus 0 0 0 <1 <1 <1 NA 0.3560 17 Labridae Anampses twistii <1 <1 <1 0 0 0 NA 0.3560 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus – – – – – – – – 20 Cheilio inermis 0 0 0 <1 <1 <1 NA 0.1680 21 Gomphosus caeruleus 1 <1 <1 0 0 0 NA 0.0025 22 Halichoeres hortulanus <1 <1 <1 <1 <1 <1 0.8187 0.5370 23 Halichoeres nebulosus 0 0 0 <1 1 1 NA 0.3560 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.1340 25 Labroides dimidiatus <1 <1 <1 <1 <1 <1 1.0000 1.0000 26 Pseudocheilinus hexataenia <1 <1 <1 0 0 0 NA 0.1682 27 Stethojulis bandanensis 1 1 2 2 1 3 0.8696 0.4630 28 Thalassoma amblycephalum – – – – – – – – 29 Thalassoma hardwicke <1 <1 <1 0 0 0 NA 0.1340 30 Thalassoma hebraicum 6 1 2 1 <1 <1 0.2567 0.0009 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 0 0 0 1 1 1 NA 0.0941 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 1 1 0 0 0 NA 0.3560 36 Cantherhines pardalis <1 <1 <1 <1 1 1 0.9447 0.7300 37 Oxymonacanthus longirostris <1 1 1 0 0 0 NA 0.3560 38 Mullidae Parupeneus cyclostomus <1 1 2 0 0 0 NA 0.3560 39 Parupeneus macronemus <1 <1 <1 1 1 1 0.2026 0.7050 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 0 0 0 NA 0.1340 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 2 1 2 0 0 0 NA 0.0388 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos 0 0 0 <1 <1 <1 NA 0.3560 48 Chromis atripectoralis 8 16 256 0 0 0 NA 0.3560 49 Chromis dimidiata <1 1 1 0 0 0 NA 0.3560 50 Chromis nigrura <1 1 2 0 0 0 NA 0.3560 51 Chromis viridis 1 2 5 7 11 143 0.0248 0.3830 52 Chromis weberi 3 3 12 0 0 0 NA 0.1210 53 Dascyllus aruanus <1 1 2 0 0 0 NA 0.3560 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.3560 55 Neoglyphidodon melas <1 <1 <1 0 0 0 NA 0.3560 56 Plectroglyphidodon dickii 1 1 2 0 0 0 NA 0.2070 57 Plectroglyphidodon johnstonianus <1 <1 <1 0 0 0 NA 0.1682 58 Plectroglyphidodon lacrymatus 3 2 4 0 0 0 NA 0.0197 59 Pomacentrus pavo <1 1 2 0 0 0 NA 0.3560 60 Pomacentrus trilineatus <1 <1 <1 1 1 2 0.1041 0.2530 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 7 6 48 4 5 27 0.6443 0.5152 63 Leptoscarus vaigiensis 0 0 0 <1 <1 <1 NA 0.1340 64 Scarus caudofasciatus <1 <1 <1 0 0 0 NA 0.3560 65 Scarus frenatus – – – – – – – – 66 Scarus ghobban – – – – – – – – 67 Scarus niger 2 2 6 0 0 0 NA 0.1536 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor <1 <1 <1 1 2 8 0.0170 0.3430 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 <1 1 2 NA 0.3560 73 Tetraodontidae Canthigaster bennetti <1 <1 <1 0 0 0 NA 0.3560 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 3 2 5 <1 1 1 0.1881 0.0591

31 species were absent in the seagrass bed. Chaetodon trifasciatus, Gomphosus caeruleus, Centropyge multispinis and Plectroglyphidodon lacrymatus showed a significant difference between their means of abundance (figure 3.4). The mean of abundance for all was higher in the coral reef. Seven species were absent in the coral reef and no one of these showed a significant difference. To this group belonged Plectorhinchus flavomaculatus, Cheilio inermis, and Lethri- nus mahsena. Three species, which were present in both habitats, showed a significant difference. Tha-

29 6

4 s

n 2 a Chaetodon trifasciatus e m

Gomphosus caeruleus f o 0 Thalassoma hebraicum e c

n Chromis viridis e r Plectroglyphidodon e f f i -2 lacrymatus d Siganus sutor

-4

-6 species of special interest

Figure 3.4: Distinctions in means of abundance for species of special interest with a significant difference for both habitat types during low tide in a neap cycle. Positive values = higher mean abundance in the coral reef, negative values = higher mean abundance in the seagrass bed. lassoma hebraicum had a significant difference between its means of abundance. It had a significantly higher mean of abundance in the coral reef. Chromis viridis and Siganus sutor showed a significant difference between their variances. The variances were both significantly higher in the seagrass bed. Labroides dimidiatus had a high non-significant difference between its means of abundance.

3.2.6. Comparison of different habitat types during low tide in a spring cycle

26 species were absent in both habitats during low tide in a spring cycle in both habitats, e.g. Calotomus carolinus, Scarus caudofasciatus, Plectroglyphidodon lacrymatus, and Pseu- docheilinus hexataenia (table 3.7).

Table 3.7: Overview of the analysis of 75 species for the comparison between both habitat types during low tide in a spring cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variances and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for CRLS from six quadrats and for SBLS from five quadrats. CRLS SBLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 <1 <1 <1 <1 <1 0.1158 0.5790 2 Acanthurus nigrofuscus <1 <1 <1 0 0 0 NA 0.1864 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 1 1 2 0 0 0 NA 0.1130 5 Ctenochaetus truncatus 1 2 4 0 0 0 NA 0.2970 6 Zebrasoma scopas 1 1 2 0 0 0 NA 0.2181 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus <1 <1 <1 0 0 0 NA 0.3890 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga <1 <1 <1 0 0 0 NA 0.3890 11 Chaetodon guttatissimus <1 <1 <1 0 0 0 NA 0.3890 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis <1 <1 <1 0 0 0 NA 0.3890 14 Chaetodon trifasciatus 1 1 2 0 0 0 NA 0.0814 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – –

30 17 Labridae Anampses twistii <1 <1 <1 0 0 0 NA 0.3890 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus <1 <1 <1 0 0 0 NA 0.3890 20 Cheilio inermis 0 0 0 1 1 1 NA 0.0352 21 Gomphosus caeruleus <1 <1 <1 0 0 0 NA 0.0738 22 Halichoeres hortulanus <1 <1 <1 0 0 0 NA 0.0738 23 Halichoeres nebulosus 0 0 0 <1 1 1 NA 0.1040 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus <1 1 1 <1 <1 <1 0.8033 0.6620 26 Pseudocheilinus hexataenia – – – – – – – – 27 Stethojulis bandanensis – – – – – – – – 28 Thalassoma amblycephalum <1 1 1 1 2 5 0.2110 0.7590 29 Thalassoma hardwicke <1 <1 <1 <1 <1 <1 0.2485 0.4920 30 Thalassoma hebraicum 2 1 2 <1 <1 <1 0.0586 0.0443 31 Lethrinidae Lethrinus harak <1 1 1 0 0 0 NA 0.3890 32 Lethrinus mahsena <1 1 1 0 0 0 NA 0.3890 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp 0 0 0 2 4 20 NA 0.2970 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis <1 <1 <1 0 0 0 NA 0.3890 37 Oxymonacanthus longirostris <1 <1 <1 0 0 0 NA 0.3890 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 1 1 2 0 0 0 NA 0.1864 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 0 0 0 NA 0.3890 41 Parapercis xanthozona 1 1 1 0 0 0 NA 0.1138 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis <1 <1 <1 0 0 0 NA 0.3890 44 Pomacanthus semicirculatus <1 <1 <1 0 0 0 NA 0.3890 45 Pomacentridae Abudefduf sexfasciatus 0 0 0 <1 <1 <1 NA 0.1310 46 Amblyglyphidodon leucogaster <1 <1 <1 0 0 0 NA 0.3890 47 Amphiprion akallopisos <1 <1 <1 0 0 0 NA 0.3890 48 Chromis atripectoralis 3 2 7 50 70 5025 1.034*10−06 0.1360 49 Chromis dimidiata <1 <1 <1 0 0 0 NA 0.3890 50 Chromis nigrura 1 3 10 0 0 0 NA 0.3890 51 Chromis viridis 6 8 79 0 0 0 NA 0.1499 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus <1 1 <1 0 0 0 NA 0.3890 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas <1 <1 <1 0 0 0 NA 0.1864 56 Plectroglyphidodon dickii 1 1 3 0 0 0 NA 0.1259 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus – – – – – – – – 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus 2 2 4 <1 <1 <1 0.0115# 0.0657 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 2 2 4 <1 <1 <1 0.0110# 0.0513 63 Leptoscarus vaigiensis 0 0 0 <1 <1 <1 NA 0.2970 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.3890 66 Scarus ghobban – – – – – – – – 67 Scarus niger <1 <1 <1 0 0 0 NA 0.3890 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor 0 0 0 5 8 64 NA 0.1070 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 2 2 4 NA 0.0443 73 Tetraodontidae Canthigaster bennetti 1 1 1 0 0 0 NA 0.1138 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 1 <1 <1 0 0 0 NA 0.0014

34 species were only present in the coral reef, e.g. Chaetodon trifasciatus, Gomphosus caeruleus, and Halichoeres hortulanus. But only Canthigaster valentini showed a significant difference between its means of abundance. Seven species were absent in the coral reef. Cheilio inermis and Sphyraena flavicauda had a significantly higher mean of abundance in the seagrass bed (figure 3.5). For the species, which occured in both habitats, the analysis showed significant differences for four species. Thalassoma hebraicum inidicated a significantly higher mean of abundance in the coral reef (figure 3.5). Chromis atripectoralis had a significant difference for an analysis of its variances (figure 3.5). The analysis revealed a significantly higher variance in the seagrass bed. Pomacentrus trilineatus and Chlorurus sordidus displayed a significantly higher variance

31 3

-2

-7

s -12 n a e -17 Cheilio inermis m

f Thalassoma hebraicum o -22 e Chromis atripectoralis c n

e Pomacentrus trilineatus

r -27 e

f Chlorurus sordidus f i

d -32 Sphyraena flavicauda

-37

-42

-47 species of special interest

Figure 3.5: Distinctions in means of abundance for species of special interest with a signiﬁcant difference in both habitat types during low tide in a spring cycle. Positive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed. in the coral reef, but both species showed an outlier in the boxplots (appendix A, ﬁgure A.14).

3.2.7. Comparison of different cycles during low tide in the coral reef

The observation indicated that 19 species were absent in both cycles during low tide in the coral reef, e.g. Plectorhinchus ﬂavomaculatus, Cheilio inermis, Calotomus carolinus, and Lep- toscarus vaigiensis (table 3.8).

Table 3.8: Overview of the analysis of 75 species for the comparison between both cycles during low tide in the coral reef in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variances and the means are also summarized. Signif- icant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for CRLN from four quadrats and for CRLS from six quadrats. CRLN CRLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 1 2 <1 <1 <1 0.0157# 0.3800 2 Acanthurus nigrofuscus <1 1 1 <1 <1 <1 0.1888 0.7350 3 Ctenochaetus binotatus 2 1 3 0 0 0 NA 0.0243 4 Ctenochaetus striatus 1 1 1 1 1 2 0.8471 0.9290 5 Ctenochaetus truncatus 0 0 0 1 2 4 NA 0.3560 6 Zebrasoma scopas 1 1 1 1 1 2 0.5749 1.0000 7 Balistidae Sufﬂamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 1 1 2 <1 <1 <1 0.0157# 0.0358# 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga 0 0 0 <1 <1 <1 NA 0.4470 11 Chaetodon guttatissimus <1 <1 <1 <1 <1 <1 0.4491 0.8610 12 Chaetodon kleinii <1 <1 <1 0 0 0 NA 0.2420 13 Chaetodon trifascialis 1 1 3 <1 <1 <1 0.0083# 0.0995 14 Chaetodon trifasciatus 1 1 1 1 1 2 0.5325 0.8518 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus ﬂavomaculatus – – – – – – – – 17 Labridae Anampses twistii <1 <1 <1 <1 <1 <1 0.6443 0.7790 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus 0 0 0 <1 <1 <1 NA 0.4470 20 Cheilio inermis – – – – – – – – 21 Gomphosus caeruleus 1 <1 <1 <1 <1 <1 0.9393 0.0598 22 Halichoeres hortulanus <1 <1 <1 <1 <1 <1 0.8537 1.0000 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.0598

32 25 Labroides dimidiatus <1 <1 <1 <1 1 1 0.9612 0.9010 26 Pseudocheilinus hexataenia <1 <1 <1 0 0 0 NA 0.0828 27 Stethojulis bandanensis 1 1 2 0 0 0 NA 0.0320 28 Thalassoma amblycephalum 0 0 0 <1 1 1 NA 0.3120 29 Thalassoma hardwicke <1 <1 <1 <1 <1 <1 0.5749 1.0000 30 Thalassoma hebraicum 6 1 2 2 1 2 0.8376 0.0025 31 Lethrinidae Lethrinus harak 0 0 0 <1 1 1 NA 0.4470 32 Lethrinus mahsena 0 0 0 <1 1 1 NA 0.4470 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 1 1 0 0 0 NA 0.2420 36 Cantherhines pardalis <1 <1 <1 <1 <1 <1 0.0970 0.2139 37 Oxymonacanthus longirostris <1 1 1 <1 <1 <1 0.6443 0.7790 38 Mullidae Parupeneus cyclostomus <1 1 2 0 0 0 NA 0.2420 39 Parupeneus macronemus <1 <1 <1 1 1 2 0.0918 0.7670 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 <1 <1 <1 0.4652 0.3122 41 Parapercis xanthozona 0 0 0 1 1 1 NA 0.1600 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 2 1 2 <1 <1 <1 0.1458 0.0421# 44 Pomacanthus semicirculatus 0 0 0 <1 <1 <1 NA 0.4470 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster 0 0 0 <1 <1 <1 NA 0.4470 47 Amphiprion akallopisos 0 0 0 <1 <1 <1 NA 0.4470 48 Chromis atripectoralis 8 16 256 3 2 7 0.0019 0.5220 49 Chromis dimidiata <1 1 1 <1 <1 <1 0.0825 0.4770 50 Chromis nigrura <1 1 2 1 3 10 0.2304 0.7500 51 Chromis viridis 1 2 5 6 8 79 0.0543 0.3290 52 Chromis weberi 3 3 12 0 0 0 NA 0.0514 53 Dascyllus aruanus <1 1 2 <1 1 1 0.6443 0.7790 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.2420 55 Neoglyphidodon melas <1 <1 <1 <1 <1 <1 0.9763 0.8070 56 Plectroglyphidodon dickii 1 1 2 1 1 3 0.7699 0.7600 57 Plectroglyphidodon johnstonianus <1 <1 <1 0 0 0 NA 0.0828 58 Plectroglyphidodon lacrymatus 3 2 4 0 0 0 NA 0.0040 59 Pomacentrus pavo <1 1 2 0 0 0 NA 0.2420 60 Pomacentrus trilineatus <1 <1 <1 2 2 4 0.0426# 0.1080 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 7 6 48 2 2 4 0.0229 0.1170 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus <1 <1 <1 0 0 0 NA 0.2420 65 Scarus frenatus 0 0 0 <1 <1 <1 NA 0.4470 66 Scarus ghobban – – – – – – – – 67 Scarus niger 2 2 6 <1 <1 <1 0.0017# 0.1013 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor <1 <1 <1 0 0 0 NA 0.2420 72 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 73 Tetraodontidae Canthigaster bennetti <1 <1 <1 1 1 1 0.1575 0.2990 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 3 2 5 1 <1 <1 0.0417 0.1127

Eleven species were absent in the coral reef during low tide in the neap cycle. Three out of this eleven were Lethrinus harak, Lethrinus mahsena, and Scarus frenatus. No species revealed significant differences. 14 species were absent during low tide in the spring cycle sampling. Ctenochaetus binotatus, Stethojulis bandanensis and Plectroglyphidodon lacrymatus displayed a significantly higher mean of abundance (figure 3.6). The analysis of species attended in both habitats showed several significant differences. Tha- lassoma hebraicum had a significantly higher mean of abundance during the neap cycle (figure 3.6). Chromis atripectoralis, Chlorurus sordidus and Canthigaster valentini had a significantly higher variance in the sampling during the neap cycle. Meiacanthus mossambicus had a significant difference in both analyses during the neap cycle, but the boxplot (appendix A, figure A.10) showed an outlier. Chaetodon trifascialis and Centropyge multispinis indicated significantly higher means of abundance during neap cycles, but the boxplots for both species revealed also outliers (appendix A, figure A.10 & figure A.11). Acanthurus leucosternon and

33 6

4 Ctenochaetus binotatus s

n Chaetodon trifascialis a

e 3 Stethojulis bandanensis m

f Thalassoma hebraicum o 2 e Chromis atripectoralis c n

e Plectroglyphidodon r

e 1 f lacrymatus f i

d Pomacentrus trilineatus 0 Chlorurus sordidus Scarus niger -1

-2 species of special interest

Figure 3.6: Distinctions in means of abundance for species of special interest with a signiﬁcant difference in both cycles during low tide in the coral reef. Positive values = higher mean of abundance during neap cycle, negative values = higher mean of abundance during spring cycle. The difference of Acanthurus leucosternon was smaller than one.

Scarus niger displayed significantly higher variances in neap cycles, but the boxplots showed also outliers (appendix A, figure A.10 & figure A.11). Pomacentrus trilineatus had a significantly higher variance in spring cycles, but the boxplot showed here also an outlier (appendix A, figure A.10). Zebrasoma scopas, Halichoeres hortulanus and Thalassoma hardwicke had high non-significant p-values for their means of abundance.

3.2.8. Comparison of different cycles during low tide in the seagrass bed

48 species were absent in both cycles during low tide in the seagrass bed, e.g. Caloto- mus carolinus, Scarus caudofasciatus, Lethrinus harak, Gomphosus caeruleus, and Plectro- glyphidodon lacrymatus (table 3.9).

Table 3.9: Overview of the analysis of 75 species for the comparison between both cycles during low tide in the seagrass bed in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variances and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for SBLN from four quadrats and for SBLS from five quadrats. SBLN SBLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 0 0 0 <1 <1 <1 NA 0.4070 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus <1 <1 <1 0 0 0 NA 0.2920 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 1 1 2 0 0 0 NA 0.1514 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii <1 <1 <1 0 0 0 NA 0.2920 13 Chaetodon trifascialis – – – – – – – –

34 14 Chaetodon trifasciatus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus ﬂavomaculatus <1 <1 <1 0 0 0 NA 0.2920 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus – – – – – – – – 20 Cheilio inermis <1 <1 <1 1 1 1 0.9824 0.7160 21 Gomphosus caeruleus – – – – – – – – 22 Halichoeres hortulanus <1 <1 <1 0 0 0 NA 0.2920 23 Halichoeres nebulosus <1 1 1 <1 1 1 0.9174 0.6850 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus <1 <1 <1 <1 <1 <1 0.8646 0.5890 26 Pseudocheilinus hexataenia – – – – – – – – 27 Stethojulis bandanensis 2 1 3 0 0 0 NA 0.0130 28 Thalassoma amblycephalum 0 0 0 1 2 5 NA 0.4070 29 Thalassoma hardwicke 0 0 0 <1 <1 <1 NA 0.4070 30 Thalassoma hebraicum 1 <1 <1 <1 <1 <1 0.4559 0.2275 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 1 1 1 0 0 0 NA 0.0582 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp 0 0 0 2 4 20 NA 0.4070 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis <1 1 1 0 0 0 NA 0.2920 37 Oxymonacanthus longirostris – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 1 1 1 0 0 0 NA 0.0892 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus 0 0 0 <1 <1 <1 NA 0.2270 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos <1 <1 <1 0 0 0 NA 0.2920 48 Chromis atripectoralis 0 0 0 50 70 5025 NA 0.2020 49 Chromis dimidiata – – – – – – – – 50 Chromis nigrura – – – – – – – – 51 Chromis viridis 7 11 143 0 0 0 NA 0.2110 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas – – – – – – – – 56 Plectroglyphidodon dickii – – – – – – – – 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus – – – – – – – – 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus 1 1 2 <1 <1 <1 0.0406# 0.1750 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 4 5 27 <1 <1 <1 0.0004# 0.1029 63 Leptoscarus vaigiensis <1 <1 <1 <1 <1 <1 0.6197 0.4071 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus – – – – – – – – 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor 1 2 8 5 8 64 0.1234 0.3730 72 Sphyraenidae Sphyraena ﬂavicauda <1 1 2 2 2 4 0.5956 0.3550 73 Tetraodontidae Canthigaster bennetti – – – – – – – – 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini <1 1 1 0 0 0 NA 0.2920

Six species were absent in the seagrass bed during low tide in the neap cycle, e.g. Acan- thurus leucosternon, Abudefduf sexfasciatus, and Chromis atripectoralis. No one of these six species showed significant differences for their means or variances. Twelve species were not present in the seagrass bed during low tide in the spring cycle. Plectorhinchus flavomaculatus, Lethrinus mahsena and Parupeneus macronemus showed this habitat use but without significant differences. Only Stethojulis bandanensis had a significant distinction between its means of abundance (figure 3.7). Pomacentrus trilineatus and Chlorurus sordidus were present in both cycles and had a sig-

35 5

4 s n a e 3 m

f o

Stethojulis bandanensis e

c Pomacentrus trilineatus n e r 2 Chlorurus sordidus e f f i d

0 species of special interest

Figure 3.7: Distinctions in means of abundance for species of special interest with a significant difference during low tide in the seagrass bed. Positive values = higher mean of abundance during neap cycle, negative values = higher mean of abundance during spring cycle. nificantly higher variance during the low neap cycle. The boxplots for both species showed outliers (appendix A, figure A.13).

3.2.9. Comparison of different tides in a neap cycle in the coral reef

The observation showed that 21 species were absent during both tides in a neap cycle in the coral reef, e.g. Plectorhinchus ﬂavomaculatus, Cheilio inermis, and Lethrinus mahsena (table 3.10).

Table 3.10: Overview of the analysis of 75 species for the comparison between both tides in a neap cycle in the coral reef in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRHN CRLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 1 1 <1 1 2 0.7797 0.3464 2 Acanthurus nigrofuscus 0 0 0 <1 1 1 NA 0.3560 3 Ctenochaetus binotatus 1 1 1 2 1 3 0.4715 0.3900 4 Ctenochaetus striatus 3 2 7 1 1 1 0.2536 0.1755 5 Ctenochaetus truncatus <1 <1 <1 0 0 0 NA 0.3560 6 Zebrasoma scopas 1 2 5 1 1 1 0.2655 0.7180 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 2 1 3 1 1 2 0.7115 0.6932 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga <1 1 1 0 0 0 NA 0.3560 11 Chaetodon guttatissimus 1 1 1 <1 <1 <1 0.2026 0.2782 12 Chaetodon kleinii 0 0 0 <1 <1 <1 NA 0.3560 13 Chaetodon trifascialis 1 1 1 1 1 3 0.6128 0.8230 14 Chaetodon trifasciatus 2 <1 <1 1 1 1 0.9447 0.1210 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectrorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii <1 <1 <1 <1 <1 <1 1.0000 1.0000 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus – – – – – – – – 20 Cheilio inermis – – – – – – – – 21 Gomphosus caeruleus 2 1 2 1 <1 <1 0.1041 0.1066 22 Halichoeres hortulanus 1 1 1 <1 <1 <1 0.2191 0.2070

36 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 <1 <1 <1 0.4282 0.6700 25 Labroides dimidiatus 1 1 1 <1 <1 <1 0.6356 0.3867 26 Pseudocheilinus hexataenia 1 2 5 <1 <1 <1 0.1688 0.5800 27 Stethojulis bandanensis 3 2 8 1 1 2 0.3950 0.4900 28 Thalassoma amblycephalum 1 2 6 0 0 0 NA 0.3560 29 Thalassoma hardwicke 0 0 0 <1 <1 <1 NA 0.1340 30 Thalassoma hebraicum 5 0 0 6 1 2 NA 0.0863 31 Lethrinidae Lethrinus harak <1 <1 <1 0 0 0 NA 0.3560 32 Lethrinus mahsena – – – – – – – – 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 <1 1 1 0.2848 0.6700 36 Cantherhines pardalis 0 0 0 <1 <1 <1 NA 0.1680 37 Oxymonacanthus longirostris 2 5 25 <1 1 1 0.0253 0.4630 38 Mullidae Parupeneus cyclostomus 0 0 0 <1 1 2 NA 0.3560 39 Parupeneus macronemus 1 1 1 <1 <1 <1 0.1535 0.3202 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 <1 <1 <1 0.4282 0.6700 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 2 1 2 2 1 2 0.9430 0.8394 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos <1 <1 <1 0 0 0 NA 0.3560 48 Chromis atripectoralis <1 <1 <1 8 16 256 0.0001 0.3700 49 Chromis dimidiata <1 1 1 <1 1 1 1.0000 1.0000 50 Chromis nigrura 1 2 4 <1 1 2 0.6482 0.8480 51 Chromis viridis 3 6 42 1 2 5 0.1331 0.6310 52 Chromis weberi 14 22 521 3 3 12 0.0127 0.3680 53 Dascyllus aruanus <1 1 2 <1 1 2 1.0000 1.0000 54 Dascyllus trimaculatus <1 <1 <1 <1 <1 <1 1.0000 1.0000 55 Neoglyphidodon melas <1 <1 <1 <1 <1 <1 1.0000 1.0000 56 Plectroglyphidodon dickii <1 1 1 1 1 2 0.5836 0.5850 57 Plectroglyphidodon johnstonianus 1 1 2 <1 <1 <1 0.5382 0.7800 58 Plectroglyphidodon lacrymatus 3 1 2 3 2 4 0.7645 0.7216 59 Pomacentrus pavo 1 2 6 <1 1 2 0.4237 0.7430 60 Pomacentrus trilineatus 2 1 3 <1 <1 <1 0.0612 0.1140 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 4 4 18 7 6 48 0.4614 0.4580 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus 0 0 0 <1 <1 <1 NA 0.3560 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.0240 66 Scarus ghobban – – – – – – – – 67 Scarus niger 0 0 0 2 2 6 NA 0.1540 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus <1 1 1 0 0 0 NA 0.3560 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.3560 71 Siganidae Siganus sutor 0 0 0 <1 <1 <1 NA 0.3560 72 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 73 Tetraodontidae Canthigaster bennetti 1 1 3 <1 <1 <1 0.0537 0.2534 74 Canthigaster solandri <1 <1 <1 0 0 0 NA 0.3560 75 Canthigaster valentini 4 1 2 3 2 5 0.4681 0.6131

Eight species were absent during high tide, e.g. Thalassoma hardwicke, Scarus caudofasciatus, Scarus niger, and Siganus sutor. No species showed significant distinctions for their means of abundance or variances. Nine species were absent during low tide, e.g. Thalassoma amblycephalum, Lethrinus harak, and Scarus frenatus. Only Scarus frenatus had a significant difference between its means of abundance (figure 3.8). From the species, which were present during both tides, three species indicated significant differences of their variances. Oxymonacanthus longirostris and Chromis weberi had significantly higher variances during high tide. Chromis atripectoralis revealed a significantly higher variance during low tide (figure 3.8). Anampses twistii, Chromis dimidiata, Dascyllus aruanus, Dascyllus trimaculatus and Neogly- phidodon melas displayed high non-significant p-values.

37 12

s 6 n a e 4 m

f o 2 e Chromis atripectoralis c n

e Chromis weberi

r 0 e f f i

d -2

-4

-6

-8 species of special interest

Figure 3.8: Distinctions in means of abundance for species of special interest with a signiﬁcant difference during different tides in a neap cycle in the coral reef. Positive values = higher mean of abundance during high tide, negative values = higher mean of abundance during low tide. The difference of Scarus frenatus was smaller than one.

3.2.10. Comparison of different tides in a spring cycle in the coral reef

18 species were absent during the samplings of different tides in a spring cycle in the coral reef, e.g. Plectorhinchus ﬂavomaculatus, Calotomus carolinus, Siganus sutor, and Sphyraena ﬂavicauda (table 3.11).

Table 3.11: Overview of the analysis of 75 species for the comparison between both tides during a spring cycle in the coral reef in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for CRHS from four quadrats and for CRLS from six quadrats. CRHS CRLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 1 1 <1 <1 <1 0.0825 0.4770 2 Acanthurus nigrofuscus 0 0 0 <1 <1 <1 NA 0.2420 3 Ctenochaetus binotatus <1 <1 <1 0 0 0 NA 0.0598 4 Ctenochaetus striatus 2 1 2 1 1 2 0.7807 0.4246 5 Ctenochaetus truncatus 0 0 0 1 2 4 NA 0.3560 6 Zebrasoma scopas 0 0 0 1 1 2 NA 0.2750 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus <1 <1 <1 <1 <1 <1 0.0970 0.2139 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga 0 0 0 <1 <1 <1 NA 0.4470 11 Chaetodon guttatissimus 0 0 0 <1 <1 <1 NA 0.4470 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 1 1 1 <1 <1 <1 0.0825 0.0175# 14 Chaetodon trifasciatus 2 1 1 1 1 2 0.8161 0.3459 15 Ephippidae Platax teira <1 <1 <1 0 0 0 NA 0.2420 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii <1 <1 <1 <1 <1 <1 0.6443 0.7790 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus 0 0 0 <1 <1 <1 NA 0.4470 20 Cheilio inermis – – – – – – – – 21 Gomphosus caeruleus 2 2 8 <1 <1 <1 0.0026 0.1007 22 Halichoeres hortulanus 1 1 1 <1 <1 <1 0.2279 0.0727 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.2420 25 Labroides dimidiatus 2 1 2 <1 1 1 0.5029 0.1209 26 Pseudocheilinus hexataenia 1 2 5 0 0 0 NA 0.1496 27 Stethojulis bandanensis 1 1 2 0 0 0 NA 0.0681

38 28 Thalassoma amblycephalum 1 2 4 <1 1 1 0.3078 0.7480 29 Thalassoma hardwicke <1 <1 <1 <1 <1 <1 0.4260 0.6100 30 Thalassoma hebraicum 6 5 30 2 1 2 0.0201 0.0864 31 Lethrinidae Lethrinus harak 0 0 0 <1 1 1 NA 0.4470 32 Lethrinus mahsena 0 0 0 <1 1 1 NA 0.4470 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 0 0 0 NA 0.2420 36 Cantherhines pardalis <1 <1 <1 <1 <1 <1 0.6443 0.7790 37 Oxymonacanthus longirostris 0 0 0 <1 <1 <1 NA 0.4470 38 Mullidae Parupeneus cyclostomus <1 <1 <1 0 0 0 NA 0.0598 39 Parupeneus macronemus 1 1 2 1 1 2 0.9393 1.0000 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 <1 <1 <1 0.4652 0.3122 41 Parapercis xanthozona 0 0 0 1 1 1 NA 0.1600 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis <1 1 1 <1 <1 <1 0.6443 0.7790 44 Pomacanthus semicirculatus <1 <1 <1 <1 <1 <1 0.4652 0.3122 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster <1 <1 <1 <1 <1 <1 0.4652 0.3122 47 Amphiprion akallopisos <1 <1 <1 <1 <1 <1 0.6443 0.7790 48 Chromis atripectoralis 0 0 0 3 2 7 NA 0.0302 49 Chromis dimidiata <1 1 1 <1 <1 <1 0.0825 0.4770 50 Chromis nigrura 1 2 6 1 3 10 0.7001 0.9670 51 Chromis viridis <1 1 2 6 8 79 0.0144 0.2580 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus <1 1 1 <1 1 1 0.7846 1.0000 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.2420 55 Neoglyphidodon melas <1 1 1 <1 <1 <1 0.1888 0.7350 56 Plectroglyphidodon dickii 0 0 0 1 1 3 NA 0.1740 57 Plectroglyphidodon johnstonianus <1 1 1 0 0 0 NA 0.2420 58 Plectroglyphidodon lacrymatus 3 2 4 0 0 0 NA 0.0027 59 Pomacentrus pavo 1 2 4 0 0 0 NA 0.2420 60 Pomacentrus trilineatus 1 <1 <1 2 2 4 0.1624 0.3160 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 5 4 19 2 2 4 0.1372 0.2260 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus 2 2 4 0 0 0 NA 0.0246 65 Scarus frenatus <1 <1 <1 <1 <1 <1 0.4491 0.8610 66 Scarus ghobban – – – – – – – – 67 Scarus niger <1 1 1 <1 <1 <1 0.0825 0.4770 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus <1 1 2 0 0 0 NA 0.2420 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.2420 71 Siganidae Siganus sutor – – – – – – – – 72 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 73 Tetraodontidae Canthigaster bennetti 1 <1 <1 1 1 1 0.5021 1.0000 74 Canthigaster solandri <1 <1 <1 0 0 0 NA 0.2420 75 Canthigaster valentini 2 2 6 1 <1 <1 0.0341 0.3420

Twelve species were absent during high tide, e.g. Chaetodon auriga, Chaetodon guttatissimus, Plectroglyphidodon dickii, and Chromis atripectoralis. Only Chromis atripectoralis had a significant difference for its means of abundance (ﬁgure 3.9).

The observations showed that 15 species were absent during low tide. Ctenochaetus binotatus, Stethojulis bandanensis and Parupeneus cyclostomus were some of these species but had no significant differences for their variances and means of abundance (figure 3.9). Plectro- glyphidodon lacrymatus and Scarus caudofasciatus were also absent during low tide and had significant distinctions for their means of abundance (figure 3.9). Chaetodon trifascialis was present during both tides and had a significantly higher mean of abundance during the high tide, but the boxplot for this species showed an outlier (appendix A, figure A.15). Gomphosus caeruleus, Thalassoma hebraicum and Canthigaster valentini were also present during both tides and had significant distinctions for their variances during high tide. Chromis viridis had a significantly higher variance during low tide (figure 3.9). Parupeneus macronemus, Dascyllus aruanus and Canthigaster bennetti displayed high non- significant p-values for their means of abundance.

39 6

4 s

n 2 Chaetodon trifascialis a

e Gomphosus caeruleus m

f Thalassoma hebraicum o 0 e Chromis atripectoralis c n

e Chromis viridis r e f

f Plectroglyphidodon i -2 d lacrymatus Scarus caudofasciatus -4

-6 species of special interest

Figure 3.9: Distinctions in means of abundance for species of special interest with a signiﬁcant difference during different tides in a spring cycle in the coral reef. Positive values = higher mean of abundance during high tide, negative values = higher mean of abundance during low tide.

3.2.11. Comparison of different tides in a neap cycle in the seagrass bed

The observations displayed that 47 species were absent during both tides in a neap cycle in the seagrass bed. To this group belonged most of the acanthurids except for Ctenochaetus striatus, Chaetodon trifascialis, Gomphosus caeruleus, and Plectroglyphidodon lacrymatus (table 3.12).

Table 3.12: Overview of the analysis of 75 species for the comparison between both tides during a neap cycle in the seagrass bed in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. SBHN SBLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon – – – – – – – – 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus <1 1 1 <1 <1 <1 0.2848 0.6700 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus <1 <1 <1 1 1 2 0.1215 0.3560 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus <1 <1 <1 0 0 0 NA 0.3560 12 Chaetodon kleinii 0 0 0 <1 <1 <1 NA 0.3560 13 Chaetodon trifascialis – – – – – – – – 14 Chaetodon trifasciatus <1 1 1 0 0 0 NA 0.3560 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0 0 0 <1 <1 <1 NA 0.3560 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus <1 <1 <1 0 0 0 NA 0.1340 20 Cheilio inermis <1 <1 <1 <1 <1 <1 1.0000 1.0000 21 Gomphosus caeruleus – – – – – – – – 22 Halichoeres hortulanus 0 0 0 <1 <1 <1 NA 0.3560 23 Halichoeres nebulosus <1 1 1 <1 1 1 1.0000 1.0000 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus 1 1 2 <1 <1 <1 0.5382 0.7800 26 Pseudocheilinus hexataenia – – – – – – – –

40 27 Stethojulis bandanensis 5 9 84 2 1 3 0.0273 0.6140 28 Thalassoma amblycephalum <1 <1 <1 0 0 0 NA 0.3560 29 Thalassoma hardwicke <1 <1 <1 0 0 0 NA 0.1340 30 Thalassoma hebraicum 2 1 2 1 <1 <1 0.3910 0.2666 31 Lethrinidae Lethrinus harak <1 1 1 0 0 0 NA 0.3560 32 Lethrinus mahsena 1 <1 <1 1 1 1 0.2330 0.7304 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis 1 1 2 <1 1 1 0.5226 0.4372 37 Oxymonacanthus longirostris – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus <1 <1 <1 1 1 1 0.2026 0.2780 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos 0 0 0 <1 <1 <1 NA 0.3560 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata – – – – – – – – 50 Chromis nigrura – – – – – – – – 51 Chromis viridis 5 11 121 7 11 143 0.8915 0.8370 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas – – – – – – – – 56 Plectroglyphidodon dickii – – – – – – – – 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus – – – – – – – – 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus 1 1 3 1 1 2 0.7115 1.0000 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 4 5 27 4 5 27 0.9845 1.0000 63 Leptoscarus vaigiensis 1 1 1 <1 <1 <1 0.2848 0.4680 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.3560 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor 5 4 18 1 2 8 0.5382 0.2516 72 Sphyraenidae Sphyraena ﬂavicauda 1 2 4 <1 1 2 0.6482 0.8480 73 Tetraodontidae Canthigaster bennetti – – – – – – – – 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 1 <1 <1 <1 1 1 0.9447 0.3202

Four species were absent during high tide. This were Chaetodon kleinii, Plectorhinchus flavomaculatus, Halichoeres hortulanus, and Amphiprion akallopisos. No one of these species had significant differences for their means of abundance or variances. Seven species were absent during low tide, e.g. Cheilinus trilobatus, and Thalassoma hardwicke. No significant distinctions occured for species only present in high tide. Stethojulis bandanensis was present during both tides and had a significantly higher variance during high tide (figure 3.10). Cheilio inermis, Halichoeres nebulosus, Pomacentrus trilineatus and Chlorurus sordidus had high non-significant p-values for their means of abundance.

41 3 s

n 2 a e m

f o

c Stethojulis bandanensis n e r e f f i 1 d

0 species of special interest

Figure 3.10: Distinctions in means of abundance for species of special interest with a signiﬁ- cant difference during different tides in a neap cycle in the seagrass bed. Positive values = higher mean of abundance during high tide, negative values = higher mean of abundance during low tide.

3.2.12. Comparison of different tides in a spring cycle in the seagrass bed

46 species were absent during both tides in a spring cycle in the seagrass bed, e.g. all chaetodontids, Plectroglyphidodon lacrymatus, and Scarus caudofasciatus (table 3.13).

Table 3.13: Overview of the analysis of 75 species for the comparison between both tides during a spring cycle in the seagrass bed in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for SBHS from four quadrats and for SBLS from five quadrats. SBHS SBLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 19.48 38.97 1518.44 154.17 344.73 118836.93 0.0046# 0.4680 2 Acanthurus nigrofuscus 57.26 114.53 13116.57 0.00 0.00 0.00 NA 0.2920 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 364.39 383.93 147402.53 0.00 0.00 0.00 NA 0.0675 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 6.82 7.92 62.65 0.00 0.00 0.00 NA 0.0905 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus – – – – – – – – 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 471.54 711.19 505788.74 0.00 0.00 0.00 NA 0.1748 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 94.30 148.21 21966.17 0.00 0.00 0.00 NA 0.1913 21 Cheilio inermis 3.60 7.20 51.85 12.32 16.67 278.03 0.1820 0.3590 22 Coris formosa 104.88 209.76 43997.58 0.00 0.00 0.00 NA 0.2920 23 Gomphosus caeruleus 5.65 11.30 127.69 0.00 0.00 0.00 NA 0.2920 24 Halichoeres hortulanus – – – – – – – – 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 18.39 36.12 1304.74 3.52 7.88 62.09 0.0139# 0.3960 28 Pseudocheilinus hexataenia 0.50 0.99 0.99 0.00 0.00 0.00 NA 0.2920 29 Stethojulis bandanensis 101.82 182.98 33480.76 0.00 0.00 0.00 NA 0.2450 30 Thalassoma hardwicke 32.42 64.85 4204.96 10.92 24.42 596.31 0.0911 0.5120

42 31 Thalassoma hebraicum 177.00 214.47 45995.30 36.59 50.10 2509.62 0.0165 0.1927 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 130.26 118.91 14138.91 0.00 0.00 0.00 NA 0.0415 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar 36.90 73.80 5446.36 0.00 0.00 0.00 NA 0.2920 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 2.92 5.84 34.09 0.00 0.00 0.00 NA 0.2920 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 27.79 55.58 3089.21 50.71 70.31 4943.72 0.7298 0.6130 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 0.00 0.00 0.00 2624.65 3595.38 12926742.26 NA 0.1930 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 400.08 471.31 222135.07 0.00 0.00 0.00 NA 0.0945 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 89.57 114.77 13171.56 5.54 12.40 153.68 0.0009# 0.1420 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus – – – – – – – – 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 124.04 143.26 20524.27 83.89 187.58 35186.92 0.6871 0.7350 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus – – – – – – – – 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 1764.39 2290.55 5246627.83 1077.81 1627.57 2648998.78 0.5183 0.6140 71 Sphyraenidae Sphyraena ﬂavicauda 23.17 46.34 2147.85 57.97 78.80 6209.92 0.4137 0.4660 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 94.21 83.23 6927.86 0.00 0.00 0.00 NA 0.0367 75 Zanclidae Zanclus cornutus – – – – – – – –

Four species were absent during the high tide sampling. But Halichoeres nebulosus, Thalas- soma amblycephalum, Ptereleotris sp and Chromis atripectoralis had no significant distinctions for their means of abundance or variances. 14 species were absent during the low tide, e.g. Ctenochaetus striatus, Calotomus carolinus, Plectorhinchus flavomaculatus, and Lethrinus mahsena. Only Lethrinus mahsena revealed a significant difference for its mean of abundance (figure 3.11). Pomacentrus trilineatus and Chlorurus sordidus were present during both tides and displayed a significantly higher variance during high tide, but the boxplots for both species showed outliers (appendix A, figure A.18).

43 3 s

n 2 a e m

f o

Lethrinus mahsena e

c Pomacentrus trilineatus n e r Chlorurus sordidus e f f i 1 d

0 species of special interest

Figure 3.11: Distinctions in means of abundance for species of special interest with a sig- niﬁcant difference during different tides in a spring cycle in the seagrass bed. Positive values = higher mean of abundance during high tide, negative values = higher mean of abundance during low tide.

3.2.13. Comparison of different habitat types during sunset in a neap cycle

The observation showed that 17 species were absent in both habitats during sunset in a neap cycle, e.g. Chaetodon guttatissimus, Lethrinus harak, Dascyllus aruanus, and Scarus caudofasciatus (table 3.14).

Table 3.14: Overview of the analysis of 75 species for the comparison between both habitat types during sunset in a neap cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from six quadrats. CRSSN SBSSN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 2 5 <1 1 1 0.1802 0.3763 2 Acanthurus nigrofuscus 1 <1 <1 0 0 0 NA 0.0209 3 Ctenochaetus binotatus 2 1 2 0 0 0 NA 0.0061 4 Ctenochaetus striatus 3 2 5 0 0 0 NA 0.0046 5 Ctenochaetus truncatus <1 <1 <1 0 0 0 NA 0.1449 6 Zebrasoma scopas 1 3 13 0 0 0 NA 0.2850 7 Balistidae Sufflamen chrysopterum <1 <1 <1 0 0 0 NA 0.3410 8 Blennidae Meiacanthus mossambicus 1 1 1 0 0 0 NA 0.0816 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga <1 <1 <1 0 0 0 NA 0.3410 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 2 1 3 0 0 0 NA 0.0209 14 Chaetodon trifasciatus 3 2 5 0 0 0 NA 0.0071# 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0 0 0 <1 <1 <1 NA 0.0734 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris <1 1 1 0 0 0 NA 0.2073 19 Cheilinus trilobatus <1 <1 <1 <1 <1 <1 1.0000 1.0000 20 Cheilio inermis 0 0 0 1 1 1 NA 0.0237 21 Gomphosus caeruleus 1 <1 <1 0 0 0 NA 0.0001 22 Halichoeres hortulanus <1 <1 <1 0 0 0 NA 0.3410 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.3410 25 Labroides dimidiatus <1 <1 <1 <1 <1 <1 0.1413 0.4010 26 Pseudocheilinus hexataenia <1 <1 <1 <1 <1 <1 1.0000 0.4956 27 Stethojulis bandanensis 0 0 0 <1 <1 <1 NA 0.3410 28 Thalassoma amblycephalum <1 1 1 0 0 0 NA 0.3410

44 29 Thalassoma hardwicke <1 1 1 <1 <1 <1 0.6552 0.7650 30 Thalassoma hebraicum 3 1 2 <1 1 2 0.9570 0.0173# 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 0 0 0 <1 <1 <1 NA 0.3410 33 Lethrinus obsoletus <1 <1 <1 0 0 0 NA 0.3410 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 0 0 0 NA 0.3410 36 Cantherhines pardalis 0 0 0 <1 <1 <1 NA 0.3410 37 Oxymonacanthus longirostris <1 <1 <1 0 0 0 NA 0.3410 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 1 2 4 0 0 0 NA 0.0619 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 0 0 0 NA 0.0646 41 Parapercis xanthozona <1 <1 <1 0 0 0 NA 0.3410 42 Plotosidae Plotosus lineatus 0 0 0 25 61 3750 NA 0.3410 43 Pomacanthidae Centropyge multispinis 1 1 1 0 0 0 NA 0.0136# 44 Pomacanthus semicirculatus <1 <1 <1 0 0 0 NA 0.3410 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster 1 1 1 0 0 0 NA 0.0816 47 Amphiprion akallopisos – – – – – – – – 48 Chromis atripectoralis 2 5 27 0 0 0 NA 0.2141 49 Chromis dimidiata <1 <1 <1 0 0 0 NA 0.3410 50 Chromis nigrura <1 2 4 0 0 0 NA 0.3410 51 Chromis viridis 8 21 450 0 0 0 NA 0.3410 52 Chromis weberi <1 1 1 0 0 0 NA 0.1560 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.3410 55 Neoglyphidodon melas – – – – – – – – 56 Plectroglyphidodon dickii 1 1 2 0 0 0 NA 0.0552 57 Plectroglyphidodon johnstonianus <1 <1 <1 0 0 0 NA 0.3410 58 Plectroglyphidodon lacrymatus 4 3 9 0 0 0 NA 0.0055 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus 0 0 0 <1 <1 <1 NA 0.3410 61 Scaridae Calotomus carolinus <1 <1 <1 0 0 0 NA 0.3410 62 Chlorurus sordidus 6 7 53 <1 1 1 0.0012# 0.0838 63 Leptoscarus vaigiensis 0 0 0 <1 <1 <1 NA 0.1740 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.3410 66 Scarus ghobban <1 <1 <1 0 0 0 NA 0.3410 67 Scarus niger <1 <1 <1 0 0 0 NA 0.3410 68 Scarus tricolor <1 <1 <1 0 0 0 NA 0.3410 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.1739 # 71 Siganidae Siganus sutor <1 <1 <1 38 67 4565 2.798*10−09 0.1950 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 4 5 32 NA 0.0828 73 Tetraodontidae Canthigaster bennetti <1 <1 <1 0 0 0 NA 0.3410 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 1 1 1 <1 1 2 0.7190 0.3620

Nine species were absent during sunset in a neap cycle in the coral reef, e.g. Sphyraena flavicauda, and Cheilio inermis. Only Cheilio inermis showed a significant difference between its mean abundances (figure 3.12). 40 species were absent during sunset in a neap cycle in the seagrass bed. Acanthurus leucosternon, Ctenochaetus binotatus, Ctenochaetus striatus, Chaetodon trifascialis, Gomphosus caeruleus and Plectroglyphidodon lacrymatus had significant distinctions of their means of abundance (figure 3.12). Chaetodon trifasciatus and Centropyge multispinis had also significant differences between their means of abundance, but the boxplots for both species showed outliers (appendix A, figure A.19 & figure A.20). Thalassoma hebraicum, Chlorurus sordidus and Siganus sutor were present in both habitats during sunset in neap cycles. Thalassoma hebraicum had a significantly higher mean of abundance in the coral reef, but the boxplot showed an outlier (appendix A, figure A.20). Chloru- rus sordidus had a significantly higher variance in the coral reef, but the boxplot for this species showed also an outlier (appendix A, figure A.20). Siganus sutor had a significantly higher variance in the seagrass bed, but the boxplot showed an outlier (appendix A, figure A.20).

45 10

-5 s n

a Acanthurus nigrofuscus Gomphosus caeruleus e -10 m

Ctenochaetus binotatus Thalassoma hebraicum f o -15 Ctenochaetus striatus Plectroglyphidodon e

c lacrymatus n e

r -20 Chaetodon trifascialis Chlorurus sordidus e f f i Chaetodon trifasciatus Siganus sutor d -25 Cheilio inermis

-30

-35

-40 species of special interest

Figure 3.12: Distinctions in means of abundance for species of special interest with a significant difference for both habitat types during sunset in a neap cycle. Positive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed.

3.2.14. Comparison of different times in a neap cycle in the coral reef

The observation revealed that 15 species were absent during different times in a neap cycle in the coral reef, e.g. Leptoscarus vaigiensis, Lethrinus harak, Lethrinus mahsena, Cheilio inermis, and Plectorhinchus ﬂavomaculatus (table 3.15).

Table 3.15: Overview of the analysis of 75 species for the comparison between different times during a neap cycle in the coral reef in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for CRSSN from siy quadrats and for CRLN from four quadrats. CRSSN CRLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 2 5 <1 1 2 0.4925 0.5900 2 Acanthurus nigrofuscus 1 <1 <1 <1 1 1 0.7698 0.4320 3 Ctenochaetus binotatus 2 1 2 2 1 3 0.5756 1.0000 4 Ctenochaetus striatus 3 2 5 1 1 1 0.3672 0.1350 5 Ctenochaetus truncatus <1 <1 <1 0 0 0 NA 0.2420 6 Zebrasoma scopas 1 3 13 1 1 1 0.0893 0.7350 7 Balistidae Sufflamen chrysopterum <1 <1 <1 0 0 0 NA 0.4470 8 Blennidae Meiacanthus mossambicus 1 1 1 1 1 2 0.6879 0.4171 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga <1 <1 <1 0 0 0 NA 0.4470 11 Chaetodon guttatissimus 0 0 0 <1 <1 <1 NA 0.2420 12 Chaetodon kleinii 0 0 0 <1 <1 <1 NA 0.2420 13 Chaetodon trifascialis 2 1 3 1 1 3 0.9763 0.6730 14 Chaetodon trifasciatus 3 2 5 1 1 1 0.1762 0.1950 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 0 0 0 <1 <1 <1 NA 0.2420 18 Bodianus axillaris <1 1 1 0 0 0 NA 0.3120 19 Cheilinus trilobatus <1 <1 <1 0 0 0 NA 0.2750 20 Cheilio inermis – – – – – – – – 21 Gomphosus caeruleus 1 <1 <1 1 <1 <1 0.5325 0.2139 22 Halichoeres hortulanus <1 <1 <1 <1 <1 <1 0.4652 0.3122 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 <1 <1 <1 0.4652 0.3122 25 Labroides dimidiatus <1 <1 <1 <1 <1 <1 0.0970 0.2139 26 Pseudocheilinus hexataenia <1 <1 <1 <1 <1 <1 0.7033 0.8860 27 Stethojulis bandanensis 0 0 0 1 1 2 NA 0.0320 28 Thalassoma amblycephalum <1 1 1 0 0 0 NA 0.4470

46 29 Thalassoma hardwicke <1 1 1 <1 <1 <1 0.3672 0.7790 30 Thalassoma hebraicum 3 1 2 6 1 2 0.8740 0.0166 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena – – – – – – – – 33 Lethrinus obsoletus <1 <1 <1 0 0 0 NA 0.4470 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 <1 <1 <1 1 1 0.0825 0.4770 36 Cantherhines pardalis 0 0 0 <1 <1 <1 NA 0.0828 37 Oxymonacanthus longirostris <1 <1 <1 <1 1 1 0.0825 0.4770 38 Mullidae Parupeneus cyclostomus 0 0 0 <1 1 2 NA 0.2420 39 Parupeneus macronemus 1 2 4 <1 <1 <1 0.0374 0.3570 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 <1 <1 <1 0.4100 0.5620 41 Parapercis xanthozona <1 <1 <1 0 0 0 NA 0.4470 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 1 1 1 2 1 2 0.6173 0.5644 44 Pomacanthus semicirculatus <1 <1 <1 0 0 0 NA 0.4470 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster 1 1 1 0 0 0 NA 0.1600 47 Amphiprion akallopisos – – – – – – – – 48 Chromis atripectoralis 2 5 27 8 16 256 0.0342# 0.4730 49 Chromis dimidiata <1 <1 <1 <1 1 1 0.6443 0.7790 50 Chromis nigrura <1 2 4 <1 1 2 0.6492 0.9460 51 Chromis viridis 8 21 450 1 2 5 0.0044# 0.5280 52 Chromis weberi <1 1 1 3 3 12 0.0563 0.1633 53 Dascyllus aruanus 0 0 0 <1 1 2 NA 0.2420 54 Dascyllus trimaculatus <1 <1 <1 <1 <1 <1 0.6443 0.7790 55 Neoglyphidodon melas 0 0 0 <1 <1 <1 NA 0.2420 56 Plectroglyphidodon dickii 1 1 2 1 1 2 0.9801 0.7350 57 Plectroglyphidodon johnstonianus <1 <1 <1 <1 <1 <1 0.7033 0.4800 58 Plectroglyphidodon lacrymatus 4 3 9 3 2 4 0.5660 0.5507 59 Pomacentrus pavo 0 0 0 <1 1 2 NA 0.2420 60 Pomacentrus trilineatus 0 0 0 <1 <1 <1 NA 0.2420 61 Scaridae Calotomus carolinus <1 <1 <1 0 0 0 NA 0.4470 62 Chlorurus sordidus 6 7 53 7 6 48 0.9917 0.8350 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus 0 0 0 <1 <1 <1 NA 0.2420 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.4470 66 Scarus ghobban <1 <1 <1 0 0 0 NA 0.4470 67 Scarus niger <1 <1 <1 2 2 6 0.0017# 0.1013 68 Scarus tricolor <1 <1 <1 0 0 0 NA 0.4470 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.2750 71 Siganidae Siganus sutor <1 <1 <1 <1 <1 <1 0.4491 0.8610 72 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 73 Tetraodontidae Canthigaster bennetti <1 <1 <1 <1 <1 <1 0.4491 0.8610 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 1 1 1 3 2 5 0.2701 0.1271

Eleven species were absent during the sunset, e.g. Chaetodon guttatissimus, Dascyllus aruanus, and Stethojulis bandanensis. Only Stethojulis bandanensis had a significant difference in its means of abundance (figure 3.13). 15 species were absent during low tide at day, e.g. Cheilinus trilobatus, Thalassoma amblycephalum, and Amblyglyphidodon leucogaster. No one of these species displayed significant differences for their means of abundance or variances. Thalassoma hebraicum was present in both times and indicated a significantly higher mean of abundance during low tide in the coral reef. Parupeneus macronemus was also present during both times and had a significantly higher variance during sunset. The same presence showed Chromis atripectoralis and Scarus niger. Both displayed significantly higher variances during low tide at day, but the boxplots showed outliers for both species (appendix A, figure A.21). Chromis viridis was also present during both times and had a significantly higher variance during sunset, but the boxplot showed also an outlier (appendix A, figure A.21). Ctenochaetus binotatus revealed a high non-significant p-value for its means of abundance.

47 8

4 s n a

e Stethojulis bandanensis m

2 f Thalassoma hebraicum o

e Parupeneus macronemus c

n 0

e Chromis atripectoralis r e

f Chromis viridis f i d -2 Scarus niger

-4

-6 species of special interest

Figure 3.13: Distinctions in means of abundance for species of special interest with a signiﬁ- cant difference for different times during a neap cycle in the coral reef. Positive values = higher mean of abundance during sunset, negative values = higher mean of abundance during low tide at day.

3.2.15. Comparison of different times in a neap cycle in the seagrass bed

49 species were absent during both times in a neap cycle in the seagrass bed, e.g. Gompho- sus caeruleus, and most chaetodontids except of Chaetodon kleinii (table 3.16).

Table 3.16: Overview of the analysis of 75 species for the comparison between different times during a neap cycle in the seagrass bed in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p- values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for SBSSN from six quadrats and for SBLN from four quadrats. SBSSN SBLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 1 1 0 0 0 NA 0.4470 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 0 0 0 <1 <1 <1 NA 0.2420 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 0 0 0 1 1 2 NA 0.1114 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii 0 0 0 <1 <1 <1 NA 0.2420 13 Chaetodon trifascialis – – – – – – – – 14 Chaetodon trifasciatus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus <1 <1 <1 <1 <1 <1 0.4491 0.3930 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus <1 <1 <1 0 0 0 NA 0.2750 20 Cheilio inermis 1 1 1 <1 <1 <1 0.5824 0.3750 21 Gomphosus caeruleus – – – – – – – – 22 Halichoeres hortulanus 0 0 0 <1 <1 <1 NA 0.2420 23 Halichoeres nebulosus 0 0 0 <1 <1 <1 NA 0.2420 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus <1 <1 <1 <1 <1 <1 0.7371 0.6730 26 Pseudocheilinus hexataenia <1 <1 <1 0 0 0 NA 0.4470 27 Stethojulis bandanensis <1 <1 <1 0 0 0 0.0055# 0.0105# 28 Thalassoma amblycephalum – – – – – – – – 29 Thalassoma hardwicke <1 <1 <1 0 0 0 NA 0.2750

48 30 Thalassoma hebraicum <1 1 2 1 <1 <1 0.2964 0.8540 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena <1 <1 <1 1 1 1 0.0331# 0.0794 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis <1 <1 <1 <1 1 1 0.6443 0.7790 37 Oxymonacanthus longirostris – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 0 0 0 1 1 1 NA 0.0598 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus 25 61 3750 0 0 0 NA 0.4470 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos 0 0 0 <1 <1 <1 NA 0.2420 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata – – – – – – – – 50 Chromis nigrura – – – – – – – – 51 Chromis viridis 0 0 0 7 11 143 NA 0.1644 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas – – – – – – – – 56 Plectroglyphidodon dickii – – – – – – – – 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus – – – – – – – – 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus <1 <1 <1 1 1 2 0.2235 0.2415 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus <1 1 1 4 5 27 0.0078# 0.1117 63 Leptoscarus vaigiensis <1 <1 <1 <1 <1 <1 0.5749 1.0000 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus – – – – – – – – 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor 38 67 4565 1 2 8 0.0002# 0.3160 72 Sphyraenidae Sphyraena ﬂavicauda 4 5 32 <1 1 2 0.0517 0.2430 73 Tetraodontidae Canthigaster bennetti – – – – – – – – 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini <1 1 2 <1 1 1 0.4491 0.8610

Eight species were absent during sunset in the seagrass bed, e.g. Chaetodon kleinii, Paru- peneus macronemus, and Chromis viridis. No species displayed significant differences for their means of abundance or variances during sunset. Six species were absent during low tide at day, e.g. Thalassoma hardwicke, Pseudocheili- nus hexataenia, and Stethojulis bandanensis. Only Stethojulis bandanensis had a significant difference between their variances (figure 3.14), but the boxplot for Stethojulis bandanensis showed an outlier (appendix A, figure A.22). Lethrinus mahsena, Chlorurus sordidus and Siganus sutor were present during both times. Lethrinus mahsena and Chlorurus sordidus displayed significantly higher variances during low tide at day, but the boxplots showed outliers for both (appendix A, figure A.22). Siganus sutor had a significantly higher variance during sunset, but also the boxplot showed an outlier (appendix A, figure A.22). Leptoscarus vaigiensis had a high non-significant p-value for its means of abundance.

49 40

30 s

n 25 a e m

f 20 Stethojulis bandanensis o

e Lethrinus mahsena c

n 15

e Chlorurus sordidus r e

f Siganus sutor f i 10 d

-5 species of special interest

Figure 3.14: Distinctions in means of abundance for species of special interest with a sig- niﬁcant difference for different times during a neap cycle in the seagrass bed. Positive values = higher of mean abundance during sunset, negative values = higher mean of abundance during low tide at day.

3.2.16. Comparison of different habitat types during sunset in a spring cycle

The observation showed that 19 species were absent during sunset in a spring cycle in both habitats, e.g. Calotomus carolinus, Lethrinus harak, Halichoeres hortulanus, and Chaetodon guttatissimus (table 3.17).

Table 3.17: Overview of the analysis of 75 species for the comparison between both habitat types during sunset in a spring cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from six quadrats. CRSSS SBSSS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 2 8 <1 <1 <1 0.0005# 0.2065 2 Acanthurus nigrofuscus <1 <1 <1 0 0 0 NA 0.3410 3 Ctenochaetus binotatus <1 <1 <1 0 0 0 NA 0.0734 4 Ctenochaetus striatus 2 3 13 0 0 0 NA 0.1009 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas <1 <1 <1 0 0 0 NA 0.3410 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 1 1 3 0 0 0 NA 0.0531 9 Carangidae Scomberoides lysan 0 0 0 3 5 32 NA 0.1470 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 1 1 1 0 0 0 NA 0.0816 14 Chaetodon trifasciatus 1 1 3 0 0 0 NA 0.0531 15 Ephippidae Platax teira 1 <1 <1 0 0 0 NA 0.0031# 16 Haemulidae Plectorhinchus flavomaculatus <1 <1 <1 <1 <1 <1 0.6186 0.5490 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus 0 0 0 <1 <1 <1 NA 0.3410 20 Cheilio inermis 0 0 0 <1 1 1 NA 0.1560 21 Gomphosus caeruleus 1 1 1 0 0 0 NA 0.0136# 22 Halichoeres hortulanus – – – – – – – – 23 Halichoeres nebulosus 0 0 0 <1 <1 <1 NA 0.3410 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus <1 1 1 <1 2 4 0.2765 0.8670 26 Pseudocheilinus hexataenia 1 1 3 <1 <1 <1 0.0036# 0.0973 27 Stethojulis bandanensis <1 <1 <1 <1 1 1 0.0848 0.5490 28 Thalassoma amblycephalum <1 2 4 0 0 0 NA 0.3410

50 29 Thalassoma hardwicke – – – – – – – – 30 Thalassoma hebraicum 3 2 6 <1 <1 <1 0.0187 0.0721 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 0 0 0 1 1 1 NA 0.0346 33 Lethrinus obsoletus <1 1 2 0 0 0 NA 0.3410 34 Microdesmidae Ptereleotris sp 0 0 0 1 2 6 NA 0.3410 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis <1 <1 <1 <1 <1 <1 1.0000 1.0000 37 Oxymonacanthus longirostris <1 <1 <1 0 0 0 NA 0.3410 38 Mullidae Parupeneus cyclostomus <1 <1 <1 0 0 0 NA 0.3410 39 Parupeneus macronemus 1 1 1 0 0 0 NA 0.0571 40 Pinguipedidae Parapercis hexophtalma <1 1 1 0 0 0 NA 0.1114 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 1 1 2 0 0 0 NA 0.1048 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus <1 <1 <1 0 0 0 NA 0.3410 46 Amblyglyphidodon leucogaster <1 <1 <1 0 0 0 NA 0.0101 47 Amphiprion akallopisos <1 <1 <1 0 0 0 NA 0.3410 48 Chromis atripectoralis <1 1 2 <1 <1 <1 0.0086# 0.4840 49 Chromis dimidiata <1 1 2 0 0 0 NA 0.3410 50 Chromis nigrura <1 1 2 0 0 0 NA 0.3410 51 Chromis viridis 1 2 4 33 59 3497 4.787*10−07# 0.2150 52 Chromis weberi 4 6 40 0 0 0 NA 0.1401 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.3410 55 Neoglyphidodon melas <1 <1 <1 0 0 0 NA 0.3410 56 Plectroglyphidodon dickii 1 2 7 0 0 0 NA 0.2090 57 Plectroglyphidodon johnstonianus <1 1 2 0 0 0 NA 0.2310 58 Plectroglyphidodon lacrymatus 3 2 4 0 0 0 NA 0.0036 59 Pomacentrus pavo <1 <1 <1 0 0 0 NA 0.3410 60 Pomacentrus trilineatus <1 <1 <1 1 1 2 0.0382 0.2200 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 6 8 69 5 5 26 0.3192 0.6861 63 Leptoscarus vaigiensis 0 0 0 1 1 1 NA 0.0493 64 Scarus caudofasciatus <1 <1 <1 0 0 0 NA 0.3410 65 Scarus frenatus <1 <1 <1 <1 <1 <1 0.1413 0.4010 66 Scarus ghobban – – – – – – – – 67 Scarus niger <1 <1 <1 0 0 0 NA 0.3410 68 Scarus tricolor <1 2 4 0 0 0 NA 0.3410 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak <1 <1 <1 0 0 0 NA 0.0005# 71 Siganidae Siganus sutor <1 <1 <1 20 26 716 8.957*10−09# 0.0879 72 Sphyraenidae Sphyraena ﬂavicauda 28 69 4816 39 63 4057 0.8553 0.7770 73 Tetraodontidae Canthigaster bennetti <1 <1 <1 0 0 0 NA 0.0734 74 Canthigaster solandri <1 1 1 0 0 0 NA 0.3410 75 Canthigaster valentini 2 2 4 1 1 1 0.3554 0.1656

Seven species were absent during sunset in the coral reef, e.g. Lethrinus mahsena, and Leptoscarus vaigiensis. Both species displayed significant differences in their means of abundance (figure 3.15). 34 species were absent during sunset in a spring cycle in the seagrass bed. Amblyglyphi- dodon leucogaster and Plectroglyphidodon lacrymatus had significant differences between their means of abundance (figure 3.15). Platax teira, Gomphosus caeruleus and Cephalopho- lis boenak revealed also significant differences between their means of abundance, but the boxplots for these species showed outliers (appendix A, figure A.23 & figure A.25). Seven species which were present in both habitats during sunset showed significant differences between their variances. Thalassoma hebraicum had a significantly higher variance in the coral reef. Pomacentrus trilineatus displayed a significantly higher variance in the seagrass bed. Acanthurus leucosternon, Pseudocheilinus hexataenia and Chromis atripectoralis had significantly higher variances in the coral reef, but the boxplots for this three species showed outliers (appendix A, figure A.23 & figure A.24). Chromis viridis and Siganus sutor indicated significantly higher variances in the seagrass bed, but also the boxplots for these species showed outliers (appendix A, figure A.24 & figure A.25).

51 5 5

0 0

Acanthurus leucosternon -5 -5 Gomphosus caeruleus Pseudocheilinus hexataenia Acanthurus leucosternon

s Thalassoma hebraicum n Gomphosus caeruleus a s -10 Lethrinus mahsena n

e -10

a Chromis viridis Pseudocheilinus e m

m f Plectroglyphidodon lacrymatus

hexataenia f o o Leptoscarus vaigiensis -15 e e -15 Thalassoma hebraicum

c Siganus sutor c n n e

r Lethrinus mahsena e e r f f i e -20-20 f

d Chromis viridis f i

d Plectroglyphidodon

-25-25 lacrymatus Leptoscarus vaigiensis

-30-30 Siganus sutor

-35 -35 speciesspecies of special of special interest interest

Figure 3.15: Distinctions in means of abundance for species of special interest with a sig- niﬁcant difference for both habitat types during sunset in a spring cycle. Pos- itive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed. The distinctions of Amblyg- lyphidodon leucogaster, Chromis atripectoralis and Pomacentrus trilineatus were smaller than one.

3.2.17. Comparison of different times in a spring cycle in the coral reef

18 species were absent during both times in a spring cycle in the coral reef, e.g. Chaetodon guttatissimus, Cheilio inermis, Lethrinus harak, and Lethrinus mahsena (table 3.18).

Table 3.18: Overview of the analysis of 75 species for the comparison between different times during a spring cycle in the coral reef in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for CRSSS from six quadrats and for CRHS from four quadrats. CRSSS CRHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 1 2 8 <1 1 1 0.1007 0.4230 2 Acanthurus nigrofuscus <1 <1 <1 0 0 0 NA 0.4470 3 Ctenochaetus binotatus <1 <1 <1 <1 <1 <1 0.6031 0.7350 4 Ctenochaetus striatus 2 3 13 2 1 2 0.2211 0.7420 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas <1 <1 <1 0 0 0 NA 0.4470 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 1 1 3 <1 <1 <1 0.3027 0.3960 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis 1 1 1 1 1 1 0.7418 0.5274 14 Chaetodon trifasciatus 1 1 3 2 1 1 0.5515 0.6013 15 Ephippidae Platax teira 1 <1 <1 <1 <1 <1 0.7418 0.0828 16 Haemulidae Plectorhinchus flavomaculatus <1 <1 <1 0 0 0 NA 0.4470 17 Labridae Anampses twistii 0 0 0 <1 <1 <1 NA 0.2420 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus – – – – – – – – 20 Cheilio inermis – – – – – – – – 21 Gomphosus caeruleus 1 1 1 2 2 8 0.1251 0.4522 22 Halichoeres hortulanus 0 0 0 1 1 1 NA 0.0053 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus 0 0 0 <1 <1 <1 NA 0.2420 25 Labroides dimidiatus 0 1 1 2 1 2 0.7090 0.1483 26 Pseudocheilinus hexataenia 1 1 3 1 2 5 0.6599 0.9070 27 Stethojulis bandanensis <1 <1 <1 1 1 2 0.0423 0.1954

52 28 Thalassoma amblycephalum <1 2 4 1 2 4 0.9592 0.9020 29 Thalassoma hardwicke 0 0 0 <1 <1 <1 NA 0.2420 30 Thalassoma hebraicum 3 2 6 6 5 30 0.1226 0.1795 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena – – – – – – – – 33 Lethrinus obsoletus <1 1 2 0 0 0 NA 0.4470 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas 0 0 0 <1 <1 <1 NA 0.2420 36 Cantherhines pardalis <1 <1 <1 <1 <1 <1 0.6443 0.7790 37 Oxymonacanthus longirostris <1 <1 <1 0 0 0 NA 0.4470 38 Mullidae Parupeneus cyclostomus <1 <1 <1 <1 <1 <1 0.4652 0.3122 39 Parupeneus macronemus 1 1 1 1 1 2 0.8403 0.8540 40 Pinguipedidae Parapercis hexophtalma <1 1 1 <1 <1 <1 0.2750 0.6160 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 1 1 2 <1 1 1 0.4679 0.4840 44 Pomacanthus semicirculatus 0 0 0 <1 <1 <1 NA 0.0598 45 Pomacentridae Abudefduf sexfasciatus <1 <1 <1 0 0 0 NA 0.4470 46 Amblyglyphidodon leucogaster <1 <1 <1 <1 <1 <1 0.7698 0.6450 47 Amphiprion akallopisos <1 <1 <1 <1 <1 <1 0.6443 0.7790 48 Chromis atripectoralis <1 1 2 0 0 0 NA 0.4470 49 Chromis dimidiata <1 1 2 <1 1 1 0.4491 0.8610 50 Chromis nigrura <1 1 2 1 2 6 0.3797 0.6640 51 Chromis viridis 1 2 4 <1 1 2 0.6744 0.8380 52 Chromis weberi 4 6 40 0 0 0 NA 0.2360 53 Dascyllus aruanus 0 0 0 <1 1 1 NA 0.2420 54 Dascyllus trimaculatus <1 <1 <1 <1 <1 <1 0.6443 0.7790 55 Neoglyphidodon melas <1 <1 <1 <1 1 1 0.0825 0.4770 56 Plectroglyphidodon dickii 1 2 7 0 0 0 NA 0.3140 57 Plectroglyphidodon johnstonianus <1 1 2 <1 1 1 0.4679 0.7230 58 Plectroglyphidodon lacrymatus 3 2 4 3 2 4 0.8920 0.7749 59 Pomacentrus pavo <1 <1 <1 1 2 4 0.0825 0.4770 60 Pomacentrus trilineatus <1 <1 <1 1 <1 <1 0.3479 0.1483 61 Scaridae Calotomus carolinus – – – – – – – – 62 Chlorurus sordidus 6 8 69 5 4 19 0.3215 0.7260 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus <1 <1 <1 2 2 4 0.0037# 0.0383# 65 Scarus frenatus <1 <1 <1 <1 <1 <1 0.4260 0.6100 66 Scarus ghobban – – – – – – – – 67 Scarus niger <1 <1 <1 <1 1 1 0.0825 0.4770 68 Scarus tricolor <1 2 4 0 0 0 NA 0.4470 69 Serranidae Anyperodon leucogrammicus 0 0 0 <1 1 2 NA 0.2420 70 Cephalopholis boenak <1 <1 <1 <1 <1 <1 0.6443 0.0767 71 Siganidae Siganus sutor <1 <1 <1 0 0 0 NA 0.4470 72 Sphyraenidae Sphyraena ﬂavicauda 28 69 4816 0 0 0 NA 0.4470 73 Tetraodontidae Canthigaster bennetti <1 <1 <1 1 <1 <1 0.9297 0.5450 74 Canthigaster solandri <1 1 1 <1 <1 <1 0.1712 0.7130 75 Canthigaster valentini 2 2 4 2 2 6 0.6602 0.9554

Eight species were absent during sunset in the coral reef, e.g. Dascyllus aruanus, Thalas- soma hardwicke, and Halichoeres hortulanus. Only Halichoeres hortulanus had a significant difference in its means of abundance (figure 3.16). Twelve species were absent during high tide at day in the coral reef, e.g. Plectorhinchus flavomaculatus, Chromis atripectoralis, Scarus tricolor and Siganus sutor. No species of this group had significant differences for their means of abundance or variances. Stethojulis bandanensis and Scarus caudofasciatus were present during both times. Stetho- julis bandanesis had a significantly higher variance during high tide at day in the coral reef. Scarus caudofasciatus had a significantly higher variance and mean of abundance during high tide at day, but the boxplot for this species showed an outlier (appendix A, figure A.26).

53 0 s

n -1 a e m

f o

e Halichoeres hortulanus c n

e Scarus caudofasciatus r e f f i -2 d

-3 species of special interest

Figure 3.16: Distinctions in means of abundance for species of special interest with a sig- niﬁcant difference for different times during a spring cycle in the coral reef. Positive values = higher mean of abundance during sunset, negative values = higher mean of abundance during high tide at day. The distinction of Stetho- julis bandanensis was smaller than one.

3.2.18. Comparison of different times in a spring cycle in the seagrass bed

45 species were absent during both times in a spring cycle in the seagrass bed, e.g. Scarus caudofasciatus, Plectroglyphidodon lacrymatus, Lethrinus harak, and all chaetodontids (table 3.19).

Table 3.19: Overview of the analysis of 75 species for the comparison between different times during a spring cycle in the seagrass bed in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p- values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for SBSSS from six quadrats and for SBHS from four quadrats. SBSSS SBHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon <1 <1 <1 <1 <1 <1 0.6443 0.7790 2 Acanthurus nigrofuscus 0 0 0 <1 <1 <1 NA 0.2420 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 0 0 0 1 1 2 NA 0.0320 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 0 0 0 <1 <1 <1 NA 0.0828 9 Carangidae Scomberoides lysan 3 5 32 0 0 0 NA 0.2440 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii – – – – – – – – 13 Chaetodon trifascialis – – – – – – – – 14 Chaetodon trifasciatus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus <1 <1 <1 <1 <1 <1 0.7698 0.6450 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus trilobatus <1 <1 <1 <1 <1 <1 0.7033 0.4800 20 Cheilio inermis <1 1 1 <1 <1 <1 0.1383 0.4330 21 Gomphosus caeruleus 0 0 0 <1 1 1 NA 0.2420 22 Halichoeres hortulanus – – – – – – – – 23 Halichoeres nebulosus <1 <1 <1 0 0 0 NA 0.4470 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus <1 2 4 1 1 2 0.5795 0.8910 26 Pseudocheilinus hexataenia <1 <1 <1 <1 <1 <1 0.6443 0.7790 27 Stethojulis bandanensis <1 1 1 4 6 44 0.0025# 0.2213

54 28 Thalassoma amblycephalum – – – – – – – – 29 Thalassoma hardwicke 0 0 0 <1 <1 <1 NA 0.2420 30 Thalassoma hebraicum <1 <1 <1 1 1 2 0.1719 0.5716 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 1 1 1 2 1 3 0.3598 0.3994 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis <1 <1 <1 0 0 0 NA 0.4470 37 Oxymonacanthus longirostris – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 0 0 0 <1 <1 <1 NA 0.2420 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus 0 0 0 <1 <1 <1 NA 0.2420 46 Amblyglyphidodon leucogaster – – – – – – – – 47 Amphiprion akallopisos – – – – – – – – 48 Chromis atripectoralis <1 <1 <1 0 0 0 NA 0.4470 49 Chromis dimidiata – – – – – – – – 50 Chromis nigrura – – – – – – – – 51 Chromis viridis 33 59 3497 9 13 174 0.0327# 0.4600 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas – – – – – – – – 56 Plectroglyphidodon dickii – – – – – – – – 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus – – – – – – – – 59 Pomacentrus pavo – – – – – – – – 60 Pomacentrus trilineatus 1 1 2 1 2 5 0.3335 0.6395 61 Scaridae Calotomus carolinus 0 0 0 <1 <1 <1 NA 0.0598 62 Chlorurus sordidus 0 0 0 <1 <1 <1 0.0683 0.2640 63 Leptoscarus vaigiensis 1 1 1 <1 <1 <1 0.8779 0.7210 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus <1 <1 <1 0 0 0 NA 0.4470 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor 0 0 0 <1 1 2 NA 0.2420 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor 20 26 716 6 8 64 0.0748 0.3290 72 Sphyraenidae Sphyraena ﬂavicauda 39 63 4057 <1 1 1 1.221*10−05 0.2650 73 Tetraodontidae Canthigaster bennetti – – – – – – – – 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 1 1 1 1 1 1 0.9913 0.9235

Ten species were absent during sunset in the seagrass bed, e.g. Meiacanthus mossambicus, Ctenochaetus striatus, Calotomus carolinus, and Chlorurus sordidus. Only Ctenochaetus striatus had a significant difference for its mean of abundance (figure 3.17). Five species were absent during high tide at day in the seagrass bed. These species were Scomberoides lysan, Halichoeres nebulosus, Cantherhines pardalis, Chromis atripectoralis and Scarus frenatus. No species of this group had significant differences for its means of abundance or variances. Stethojulis bandanensis, Chromis viridis and Sphyraena flavicauda were present during both times in a spring cycle in the seagrass bed. Stethojulis bandanensis had a significantly higher variance during high tide at day, but the boxplot showed an outlier (appendix A, figure A.27). Chromis viridis displayed a significantly higher variance during sunset, but the boxplot showed also an outlier (appendix A, figure A.27). Sphyraena flavicauda indicated a significantly higher variance during sunset (figure 3.17).

55 50

40 s

n 30 a e m

f Ctenochaetus striatus o 20 e Stethojulis bandanensis c n

e Chromis viridis r e

f Sphyraena flavicauda f i 10 d

-10 species of special interest

Figure 3.17: Distinctions in means of abundance for species of special interest with a sig- niﬁcant difference for different times during a spring cycle in the seagrass bed. Positive values = higher mean of abundance during sunset, negative values = higher mean of abundance during high tide at day.

3.2.19. Comparison of different habitat types during sunrise in a neap cycle

The observation showed that 26 species were absent in both habitats during sunrise in a neap cycle, e.g. all lethrinids, Dascyllus aruanus, Leptoscarus vaigiensis, and Scarus niger (table 3.20).

Table 3.20: Overview of the analysis of 75 species for the comparison between both habitat types during sunrise in a neap cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from three quadrats. CRSRN SBSRN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 2 3 9 <1 <1 <1 0.0690 0.2630 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus <1 <1 <1 0 0 0 NA 0.3740 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum <1 <1 <1 0 0 0 NA 0.3740 8 Blennidae Meiacanthus mossambicus 4 2 7 0 0 0 NA 0.0589 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus <1 <1 <1 0 0 0 NA 0.3740 12 Chaetodon kleinii <1 <1 <1 0 0 0 NA 0.3740 13 Chaetodon trifascialis 1 1 1 0 0 0 NA 0.1161 14 Chaetodon trifasciatus 2 0 0 0 0 0 NA <2*e−16 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0 0 0 <1 1 1 NA 0.3740 17 Labridae Anampses twistii <1 <1 <1 0 0 0 NA 0.3740 18 Bodianus axillaris <1 <1 <1 0 0 0 NA 0.3740 19 Cheilinus trilobatus 0 0 0 <1 1 1 NA 0.3740 20 Cheilio inermis 0 0 0 <1 <1 <1 NA 0.3740 21 Gomphosus caeruleus 1 1 2 0 0 0 NA 0.2051 22 Halichoeres hortulanus <1 <1 <1 0 0 0 NA 0.3740 23 Halichoeres nebulosus – – – – – – – – 24 Hemigymnus fasciatus <1 <1 <1 0 0 0 NA 0.3740 25 Labroides dimidiatus 1 1 1 1 2 5 0.3158 0.8300 26 Pseudocheilinus hexataenia <1 1 1 0 0 0 NA 0.3740 27 Stethojulis bandanensis <1 <1 <1 5 5 30 0.0217 0.1710 28 Thalassoma amblycephalum 1 2 5 0 0 0 NA 0.3740

56 29 Thalassoma hardwicke 0 0 0 <1 1 1 NA 0.3740 30 Thalassoma hebraicum 3 2 4 2 1 3 0.8182 0.4418 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena – – – – – – – – 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas <1 1 1 0 0 0 NA 0.3740 36 Cantherhines pardalis 1 1 1 2 0 0 NA 0.1583 37 Oxymonacanthus longirostris <1 1 1 0 0 0 NA 0.3740 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 1 1 2 <1 <1 <1 0.2500 0.3486 40 Pinguipedidae Parapercis hexophtalma <1 1 1 0 0 0 NA 0.3740 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 2 2 4 0 0 0 NA 0.1242 44 Pomacanthus semicirculatus – – – – – – – – 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster <1 <1 <1 <1 <1 <1 1.0000 1.0000 47 Amphiprion akallopisos <1 <1 <1 <1 <1 <1 1.0000 1.0000 48 Chromis atripectoralis 10 17 300 8 14 208 0.8197 0.9040 49 Chromis dimidiata <1 <1 <1 0 0 0 NA 0.3740 50 Chromis nigrura – – – – – – – – 51 Chromis viridis 28 17 316 60 19 376 0.9129 0.0979 52 Chromis weberi – – – – – – – – 53 Dascyllus aruanus – – – – – – – – 54 Dascyllus trimaculatus – – – – – – – – 55 Neoglyphidodon melas 1 1 2 0 0 0 NA 0.1318 56 Plectroglyphidodon dickii 1 1 1 0 0 0 NA 0.1583 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus 2 1 1 0 0 0 NA 0.0257 59 Pomacentrus pavo 1 2 8 0 0 0 NA 0.3740 60 Pomacentrus trilineatus 1 1 1 2 1 3 0.5000 0.4350 61 Scaridae Calotomus carolinus 1 1 3 0 0 0 NA 0.3740 62 Chlorurus sordidus 6 5 32 <1 <1 <1 0.0204 0.1611 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus 2 2 7 0 0 0 NA 0.2610 65 Scarus frenatus 1 1 1 0 0 0 NA 0.1583 66 Scarus ghobban – – – – – – – – 67 Scarus niger – – – – – – – – 68 Scarus tricolor <1 1 1 0 0 0 NA 0.3740 69 Serranidae Anyperodon leucogrammicus <1 <1 <1 0 0 0 NA 0.3740 70 Cephalopholis boenak 1 1 1 0 0 0 NA 0.1583 71 Siganidae Siganus sutor 0 0 0 19 9 91 NA 0.0261 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 11 9 90 NA 0.1080 73 Tetraodontidae Canthigaster bennetti 1 1 1 0 0 0 NA 0.1583 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 3 0 0 1 1 2 NA 0.1318

Six species were absent during sunrise in the coral reef, e.g. Siganus sutor, and Sphyraena flavicauda. Siganus sutor had a significant difference between its means of abundance (figure 3.18). 30 species were absent during sunrise in the seagrass bed, e.g. Chaetodon trifasciatus, and Plectroglyphidodon lacrymatus. Both had significant differences for their means of abundance. Stethojulis bandanensis and Chlorurus sordidus were present in both habitats during sunrise. Stethojulis bandanensis had a significantly higher variance in the seagrass bed (figure 3.18). Chlorurus sordidus displayed a significantly higher variance in the coral reef (figure 3.18). Amblyglyphidodon leucogaster and Amphiprion akallopisos inidicated both high non-significant p-values for their means of abundance.

57 10

0 s n a

e Chaetodon trifasciatus m

-5 f Stethojulis bandanensis o

e Plectroglyphidodon c

n -10 lacrymatus e r e

f Chlorurus sordidus f i d -15 Siganus sutor

-20

-25 species of special interest

Figure 3.18: Distinctions in means of abundance for species of special interest with a significant difference for both habitat types during sunrise in a neap cycle. Positive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed.

3.2.20. Comparison of different habitat types during sunrise in a spring cycle

28 species were absent in both habitats during sunrise in a spring cycle, e.g. Ctenochaetus striatus, Ctenochaetus truncatus, Chaetodon guttatissimus, Halichoeres hortulanus, and Thalas- soma hardwicke (table 3.21).

Table 3.21: Overview of the analysis of 75 species for the comparison between both habitat types during sunrise in a spring cycle in terms of abundance. Mean of abundance, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix A) showed at minimum one outlier between both samplings. The means were calculated for both samplings from three quadrats. CRSRS SBSRS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 2 3 12 <1 1 1 0.2000 0.5610 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus – – – – – – – – 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas 0 0 0 <1 1 1 NA 0.3740 7 Balistidae Sufflamen chrysopterum <1 1 1 0 0 0 NA 0.3740 8 Blennidae Meiacanthus mossambicus 2 0 0 <1 <1 <1 NA 0.0075 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon auriga – – – – – – – – 11 Chaetodon guttatissimus – – – – – – – – 12 Chaetodon kleinii <1 <1 <1 <1 <1 <1 1.0000 1.0000 13 Chaetodon trifascialis <1 1 1 0 0 0 NA 0.3740 14 Chaetodon trifasciatus 2 0 0 0 0 0 NA <2*e−16 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0 0 0 1 <1 <1 NA 0.0016 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris <1 <1 <1 0 0 0 NA 0.3740 19 Cheilinus trilobatus 0 0 0 <1 <1 <1 NA 0.3740 20 Cheilio inermis 0 0 0 1 2 5 NA 0.3740 21 Gomphosus caeruleus 1 1 1 <1 <1 <1 0.4000 0.2508 22 Halichoeres hortulanus – – – – – – – – 23 Halichoeres nebulosus 0 0 0 <1 <1 <1 NA 0.3740 24 Hemigymnus fasciatus – – – – – – – – 25 Labroides dimidiatus 1 1 3 1 1 2 0.8750 0.6430 26 Pseudocheilinus hexataenia – – – – – – – – 27 Stethojulis bandanensis 0 0 0 3 4 16 NA 0.1910 28 Thalassoma amblycephalum 1 2 8 0 0 0 NA 0.3740

58 29 Thalassoma hardwicke – – – – – – – – 30 Thalassoma hebraicum 3 1 3 1 1 2 0.8750 0.2794 31 Lethrinidae Lethrinus harak – – – – – – – – 32 Lethrinus mahsena 0 0 0 1 2 4 NA 0.2380 33 Lethrinus obsoletus – – – – – – – – 34 Microdesmidae Ptereleotris sp – – – – – – – – 35 Monacanthidae Amanses scopas – – – – – – – – 36 Cantherhines pardalis <1 1 1 <1 <1 <1 0.4000 0.6780 37 Oxymonacanthus longirostris 1 1 1 0 0 0 NA 0.1161 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 1 <1 <1 <1 <1 <1 1.0000 0.0474 40 Pinguipedidae Parapercis hexophtalma <1 <1 <1 0 0 0 NA 0.3740 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus 0 0 0 15 25 675 NA 0.3740 43 Pomacanthidae Centropyge multispinis <1 1 1 0 0 0 NA 0.3740 44 Pomacanthus semicirculatus <1 <1 <1 0 0 0 NA 0.3740 45 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 46 Amblyglyphidodon leucogaster <1 <1 <1 0 0 0 NA 0.1161 47 Amphiprion akallopisos <1 <1 <1 <1 <1 <1 1.0000 1.0000 48 Chromis atripectoralis 10 17 300 57 57 3306 0.1664 0.2440 49 Chromis dimidiata <1 <1 <1 0 0 0 NA 0.3740 50 Chromis nigrura <1 1 1 0 0 0 NA 0.3740 51 Chromis viridis 5 2 6 15 25 675 0.0186 0.5690 52 Chromis weberi 19 24 596 0 0 0 NA 0.2360 53 Dascyllus aruanus 1 1 3 0 0 0 NA 0.3740 54 Dascyllus trimaculatus <1 <1 <1 0 0 0 NA 0.3740 55 Neoglyphidodon melas <1 1 1 0 0 0 NA 0.3740 56 Plectroglyphidodon dickii <1 <1 <1 0 0 0 NA 0.3740 57 Plectroglyphidodon johnstonianus – – – – – – – – 58 Plectroglyphidodon lacrymatus 2 1 1 0 0 0 NA 0.0257 59 Pomacentrus pavo <1 <1 <1 0 0 0 NA 0.3740 60 Pomacentrus trilineatus 0 0 0 <1 <1 <1 NA 0.3740 61 Scaridae Calotomus carolinus <1 <1 <1 0 0 0 NA 0.1161 62 Chlorurus sordidus 6 7 57 3 3 10 0.3054 0.5620 63 Leptoscarus vaigiensis – – – – – – – – 64 Scarus caudofasciatus – – – – – – – – 65 Scarus frenatus – – – – – – – – 66 Scarus ghobban 0 0 0 1 2 5 NA 0.3740 67 Scarus niger <1 <1 <1 0 0 0 NA 0.1161 68 Scarus tricolor – – – – – – – – 69 Serranidae Anyperodon leucogrammicus – – – – – – – – 70 Cephalopholis boenak – – – – – – – – 71 Siganidae Siganus sutor <1 <1 <1 11 3 9 0.0690 0.0036 72 Sphyraenidae Sphyraena ﬂavicauda 0 0 0 2 2 7 NA 0.2610 73 Tetraodontidae Canthigaster bennetti 1 1 3 0 0 0 NA 0.3740 74 Canthigaster solandri – – – – – – – – 75 Canthigaster valentini 5 2 4 1 1 1 0.5000 0.0514

Eleven species were absent during sunrise in the coral reef, e.g. Plectorhinchus flavomaculatus, Pomacentrus trilineatus, Lethrinus mahsena, and Stethojulis bandanensis. Only Plectorhinchus flavomaculatus had a significant difference for its means of abundance (figure 3.19). 22 species were absent during sunrise in the seagrass bed, e.g. Chaetodon trifasciatus, Plectroglyphidodon lacrymatus, and Calotomus carolinus. Chaetodon trifasciatus and Plectro- glyphidodon lacrymatus had significant differences for their means of abundance (figure 3.19). Meiacanthus mossambicus, Parupeneus macronemus, Chromis viridis and Siganus sutor were present in both habitats during sunrise. Meiacanthus mossambicus and Parupeneus macronemus had significantly higher means of abundance in the coral reef. Chromis viridis displayed a significantly higher variance in the seagrass bed and Siganus sutor had a significantly higher mean of abundance in the seagrass bed (figure 3.19). Amphiprion akallopisos indicated a high non-significant p-value for its means of abundance.

59 4

0 s

n Chaetodon trifasciatus a

e -2 Plectorhinchus m

f flavomaculatus o

e -4 Parupeneus macronemus c n

e Chromis viridis r

e -6 f Plectroglyphidodon f i

d lacrymatus -8 Siganus sutor

-10

-12 species of special interest

Figure 3.19: Distinctions in means of abundance for species of special interest with a significant difference for both habitat types during sunrise in a spring cycle. Positive values = higher mean of abundance in the coral reef, negative values = higher mean of abundance in the seagrass bed.

3.3. Analysis in terms of biomass

3.3.1. Comparison of different habitat types during high tide in a neap cycle

The observation showed that 28 species were absent in both habitats during high tide in a neap cycle, e.g. Diodon liturosus, Plectorhinchus ﬂavomaculatus, Lutjanus bohar, Caloto- mus carolinus, and Scarus caudofasciatus (table 3.22).

Table 3.22: Overview of the analysis of 75 species for the comparison between both habitat types during high tide in a neap cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRHN SBHN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 341.45 320.34 102620.49 0.00 0.00 0.00 NA 0.0770 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus 157.02 205.11 42069.86 0.00 0.00 0.00 NA 0.1763 4 Ctenochaetus striatus 743.88 406.27 165056.53 146.79 293.59 86195.04 0.6066 0.0546 5 Ctenochaetus truncatus 37.35 74.70 5579.60 0.00 0.00 0.00 NA 0.3560 6 Zebrasoma scopas 300.00 464.48 215745.06 0.00 0.00 0.00 NA 0.2440 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 29.41 33.58 1127.35 0.49 0.98 0.96 8.881*10−05 0.1360 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 83.37 100.45 10089.89 7.67 15.35 235.59 0.0119 0.1871 11 Chaetodon trifascialis 47.67 41.24 1700.99 0.00 0.00 0.00 NA 0.0595 12 Chaetodon trifasciatus 348.34 130.36 16993.76 67.75 135.50 18359.48 0.9512 0.0245 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 12.40 24.81 615.35 0.00 0.00 0.00 NA 0.3560 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus 0.00 0.00 0.00 16.69 33.38 1114.29 NA 0.3560 20 Cheilinus trilobatus 0.00 0.00 0.00 77.94 89.99 8098.72 NA 0.1340 21 Cheilio inermis 0.00 0.00 0.00 26.83 33.26 1106.55 NA 0.1570 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 57.21 34.91 1219.04 0.00 0.00 0.00 NA 0.0174 24 Halichoeres hortulanus 128.11 186.01 34600.32 0.00 0.00 0.00 NA 0.2176 25 Hemigymnus fasciatus 135.20 190.44 36269.12 0.00 0.00 0.00 NA 0.2053

60 26 Hemigymnus melapterus 73.16 146.32 21409.69 0.00 0.00 0.00 NA 0.3560 27 Labroides dimidiatus 18.98 21.58 465.58 26.11 46.53 2165.22 0.2422 0.7870 28 Pseudocheilinus hexataenia 24.06 37.90 1436.66 0.00 0.00 0.00 NA 0.2490 29 Stethojulis bandanensis 101.95 79.49 6319.09 131.99 261.28 68268.33 0.0817 0.8330 30 Thalassoma hardwicke 0.00 0.00 0.00 46.07 61.40 3770.08 NA 0.1840 31 Thalassoma hebraicum 548.77 266.23 70878.22 327.74 302.32 91398.66 0.8383 0.3146 32 Lethrinidae Lethrinus harak 128.10 256.19 65635.60 278.21 556.42 309601.20 0.2344 0.6410 33 Lethrinus mahsena 0.00 0.00 0.00 97.69 37.60 1413.89 NA 0.0020 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 4.09 8.18 66.97 0.00 0.00 0.00 NA 0.3560 37 Cantherhines pardalis 0.00 0.00 0.00 135.88 159.43 25418.64 NA 0.1390 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 86.07 89.65 8036.87 2.92 5.84 34.09 0.0010 0.1149 40 Pinguipedidae Parapercis hexophtalma 96.84 112.73 12708.61 0.00 0.00 0.00 NA 0.1366 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 156.31 159.59 25469.04 0.00 0.00 0.00 NA 0.0977 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 8.59 17.18 295.31 0.00 0.00 0.00 NA 0.3560 49 Chromis dimidiata 13.86 27.72 768.39 0.00 0.00 0.00 NA 0.3560 50 Chromis viridis 209.55 419.10 175647.79 139.73 279.46 78095.12 0.5232 0.7910 51 Chromis weberi 998.15 1816.22 3298642.87 0.00 0.00 0.00 NA 0.3140 52 Neoglyphidodon melas 6.93 13.86 192.10 0.00 0.00 0.00 NA 0.3560 53 Plectroglyphidodon dickii 34.57 69.14 4780.61 0.00 0.00 0.00 NA 0.3560 54 Plectroglyphidodon lacrymatus 233.13 198.16 39268.10 0.00 0.00 0.00 NA 0.0569 55 Pomacentrus trilineatus 118.20 93.09 8666.52 66.03 114.33 13071.03 0.7491 0.5050 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 323.05 427.42 182689.63 1306.03 1564.79 2448565.23 0.0609 0.2710 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 0.00 0.00 0.00 89.81 119.34 14241.66 NA 0.1830 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus 50.13 54.13 2929.63 76.60 153.20 23471.65 0.1213 0.7570 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber 31.85 63.70 4057.65 0.00 0.00 0.00 NA 0.3560 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus 43.15 86.30 7447.36 0.00 0.00 0.00 NA 0.3560 69 Cephalopholis boenak 33.10 66.20 4382.14 0.00 0.00 0.00 NA 0.3560 70 Siganidae Siganus sutor 0.00 0.00 0.00 1325.00 1811.15 3280275.03 NA 0.1940 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 19.71 39.42 1553.92 NA 0.3560 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 77.26 92.40 8537.47 0.00 0.00 0.00 NA 0.1455 74 Canthigaster valentini 162.43 46.51 2162.78 79.68 54.83 3006.71 0.7859 0.0607 75 Zanclidae Zanclus cornutus – – – – – – – –

Nine species were absent in the coral reef, e.g. Lethrinus mahsena, Cheilinus trilobatus, and Cheilio inermis. Lethrinus mahsena had a significant difference for its variance (figure 3.20). 24 species were absent in the seagrass bed, e.g. Acanthurus leucosternon, Chaetodon trifascialis, and Gomphosus caeruleus. Only Gomphosus caeruleus had a significant difference for its means of biomass (figure 3.20). Meiacanthus mossambicus, Chaetodon guttatissimus, Chaetodon trifasciatus and Parupeneus macronemus were present in both habitat types during high tide in a neap cycle. Chaetodon trifasciatus had a significantly higher mean of biomass in the coral reef (figure 3.20). Meiacanthus mossambicus, Chaetodon guttatissimus and Parupeneus macronemus had significantly higher variances in the coral reef.

61 300

250 ] ²

m 200 5 2 / g [ 150 s

n Chaetodon guttatissimus a

e Chaetodon trifasciatus

m 100

f Gomphosus caeruleus o

e Lethrinus mahsena c 50 n

e Parupeneus macronemus r e f f

i 0 d

-50

-100 species of special interest

Figure 3.20: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during high tide in a neap cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed.

3.3.2. Comparison of different habitat types during high tide in a spring cycle

25 species were absent in both habitats during high tide in a spring cycle, e.g. Chaetodon guttatissimus, Diodon liturosus, and Lethrinus harak (table 3.23).

Table 3.23: Overview of the analysis of 75 species for the comparison between both habitat types during high tide in a spring cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both sampling from four quadrats. CRHS SBHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 64.63 129.26 16707.68 19.48 38.97 1518.44 0.0794 0.5280 2 Acanthurus nigrofuscus 0.00 0.00 0.00 57.26 114.53 13116.57 NA 0.3560 3 Ctenochaetus binotatus 153.18 191.72 36756.88 0.00 0.00 0.00 NA 0.1611 4 Ctenochaetus striatus 356.01 251.09 63045.75 364.39 383.93 147402.53 0.5034 0.9716 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 9.50 12.12 146.96 6.82 7.92 62.65 0.5370 0.7420 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis 63.12 27.75 769.79 0.00 0.00 0.00 NA 0.0038 12 Chaetodon trifasciatus 256.32 88.31 7798.79 0.00 0.00 0.00 NA 0.0012 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira 263.49 526.98 277708.60 0.00 0.00 0.00 NA 0.3560 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 471.54 711.19 505788.74 NA 0.2330 17 Labridae Anampses twistii 29.40 58.80 3457.44 0.00 0.00 0.00 NA 0.3560 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 0.00 0.00 0.00 94.30 148.21 21966.17 NA 0.2510 21 Cheilio inermis 0.00 0.00 0.00 3.60 7.20 51.85 NA 0.3560 22 Coris formosa 0.00 0.00 0.00 104.88 209.76 43997.58 NA 0.3560 23 Gomphosus caeruleus 101.70 110.72 12259.57 5.65 11.30 127.69 0.0037 0.1360 24 Halichoeres hortulanus 136.56 102.80 10567.12 0.00 0.00 0.00 NA 0.0379 25 Hemigymnus fasciatus 34.20 68.40 4678.56 0.00 0.00 0.00 NA 0.3560 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 17.62 12.46 155.22 18.39 36.12 1304.74 0.1075 0.9600 28 Pseudocheilinus hexataenia 31.35 61.37 3766.60 0.50 0.99 0.99 1.482*10−05 0.3540 29 Stethojulis bandanensis 67.48 97.54 9514.17 101.82 182.98 33480.76 0.3303 0.7520 30 Thalassoma hardwicke 13.65 27.30 745.38 32.42 64.85 4204.96 0.1914 0.6140

62 31 Thalassoma hebraicum 1360.93 1587.56 2520344.99 177.00 214.47 45995.30 0.0081 0.1898 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 0.00 0.00 0.00 130.26 118.91 14138.91 NA 0.0712 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar 0.00 0.00 0.00 36.90 73.80 5446.36 NA 0.3560 36 Monacanthidae Amanses scopas 14.01 28.01 784.82 0.00 0.00 0.00 NA 0.3560 37 Cantherhines pardalis 41.93 83.87 7033.35 0.00 0.00 0.00 NA 0.3560 38 Mullidae Parupeneus cyclostomus 49.60 57.27 3280.21 0.00 0.00 0.00 NA 0.1340 39 Parupeneus macronemus 132.62 153.71 23628.16 2.92 5.84 34.09 0.0002 0.1429 40 Pinguipedidae Parapercis hexophtalma 65.80 84.23 7093.95 0.00 0.00 0.00 NA 0.1692 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 47.42 94.84 8994.15 0.00 0.00 0.00 NA 0.3560 44 Pomacanthus semicirculatus 304.77 376.14 141484.71 0.00 0.00 0.00 NA 0.1562 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 0.00 0.00 0.00 27.79 55.58 3089.21 NA 0.3560 47 Amblyglyphidodon leucogaster 39.77 45.92 2108.74 0.00 0.00 0.00 NA 0.1340 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata 13.86 27.72 768.39 0.00 0.00 0.00 NA 0.3560 50 Chromis viridis 19.05 38.11 1452.18 400.08 471.31 222135.07 0.0018 0.1580 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas 7.85 15.69 246.31 0.00 0.00 0.00 NA 0.3560 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus 223.46 153.55 23577.84 0.00 0.00 0.00 NA 0.0269 55 Pomacentrus trilineatus 74.79 80.26 6442.38 89.57 114.77 13171.56 0.5714 0.8400 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 876.56 626.37 392339.01 0.00 0.00 0.00 NA 0.0312 58 Chlorurus strongylocephalus 83.38 166.76 27808.75 0.00 0.00 0.00 NA 0.3560 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 0.00 0.00 0.00 124.04 143.26 20524.27 NA 0.1340 61 Scarus caudofasciatus 233.00 201.51 40607.02 0.00 0.00 0.00 NA 0.0602 62 Scarus frenatus 31.76 63.53 4035.70 0.00 0.00 0.00 NA 0.3560 63 Scarus niger 86.52 173.03 29939.68 0.00 0.00 0.00 NA 0.3560 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber 68.53 137.07 18787.06 0.00 0.00 0.00 NA 0.3560 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus 90.67 181.35 32887.26 0.00 0.00 0.00 NA 0.3560 69 Cephalopholis boenak 33.10 66.20 4382.14 0.00 0.00 0.00 NA 0.3560 70 Siganidae Siganus sutor 0.00 0.00 0.00 1764.39 2290.55 5246627.83 NA 0.1740 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 23.17 46.34 2147.85 NA 0.3560 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 46.00 40.87 1670.73 0.00 0.00 0.00 NA 0.0666 74 Canthigaster valentini 177.87 228.66 52285.79 94.21 83.23 6927.86 0.1314 0.5168 75 Zanclidae Zanclus cornutus – – – – – – – –

Eleven species were absent in the coral reef, e.g. Plectorhinchus flavomaculatus, Cheili- nus trilobatus, Lethrinus mahsena, Leptoscarus vaigiensis, and Siganus sutor. No one of these species had significant differences for its means of biomass or variance. 26 species were absent in the seagrass bed, e.g. Chaetodon trifascialis, Chaetodon trifasciatus, Halichoeres hortulanus, Plectroglyphidodon lacrymatus, and Chlorurus sordidus. All five species had a significant difference between their means of biomass (figure 3.21). Gomphosus caeruleus, Pseudocheilinus hexataenia, Thalassoma hebraicum and Parupeneus macronemus were present in both habitats. All four species had a significantly higher variance in the coral reef (figure 3.21). Chromis viridis was also present in both habitats and had a significantly higher variance in the seagrass bed (figure 3.21).

63 1300

1100 ]

² 900 Chaetodon trifascialis m

5 Chaetodon trifasciatus 2 / 700 g Gomphosus caeruleus [

s Halichoeres hortulanus n

a 500 Pseudocheilinus e m

hexataenia f

o 300 Thalassoma hebraicum e c

n Parupeneus macronemus

e 100 r Chromis viridis e f f i Plectroglyphidodon d -100 lacrymatus -300 Chlorurus sordidus

-500 species of special interest

Figure 3.21: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitats during high tide in a spring cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed.

3.3.3. Comparison of different cycles during high tide in the coral reef

The observation showed that 28 species were absent during high tide in both cycles in the coral reef, e.g. Diodon liturosus, Cheilio inermis, Lethrinus mahsena, Lutjanus bohar, and Lep- toscarus vaigiensis (table 3.24).

Table 3.24: Overview of the analysis of 75 species for the comparison between both cycles during high tide in the coral reef in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRHN CRHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 341.45 320.34 102620.49 64.63 129.26 16707.68 0.1710 0.1603 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus 157.02 205.11 42069.86 153.18 191.72 36756.88 0.9157 0.9800 4 Ctenochaetus striatus 743.88 406.27 165056.53 356.01 251.09 63045.75 0.4500 0.1556 5 Ctenochaetus truncatus 37.35 74.70 5579.60 0.00 0.00 0.00 NA 0.3560 6 Zebrasoma scopas 300.00 464.48 215745.06 0.00 0.00 0.00 NA 0.2440 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 29.41 33.58 1127.35 9.50 12.12 146.96 0.1244 0.3060 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 83.37 100.45 10089.89 0.00 0.00 0.00 NA 0.1479 11 Chaetodon trifascialis 47.67 41.24 1700.99 63.12 27.75 769.79 0.5260 0.5564 12 Chaetodon trifasciatus 348.34 130.36 16993.76 256.32 88.31 7798.79 0.5367 0.2875 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira 0.00 0.00 0.00 263.49 526.98 277708.60 NA 0.3560 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 12.40 24.81 615.35 29.40 58.80 3457.44 0.1922 0.6150 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus – – – – – – – – 21 Cheilio inermis – – – – – – – – 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 57.21 34.91 1219.04 101.70 110.72 12259.57 0.0903 0.4710 24 Halichoeres hortulanus 128.11 186.01 34600.32 136.56 102.80 10567.12 0.3576 0.9390 25 Hemigymnus fasciatus 135.20 190.44 36269.12 34.20 68.40 4678.56 0.1270 0.3570 26 Hemigymnus melapterus 73.16 146.32 21409.69 0.00 0.00 0.00 NA 0.3560 27 Labroides dimidiatus 18.98 21.58 465.58 17.62 12.46 155.22 0.3706 0.9069 28 Pseudocheilinus hexataenia 24.06 37.90 1436.66 31.35 61.37 3766.60 0.4553 0.8520

64 29 Stethojulis bandanensis 101.95 79.49 6319.09 67.48 97.54 9514.17 0.7448 0.6035 30 Thalassoma hardwicke 0.00 0.00 0.00 13.65 27.30 745.38 NA 0.3560 31 Thalassoma hebraicum 548.77 266.23 70878.22 1360.93 1587.56 2520344.99 0.0152 0.3520 32 Lethrinidae Lethrinus harak 128.10 256.19 65635.60 0.00 0.00 0.00 NA 0.3560 33 Lethrinus mahsena – – – – – – – – 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 4.09 8.18 66.97 14.01 28.01 784.82 0.0688 0.5180 37 Cantherhines pardalis 0.00 0.00 0.00 41.93 83.87 7033.35 NA 0.3560 38 Mullidae Parupeneus cyclostomus 0.00 0.00 0.00 49.60 57.27 3280.21 NA 0.1340 39 Parupeneus macronemus 86.07 89.65 8036.87 132.62 153.71 23628.16 0.4005 0.6190 40 Pinguipedidae Parapercis hexophtalma 96.84 112.73 12708.61 65.80 84.23 7093.95 0.6442 0.6747 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 156.31 159.59 25469.04 47.42 94.84 8994.15 0.4178 0.2856 44 Pomacanthus semicirculatus 0.00 0.00 0.00 304.77 376.14 141484.71 NA 0.1560 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 0.00 0.00 0.00 39.77 45.92 2108.74 NA 0.1340 48 Chromis atripectoralis 8.59 17.18 295.31 0.00 0.00 0.00 NA 0.3560 49 Chromis dimidiata 13.86 27.72 768.39 13.86 27.72 768.39 1.0000 1.0000 50 Chromis viridis 209.55 419.10 175647.79 19.05 38.11 1452.18 0.0025 0.4000 51 Chromis weberi 998.15 1816.22 3298642.87 0.00 0.00 0.00 NA 0.3140 52 Neoglyphidodon melas 6.93 13.86 192.10 7.85 15.69 246.31 0.8711 0.9450 53 Plectroglyphidodon dickii 34.57 69.14 4780.61 0.00 0.00 0.00 NA 0.3560 54 Plectroglyphidodon lacrymatus 233.13 198.16 39268.10 223.46 153.55 23577.84 0.6853 0.9420 55 Pomacentrus trilineatus 118.20 93.09 8666.52 74.79 80.26 6442.38 0.8093 0.5060 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 323.05 427.42 182689.63 876.56 626.37 392339.01 0.5472 0.1950 58 Chlorurus strongylocephalus 0.00 0.00 0.00 83.38 166.76 27808.75 NA 0.3560 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 0.00 0.00 0.00 233.00 201.51 40607.02 NA 0.0602 62 Scarus frenatus 50.13 54.13 2929.63 31.76 63.53 4035.70 0.7976 0.6730 63 Scarus niger 0.00 0.00 0.00 86.52 173.03 29939.68 NA 0.3560 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber 31.85 63.70 4057.65 68.53 137.07 18787.06 0.2386 0.6440 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus 43.15 86.30 7447.36 90.67 181.35 32887.26 0.2548 0.6530 69 Cephalopholis boenak 33.10 66.20 4382.14 33.10 66.20 4382.14 1.0000 1.0000 70 Siganidae Siganus sutor – – – – – – – – 71 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 77.26 92.40 8537.47 46.00 40.87 1670.73 0.2166 0.5590 74 Canthigaster valentini 162.43 46.51 2162.78 177.87 228.66 52285.79 0.0262 0.8986 75 Zanclidae Zanclus cornutus – – – – – – – –

Nine species were absent in the spring cycle, e.g. Chaetodon guttatissimus, Zebrasoma scopas, and Hemigymnus melapterus. No one of these species had a significant difference for its means of biomass or variances. Eight species were absent in the neap cycle, e.g. Thalassoma hardwicke, Amblyglyphidodon leucogaster, and Scarus caudofasciatus. Also no species had a significant difference for its means of biomass or variances. Thalassoma hebraicum, Chromis viridis and Canthigaster valentini were present in both cycles. Thalassoma hebraicum had a significantly higher variance during the spring cycle (figure 3.22). Chromis viridis and Canthigaster valentini had significantly higher variances during the neap cycle (figure 3.22). Chromis dimidiata and Cephalopholis boenak had high non-significant p-values for their means of biomass.

65 200

0 ] ² m 5 2 / -200 g [

s n a e

m -400

Thalassoma hebraicum f o

Chromis viridis e c n

e -600 r e f f i d -800

-1000 species of special interest

Figure 3.22: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both cycles during high tide in the coral reef. Positive values = higher mean of biomass in the neap cycle, negative values = higher mean of biomass in the spring cycle.

3.3.4. Comparison of different cycles during high tide in the seagrass bed

44 species were absent during both cycles during high tide in the seagrass bed, e.g. Chaetodon trifasciatus, Diodon liturosus, Halichoeres hortulanus, Plectroglyphidodon lacrymatus, and Sca- rus caudofasciatus (table 3.25).

Table 3.25: Overview of the analysis of 75 species for the comparison between both cycles during high tide in the seagrass bed in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. SBHN SBHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 0.00 0.00 0.00 19.48 38.97 1518.44 NA 0.3560 2 Acanthurus nigrofuscus 0.00 0.00 0.00 57.26 114.53 13116.57 NA 0.3560 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 146.79 293.59 86195.04 364.39 383.93 147402.53 0.6697 0.4020 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 0.49 0.98 0.96 6.82 7.92 62.65 0.0062 0.1630 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 7.67 15.35 235.59 0.00 0.00 0.00 NA 0.3560 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus 67.75 135.50 18359.48 0.00 0.00 0.00 NA 0.3560 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 471.54 711.19 505788.74 NA 0.2330 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus 16.69 33.38 1114.29 0.00 0.00 0.00 NA 0.3560 20 Cheilinus trilobatus 77.94 89.99 8098.72 94.30 148.21 21966.17 0.4341 0.8580 21 Cheilio inermis 26.83 33.26 1106.55 3.60 7.20 51.85 0.0297 0.2182 22 Coris formosa 0.00 0.00 0.00 104.88 209.76 43997.58 NA 0.3560 23 Gomphosus caeruleus 0.00 0.00 0.00 5.65 11.30 127.69 NA 0.3560 24 Halichoeres hortulanus – – – – – – – – 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 26.11 46.53 2165.22 18.39 36.12 1304.74 0.6904 0.8020 28 Pseudocheilinus hexataenia 0.00 0.00 0.00 0.50 0.99 0.99 NA 0.3560

66 29 Stethojulis bandanensis 131.99 261.28 68268.33 101.82 182.98 33480.76 0.5720 0.8560 30 Thalassoma hardwicke 46.07 61.40 3770.08 32.42 64.85 4204.96 0.9309 0.7690 31 Thalassoma hebraicum 327.74 302.32 91398.66 177.00 214.47 45995.30 0.5870 0.4473 32 Lethrinidae Lethrinus harak 278.21 556.42 309601.20 0.00 0.00 0.00 NA 0.3560 33 Lethrinus mahsena 278.21 556.42 309601.20 130.26 118.91 14138.91 0.0897 0.6186 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar 0.00 0.00 0.00 36.90 73.80 5446.36 NA 0.3560 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 135.88 159.43 25418.64 0.00 0.00 0.00 NA 0.1391 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 2.92 5.84 34.09 2.92 5.84 34.09 1.0000 1.0000 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 0.00 0.00 0.00 27.79 55.58 3089.21 NA 0.3560 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 139.73 279.46 78095.12 400.08 471.31 222135.07 0.4132 0.3790 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 66.03 114.33 13071.03 89.57 114.77 13171.56 0.9931 0.7810 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 1306.03 1564.79 2448565.23 0.00 0.00 0.00 NA 0.1461 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 89.81 119.34 14241.66 124.04 143.26 20524.27 0.7716 0.7260 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus 76.60 153.20 23471.65 0.00 0.00 0.00 NA 0.3560 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 1325.00 1811.15 3280275.03 1764.39 2290.55 5246627.83 0.7089 0.7740 71 Sphyraenidae Sphyraena ﬂavicauda 19.71 39.42 1553.92 23.17 46.34 2147.85 0.7950 0.9120 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 79.68 54.83 3006.71 94.21 83.23 6927.86 0.5112 0.7811 75 Zanclidae Zanclus cornutus – – – – – – – –

Eight species were absent during the neap cycle, e.g. Acanthurus leucosternon, Gompho- sus caeruleus, and Lutjanus bohar. No one of these species had a significant difference for its means of biomass or variances. Seven species were absent during the spring cycle, e.g. Chlorurus sordidus, Chaetodon trifasciatus, and Lethrinus harak. But no significant differences occured. Meiacanthus mossambicus was present in both cycles and had a significantly higher variance during the spring cycle. Cheilio inermis was also present in both cycles and had a significantly higher variance in the neap cycle (figure 3.23). Parupeneus macronemus had a high non-significant p-value for its means of biomass.

67 25

] 20 ² m 5 2 / g [

s 15 n a e m

f Cheilio inermis o

e 10 c n e r e f f i d 5

0 species of special interest

Figure 3.23: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both cycles during high tide in the seagrass bed. Positive values = higher mean of biomass in the neap cycle, negative values = higher mean of biomass in the spring cycle.

3.3.5. Comparison of different habitat types during low tide in a neap cycle

The observation showed that 32 species were absent in both habitat types during low tide in a neap cycle, e.g. Diodon liturosus, Lethrinus harak, Lutjanus bohar, Calotomus carolinus, and Scarus frenatus (table 3.26).

Table 3.26: Overview of the analysis of 75 species for the comparison between both habitat types during low tide in a neap cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRLN SBLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 151.26 302.53 91522.20 0.00 0.00 0.00 NA 0.3560 2 Acanthurus nigrofuscus 80.80 161.60 26113.10 0.00 0.00 0.00 NA 0.3560 3 Ctenochaetus binotatus 434.01 318.39 101375.34 0.00 0.00 0.00 NA 0.0344 4 Ctenochaetus striatus 294.65 253.97 64501.69 49.29 98.57 9716.51 0.1543 0.1217 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas 157.96 182.39 33266.72 0.00 0.00 0.00 NA 0.1340 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 53.52 47.51 2257.41 9.99 12.98 168.56 0.0601 0.1268 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 7.67 15.35 235.59 0.00 0.00 0.00 NA 0.3560 11 Chaetodon trifascialis 83.37 99.15 9831.37 0.00 0.00 0.00 NA 0.1435 12 Chaetodon trifasciatus 203.25 135.50 18359.48 0.00 0.00 0.00 NA 0.0240 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 719.66 1439.31 2071625.69 NA 0.3560 17 Labridae Anampses twistii 12.40 24.81 615.35 0.00 0.00 0.00 NA 0.3560 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus – – – – – – – – 21 Cheilio inermis 0.00 0.00 0.00 76.54 140.97 19871.20 NA 0.3180 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 67.09 76.85 5906.33 0.00 0.00 0.00 NA 0.1327 24 Halichoeres hortulanus 41.83 55.84 3118.40 12.33 24.66 608.09 0.2093 0.3710 25 Hemigymnus fasciatus 101.00 128.20 16433.98 0.00 0.00 0.00 NA 0.1660 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 6.61 8.43 71.14 6.61 8.43 71.14 1.0000 1.0000 28 Pseudocheilinus hexataenia 12.41 15.85 251.16 0.00 0.00 0.00 NA 0.1656

68 29 Stethojulis bandanensis 59.38 45.27 2049.35 161.56 193.18 37317.20 0.0395 0.3420 30 Thalassoma hardwicke 36.46 62.62 3921.31 0.00 0.00 0.00 NA 0.2890 31 Thalassoma hebraicum 803.68 286.94 82333.29 74.53 97.40 9486.13 0.1097 0.0030 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 0.00 0.00 0.00 105.06 127.05 16141.64 NA 0.1500 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 47.55 95.09 9042.39 0.00 0.00 0.00 NA 0.3560 37 Cantherhines pardalis 125.80 160.59 25788.94 83.87 167.73 28133.39 0.9450 0.7300 38 Mullidae Parupeneus cyclostomus 98.04 196.08 38445.41 0.00 0.00 0.00 NA 0.3560 39 Parupeneus macronemus 121.32 101.69 10340.83 11.68 13.48 181.82 0.0073 0.0762 40 Pinguipedidae Parapercis hexophtalma 30.54 41.16 1693.91 0.00 0.00 0.00 NA 0.1885 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 245.00 208.72 43563.24 0.00 0.00 0.00 NA 0.0571 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 472.02 944.04 891209.32 0.00 0.00 0.00 NA 0.3560 49 Chromis dimidiata 13.86 27.72 768.39 0.00 0.00 0.00 NA 0.3560 50 Chromis viridis 38.11 60.48 3657.35 209.58 354.67 125790.88 0.0160 0.3770 51 Chromis weberi 215.61 342.08 117017.47 0.00 0.00 0.00 NA 0.2540 52 Neoglyphidodon melas 6.93 13.86 192.10 0.00 0.00 0.00 NA 0.3560 53 Plectroglyphidodon dickii 86.62 151.32 22898.41 0.00 0.00 0.00 NA 0.2960 54 Plectroglyphidodon lacrymatus 209.60 160.07 25622.70 0.00 0.00 0.00 NA 0.0393 55 Pomacentrus trilineatus 22.62 45.24 2046.63 50.34 68.87 4743.21 0.5024 0.5250 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 1445.78 835.77 698505.75 0.00 0.00 0.00 NA 0.0135 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 0.00 0.00 0.00 62.99 72.73 5289.59 NA 0.1340 61 Scarus caudofasciatus 83.38 166.76 27808.75 0.00 0.00 0.00 NA 0.3560 62 Scarus frenatus – – – – – – – – 63 Scarus niger 236.06 327.98 107569.60 0.00 0.00 0.00 NA 0.2000 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 105.89 211.79 44854.95 352.07 561.91 315743.39 0.1437 0.4440 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 4.43 8.86 78.50 NA 0.3560 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 23.89 47.78 2282.49 0.00 0.00 0.00 NA 0.3560 74 Canthigaster valentini 182.10 133.41 17799.46 43.50 87.00 7568.78 0.5006 0.1321 75 Zanclidae Zanclus cornutus – – – – – – – –

Five species were absent in the coral reef, e.g. Plectorhinchus flavomaculatus, Cheilio inermis, Lethrinus mahsena, Leptoscarus vaigiensis, and Sphyraena flavicauda. No species displayed a significant difference for its means of biomass or variance. 26 species were absent in the seagrass bed, e.g. Ctenochaetus binotatus, Chaetodon trifasciatus, Plectroglyphidodon lacrymatus, and Chlorurus sordidus. All four species had significant differences for their means of biomass (figure 3.24). Stethojulis bandanensis, Thalassoma hebraicum, Parupeneus macronemus and Chromis viridis were present in both habitats. Thalassoma hebraicum had a significantly higher mean in the coral reef (figure 3.24). Parupeneus macronemus had a significantly higher variance in the coral reef (figure 3.24). Stethojulis bandanensis and Chromis viridis displayed significantly higher variances in the seagrass bed (figure 3.24). Labroides dimidiatus had a high non- significant p-value for its means of biomass.

69 1600

1400

] 1200 ² m 5

2 1000 Ctenochaetus binotatus / g [

Chaetodon trifasciatus

s 800 n Stethojulis bandanensis a

e Thalassoma hebraicum

m 600

f Parupeneus macronemus o

e 400 Chromis viridis c n

e Plectroglyphidodon r 200 e

f lacrymatus f i d 0 Chlorurus sordidus

-200

-400 species of special interest

Figure 3.24: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during low tide in a neap cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed.

3.3.6. Comparison of different habitat types during low tide in a spring cycle

32 species were absent in both habitats during low tide in a spring cycle, e.g. Plectorhinchus ﬂa- vomaculatus, Diodon liturosus, Stethojulis bandanensis, Lutjanus bohar, and Scarus caudofasciatus (table 3.27).

Table 3.27: Overview of the analysis of 75 species for the comparison between both habitat types during low tide in a spring cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Sig- nificant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for CRLS from six quadrats and for SBLS from five quadrats. CRLS SBLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 12.99 31.82 1012.29 154.17 344.73 118836.93 7.94*10−05# 0.3390 2 Acanthurus nigrofuscus 91.78 182.62 33351.50 0.00 0.00 0.00 NA 0.2950 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 242.93 310.52 96423.33 0.00 0.00 0.00 NA 0.1171 5 Ctenochaetus truncatus 88.90 156.44 24473.82 0.00 0.00 0.00 NA 0.2399 6 Zebrasoma scopas 157.96 245.53 60285.37 0.00 0.00 0.00 NA 0.1878 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 2.11 5.17 26.72 0.00 0.00 0.00 NA 0.3890 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 33.64 82.41 6791.21 0.00 0.00 0.00 NA 0.3890 11 Chaetodon trifascialis 4.42 10.82 117.13 0.00 0.00 0.00 NA 0.3890 12 Chaetodon trifasciatus 229.81 312.99 97965.87 0.00 0.00 0.00 NA 0.1382 13 Dasyatidae Taeniura lymma 92.80 227.31 51671.04 0.00 0.00 0.00 NA 0.3890 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 19.60 48.01 2304.96 0.00 0.00 0.00 NA 0.3890 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 25.98 63.63 4049.36 0.00 0.00 0.00 NA 0.3890 21 Cheilio inermis 0.00 0.00 0.00 12.32 16.67 278.03 NA 0.1010 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 18.83 35.49 1259.87 0.00 0.00 0.00 NA 0.2720 24 Halichoeres hortulanus 30.29 47.02 2211.34 0.00 0.00 0.00 NA 0.1890 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 8.41 13.89 193.05 3.52 7.88 62.09 0.3062 0.5080 28 Pseudocheilinus hexataenia – – – – – – – –

70 29 Stethojulis bandanensis – – – – – – – – 30 Thalassoma hardwicke 47.66 101.76 10355.02 10.92 24.42 596.31 0.0166# 0.4560 31 Thalassoma hebraicum 143.97 133.12 17721.08 36.59 50.10 2509.62 0.0804 0.1239 32 Lethrinidae Lethrinus harak 256.19 627.55 393813.58 0.00 0.00 0.00 NA 0.3890 33 Lethrinus mahsena 79.87 195.63 38271.14 0.00 0.00 0.00 NA 0.3890 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 11.56 28.31 801.58 0.00 0.00 0.00 NA 0.3890 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 382.79 679.13 461214.44 0.00 0.00 0.00 NA 0.2430 40 Pinguipedidae Parapercis hexophtalma 14.51 35.55 1263.48 0.00 0.00 0.00 NA 0.3890 41 Parapercis xanthozona 78.03 108.79 11836.29 0.00 0.00 0.00 NA 0.1468 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 31.61 77.43 5996.10 0.00 0.00 0.00 NA 0.3890 44 Pomacanthus semicirculatus 38.13 93.41 8724.91 0.00 0.00 0.00 NA 0.3890 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 0.00 0.00 0.00 50.71 70.31 4943.72 NA 0.1080 47 Amblyglyphidodon leucogaster 13.26 32.47 1054.37 0.00 0.00 0.00 NA 0.3890 48 Chromis atripectoralis 408.65 406.46 165212.48 2624.65 3595.38 12926742.26 0.0002 0.1640 49 Chromis dimidiata 4.62 11.32 128.07 0.00 0.00 0.00 NA 0.3890 50 Chromis viridis 177.83 222.64 49567.81 0.00 0.00 0.00 NA 0.1107 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas 9.24 14.31 204.90 0.00 0.00 0.00 NA 0.1864 53 Plectroglyphidodon dickii 110.65 171.24 29322.49 0.00 0.00 0.00 NA 0.1862 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 142.65 116.47 13565.65 5.54 12.40 153.68 0.0007# 0.0289# 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 556.42 663.87 440717.50 0.00 0.00 0.00 NA 0.0963 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 0.00 0.00 0.00 83.89 187.58 35186.92 NA 0.2970 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus 353.20 865.16 748498.23 0.00 0.00 0.00 NA 0.3890 63 Scarus niger 103.43 253.36 64190.51 0.00 0.00 0.00 NA 0.3890 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 0.00 0.00 0.00 1077.81 1627.57 2648998.78 NA 0.1350 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 57.97 78.80 6209.92 NA 0.1020 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 40.49 53.83 2897.26 0.00 0.00 0.00 NA 0.1308 74 Canthigaster valentini 77.17 65.30 4263.67 0.00 0.00 0.00 NA 0.0276# 75 Zanclidae Zanclus cornutus 59.38 145.45 21155.61 0.00 0.00 0.00 NA 0.3890

Five species were absent in the coral reef, e.g. Cheilio inermis, Abudefduf sexfasciatus, Lep- toscarus vaigiensis, Siganus sutor, and Sphyraena flavicauda. No one of these species displayed a significant difference for its means of biomass or variances. 32 species were absent in the seagrass bed, e.g. Ctenochaetus striatus, Chaetodon trifasciatus, Gomphosus caeruleus, Chlorurus sordidus, and Canthigaster valentini. Only Canthigaster valentini had a significant difference for its means of biomass, but the boxplot showed an outlier (appendix B, figure B.8). Acanthurus leucosternon, Thalassoma hardwicke, Chromis atripectoralis and Pomacentrus trilineatus were present in both habitats. Acanthurus leucosternon had a significantly higher variance in the seagrass bed (figure 3.25), but the boxplot showed an outlier (appendix B, figure B.8). Chromis atripectoralis had a significantly higher variance in the seagrass bed (figure 3.25). Thalassoma hardwicke had a significantly higher variance in the coral reef, but the boxplot showed also an outlier (appendix B, figure B.8). Pomacentrus trilineatus displayed a significantly higher variance and means of biomass, but the boxplot showed as well an outlier (appendix B, figure B.8).

71 200

] -300 ² m 5 2 / g [

s -800 n

a Acanthurus leucosternon e m

Thalassoma hardwicke f o Chromis atripectoralis

e -1300 c

n Pomacentrus trilineatus e r e f f i d -1800

-2300 species of special interest

Figure 3.25: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during low tide in a spring cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed.

3.3.7. Comparison of different cycles during low tide in the coral reef

The observation displayed that 27 were absent in both cycles during low tide in the coral reef, e.g. Diodon liturosus, Plectorhinchus ﬂavomaculatus, Cheilio inermis, Lutjanus bohar, and Sphyraena ﬂavicauda (table 3.28).

Table 3.28: Overview of the analysis of 75 species for the comparison between both cycles during low tide in the coral reef in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for CRLN from four quadrats and for CRLS from six quadrats. CRLN CRLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 151.26 302.53 91522.20 12.99 31.82 1012.29 0.0002# 0.2850 2 Acanthurus nigrofuscus 80.80 161.60 26113.10 91.78 182.62 33351.50 0.8930 0.9240 3 Ctenochaetus binotatus 434.01 318.39 101375.34 0.00 0.00 0.00 NA 0.0087 4 Ctenochaetus striatus 294.65 253.97 64501.69 242.93 310.52 96423.33 0.7888 0.7899 5 Ctenochaetus truncatus 0.00 0.00 0.00 88.90 156.44 24473.82 NA 0.2980 6 Zebrasoma scopas 157.96 182.39 33266.72 157.96 245.53 60285.37 0.6624 1.0000 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 53.52 47.51 2257.41 2.11 5.17 26.72 0.0002# 0.0265# 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 7.67 15.35 235.59 33.64 82.41 6791.21 0.0199# 0.5590 11 Chaetodon trifascialis 83.37 99.15 9831.37 4.42 10.82 117.13 0.0002# 0.0814 12 Chaetodon trifasciatus 203.25 135.50 18359.48 229.81 312.99 97965.87 0.1990 0.8790 13 Dasyatidae Taeniura lymma 0.00 0.00 0.00 92.80 227.31 51671.04 NA 0.4470 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 12.40 24.81 615.35 19.60 48.01 2304.96 0.3093 0.7940 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 0.00 0.00 0.00 25.98 63.63 4049.36 NA 0.4470 21 Cheilio inermis – – – – – – – – 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 67.09 76.85 5906.33 18.83 35.49 1259.87 0.1264 0.2093 24 Halichoeres hortulanus 41.83 55.84 3118.40 30.29 47.02 2211.34 0.6864 0.7320 25 Hemigymnus fasciatus 101.00 128.20 16433.98 0.00 0.00 0.00 NA 0.0813 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 6.61 8.43 71.14 8.41 13.89 193.05 0.4543 0.8310 28 Pseudocheilinus hexataenia 12.41 15.85 251.16 0.00 0.00 0.00 NA 0.0810

72 29 Stethojulis bandanensis 59.38 45.27 2049.35 0.00 0.00 0.00 NA 0.0106 30 Thalassoma hardwicke 36.46 62.62 3921.31 47.66 101.76 10355.02 0.4552 0.8510 31 Thalassoma hebraicum 803.68 286.94 82333.29 143.97 133.12 17721.08 0.1312 0.0011 32 Lethrinidae Lethrinus harak 0.00 0.00 0.00 256.19 627.55 393813.58 NA 0.4470 33 Lethrinus mahsena 0.00 0.00 0.00 79.87 195.63 38271.14 NA 0.4470 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 47.55 95.09 9042.39 0.00 0.00 0.00 NA 0.2420 37 Cantherhines pardalis 125.80 160.59 25788.94 11.56 28.31 801.58 0.0021# 0.1169 38 Mullidae Parupeneus cyclostomus 98.04 196.08 38445.41 0.00 0.00 0.00 NA 0.2420 39 Parupeneus macronemus 121.32 101.69 10340.83 382.79 679.13 461214.44 0.0103# 0.4750 40 Pinguipedidae Parapercis hexophtalma 30.54 41.16 1693.91 14.51 35.55 1263.48 0.7209 0.5300 41 Parapercis xanthozona 0.00 0.00 0.00 78.03 108.79 11836.29 NA 0.1980 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 245.00 208.72 43563.24 31.61 77.43 5996.10 0.0576 0.0480# 44 Pomacanthus semicirculatus 0.00 0.00 0.00 38.13 93.41 8724.91 NA 0.4470 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 0.00 0.00 0.00 13.26 32.47 1054.37 NA 0.4470 48 Chromis atripectoralis 472.02 944.04 891209.32 408.65 406.46 165212.48 0.1004 0.8860 49 Chromis dimidiata 13.86 27.72 768.39 4.62 11.32 128.07 0.0883 0.4830 50 Chromis viridis 38.11 60.48 3657.35 177.83 222.64 49567.81 0.0570 0.2630 51 Chromis weberi 215.61 342.08 117017.47 0.00 0.00 0.00 NA 0.1493 52 Neoglyphidodon melas 6.93 13.86 192.10 9.24 14.31 204.90 0.9763 0.8070 53 Plectroglyphidodon dickii 86.62 151.32 22898.41 110.65 171.24 29322.49 0.8935 0.8260 54 Plectroglyphidodon lacrymatus 209.60 160.07 25622.70 0.00 0.00 0.00 NA 0.0105 55 Pomacentrus trilineatus 22.62 45.24 2046.63 142.65 116.47 13565.65 0.1485 0.0887 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 1445.78 835.77 698505.75 556.42 663.87 440717.50 0.6081 0.0970 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 83.38 166.76 27808.75 0.00 0.00 0.00 NA 0.2420 62 Scarus frenatus 0.00 0.00 0.00 353.20 865.16 748498.23 NA 0.4470 63 Scarus niger 236.06 327.98 107569.60 103.43 253.36 64190.51 0.5720 0.4890 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 105.89 211.79 44854.95 0.00 0.00 0.00 NA 0.2420 71 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 23.89 47.78 2282.49 40.49 53.83 2897.26 0.9079 0.6380 74 Canthigaster valentini 182.10 133.41 17799.46 77.17 65.30 4263.67 0.1577 0.1311 75 Zanclidae Zanclus cornutus 0.00 0.00 0.00 59.38 145.45 21155.61 NA 0.4470

Ten species were absent during the neap cycle, e.g. Ctenochaetus truncatus, Lethrinus harak, and Lethrinus mahsena. No species had a significant difference for its means of biomass or variances. Ten species were absent during the spring cycle, e.g. Ctenochaetus binotatus, Stethojulis bandanensis, and Plectroglyphidodon lacrymatus. This three species had a significant difference for their means of biomass (figure 3.26). Eight species, which were present in both cycles, had significant differences for their means of biomass or variances. Acanthurus leucosternon, Chaetodon trifascialis and Cantherhines pardalis had significantly higher variances in the neap cycle, but all three boxplots indicated outliers (appendix B, figure B.9 & figure B.10). Meiacanthus mossambicus had a significantly higher mean biomass and variance in the neap cycle, but the boxplot displayed also an outlier (appendix B, figure B.9). Thalassoma hebraicum and Centropyge multispinis had significantly higher means of biomass in the neap cycle. The boxplot for Centropyge multispinis showed an outlier (appendix B, figure B.10). Chaetodon guttatissimus and Parupeneus macronemus had significantly higher variances in the spring cycle (figure 3.26), but the boxplots indicated outliers for both (appendix B, figure B.9 & figure B.10).

73 800

600 ] ² m 5

2 Acanthurus leucosternon / 400 g [

Ctenochaetus binotatus s

n Chaetodon guttatissimus a

e Chaetodon trifascialis

m 200

f Stethojulis bandanensis o

e Thalassoma hebraicum c n

e 0 Parupeneus macronemus r e f

f Plectroglyphidodon i

d lacrymatus -200

-400 species of special interest

Figure 3.26: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both cycles during high tide in the coral reef. Positive values = higher mean of biomass in the neap cycle, negative values = higher mean of biomass in the spring cycle.

Zebrasoma scopas had a high non-signiﬁcant p-value for its means of biomass.

3.3.8. Comparison of different cycles during low tide in the seagrass bed

54 species were absent in both cycles during low tide in the seagrass bed, e.g. Gompho- sus caeruleus, all chaetodontids, most scarids except from Leptoscarus vaigiensis (table 3.29).

Table 3.29: Overview of the analysis of 75 species for the comparison between both cycles during low tide in the seagrass bed in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for SBLN from four quadrats and for SBLS from five quadrats. SBLN SBLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 0.00 0.00 0.00 154.17 344.73 118836.93 NA 0.4070 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 49.29 98.57 9716.51 0.00 0.00 0.00 NA 0.2920 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 9.99 12.98 168.56 0.00 0.00 0.00 NA 0.1205 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus – – – – – – – – 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 719.66 1439.31 2071625.69 0.00 0.00 0.00 NA 0.2920 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus – – – – – – – – 21 Cheilio inermis 76.54 140.97 19871.20 12.32 16.67 278.03 0.0013 0.3380 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus – – – – – – – – 24 Halichoeres hortulanus 12.33 24.66 608.09 0.00 0.00 0.00 NA 0.2920 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – –

74 27 Labroides dimidiatus 6.61 8.43 71.14 3.52 7.88 62.09 0.8646 0.5890 28 Pseudocheilinus hexataenia – – – – – – – – 29 Stethojulis bandanensis 161.56 193.18 37317.20 0.00 0.00 0.00 NA 0.0987 30 Thalassoma hardwicke 0.00 0.00 0.00 10.92 24.42 596.31 NA 0.4070 31 Thalassoma hebraicum 74.53 97.40 9486.13 36.59 50.10 2509.62 0.2275 0.4686 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 105.06 127.05 16141.64 0.00 0.00 0.00 NA 0.1020 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 83.87 167.73 28133.39 0.00 0.00 0.00 NA 0.2920 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 11.68 13.48 181.82 0.00 0.00 0.00 NA 0.0892 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 0.00 0.00 0.00 50.71 70.31 4943.72 NA 0.1980 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 0.00 0.00 0.00 2624.65 3595.38 12926742.26 NA 0.1930 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 209.58 354.67 125790.88 0.00 0.00 0.00 NA 0.2200 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 50.34 68.87 4743.21 5.54 12.40 153.68 0.0066# 0.1919 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus – – – – – – – – 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 62.99 72.73 5289.59 83.89 187.58 35186.92 0.1520 0.8420 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus – – – – – – – – 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 352.07 561.91 315743.39 1077.81 1627.57 2648998.78 0.1117 0.4270 71 Sphyraenidae Sphyraena ﬂavicauda 4.43 8.86 78.50 57.97 78.80 6209.92 0.0048# 0.2260 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 43.50 87.00 7568.78 0.00 0.00 0.00 NA 0.2920 75 Zanclidae Zanclus cornutus – – – – – – – –

Four species were absent in the neap cycle. These were Acanthurus leucosternon, Thalas- soma hardwicke, Abudefduf sexfasciatus, and Chromis atripectoralis, but without a significant difference. Ten species were present in the seagrass bed, e.g. Lethrinus mahsena, Stethojulis bandanensis, and Parupeneus macronemus. No one of these species had significant differences for their means of biomass or variances. Cheilio inermis, Pomacentrus trilineatus and Sphyraena flavicauda were present in both habitats. Cheilio inermis had a significantly higher variance in the neap cycle (figure 3.27). Pomacentrus trilineatus displayed a significantly higher variance in the neap cycle (figure 3.27), but the boxplot showed an outlier (appendix B, figure B.11). Sphyraena flavicauda had a significantly higher variance in the spring cycle (figure 3.27), but the boxplot indicated an outlier as well (appendix B, figure B.11).

75 80

60 ] ² m

5 40 2 / g [

n 20 a

e Cheilio inermis m

f Pomacentrus trilineatus o

e Sphyraena flavicauda c n e r

e -20 f f i d -40

-60 species of special interest

Figure 3.27: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both cycles during low tide in the seagrass bed. Positive values = higher mean of biomass in the neap cycle, negative values = higher mean of biomass in the spring cycle.

3.3.9. Comparison of different tides in a neap cycle in the coral reef

The observation revealed that 30 species were absent during both tides in a neap cycle in the coral reef, e.g. Diodon liturosus, Plectorhinchus ﬂavomaculatus, Cheilio inermis, Lethri- nus mahsena, and Lutjanus bohar (table 3.30).

Table 3.30: Overview of the analysis of 75 species for the comparison between both tides in a neap cycle in the coral reef in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. CRHN CRLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 341.45 320.34 102620.49 151.26 302.53 91522.20 0.9270 0.4210 2 Acanthurus nigrofuscus 0.00 0.00 0.00 80.80 161.60 26113.10 NA 0.3560 3 Ctenochaetus binotatus 157.02 205.11 42069.86 434.01 318.39 101375.34 0.4882 0.1940 4 Ctenochaetus striatus 743.88 406.27 165056.53 294.65 253.97 64501.69 0.4600 0.1098 5 Ctenochaetus truncatus 37.35 74.70 5579.60 0.00 0.00 0.00 NA 0.3560 6 Zebrasoma scopas 300.00 464.48 215745.06 157.96 182.39 33266.72 0.1591 0.5900 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 29.41 33.58 1127.35 53.52 47.51 2257.41 0.5890 0.4400 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 83.37 100.45 10089.89 7.67 15.35 235.59 0.0119 0.1871 11 Chaetodon trifascialis 47.67 41.24 1700.99 83.37 99.15 9831.37 0.1845 0.5340 12 Chaetodon trifasciatus 348.34 130.36 16993.76 203.25 135.50 18359.48 0.9512 0.1740 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 12.40 24.81 615.35 12.40 24.81 615.35 1.0000 1.0000 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus – – – – – – – – 21 Cheilio inermis – – – – – – – – 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 57.21 34.91 1219.04 67.09 76.85 5906.33 0.2284 0.8210 24 Halichoeres hortulanus 128.11 186.01 34600.32 41.83 55.84 3118.40 0.0788 0.4080 25 Hemigymnus fasciatus 135.20 190.44 36269.12 101.00 128.20 16433.98 0.5318 0.7750 26 Hemigymnus melapterus 73.16 146.32 21409.69 0.00 0.00 0.00 NA 0.3560 27 Labroides dimidiatus 18.98 21.58 465.58 6.61 8.43 71.14 0.1621 0.3270 28 Pseudocheilinus hexataenia 24.06 37.90 1436.66 12.41 15.85 251.16 0.1844 0.5890

76 29 Stethojulis bandanensis 101.95 79.49 6319.09 59.38 45.27 2049.35 0.3777 0.3861 30 Thalassoma hardwicke 0.00 0.00 0.00 36.46 62.62 3921.31 NA 0.2890 31 Thalassoma hebraicum 548.77 266.23 70878.22 803.68 286.94 82333.29 0.9051 0.2401 32 Lethrinidae Lethrinus harak 128.10 256.19 65635.60 0.00 0.00 0.00 NA 0.3560 33 Lethrinus mahsena – – – – – – – – 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 4.09 8.18 66.97 47.55 95.09 9042.39 0.0020 0.3970 37 Cantherhines pardalis 0.00 0.00 0.00 125.80 160.59 25788.94 NA 0.1680 38 Mullidae Parupeneus cyclostomus 0.00 0.00 0.00 98.04 196.08 38445.41 NA 0.3560 39 Parupeneus macronemus 86.07 89.65 8036.87 121.32 101.69 10340.83 0.8433 0.6220 40 Pinguipedidae Parapercis hexophtalma 96.84 112.73 12708.61 30.54 41.16 1693.91 0.1320 0.3115 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 156.31 159.59 25469.04 245.00 208.72 43563.24 0.6697 0.5240 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 8.59 17.18 295.31 472.02 944.04 891209.32 1.982*10−05 0.3640 49 Chromis dimidiata 13.86 27.72 768.39 13.86 27.72 768.39 1.0000 1.0000 50 Chromis viridis 209.55 419.10 175647.79 38.11 60.48 3657.35 0.0099 0.4490 51 Chromis weberi 998.15 1816.22 3298642.87 215.61 342.08 117017.47 0.0213 0.4300 52 Neoglyphidodon melas 6.93 13.86 192.10 6.93 13.86 192.10 1.0000 1.0000 53 Plectroglyphidodon dickii 34.57 69.14 4780.61 86.62 151.32 22898.41 0.2300 0.5540 54 Plectroglyphidodon lacrymatus 233.13 198.16 39268.10 209.60 160.07 25622.70 0.7322 0.8611 55 Pomacentrus trilineatus 118.20 93.09 8666.52 22.62 45.24 2046.63 0.2619 0.1140 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 323.05 427.42 182689.63 1445.78 835.77 698505.75 0.3002 0.0539 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 0.00 0.00 0.00 83.38 166.76 27808.75 NA 0.3560 62 Scarus frenatus 50.13 54.13 2929.63 0.00 0.00 0.00 NA 0.1124 63 Scarus niger 0.00 0.00 0.00 236.06 327.98 107569.60 NA 0.2000 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber 31.85 63.70 4057.65 0.00 0.00 0.00 NA 0.3560 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus 43.15 86.30 7447.36 0.00 0.00 0.00 NA 0.3560 69 Cephalopholis boenak 33.10 66.20 4382.14 0.00 0.00 0.00 NA 0.3560 70 Siganidae Siganus sutor 0.00 0.00 0.00 105.89 211.79 44854.95 NA 0.3560 71 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 77.26 92.40 8537.47 23.89 47.78 2282.49 0.3106 0.3458 74 Canthigaster valentini 162.43 46.51 2162.78 182.10 133.41 17799.46 0.1156 0.7891 75 Zanclidae Zanclus cornutus – – – – – – – –

Seven species were absent during high tide in a neap cycle, e.g. Thalassoma hardwicke, Scarus niger, and Siganus sutor. No species of this group had significant differences for its means of biomass or variances. Also seven species were absent during low tide in a neap cycle, e.g. Scarus frenatus, Lethri- nus harak, and Ctenochaetus truncatus. But also no species had a significant difference for its means of biomass or variances. Chaetodon guttatissimus, Chromis viridis and Chromis weberi were present during both tides and inidicated significantly higher variances during the high tide (figure 3.28). Amanses scopas and Chromis atripectoralis had significantly higher variances in the low tide. Anampses twistii, Chromis dimidiata and Neoglyphidodon melas had high non-significant p- values for their means of biomass.

77 900

700 ] ² m

5 500 2 / g [

n 300 a Chaetodon guttatissimus e m

Chromis atripectoralis f o 100 Chromis viridis e c

n Chromis weberi e r

e -100 f f i d -300

-500 species of special interest

Figure 3.28: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both tides in a neap cycle in the coral reef. Positive values = higher mean of biomass in the high tide, negative values = higher mean of biomass in the low tide.

3.3.10. Comparison of different tides in a spring cycle in the coral reef

24 species were absent during both tides in a spring cycle in the coral reef, e.g. Diodon liturosus, Cheilio inermis, Leptoscarus vaigiensis, Siganus sutor, and Sphyraena ﬂavicauda (table 3.31).

Table 3.31: Overview of the analysis of 75 species for the comparison between both tides in a spring cycle in the coral reef in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for CRHS from four quadrats and for CRLS from six quadrats. CRHS CRLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 64.63 129.26 16707.68 12.99 31.82 1012.29 0.0100# 0.3630 2 Acanthurus nigrofuscus 0.00 0.00 0.00 91.78 182.62 33351.50 NA 0.3540 3 Ctenochaetus binotatus 153.18 191.72 36756.88 0.00 0.00 0.00 NA 0.0779 4 Ctenochaetus striatus 356.01 251.09 63045.75 242.93 310.52 96423.33 0.7742 0.5617 5 Ctenochaetus truncatus 0.00 0.00 0.00 88.90 156.44 24473.82 NA 0.2980 6 Zebrasoma scopas 0.00 0.00 0.00 157.96 245.53 60285.37 NA 0.2430 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 9.50 12.12 146.96 2.11 5.17 26.72 0.1104 0.2166 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 0.00 0.00 0.00 33.64 82.41 6791.21 NA 0.4470 11 Chaetodon trifascialis 63.12 27.75 769.79 4.42 10.82 117.13 0.0750 0.0014# 12 Chaetodon trifasciatus 256.32 88.31 7798.79 229.81 312.99 97965.87 0.0632 0.8748 13 Dasyatidae Taeniura lymma 0.00 0.00 0.00 92.80 227.31 51671.04 NA 0.4470 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira 263.49 526.98 277708.60 0.00 0.00 0.00 NA 0.2420 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 29.40 58.80 3457.44 19.60 48.01 2304.96 0.6443 0.7790 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 0.00 0.00 0.00 25.98 63.63 4049.36 NA 0.4470 21 Cheilio inermis – – – – – – – – 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 101.70 110.72 12259.57 18.83 35.49 1259.87 0.0308# 0.1179 24 Halichoeres hortulanus 136.56 102.80 10567.12 30.29 47.02 2211.34 0.1245 0.0545 25 Hemigymnus fasciatus 34.20 68.40 4678.56 0.00 0.00 0.00 NA 0.2420 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 17.62 12.46 155.22 8.41 13.89 193.05 0.8811 0.3276 28 Pseudocheilinus hexataenia 31.35 61.37 3766.60 0.00 0.00 0.00 NA 0.2320 29 Stethojulis bandanensis 67.48 97.54 9514.17 0.00 0.00 0.00 NA 0.1184 30 Thalassoma hardwicke 13.65 27.30 745.38 47.66 101.76 10355.02 0.0560 0.5410

78 31 Thalassoma hebraicum 1360.93 1587.56 2520344.99 143.97 133.12 17721.08 5.83*10−05 0.0899 32 Lethrinidae Lethrinus harak 0.00 0.00 0.00 256.19 627.55 393813.58 NA 0.4470 33 Lethrinus mahsena 0.00 0.00 0.00 79.87 195.63 38271.14 NA 0.4470 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 14.01 28.01 784.82 0.00 0.00 0.00 NA 0.2420 37 Cantherhines pardalis 41.93 83.87 7033.35 11.56 28.31 801.58 0.0380# 0.4240 38 Mullidae Parupeneus cyclostomus 49.60 57.27 3280.21 0.00 0.00 0.00 NA 0.0598 39 Parupeneus macronemus 132.62 153.71 23628.16 382.79 679.13 461214.44 0.0341# 0.4970 40 Pinguipedidae Parapercis hexophtalma 65.80 84.23 7093.95 14.51 35.55 1263.48 0.0933 0.2131 41 Parapercis xanthozona 0.00 0.00 0.00 78.03 108.79 11836.29 NA 0.1980 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 47.42 94.84 8994.15 31.61 77.43 5996.10 0.6443 0.7790 44 Pomacanthus semicirculatus 304.77 376.14 141484.71 38.13 93.41 8724.91 0.0105# 0.1261 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 39.77 45.92 2108.74 13.26 32.47 1054.37 0.4652 0.3122 48 Chromis atripectoralis 0.00 0.00 0.00 408.65 406.46 165212.48 NA 0.0842 49 Chromis dimidiata 13.86 27.72 768.39 4.62 11.32 128.07 0.0883 0.4830 50 Chromis viridis 19.05 38.11 1452.18 177.83 222.64 49567.81 0.0150 0.2030 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas 7.85 15.69 246.31 9.24 14.31 204.90 0.8296 0.8730 53 Plectroglyphidodon dickii 0.00 0.00 0.00 110.65 171.24 29322.49 NA 0.2410 54 Plectroglyphidodon lacrymatus 223.46 153.55 23577.84 0.00 0.00 0.00 NA 0.0062 55 Pomacentrus trilineatus 74.79 80.26 6442.38 142.65 116.47 13565.65 0.5728 0.3430 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 876.56 626.37 392339.01 556.42 663.87 440717.50 0.9859 0.4677 58 Chlorurus strongylocephalus 83.38 166.76 27808.75 0.00 0.00 0.00 NA 0.2420 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 233.00 201.51 40607.02 0.00 0.00 0.00 NA 0.0192 62 Scarus frenatus 31.76 63.53 4035.70 353.20 865.16 748498.23 0.0012# 0.4880 63 Scarus niger 86.52 173.03 29939.68 103.43 253.36 64190.51 0.5623 0.9100 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber 68.53 137.07 18787.06 0.00 0.00 0.00 NA 0.2420 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus 90.67 181.35 32887.26 0.00 0.00 0.00 NA 0.2420 69 Cephalopholis boenak 33.10 66.20 4382.14 0.00 0.00 0.00 NA 0.2420 70 Siganidae Siganus sutor – – – – – – – – 71 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 46.00 40.87 1670.73 40.49 53.83 2897.26 0.6994 0.8634 74 Canthigaster valentini 177.87 228.66 52285.79 77.17 65.30 4263.67 0.0193# 0.3264 75 Zanclidae Zanclus cornutus 0.00 0.00 0.00 59.38 145.45 21155.61 NA 0.4470

Twelve species were absent during high tide in a spring cycle, e.g. Chromis atripectoralis, Plectroglyphidodon dickii, and Zebrasoma scopas. No one of these twelve species displayed significant differences for its means of biomass or variances. 13 species were absent during low tide in a spring cycle, e.g. Ctenochaetus binotatus, Plectroglyphidodon lacrymatus, and Scarus caudofasciatus. Plectroglyphidodon lacrymatus and Scarus caudofasciatus had significant differences for their means of biomass (figure 3.29). Ten species which were present during both tides in a spring cycle indicated significant differences for their means of biomass or variances. Chaetodon trifascialis had a significantly higher mean of biomass in the high tide (figure 3.29), but the boxplot for this species showed an outlier (appendix B, figure B.13). Acanthurus leucosternon, Gomphosus caeruleus, Tha- lassoma hebraicum, Cantherhines pardalis, Pomacanthus semicirculatus and Canthigaster valentini had significantly higher variances in the high tide, but only the boxplot for Thalas- soma hebraicum showed no outlier (appendix B, figure B.13 & figure B.14). Parupeneus macronemus, Chromis viridis and Scarus frenatus displayed significantly higher variances during the low tide, but the boxplots for Parupeneus macronemus and Scarus frenatus showed outliers (appendix B, figure B.14).

79 1400

1200 ]

² 1000

m Acanthurus leucosternon 5 2 / 800 Chaetodon trifascialis g [ Gomphosus caeruleus s n

a 600 Thalassoma hebraicum e

m Parupeneus macronemus

o 400

Chromis viridis e

c Plectroglyphidodon n

e 200 lacrymatus r e f

f Scarus caudofasciatus i

d 0 Scarus frenatus -200

-400 species of special interest

Figure 3.29: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both tides in a spring cycle in the coral reef. Positive values = higher mean of biomass in the high tide, negative values = higher mean of biomass in the low tide

3.3.11. Comparison of different tides in a neap cycle in the seagrass bed

The observation indicated that 50 species were absent during both tides in a neap cycle in the seagrass bed, e.g. most acanthurids, Diodon liturosus, Gomphosus caeruleus, Plectroglyphi- dodon lacrymatus, and Scarus caudofasciatus (table 3.32).

Table 3.32: Overview of the analysis of 75 species for the comparison between both tides in a neap cycle in the seagrass bed in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from four quadrats. SBHN SBLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon – – – – – – – – 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 146.79 293.59 86195.04 49.29 98.57 9716.51 0.1060 0.5520 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 0.49 0.98 0.96 9.99 12.98 168.56 0.0016 0.1920 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 7.67 15.35 235.59 0.00 0.00 0.00 NA 0.3560 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus 67.75 135.50 18359.48 0.00 0.00 0.00 NA 0.3560 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 719.66 1439.31 2071625.69 NA 0.3560 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus 16.69 33.38 1114.29 0.00 0.00 0.00 NA 0.3560 20 Cheilinus trilobatus 77.94 89.99 8098.72 0.00 0.00 0.00 NA 0.1340 21 Cheilio inermis 26.83 33.26 1106.55 76.54 140.97 19871.20 0.0397 0.5160 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus – – – – – – – – 24 Halichoeres hortulanus 0.00 0.00 0.00 12.33 24.66 608.09 NA 0.3560 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 26.11 46.53 2165.22 6.61 8.43 71.14 0.0201 0.4430 28 Pseudocheilinus hexataenia – – – – – – – –

80 29 Stethojulis bandanensis 131.99 261.28 68268.33 161.56 193.18 37317.20 0.6322 0.8620 30 Thalassoma hardwicke 46.07 61.40 3770.08 0.00 0.00 0.00 NA 0.1836 31 Thalassoma hebraicum 327.74 302.32 91398.66 74.53 97.40 9486.13 0.0953 0.1621 32 Lethrinidae Lethrinus harak 278.21 556.42 309601.20 0.00 0.00 0.00 NA 0.3560 33 Lethrinus mahsena 97.69 37.60 1413.89 105.06 127.05 16141.64 0.0752 0.9136 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 135.88 159.43 25418.64 83.87 167.73 28133.39 0.9359 0.6690 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 2.92 5.84 34.09 11.68 13.48 181.82 0.2246 0.2880 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 139.73 279.46 78095.12 209.58 354.67 125790.88 0.7047 0.7670 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 66.03 114.33 13071.03 50.34 68.87 4743.21 0.4293 0.8210 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 1306.03 1564.79 2448565.23 0.00 0.00 0.00 NA 0.1461 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 89.81 119.34 14241.66 62.99 72.73 5289.59 0.4377 0.7150 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus 76.60 153.20 23471.65 0.00 0.00 0.00 NA 0.3560 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 1325.00 1811.15 3280275.03 352.07 561.91 315743.39 0.0860 0.3443 71 Sphyraenidae Sphyraena ﬂavicauda 19.71 39.42 1553.92 4.43 8.86 78.50 0.0367 0.4800 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 79.68 54.83 3006.71 43.50 87.00 7568.78 0.4693 0.5074 75 Zanclidae Zanclus cornutus – – – – – – – –

Two species were absent during high tide in a neap cycle. These were Plectorhinchus flavomaculatus and Halichoeres hortulanus. Both revealed no significant differences for their means of biomass or variances. Eight species were absent during low tide in a neap cycle, e.g. Cheilinus trilobatus, Tha- lassoma hardwicke, and Chlorurus sordidus. No one of these species had significant differences for its means of biomass or variances. Meiacanthus mossambicus, Cheilio inermis, Labroides dimidiatus and Sphyraena flavicauda were present during both tides. Meiacan- thus mossambicus and Cheilio inermis had significantly higher variances during low tide (figure 3.30). Labroides dimidiatus and Sphyraena flavicauda had significantly higher variances during high tide (figure 3.30).

81 30

20 ]

² 10 m 5 2 / 0 g [

s n

a -10 e Cheilio inermis m

f Labroides dimidiatus o -20

e Sphyraena flavicauda c n

e -30 r e f f i

d -40

-50

-60 species of special interest

Figure 3.30: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both tides in a neap cycle in the seagrass bed. Positive values = higher mean of biomass in the high tide, negative values = higher mean of biomass in the low tide.

3.3.12. Comparison of different tides in a spring cycle in the seagrass bed

50 species were absent during both tides in a spring cycle in the seagrass bed, e.g. all chaetodontids, Diodon liturosus, Lethrinus harak, Plectroglyphidodon lacrymatus, and Chloru- rus sordidus (table 3.33).

Table 3.33: Overview of the analysis of 75 species for the comparison between both tides in a spring cycle in the seagrass bed in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for SBHS from four quadrats and for SBLS from five quadrats. SBHS SBLS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 19.48 38.97 1518.44 154.17 344.73 118836.93 0.0046# 0.4680 2 Acanthurus nigrofuscus 57.26 114.53 13116.57 0.00 0.00 0.00 NA 0.2920 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 364.39 383.93 147402.53 0.00 0.00 0.00 NA 0.0675 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 6.82 7.92 62.65 0.00 0.00 0.00 NA 0.0905 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus – – – – – – – – 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 471.54 711.19 505788.74 0.00 0.00 0.00 NA 0.1748 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 94.30 148.21 21966.17 0.00 0.00 0.00 NA 0.1913 21 Cheilio inermis 3.60 7.20 51.85 12.32 16.67 278.03 0.1820 0.3590 22 Coris formosa 104.88 209.76 43997.58 0.00 0.00 0.00 NA 0.2920 23 Gomphosus caeruleus 5.65 11.30 127.69 0.00 0.00 0.00 NA 0.2920 24 Halichoeres hortulanus – – – – – – – – 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 18.39 36.12 1304.74 3.52 7.88 62.09 0.0139# 0.3960 28 Pseudocheilinus hexataenia 0.50 0.99 0.99 0.00 0.00 0.00 NA 0.2920

82 29 Stethojulis bandanensis 101.82 182.98 33480.76 0.00 0.00 0.00 NA 0.2450 30 Thalassoma hardwicke 32.42 64.85 4204.96 10.92 24.42 596.31 0.0911 0.5120 31 Thalassoma hebraicum 177.00 214.47 45995.30 36.59 50.10 2509.62 0.0165 0.1927 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 130.26 118.91 14138.91 0.00 0.00 0.00 NA 0.0415 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar 36.90 73.80 5446.36 0.00 0.00 0.00 NA 0.2920 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis – – – – – – – – 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 2.92 5.84 34.09 0.00 0.00 0.00 NA 0.2920 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 27.79 55.58 3089.21 50.71 70.31 4943.72 0.7298 0.6130 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 0.00 0.00 0.00 2624.65 3595.38 12926742.26 NA 0.1930 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 400.08 471.31 222135.07 0.00 0.00 0.00 NA 0.0945 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 89.57 114.77 13171.56 5.54 12.40 153.68 0.0009# 0.1420 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus – – – – – – – – 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 124.04 143.26 20524.27 83.89 187.58 35186.92 0.6871 0.7350 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus – – – – – – – – 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 1764.39 2290.55 5246627.83 1077.81 1627.57 2648998.78 0.5183 0.6140 71 Sphyraenidae Sphyraena ﬂavicauda 23.17 46.34 2147.85 57.97 78.80 6209.92 0.4137 0.4660 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 94.21 83.23 6927.86 0.00 0.00 0.00 NA 0.0367 75 Zanclidae Zanclus cornutus – – – – – – – –

One species was absent during high tide in a spring cycle. This was Chromis atripectoralis, but it revealed no significant difference for its means of biomass or variances. 14 species were absent during low tide in a spring cycle, e.g. Ctenochaetus striatus, Lethri- nus mahsena, and Canthigaster valentini. Lethrinus mahsena and Canthigaster valentini had significant differences in their means of biomass (figure 3.31). Acanthurus leucosternon, Labroides dimidiatus, Thalassoma hebraicum and Pomacentrus trilineatus were present during both tides in a spring cycle. Acanthurus leucosternon revealed a significantly higher variance during low tide, but the boxplot showed an outlier (appendix B, figure B.16). Labroides dimidiatus, Thalassoma hebraicum and Pomacentrus trilineatus indicated significantly higher variances during high tide and only the boxplot for Thalassoma hebraicum showed no outlier (appendix B, figure B.16).

83 150

100 ] ² m 5 2 / 50 g [

n Acanthurus leucosternon a

e Labroides dimidiatus

m 0

f Thalassoma hebraicum o

e Lethrinus mahsena c n

e -50 Pomacentrus trilineatus r e f f i d -100

-150 species of special interest

Figure 3.31: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both tides in a spring cycle in the seagrass bed. Positive values = higher mean of biomass in the high tide, negative values = higher mean of biomass in the low tide.

3.3.13. Comparison of different habitat types during sunset in a neap cycle

The observation revealed that 17 species were absent in both habitats during sunset in a neap cycle, e.g. Diodon liturosus, Abudefduf sexfasciatus, Lethrinus harak, and Scarus caudofasciatus (table 3.34).

Table 3.34: Overview of the analysis of 75 species for the comparison between both habitat types during sunset in a neap cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from six quadrats. CRSSN SBSSN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 151.12 235.40 55414.88 56.08 137.36 18866.51 0.2641 0.4128 2 Acanthurus nigrofuscus 161.60 173.18 29992.11 0.00 0.00 0.00 NA 0.0454 3 Ctenochaetus binotatus 353.19 268.11 71880.78 0.00 0.00 0.00 NA 0.0091 4 Ctenochaetus striatus 548.28 325.80 106142.99 0.00 0.00 0.00 NA 0.0021 5 Ctenochaetus truncatus 49.80 77.15 5951.58 0.00 0.00 0.00 NA 0.1449 6 Zebrasoma scopas 221.22 496.83 246844.94 0.00 0.00 0.00 NA 0.3010 7 Balistidae Sufflamen chrysopterum 25.98 63.63 4049.22 0.00 0.00 0.00 NA 0.3410 8 Blennidae Meiacanthus mossambicus 12.66 16.02 256.51 0.00 0.00 0.00 NA 0.0807 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis 101.47 89.35 7983.04 0.00 0.00 0.00 NA 0.0194 12 Chaetodon trifasciatus 468.44 417.28 174118.59 0.00 0.00 0.00 NA 0.0205# 13 Dasyatidae Taeniura lymma 92.80 227.31 51671.04 0.00 0.00 0.00 NA 0.3410 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 940.72 1338.40 1791323.14 NA 0.1160 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris 83.04 150.84 22753.69 0.00 0.00 0.00 NA 0.2070 19 Cheilinus chlorourus 0.00 0.00 0.00 36.91 63.58 4042.74 NA 0.1850 20 Cheilinus trilobatus 77.94 130.41 17007.32 117.42 278.29 77444.38 0.1222 0.7600 21 Cheilio inermis 0.00 0.00 0.00 119.45 140.38 19705.50 NA 0.0636 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 51.32 36.88 1360.43 0.00 0.00 0.00 NA 0.0067 24 Halichoeres hortulanus 8.22 20.13 405.39 0.00 0.00 0.00 NA 0.3410 25 Hemigymnus fasciatus 76.95 188.49 35527.82 0.00 0.00 0.00 NA 0.3410 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 0.16 0.40 0.16 4.40 7.37 54.33 5.037*10−06# 0.1900 28 Pseudocheilinus hexataenia 6.18 13.23 174.94 5.52 13.52 182.66 0.9631 0.9330

84 29 Stethojulis bandanensis 0.00 0.00 0.00 2.49 6.10 37.23 NA 0.3410 30 Thalassoma hardwicke 48.61 104.06 10828.79 39.82 62.02 3846.79 0.2824 0.8640 31 Thalassoma hebraicum 486.67 428.54 183646.87 54.76 96.54 9319.74 0.0053# 0.0366# 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 0.00 0.00 0.00 26.62 65.21 4252.35 NA 0.3410 34 Lethrinus obsoletus 83.96 205.66 42296.59 0.00 0.00 0.00 NA 0.3410 35 Lutjanidae Lutjanus bohar 24.60 60.26 3630.90 0.00 0.00 0.00 NA 0.3410 36 Monacanthidae Amanses scopas 9.34 22.87 523.21 0.00 0.00 0.00 NA 0.3410 37 Cantherhines pardalis 0.00 0.00 0.00 39.51 96.79 9367.86 NA 0.3410 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 255.18 388.62 151025.60 0.00 0.00 0.00 NA 0.1390 40 Pinguipedidae Parapercis hexophtalma 51.01 57.04 3254.13 0.00 0.00 0.00 NA 0.0533 41 Parapercis xanthozona 12.75 31.24 976.12 0.00 0.00 0.00 NA 0.3410 42 Plotosidae Plotosus lineatus 0.00 0.00 0.00 178.25 436.62 190638.78 NA 0.3410 43 Pomacanthidae Centropyge multispinis 113.57 70.97 5037.05 0.00 0.00 0.00 NA 0.0029 44 Pomacanthus semicirculatus 148.96 364.87 133131.51 0.00 0.00 0.00 NA 0.3410 45 Pygoplites diacanthus 67.85 87.73 7696.95 0.00 0.00 0.00 NA 0.0877 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 70.26 103.14 10638.34 0.00 0.00 0.00 NA 0.1260 48 Chromis atripectoralis 415.04 791.87 627051.01 0.00 0.00 0.00 NA 0.2282 49 Chromis dimidiata 19.70 48.25 2328.51 0.00 0.00 0.00 NA 0.3410 50 Chromis viridis 491.08 1202.89 1446952.30 0.00 0.00 0.00 NA 0.3410 51 Chromis weberi 75.40 120.26 14462.88 0.00 0.00 0.00 NA 0.1555 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii 75.69 135.32 18310.92 0.00 0.00 0.00 NA 0.2011 54 Plectroglyphidodon lacrymatus 238.97 166.73 27800.28 0.00 0.00 0.00 NA 0.0056 55 Pomacentrus trilineatus 0.00 0.00 0.00 5.23 12.81 164.21 NA 0.3410 56 Scaridae Calotomus carolinus 96.88 237.32 56318.94 0.00 0.00 0.00 NA 0.3410 57 Chlorurus sordidus 996.59 1044.98 1091993.63 0.00 0.00 0.00 NA 0.0416 58 Chlorurus strongylocephalus 96.71 236.90 56122.54 0.00 0.00 0.00 NA 0.3410 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 0.00 0.00 0.00 180.52 337.00 113571.90 NA 0.2190 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus 42.35 103.74 10761.86 0.00 0.00 0.00 NA 0.3410 63 Scarus niger 58.24 142.66 20353.03 0.00 0.00 0.00 NA 0.3410 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor 28.22 69.13 4778.99 0.00 0.00 0.00 NA 0.3410 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak 53.26 84.32 7109.10 0.00 0.00 0.00 NA 0.1529 70 Siganidae Siganus sutor 43.83 107.37 11527.42 3965.68 4727.22 22346651.48 6.556*10−08# 0.0696 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 31.18 43.45 1887.50 NA 0.1080 72 Tetraodontidae Arothron mappa 185.90 455.36 207350.90 0.00 0.00 0.00 NA 0.3410 73 Canthigaster bennetti 9.83 24.07 579.42 0.00 0.00 0.00 NA 0.3410 74 Canthigaster valentini 52.98 49.81 2481.34 38.62 94.60 8948.67 0.1832 0.7490 75 Zanclidae Zanclus cornutus 118.76 290.90 84622.45 0.00 0.00 0.00 NA 0.3410

Ten species were absent in the coral reef, e.g. Plectorhinchus flavomaculatus, Leptoscarus vaigiensis, and Sphyraena flavicauda. All these species had no significant differences for their means of biomass or variances. 40 species were absent in the seagrass bed. Some of these species were Acanthurus nigrofuscus, Ctenochaetus binotatus, Ctenochaetus striatus, Chaetodon trifascialis, Chaetodon trifasciatus, Gomphosus caeruleus, Centropyge multispinis, Plectroglyphidodon lacrymatus, and Chlorurus sordidus. All these species had significant differences for their means of biomass (figure 3.32). Only the boxplot of Chaetodon trifasciatus showed an outlier (appendix B, figure B.17). Labroides dimidiatus, Thalassoma hebraicum and Siganus sutor were present in both habitats during sunset. Thalassoma hebraicum had significantly higher mean of biomass and variance in the coral reef. Labroides dimidiatus and Siganus sutor had significantly higher variances in the seagrass bed. The boxplots for all three species showed outliers (appendix B, figure B.18).

85 1500 1000 500 ] ²

m Acanthurus nigrofuscus 5 0 2 / Ctenochaetus binotatus g [

-500

s Ctenochaetus striatus n

a -1000 Chaetodon trifascialis e m

Chaetodon trifasciatus f -1500 o Thalassoma hebraicum e

c -2000 n Plectroglyphidodon e r lacrymatus e

f -2500 f i Chlorurus sordidus d -3000 Siganus sutor -3500 -4000 species of special interest

Figure 3.32: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during sunset in a neap cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed. The distinctions of Labroides dimidiatus and Gom- phosus caeruleus were smaller than 100g/25m2.

3.3.14. Comparison of different times in a neap cycle in the coral reef

The observation indicated that 19 species were absent during sunset and low tide at day in a neap cycle in the coral reef, e.g. Diodon liturosus, Plectorhinchus ﬂavomaculatus. Lethri- nus harak, Lethrinus mahsena, and Sphyraena ﬂavicauda (table 3.35).

Table 3.35: Overview of the analysis of 75 species for the comparison between different times in a neap cycle in the coral reef in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for CRSSN from siy quadrats and for CRLN from four quadrats. CRSSN CRLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 151.12 235.40 55414.88 151.26 302.53 91522.20 0.5805 0.9990 2 Acanthurus nigrofuscus 161.60 173.18 29992.11 80.80 161.60 26113.10 0.9700 0.4800 3 Ctenochaetus binotatus 353.19 268.11 71880.78 434.01 318.39 101375.34 0.6864 0.6758 4 Ctenochaetus striatus 548.28 325.80 106142.99 294.65 253.97 64501.69 0.7226 0.2277 5 Ctenochaetus truncatus 49.80 77.15 5951.58 0.00 0.00 0.00 NA 0.2420 6 Zebrasoma scopas 221.22 496.83 246844.94 157.96 182.39 33266.72 0.1299 0.8170 7 Balistidae Sufflamen chrysopterum 25.98 63.63 4049.22 0.00 0.00 0.00 NA 0.4470 8 Blennidae Meiacanthus mossambicus 12.66 16.02 256.51 53.52 47.51 2257.41 0.0388 0.0806 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 0.00 0.00 0.00 7.67 15.35 235.59 NA 0.2420 11 Chaetodon trifascialis 101.47 89.35 7983.04 83.37 99.15 9831.37 0.7763 0.7740 12 Chaetodon trifasciatus 468.44 417.28 174118.59 203.25 135.50 18359.48 0.0933 0.2620 13 Dasyatidae Taeniura lymma 92.80 227.31 51671.04 0.00 0.00 0.00 NA 0.4470 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus – – – – – – – – 17 Labridae Anampses twistii 0.00 0.00 0.00 12.40 24.81 615.35 NA 0.2420 18 Bodianus axillaris 83.04 150.84 22753.69 0.00 0.00 0.00 NA 0.3120 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 77.94 130.41 17007.32 0.00 0.00 0.00 NA 0.2750 21 Cheilio inermis – – – – – – – – 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 51.32 36.88 1360.43 67.09 76.85 5906.33 0.1457 0.6699 24 Halichoeres hortulanus 8.22 20.13 405.39 41.83 55.84 3118.40 0.0497# 0.2046 25 Hemigymnus fasciatus 76.95 188.49 35527.82 101.00 128.20 16433.98 0.5573 0.8310 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 0.16 0.40 0.16 6.61 8.43 71.14 3.451*10−06# 0.0898

86 28 Pseudocheilinus hexataenia 6.18 13.23 174.94 12.41 15.85 251.16 0.6697 0.5100 29 Stethojulis bandanensis 0.00 0.00 0.00 59.38 45.27 2049.35 NA 0.0106 30 Thalassoma hardwicke 48.61 104.06 10828.79 36.46 62.62 3921.31 0.4363 0.8430 31 Thalassoma hebraicum 486.67 428.54 183646.87 803.68 286.94 82333.29 0.5414 0.2341 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena – – – – – – – – 34 Lethrinus obsoletus 83.96 205.66 42296.59 0.00 0.00 0.00 NA 0.4470 35 Lutjanidae Lutjanus bohar 24.60 60.26 3630.90 0.00 0.00 0.00 NA 0.4470 36 Monacanthidae Amanses scopas 9.34 22.87 523.21 47.55 95.09 9042.39 0.0091# 0.3600 37 Cantherhines pardalis 0.00 0.00 0.00 125.80 160.59 25788.94 NA 0.0826 38 Mullidae Parupeneus cyclostomus 0.00 0.00 0.00 98.04 196.08 38445.41 NA 0.2420 39 Parupeneus macronemus 255.18 388.62 151025.60 121.32 101.69 10340.83 0.0514 0.5270 40 Pinguipedidae Parapercis hexophtalma 51.01 57.04 3254.13 30.54 41.16 1693.91 0.6265 0.5560 41 Parapercis xanthozona 12.75 31.24 976.12 0.00 0.00 0.00 NA 0.4470 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 113.57 70.97 5037.05 245.00 208.72 43563.24 0.0406 0.1830 44 Pomacanthus semicirculatus 148.96 364.87 133131.51 0.00 0.00 0.00 NA 0.4470 45 Pygoplites diacanthus 67.85 87.73 7696.95 0.00 0.00 0.00 NA 0.1680 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 70.26 103.14 10638.34 0.00 0.00 0.00 NA 0.2190 48 Chromis atripectoralis 415.04 791.87 627051.01 472.02 944.04 891209.32 0.6808 0.9200 49 Chromis dimidiata 19.70 48.25 2328.51 13.86 27.72 768.39 0.3850 0.8310 50 Chromis viridis 491.08 1202.89 1446952.30 38.11 60.48 3657.35 0.0004# 0.4820 51 Chromis weberi 75.40 120.26 14462.88 215.61 342.08 117017.47 0.0458 0.3720 52 Neoglyphidodon melas 0.00 0.00 0.00 6.93 13.86 192.10 NA 0.2420 53 Plectroglyphidodon dickii 75.69 135.32 18310.92 86.62 151.32 22898.41 0.7731 0.9070 54 Plectroglyphidodon lacrymatus 238.97 166.73 27800.28 209.60 160.07 25622.70 0.9919 0.7895 55 Pomacentrus trilineatus 0.00 0.00 0.00 22.62 45.24 2046.63 NA 0.2420 56 Scaridae Calotomus carolinus 96.88 237.32 56318.94 0.00 0.00 0.00 NA 0.4470 57 Chlorurus sordidus 996.59 1044.98 1091993.63 1445.78 835.77 698505.75 0.7570 0.4943 58 Chlorurus strongylocephalus 96.71 236.90 56122.54 0.00 0.00 0.00 NA 0.4470 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 0.00 0.00 0.00 83.38 166.76 27808.75 NA 0.2420 62 Scarus frenatus 42.35 103.74 10761.86 0.00 0.00 0.00 NA 0.4470 63 Scarus niger 58.24 142.66 20353.03 236.06 327.98 107569.60 0.1036 0.2654 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor 28.22 69.13 4778.99 0.00 0.00 0.00 NA 0.4470 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak 53.26 84.32 7109.10 0.00 0.00 0.00 NA 0.2510 70 Siganidae Siganus sutor 43.83 107.37 11527.42 105.89 211.79 44854.95 0.1749 0.5520 71 Sphyraenidae Sphyraena ﬂavicauda – – – – – – – – 72 Tetraodontidae Arothron mappa 185.90 455.36 207350.90 0.00 0.00 0.00 NA 0.4470 73 Canthigaster bennetti 9.83 24.07 579.42 23.89 47.78 2282.49 0.1718 0.5480 74 Canthigaster valentini 52.98 49.81 2481.34 182.10 133.41 17799.46 0.0579 0.0582 75 Zanclidae Zanclus cornutus 118.76 290.90 84622.45 0.00 0.00 0.00 NA 0.4470

Eight species were absent during sunset, e.g. Stethojulis bandanensis, Chaetodon guttatissimus, and Scarus caudofasciatus. Only Stethojulis bandanensis displayed a significant difference for its means of biomass (figure 3.33). Seven species were present during both times and had significant differences in their variances. Chromis viridis had a significantly higher variance during sunset (figure 3.33). The boxplot for Chromis viridis showed an outlier (appendix B, figure 14.2). Meiacanthus mossambicus, Halichoeres hortulanus, Labroides dimidiatus, Amanses scopas, Centropyge multispinis and Chromis weberi had significantly higher variances during low tide at day (figure 3.33). Only the boxplots of Meiacanthus mossambicus and Chromis weberi displayed no outlier (appendix B, figure B.19 & figure B.20).

87 500

400 ] ² m

5 300 2 / g [

n 200 a Halichoeres hortulanus e m

Stethojulis bandanensis f o 100 Chromis viridis e c

n Chromis weberi e r

e 0 f f i d -100

-200 species of special interest

Figure 3.33: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for different times in a neap cycle in the coral reef. Positive values = higher mean of biomass during sunset, negative values = higher mean of biomass during low tide at day. The distinction of Labroides dimidiatus was smaller than 10g/25m2.

3.3.15. Comparison of different times in a neap cycle in the seagrass bed

The observation displayed that 52 species were absent during the samplings for sunset and low tide at day in a neap cycle in the seagrass bed, e.g. all chaetodontids, Gomphosus caeruleus, Lutjanus bohar, Plectroglyphidodon lacrymatus, and Chlorurus sordidus (table 3.36).

Table 3.36: Overview of the analysis of 75 species for the comparison between different times in a neap cycle in the seagrass bed in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for SBSSN from six quadrats and for SBLN from four quadrats. SBSSN SBLN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 56.08 137.36 18866.51 0.00 0.00 0.00 NA 0.4470 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 0.00 0.00 0.00 49.29 98.57 9716.51 NA 0.2420 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 0.00 0.00 0.00 9.99 12.98 168.56 NA 0.0852 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus – – – – – – – – 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 940.72 1338.40 1791323.14 719.66 1439.31 2071625.69 0.8247 0.8100 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus 36.91 63.58 4042.74 0.00 0.00 0.00 NA 0.2880 20 Cheilinus trilobatus 117.42 278.29 77444.38 0.00 0.00 0.00 NA 0.4320 21 Cheilio inermis 119.45 140.38 19705.50 76.54 140.97 19871.20 0.9200 0.6510 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus – – – – – – – – 24 Halichoeres hortulanus 0.00 0.00 0.00 12.33 24.66 608.09 NA 0.2420 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 4.40 7.37 54.33 6.61 8.43 71.14 0.7371 0.6730

88 28 Pseudocheilinus hexataenia 5.52 13.52 182.66 0.00 0.00 0.00 NA 0.4470 29 Stethojulis bandanensis 2.49 6.10 37.23 161.56 193.18 37317.20 4.649*10−07# 0.0711 30 Thalassoma hardwicke 39.82 62.02 3846.79 0.00 0.00 0.00 NA 0.2440 31 Thalassoma hebraicum 54.76 96.54 9319.74 74.53 97.40 9486.13 0.9138 0.7590 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 26.62 65.21 4252.35 105.06 127.05 16141.64 0.1860 0.2300 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 39.51 96.79 9367.86 83.87 167.73 28133.39 0.2681 0.6070 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 0.00 0.00 0.00 11.68 13.48 181.82 NA 0.0598 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus 178.25 436.62 190638.78 0.00 0.00 0.00 NA 0.4470 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis – – – – – – – – 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 0.00 0.00 0.00 209.58 354.67 125790.88 NA 0.1731 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 5.23 12.81 164.21 50.34 68.87 4743.21 0.0026# 0.1459 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus – – – – – – – – 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 180.52 337.00 113571.90 62.99 72.73 5289.59 0.0297# 0.5190 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus – – – – – – – – 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 3965.68 4727.22 22346651.48 352.07 561.91 315743.39 0.0052 0.1740 71 Sphyraenidae Sphyraena ﬂavicauda 31.18 43.45 1887.50 4.43 8.86 78.50 0.0266 0.2680 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 38.62 94.60 8948.67 43.50 87.00 7568.78 0.9481 0.9370 75 Zanclidae Zanclus cornutus – – – – – – – –

Five species were absent during sunset. These were Ctenochaetus striatus, Meiacanthus mossambicus, Halichoeres hortulanus, Parupeneus macronemus, and Chromis viridis. No one of these species had significant differences for its means of biomass or variances. Six species were absent during low tide at day. These were Acanthurus leucosternon, Cheili- nus chlorourus, Cheilinus trilobatus, Pseudocheilinus hexataenia, Thalassoma hardwicke, and Plotosus lineatus. Also no one of these species indicated significant differences for its means of biomass or variances. Five species were present during both times and had significant differences for their variances. Leptoscarus vaigiensis, Siganus sutor and Sphyraena flavicauda had significantly higher variances during sunset (figure 3.34). The boxplot for Leptoscarus vaigiensis showed an outlier (appendix B, figure B.21). Stetho- julis bandanensis and Pomacentrus trilineatus displayed significantly higher variances during low tide at day (figure 3.34). The boxplots showed outliers for both species (appendix B, figure B.21).

89 4000

3500 ]

² 3000 m 5 2 / 2500 g [

s n

a 2000 e Stethojulis bandanensis m

f Leptoscarus vaigiensis o 1500

e Siganus sutor c n

e 1000 r e f f i

d 500

-500 species of special interest

Figure 3.34: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for different times in a neap cycle in the seagrass bed. Positive values = higher mean of biomass during sunset, negative values = higher mean of biomass during low tide at day.

3.3.16. Comparison of different habitat types during sunset in a spring cycle

24 species were absent in both habitat types during sunset in a spring cycle, e.g. Chaetodon guttatissimus, Diodon liturosus, Thalassoma hardwicke, Lethrinus harak, and Lutjanus bohar (table 3.37).

Table 3.37: Overview of the analysis of 75 species for the comparison between both habitat types during sunset in a spring cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from six quadrats. CRSSS SBSSS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 211.31 355.59 126446.76 12.99 31.82 1012.29 6.099*10−05# 0.2036 2 Acanthurus nigrofuscus 15.69 38.43 1476.92 0.00 0.00 0.00 NA 0.3410 3 Ctenochaetus binotatus 74.13 123.58 15272.76 0.00 0.00 0.00 NA 0.1732 4 Ctenochaetus striatus 314.11 372.73 138930.69 0.00 0.00 0.00 NA 0.0660 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas 31.63 77.48 6003.12 0.00 0.00 0.00 NA 0.3410 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 24.11 24.58 604.38 0.00 0.00 0.00 NA 0.0367 9 Carangidae Scomberoides lysan 0.00 0.00 0.00 822.31 1281.78 1642972.48 NA 0.1470 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis 32.39 45.61 2079.97 0.00 0.00 0.00 NA 0.1119 12 Chaetodon trifasciatus 193.46 213.01 45372.85 0.00 0.00 0.00 NA 0.0503 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira 833.34 562.78 316721.08 0.00 0.00 0.00 NA 0.0046 16 Haemulidae Plectorhinchus flavomaculatus 63.79 156.25 24413.13 832.82 1312.41 1722424.95 0.0003# 0.1850 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus 0.00 0.00 0.00 84.27 206.42 42611.15 NA 0.3410 20 Cheilinus trilobatus 0.00 0.00 0.00 21.82 53.45 2857.20 NA 0.3410 21 Cheilio inermis 0.00 0.00 0.00 66.31 153.51 23565.34 NA 0.3140 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 37.67 46.37 2149.71 0.00 0.00 0.00 NA 0.0758 24 Halichoeres hortulanus – – – – – – – – 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus 25.19 61.70 3806.46 0.00 0.00 0.00 NA 0.3410 27 Labroides dimidiatus 4.57 7.72 59.66 7.34 17.98 323.38 0.0952 0.7460 28 Pseudocheilinus hexataenia 10.60 11.19 125.25 2.76 6.76 45.67 0.2964 0.1739

90 29 Stethojulis bandanensis 10.52 19.39 375.91 7.81 13.24 175.20 0.4290 0.7860 30 Thalassoma hardwicke – – – – – – – – 31 Thalassoma hebraicum 272.69 275.72 76024.06 65.49 51.80 2683.66 0.0022 0.1006 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 0.00 0.00 0.00 60.40 74.62 5567.74 NA 0.0756 34 Lethrinus obsoletus 99.41 243.50 59292.17 0.00 0.00 0.00 NA 0.3410 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 11.56 28.31 801.58 27.96 68.48 4688.90 0.0731 0.5980 38 Mullidae Parupeneus cyclostomus 16.53 40.50 1640.11 0.00 0.00 0.00 NA 0.3410 39 Parupeneus macronemus 281.60 356.90 127377.32 0.00 0.00 0.00 NA 0.0821 40 Pinguipedidae Parapercis hexophtalma 87.40 135.65 18401.91 0.00 0.00 0.00 NA 0.1456 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 88.40 150.28 22584.90 0.00 0.00 0.00 NA 0.1802 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus 36.80 90.14 8125.44 0.00 0.00 0.00 NA 0.3410 46 Pomacentridae Abudefduf sexfasciatus 37.05 90.76 8237.89 0.00 0.00 0.00 NA 0.3410 47 Amblyglyphidodon leucogaster 34.47 36.50 1332.61 0.00 0.00 0.00 NA 0.0433 48 Chromis atripectoralis 54.32 133.05 17701.38 5.73 14.03 196.87 0.0001# 0.3940 49 Chromis dimidiata 39.40 96.51 9314.06 0.00 0.00 0.00 NA 0.3410 50 Chromis viridis 33.87 71.25 5076.35 1363.24 2702.87 7305505.56 1.387*101-07# 0.2560 51 Chromis weberi 209.64 390.12 152192.27 0.00 0.00 0.00 NA 0.2175 52 Neoglyphidodon melas 15.08 36.94 1364.42 0.00 0.00 0.00 NA 0.3410 53 Plectroglyphidodon dickii 36.72 71.96 5178.02 0.00 0.00 0.00 NA 0.2400 54 Plectroglyphidodon lacrymatus 192.99 152.96 23396.91 0.00 0.00 0.00 NA 0.0115 55 Pomacentrus trilineatus 19.70 36.40 1325.28 24.32 32.75 1072.67 0.8273 0.8200 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 1007.33 953.06 908320.61 0.00 0.00 0.00 NA 0.0270 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid 72.00 176.36 31104.00 0.00 0.00 0.00 NA 0.3410 60 Leptoscarus vaigiensis 0.00 0.00 0.00 209.90 291.95 85234.93 NA 0.1090 61 Scarus caudofasciatus 28.22 69.13 4778.99 0.00 0.00 0.00 NA 0.3410 62 Scarus frenatus 128.39 296.85 88117.13 0.00 0.00 0.00 NA 0.3140 63 Scarus niger 28.84 70.64 4989.95 0.00 0.00 0.00 NA 0.3410 64 Scarus rubroviolaceus 75.41 82.60 6823.44 0.00 0.00 0.00 NA 0.0493 65 Scarus scaber – – – – – – – – 66 Scarus tricolor 193.16 473.14 223864.22 0.00 0.00 0.00 NA 0.3410 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak 58.59 42.28 1787.55 0.00 0.00 0.00 NA 0.0067# 70 Siganidae Siganus sutor 38.18 93.51 8744.70 3009.27 4184.64 17511253.75 6.036*10−08# 0.1130 71 Sphyraenidae Sphyraena ﬂavicauda 480.84 1177.81 1387245.21 3308.22 5223.88 27288909.35 0.0053# 0.2250 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 19.65 24.07 579.42 0.00 0.00 0.00 NA 0.0747 74 Canthigaster valentini 80.01 79.85 6375.57 62.74 69.53 4834.41 0.7721 0.6997 75 Zanclidae Zanclus cornutus – – – – – – – –

Six species were absent in the coral reef. These were Scomberoides lysan, Cheilinus chlorourus, Cheilinus trilobatus, Cheilio inermis, Lethrinus mahsena, and Leptoscarus vaigiensis. No one of these species indicated a significant difference for its means of biomass or variances. 32 species were absent in the seagrass bed. To these species belonged Meiacanthus mossambicus, Platax teira, Amblyglyphidodon leucogaster, Plectroglyphidodon lacrymatus, Chlorurus sordidus, Scarus rubroviolaceus, and Cephalopholis boenak. All these species had significant differences for their means (figure 3.35). The boxplot of Cephalopholis boenak showed an outlier (appendix B, figure B.23). Seven species were present in both habitats during sunset and had significant differences for their means of biomass or variances. Acanthurus leucosternon, Thalassoma hebraicum and Chromis atripectoralis had significantly higher variances in the coral reef (figure 3.35). The boxplot of Acanthurus leucosternon and Chromis atripectoralis showed outliers (appendix B, figure B.22 & figure B.23). Plectorhinchus flavomaculatus, Chromis viridis, Siganus sutor and Sphyraena flavicauda had significantly higher variances in the seagrass bed. The boxplots showed outliers for all four species (appendix B, figure B.22, figure B.23 & figure B.24).

91 1200 800 400 ] ² m

5 0 Acanthurus leucosternon 2 /

g Plectorhinchus [

-400

s flavomaculatus n

a -800 Thalassoma hebraicum e m

Chromis viridis f -1200 o Plectroglyphidodon e

c -1600 lacrymatus n e

r Chlorurus sordidus e

f -2000 f

i Siganus sutor d -2400 Sphyraena flavicauda -2800 -3200 species of special interest

Figure 3.35: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during sunset in a spring cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed. The distinctions of Amblyglyphidodon leucogaster, Chromis atripectoralis and Scarus rubroviolaceus were smaller than 100g/25m2.

3.3.17. Comparison of different times in a spring cycle in the coral reef

21 species were absent during the samplings for sunset and high tide at day in a spring cycle in the coral reef, e.g. Chaetodon guttatissimus, Diodon liturosus, Lethrinus harak, Lethri- nus mahsena, and Leptoscarus vaigiensis (table 3.38).

Table 3.38: Overview of the analysis of 75 species for the comparison between different times in a spring cycle in the coral reef in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Significant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for CRSSS from six quadrats and for CRHS from four quadrats. CRSSS CRHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 211.31 355.59 126446.76 64.63 129.26 16707.68 0.1272 0.4600 2 Acanthurus nigrofuscus 15.69 38.43 1476.92 0.00 0.00 0.00 NA 0.4470 3 Ctenochaetus binotatus 74.13 123.58 15272.76 153.18 191.72 36756.88 0.3662 0.4448 4 Ctenochaetus striatus 314.11 372.73 138930.69 356.01 251.09 63045.75 0.5478 0.8497 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas 31.63 77.48 6003.12 0.00 0.00 0.00 NA 0.4470 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 24.11 24.58 604.38 9.50 12.12 146.96 0.2733 0.3080 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis 32.39 45.61 2079.97 63.12 27.75 769.79 0.4395 0.2629 12 Chaetodon trifasciatus 193.46 213.01 45372.85 256.32 88.31 7798.79 0.1776 0.5965 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira 833.34 562.78 316721.08 263.49 526.98 277708.60 0.9755 0.1470 16 Haemulidae Plectorhinchus flavomaculatus 63.79 156.25 24413.13 0.00 0.00 0.00 NA 0.4470 17 Labridae Anampses twistii 0.00 0.00 0.00 29.40 58.80 3457.44 NA 0.2420 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus – – – – – – – – 21 Cheilio inermis – – – – – – – – 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 37.67 46.37 2149.71 101.70 110.72 12259.57 0.0916 0.2350 24 Halichoeres hortulanus 0.00 0.00 0.00 136.56 102.80 10567.12 NA 0.0100 25 Hemigymnus fasciatus 0.00 0.00 0.00 34.20 68.40 4678.56 NA 0.2420 26 Hemigymnus melapterus 25.19 61.70 3806.46 0.00 0.00 0.00 NA 0.4470 27 Labroides dimidiatus 4.57 7.72 59.66 17.62 12.46 155.22 0.3648 0.0761

92 28 Pseudocheilinus hexataenia 10.60 11.19 125.25 31.35 61.37 3766.60 0.0028 0.4360 29 Stethojulis bandanensis 10.52 19.39 375.91 67.48 97.54 9514.17 0.0037# 0.1903 30 Thalassoma hardwicke 0.00 0.00 0.00 13.65 27.30 745.38 NA 0.2420 31 Thalassoma hebraicum 272.69 275.72 76024.06 1360.93 1587.56 2520344.99 0.0020 0.1290 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena – – – – – – – – 34 Lethrinus obsoletus 99.41 243.50 59292.17 0.00 0.00 0.00 NA 0.4470 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas 0.00 0.00 0.00 14.01 28.01 784.82 NA 0.2420 37 Cantherhines pardalis 11.56 28.31 801.58 41.93 83.87 7033.35 0.0380# 0.4240 38 Mullidae Parupeneus cyclostomus 16.53 40.50 1640.11 49.60 57.27 3280.21 0.4652 0.3122 39 Parupeneus macronemus 281.60 356.90 127377.32 132.62 153.71 23628.16 0.1965 0.4610 40 Pinguipedidae Parapercis hexophtalma 87.40 135.65 18401.91 65.80 84.23 7093.95 0.4627 0.7860 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 88.40 150.28 22584.90 47.42 94.84 8994.15 0.4814 0.6450 44 Pomacanthus semicirculatus 0.00 0.00 0.00 304.77 376.14 141484.71 NA 0.0745 45 Pygoplites diacanthus 36.80 90.14 8125.44 0.00 0.00 0.00 NA 0.4470 46 Pomacentridae Abudefduf sexfasciatus 37.05 90.76 8237.89 0.00 0.00 0.00 NA 0.4470 47 Amblyglyphidodon leucogaster 34.47 36.50 1332.61 39.77 45.92 2108.74 0.6091 0.8436 48 Chromis atripectoralis 54.32 133.05 17701.38 0.00 0.00 0.00 NA 0.4470 49 Chromis dimidiata 39.40 96.51 9314.06 13.86 27.72 768.39 0.0655 0.6250 50 Chromis viridis 33.87 71.25 5076.35 19.05 38.11 1452.18 0.3288 0.7160 51 Chromis weberi 209.64 390.12 152192.27 0.00 0.00 0.00 NA 0.3230 52 Neoglyphidodon melas 15.08 36.94 1364.42 7.85 15.69 246.31 0.1861 0.7230 53 Plectroglyphidodon dickii 36.72 71.96 5178.02 0.00 0.00 0.00 NA 0.3470 54 Plectroglyphidodon lacrymatus 192.99 152.96 23396.91 223.46 153.55 23577.84 0.9243 0.7643 55 Pomacentrus trilineatus 19.70 36.40 1325.28 74.79 80.26 6442.38 0.1196 0.1718 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus 1007.33 953.06 908320.61 876.56 626.37 392339.01 0.5207 0.8162 58 Chlorurus strongylocephalus 0.00 0.00 0.00 83.38 166.76 27808.75 NA 0.2420 59 Hipposcarus harid 72.00 176.36 31104.00 0.00 0.00 0.00 NA 0.4470 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 28.22 69.13 4778.99 233.00 201.51 40607.02 0.0413# 0.0466# 62 Scarus frenatus 128.39 296.85 88117.13 31.76 63.53 4035.70 0.0289# 0.5460 63 Scarus niger 28.84 70.64 4989.95 86.52 173.03 29939.68 0.0825 0.4770 64 Scarus rubroviolaceus 75.41 82.60 6823.44 0.00 0.00 0.00 NA 0.1110 65 Scarus scaber 0.00 0.00 0.00 68.53 137.07 18787.06 NA 0.2420 66 Scarus tricolor 193.16 473.14 223864.22 0.00 0.00 0.00 NA 0.4470 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus 0.00 0.00 0.00 90.67 181.35 32887.26 NA 0.2420 69 Cephalopholis boenak 58.59 42.28 1787.55 33.10 66.20 4382.14 0.3567 0.4690 70 Siganidae Siganus sutor 38.18 93.51 8744.70 0.00 0.00 0.00 NA 0.4470 71 Sphyraenidae Sphyraena ﬂavicauda 480.84 1177.81 1387245.21 0.00 0.00 0.00 NA 0.4470 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 19.65 24.07 579.42 46.00 40.87 1670.73 0.2766 0.2292 74 Canthigaster valentini 80.01 79.85 6375.57 177.87 228.66 52285.79 0.0448 0.3520 75 Zanclidae Zanclus cornutus – – – – – – – –

Nine species were absent during sunset, e.g. Halichoeres hortulanus, Thalassoma hardwicke, and Chlorurus strongylocephalus. Halichoeres hortulanus displayed a significant difference for its means of biomass (figure 3.36). 15 species were absent during high tide at day, e.g. Plectorhinchus flavomaculatus, Scarus rubroviolaceus, Siganus sutor, and Sphyraena flavicauda. No one of these 15 species revealed significant differences for its means of biomass or variances. Seven species were present in both habitats and had significant differences for their means of biomass or variances. Scarus frenatus indicated a significantly higher variance during sunset (figure 3.36). The boxplot showed an outlier for this species (appendix B, figure B.26). Scarus caudofasciatus had significantly higher means of biomass and variances during high tide at day (figure 3.36). But the boxplot showed also an outlier for this species (appendix B, figure B.25). Pseudocheilinus hexataenia, Stethojulis bandanensis, Thalassoma hebraicum, Cantherhines pardalis and Canthigaster valentini had significantly higher variances during high tide at day (figure 3.36). The boxplots of Stethojulis bandanensis and Cantherhines pardalis showed outliers (appendix B, figure B.25 & figure B.26).

93 200

0 ] ² m

5 -200 2 / g [

n -400 Halichoeres hortulanus a

e Stethojulis bandanensis m

f Thalassoma hebraicum o

-600

e Scarus caudofasciatus c n

e Scarus frenatus r

e -800 f f i d -1000

-1200 species of special interest

Figure 3.36: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for different times in a spring cycle in the coral reef. Positive values = higher mean of biomass during sunset, negative values = higher mean of biomass during low tide at day. The distinction of Pseudocheilinus hexataenia was smaller than 50g/25m2.

3.3.18. Comparison of different times in a spring cycle in the seagrass bed

47 species were absent during the samplings for sunset and high tide in a spring cycle in the seagrass bed, e.g. all chaetodontids, Diodon liturosus, Lethrinus harak, Plectroglyphi- dodon lacrymatus, and Chlorurus sordidus (table 3.39).

Table 3.39: Overview of the analysis of 75 species for the comparison between different times in a spring cycle in the seagrass bed in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for SBSSS from six quadrats and for SBHS from four quadrats. SBSSS SBHS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 12.99 31.82 1012.29 19.48 38.97 1518.44 0.6443 0.7790 2 Acanthurus nigrofuscus 0.00 0.00 0.00 57.26 114.53 13116.57 NA 0.2420 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 0.00 0.00 0.00 364.39 383.93 147402.53 NA 0.0431 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum – – – – – – – – 8 Blennidae Meiacanthus mossambicus 0.00 0.00 0.00 6.82 7.92 62.65 NA 0.0609 9 Carangidae Scomberoides lysan 822.31 1281.78 1642972.48 0.00 0.00 0.00 NA 0.2440 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis – – – – – – – – 12 Chaetodon trifasciatus – – – – – – – – 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus – – – – – – – – 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 832.82 1312.41 1722424.95 471.54 711.19 505788.74 0.3418 0.6320 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris – – – – – – – – 19 Cheilinus chlorourus 84.27 206.42 42611.15 0.00 0.00 0.00 NA 0.4470 20 Cheilinus trilobatus 21.82 53.45 2857.20 94.30 148.21 21966.17 0.0509 0.2954 21 Cheilio inermis 66.31 153.51 23565.34 3.60 7.20 51.85 0.0003# 0.4460 22 Coris formosa 0.00 0.00 0.00 104.88 209.76 43997.58 NA 0.2420 23 Gomphosus caeruleus 0.00 0.00 0.00 5.65 11.30 127.69 NA 0.2420 24 Halichoeres hortulanus – – – – – – – – 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 7.34 17.98 323.38 18.39 36.12 1304.74 0.1634 0.5310

94 28 Pseudocheilinus hexataenia 2.76 6.76 45.67 0.50 0.99 0.99 0.0092# 0.5310 29 Stethojulis bandanensis 7.81 13.24 175.20 101.82 182.98 33480.76 2.877*10−05 0.2320 30 Thalassoma hardwicke 0.00 0.00 0.00 32.42 64.85 4204.96 NA 0.2420 31 Thalassoma hebraicum 65.49 51.80 2683.66 177.00 214.47 45995.30 0.0092 0.2440 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 60.40 74.62 5567.74 130.26 118.91 14138.91 0.3385 0.2810 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar 0.00 0.00 0.00 36.90 73.80 5446.36 NA 0.2420 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 27.96 68.48 4688.90 0.00 0.00 0.00 NA 0.4470 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 0.00 0.00 0.00 2.92 5.84 34.09 NA 0.2420 40 Pinguipedidae Parapercis hexophtalma – – – – – – – – 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis – – – – – – – – 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus 0.00 0.00 0.00 27.79 55.58 3089.21 NA 0.2420 47 Amblyglyphidodon leucogaster – – – – – – – – 48 Chromis atripectoralis 5.73 14.03 196.87 0.00 0.00 0.00 NA 0.4470 49 Chromis dimidiata – – – – – – – – 50 Chromis viridis 1363.24 2702.87 7305505.56 400.08 471.31 222135.07 0.0160# 0.5090 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas – – – – – – – – 53 Plectroglyphidodon dickii – – – – – – – – 54 Plectroglyphidodon lacrymatus – – – – – – – – 55 Pomacentrus trilineatus 24.32 32.75 1072.67 89.57 114.77 13171.56 0.0191 0.2144 56 Scaridae Calotomus carolinus – – – – – – – – 57 Chlorurus sordidus – – – – – – – – 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis 209.90 291.95 85234.93 124.04 143.26 20524.27 0.2705 0.6050 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus – – – – – – – – 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans – – – – – – – – 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 3009.27 4184.64 17511253.75 1764.39 2290.55 5246627.83 0.3500 0.6060 71 Sphyraenidae Sphyraena ﬂavicauda 3308.22 5223.88 27288909.35 23.17 46.34 2147.85 2.226*10−06 0.2530 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti – – – – – – – – 74 Canthigaster valentini 62.74 69.53 4834.41 94.21 83.23 6927.86 0.6762 0.5348 75 Zanclidae Zanclus cornutus – – – – – – – –

Nine species were absent during sunset, e.g. Ctenochaetus striatus, Meiacanthus mossambicus, and Gomphosus caeruleus. Only Ctenochaetus striatus displayed a significant difference for its means of biomass (figure 3.37). Four species were absent during high tide at day. These were Scomberoides lysan, Cheil- inus chlorourus, Cantherhines pardalis, and Chromis atripectoralis. No one of these species revealed significant differences for its means of biomass or variances. Seven species were present during both times and indicated significant differences for their variances. Cheilio inermis, Pseudocheilinus hexataenia, Chromis viridis and Sphyraena flavicauda had significantly higher variances during sunset (figure 3.37). The boxplot of Sphyraena flavicauda showed no outlier (appendix B, figure B.28). The other boxplots showed outliers (appendix B, figure B.27). Stethojulis bandanensis, Thalassoma hebraicum and Pomacen- trus trilineatus displayed significantly higher variances during high tide at day (figure 3.37).

95 3500

3000 ] ²

m 2500 5 2 / g [ 2000 s n

a Ctenochaetus striatus e

m 1500

Thalassoma hebraicum f o

Chromis viridis e

c 1000

n Sphyraena flavicauda e r e f f

i 500 d

-500 species of special interest

Figure 3.37: Distinctions in means of biomass for species of special interest with a sig- niﬁcant difference for different times in a spring cycle in the seagrass bed. Positive values = higher mean of biomass during sunset, negative values = higher mean of biomass during low tide at day. The distinction of Cheilio inermis, Pseudocheilinus hexataenia, Stethojulis bandanensis and Poma- centrus trilineatus were smaller than 100g/25m2.

3.3.19. Comparison of different habitat types during sunrise in a neap cycle

The observation revealed that 25 species were absent during the samplings for sunrise in a neap cycle in both habitats, e.g. Ctenochaetus binotatus, all lethrinids, Cheilinus chlorourus, and Leptoscarus vaigiensis (table 3.40).

Table 3.40: Overview of the analysis of 75 species for the comparison between both habitat types during sunrise in a neap cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from three quadrats. CRSRN SBSRN statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 416.19 634.77 402929.37 115.51 200.07 40029.15 0.1811 0.4780 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus 27.27 47.23 2230.52 0.00 0.00 0.00 NA 0.3740 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas – – – – – – – – 7 Balistidae Sufflamen chrysopterum 64.33 111.42 12415.23 0.00 0.00 0.00 NA 0.3740 8 Blennidae Meiacanthus mossambicus 68.60 39.77 1581.80 0.00 0.00 0.00 NA 0.0390 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus 10.23 17.72 314.12 0.00 0.00 0.00 NA 0.3740 11 Chaetodon trifascialis 93.49 86.03 7400.44 0.00 0.00 0.00 NA 0.1329 12 Chaetodon trifasciatus 270.99 0.00 0.00 0.00 0.00 0.00 NA <2*10−16 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus 1877.18 3251.37 10571380.87 0.00 0.00 0.00 NA 0.3740 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 1606.10 2781.85 7738694.01 NA 0.3740 17 Labridae Anampses twistii 39.20 67.90 4609.92 0.00 0.00 0.00 NA 0.3740 18 Bodianus axillaris 41.52 71.91 5171.29 0.00 0.00 0.00 NA 0.3740 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 0.00 0.00 0.00 352.92 611.28 373665.42 NA 0.3740 21 Cheilio inermis 0.00 0.00 0.00 4.80 8.31 69.14 NA 0.3740 22 Coris formosa 279.67 484.41 234653.75 0.00 0.00 0.00 NA 0.3740 23 Gomphosus caeruleus 68.27 87.33 7626.15 0.00 0.00 0.00 NA 0.2480 24 Halichoeres hortulanus 39.33 68.12 4640.17 0.00 0.00 0.00 NA 0.3740 25 Hemigymnus fasciatus 89.06 154.26 23796.39 0.00 0.00 0.00 NA 0.3740

96 26 Hemigymnus melapterus 97.55 168.96 28546.25 0.00 0.00 0.00 NA 0.3740 27 Labroides dimidiatus 6.20 5.39 29.06 27.12 46.98 2207.15 0.0274 0.4890 28 Pseudocheilinus hexataenia 11.04 19.11 365.32 0.00 0.00 0.00 NA 0.3740 29 Stethojulis bandanensis 4.98 8.63 74.47 135.76 172.98 29920.69 0.0050 0.2610 30 Thalassoma hardwicke 0.00 0.00 0.00 36.40 63.05 3975.38 NA 0.3740 31 Thalassoma hebraicum 513.77 381.46 145508.81 181.80 169.45 28714.67 0.3288 0.2405 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena – – – – – – – – 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar 170.92 296.04 87642.50 0.00 0.00 0.00 NA 0.3740 36 Monacanthidae Amanses scopas 63.39 109.80 12056.52 0.00 0.00 0.00 NA 0.3740 37 Cantherhines pardalis 134.94 121.89 14858.34 390.47 95.28 9077.75 0.7583 0.0462 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 148.31 141.38 19988.19 43.28 65.11 4239.90 0.3477 0.3080 40 Pinguipedidae Parapercis hexophtalma 87.73 151.95 23089.15 0.00 0.00 0.00 NA 0.3740 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus – – – – – – – – 43 Pomacanthidae Centropyge multispinis 199.04 190.37 36239.81 0.00 0.00 0.00 NA 0.1442 44 Pomacanthus semicirculatus – – – – – – – – 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 26.51 45.92 2108.74 26.51 45.92 2108.74 1.0000 1.0000 48 Chromis atripectoralis 657.72 1139.21 1297802.67 286.41 496.08 246091.33 0.3187 0.6320 49 Chromis dimidiata 9.24 16.00 256.13 0.00 0.00 0.00 NA 0.3740 50 Chromis viridis 1016.11 973.22 947150.17 2049.18 221.92 49246.57 0.0986 0.1475 51 Chromis weberi – – – – – – – – 52 Neoglyphidodon melas 240.83 216.38 46821.44 0.00 0.00 0.00 NA 0.1261 53 Plectroglyphidodon dickii 80.80 111.66 12467.92 0.00 0.00 0.00 NA 0.2790 54 Plectroglyphidodon lacrymatus 139.12 61.81 3821.00 0.00 0.00 0.00 NA 0.0180 55 Pomacentrus trilineatus 40.62 48.38 2340.83 97.28 105.05 11036.24 0.3476 0.4440 56 Scaridae Calotomus carolinus 271.20 469.73 220642.69 0.00 0.00 0.00 NA 0.3740 57 Chlorurus sordidus 1565.28 1680.63 2824528.44 0.00 0.00 0.00 NA 0.1820 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus 338.67 448.02 200717.51 0.00 0.00 0.00 NA 0.2610 62 Scarus frenatus 186.84 222.83 49653.32 0.00 0.00 0.00 NA 0.2200 63 Scarus niger – – – – – – – – 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor 167.62 290.32 84287.00 0.00 0.00 0.00 NA 0.3740 67 Scorpaenidae Pterois volitans 0.00 0.00 0.00 124.44 215.54 46458.24 NA 0.3740 68 Serranidae Anyperodon leucogrammicus 49.06 84.97 7220.54 0.00 0.00 0.00 NA 0.3740 69 Cephalopholis boenak 80.66 70.78 5009.59 0.00 0.00 0.00 NA 0.1194 70 Siganidae Siganus sutor 0.00 0.00 0.00 4377.12 1848.16 3415678.83 NA 0.0148 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 541.43 544.97 296992.60 NA 0.1610 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 73.53 65.36 4272.00 0.00 0.00 0.00 NA 0.1229 74 Canthigaster valentini 125.34 33.57 1126.74 96.62 101.77 10357.08 0.1951 0.6638 75 Zanclidae Zanclus cornutus 118.76 205.70 42311.22 0.00 0.00 0.00 NA 0.3740

Seven species were absent in the coral reef, e.g. Plectorhinchus flavomaculatus, Siganus sutor, and Sphyraena flavicauda. Siganus sutor was the only species with a significant difference for its means of biomass (figure 3.38). 32 species were absent in the seagrass bed, e.g. Meiacanthus mossambicus, Chaetodon trifasciatus, Diodon liturosus, Lutjanus bohar, and Plectroglyphidodon lacrymatus. Meiacanthus mossambicus, Chaetodon trifasciatus and Plectroglyphidodon lacrymatus displayed a significant difference for their means of biomass (figure 3.38). Three species were present in both habitats and indicated significant differences for their means of biomass or variances. Cantherhines pardalis had a significantly higher mean of biomass in the coral reef. Labroides dimidiatus and Stethojulis bandanensis revealed significantly higher variances in the seagrass bed (figure 3.38). Amblyglyphidodon leucogaster had a high non-significant p-value for its means of biomass.

97 300

250

] 200 ² m 5

2 150 / g [

s 100 n Chaetodon trifasciatus a

e Labroides dimidiatus

m 50

f Stethojulis bandanensis o

e 0 Plectroglyphidodon c n

e lacrymatus r -50 e f f i d -100

-150

-200 species of special interest

Figure 3.38: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during sunrise in a neap cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed.

3.3.20. Comparison of different habitat types during sunrise in a spring cycle

36 species were absent during the samplings for sunrise in a spring cycle in both habitat types, e.g. Chaetodon guttatissimus, Halichoeres hortulanus, Pseudocheilinus hexataenia, Thalas- soma hardwicke, and Lutjanus bohar (table 3.41).

Table 3.41: Overview of the analysis of 75 species for the comparison between both habitat types during sunrise in a spring cycle in terms of biomass. Mean of biomass, standard deviation and variance are shown for both samplings. The p-values for the statistical analysis of the variance and the means are also summarized. Signifi- cant differences are marked in bold letters. # indicates species, where boxplots (appendix B) showed at minimum one outlier between both samplings. The means were calculated for both samplings from three quadrats. CRSRS SBSRS statistics no. family species mean sd variance mean sd variance F-test GLM 1 Acanthuridae Acanthurus leucosternon 416.48 721.37 520372.39 175.71 304.33 92617.95 0.3023 0.6230 2 Acanthurus nigrofuscus – – – – – – – – 3 Ctenochaetus binotatus – – – – – – – – 4 Ctenochaetus striatus – – – – – – – – 5 Ctenochaetus truncatus – – – – – – – – 6 Zebrasoma scopas 0.00 0.00 0.00 147.35 255.21 65132.34 NA 0.3740 7 Balistidae Sufflamen chrysopterum 128.66 222.85 49660.91 0.00 0.00 0.00 NA 0.3740 8 Blennidae Meiacanthus mossambicus 33.69 14.49 209.82 4.22 7.31 53.44 0.4257 0.0367 9 Carangidae Scomberoides lysan – – – – – – – – 10 Chaetodontidae Chaetodon guttatissimus – – – – – – – – 11 Chaetodon trifascialis 37.05 64.18 4119.08 0.00 0.00 0.00 NA 0.3740 12 Chaetodon trifasciatus 270.99 0.00 0.00 0.00 0.00 0.00 NA <2*10−16 13 Dasyatidae Taeniura lymma – – – – – – – – 14 Diodontidae Diodon liturosus 2497.25 4325.37 18708794.46 0.00 0.00 0.00 NA 0.3740 15 Ephippidae Platax teira – – – – – – – – 16 Haemulidae Plectorhinchus flavomaculatus 0.00 0.00 0.00 1557.76 786.00 617801.61 NA 0.0264 17 Labridae Anampses twistii – – – – – – – – 18 Bodianus axillaris 41.52 71.91 5171.29 0.00 0.00 0.00 NA 0.3740 19 Cheilinus chlorourus – – – – – – – – 20 Cheilinus trilobatus 0.00 0.00 0.00 101.83 176.38 31108.63 NA 0.3740 21 Cheilio inermis 0.00 0.00 0.00 25.95 44.95 2020.94 NA 0.3740 22 Coris formosa – – – – – – – – 23 Gomphosus caeruleus 76.75 93.44 8731.47 30.13 52.19 2724.05 0.4710 0.4920 24 Halichoeres hortulanus – – – – – – – – 25 Hemigymnus fasciatus – – – – – – – – 26 Hemigymnus melapterus – – – – – – – – 27 Labroides dimidiatus 6.20 10.74 115.29 37.75 33.46 1119.58 0.1922 0.1980 28 Pseudocheilinus hexataenia – – – – – – – –

98 29 Stethojulis bandanensis 0.00 0.00 0.00 105.86 103.26 10662.87 NA 0.1510 30 Thalassoma hardwicke – – – – – – – – 31 Thalassoma hebraicum 483.28 204.44 41796.34 79.04 73.62 5420.10 0.2301 0.0322 32 Lethrinidae Lethrinus harak – – – – – – – – 33 Lethrinus mahsena 0.00 0.00 0.00 108.55 135.58 18380.59 NA 0.2380 34 Lethrinus obsoletus – – – – – – – – 35 Lutjanidae Lutjanus bohar – – – – – – – – 36 Monacanthidae Amanses scopas – – – – – – – – 37 Cantherhines pardalis 46.23 80.08 6412.64 55.91 96.84 9377.80 0.8127 0.9010 38 Mullidae Parupeneus cyclostomus – – – – – – – – 39 Parupeneus macronemus 191.90 162.82 26510.84 3.89 6.74 45.46 0.0036 0.1170 40 Pinguipedidae Parapercis hexophtalma 58.71 101.68 10339.27 0.00 0.00 0.00 NA 0.3740 41 Parapercis xanthozona – – – – – – – – 42 Plotosidae Plotosus lineatus 0.00 0.00 0.00 353.71 612.65 375337.69 NA 0.3740 43 Pomacanthidae Centropyge multispinis 63.23 109.51 11992.20 0.00 0.00 0.00 NA 0.3740 44 Pomacanthus semicirculatus 76.27 132.10 17449.81 0.00 0.00 0.00 NA 0.3740 45 Pygoplites diacanthus – – – – – – – – 46 Pomacentridae Abudefduf sexfasciatus – – – – – – – – 47 Amblyglyphidodon leucogaster 34.47 40.81 1665.76 0.00 0.00 0.00 NA 0.2170 48 Chromis atripectoralis 343.69 595.29 354371.52 2755.58 3228.41 10422611.84 0.0658 0.2720 49 Chromis dimidiata 9.24 16.00 256.13 0.00 0.00 0.00 NA 0.3740 50 Chromis viridis 143.96 63.93 4087.62 1142.99 1979.71 3919265.82 0.0021 0.4320 51 Chromis weberi 1520.37 2371.15 5622336.34 0.00 0.00 0.00 NA 0.3290 52 Neoglyphidodon melas 139.63 241.85 58489.09 0.00 0.00 0.00 NA 0.3740 53 Plectroglyphidodon dickii 11.39 19.73 389.39 0.00 0.00 0.00 NA 0.3740 54 Plectroglyphidodon lacrymatus 47.42 17.16 294.52 0.00 0.00 0.00 NA 0.0083 55 Pomacentrus trilineatus 0.00 0.00 0.00 9.24 16.00 256.13 NA 0.3740 56 Scaridae Calotomus carolinus 369.37 506.81 256854.78 0.00 0.00 0.00 NA 0.2750 57 Chlorurus sordidus 1537.60 1434.59 2058055.90 0.00 0.00 0.00 NA 0.1370 58 Chlorurus strongylocephalus – – – – – – – – 59 Hipposcarus harid – – – – – – – – 60 Leptoscarus vaigiensis – – – – – – – – 61 Scarus caudofasciatus – – – – – – – – 62 Scarus frenatus – – – – – – – – 63 Scarus niger 232.97 201.76 40706.05 0.00 0.00 0.00 NA 0.1161 64 Scarus rubroviolaceus – – – – – – – – 65 Scarus scaber – – – – – – – – 66 Scarus tricolor – – – – – – – – 67 Scorpaenidae Pterois volitans 0.00 0.00 0.00 248.89 215.54 46458.24 NA 0.1160 68 Serranidae Anyperodon leucogrammicus – – – – – – – – 69 Cephalopholis boenak – – – – – – – – 70 Siganidae Siganus sutor 141.19 244.55 59806.60 2348.57 157.92 24939.83 0.5864 0.0002 71 Sphyraenidae Sphyraena ﬂavicauda 0.00 0.00 0.00 30.22 36.62 1341.03 NA 0.2250 72 Tetraodontidae Arothron mappa – – – – – – – – 73 Canthigaster bennetti 51.50 89.21 7958.05 0.00 0.00 0.00 NA 0.3740 74 Canthigaster valentini 260.57 115.86 13423.00 77.24 66.89 4474.33 0.5032 0.0761 75 Zanclidae Zanclus cornutus – – – – – – – –

Ten species were absent in the coral reef, e.g. Plectorhinchus flavomaculatus, Lethrinus mahsena, Stethojulis bandanensis, and Pterois volitans. Only Plectorhinchus flavomaculatus revealed a significant difference for its means of biomass (figure 3.39). 18 species were absent in the seagrass bed, e.g. Chaetodon trifasciatus, Diodon liturosus, Plectroglyphidodon lacrymatus, and Chlorurus sordidus. Chaetodon trifasciatus and Plectro- glyphidodon lacrymatus inidicated a significant difference for their means of biomass (figure 3.39). Five species were present in both habitats and had significant differences for their means of biomass or variances. Meiacanthus mossambicus and Thalassoma hebraicum displayed significantly higher means of biomass in the coral reef (figure 3.39). Parupeneus macronemus had a significantly higher variance in the coral reef (figure 3.39). Siganus sutor indicated a significantly higher mean of biomass in the seagrass bed (figure 3.39). Chromis viridis revealed a significantly higher variance in the seagrass bed (figure 3.39).

99 1000

500 ] ² m

5 0 2 / g [

Chaetodon trifasciatus s

n -500 Plectorhinchus a

e flavomaculatus m

f Thalassoma hebraicum o

-1000

e Parupeneus macronemus c n

e Chromis viridis r

e -1500 f Siganus sutor f i d -2000

-2500 species of special interest

Figure 3.39: Distinctions in means of biomass for species of special interest with a signiﬁcant difference for both habitat types during sunrise in a spring cycle. Positive values = higher mean of biomass in the coral reef, negative values = higher mean of biomass in the seagrass bed. The distinction of Plectroglyphidodon lacrymatus was smaller than 100g/25m2.

100 4. Discussion

4.1. Fish community composition in East African tropical waters

The observed ﬁsh community composition seemed to be typical for East African tropical waters. This statement was substantiated from the results of previous studies from Lugendo et al. (2007), Dorenbosch et al. (2005a), and Bergman et al. (2001).

In this study the most species could be identiﬁed in comparison with the three mentioned studies. But these species are belonging to less families in comparison with Lugendo et al. (2007). 18 families were missing in this study and six families were missing in the study of Lugendo et al. (2007). Lugendo and co-workers could observe more species in the important families haemulids, mullids, and siganids. Whereas in this study were identiﬁed more species out of the acanthurids, labrids, scarids, and serranids.

Dorenbosch and co-workers analysed in (2005a) 76 species out of 14 families. There was an overlap with this study of twelve observed families. Also Bergman et al. (2001) identiﬁed less species. There was an overlap of 28 species with this study.

4.2. Comparison of the ﬁsh community composition in the coral reef and seagrass bed and the inﬂuence of lunar cycles, tidal amplitudes or diel cycle on this composition

The ﬁsh community composition was in parts different between the coral reef and the seagrass bed (table 3.1). More than 50 percent of all counted species were only present in the coral reef and ten percent were only present in the seagrass bed. Less than 40 percent of all species were seen in both habitats. The ﬁsh community differed between different times. 45 percent of all counted species were seen during twilight and daytime. 13 percent of all counted species were only seen during daytime and 14 percent only during twilight samplings. 21 percent of all counted species could only be counted during daytime and sunset samplings and 6 percent were seen during daytime and sunrise.

Dorenbosch evaluated in 2005 a seagrass-reef gradient and classified the observed species in four categories. These were reef residents, seagrass residents, nursery species, and gen- eralists [Dorenbosch et al., 2005b]. Reef residents were seen almost on the reef, e.g. Acanthurus leucosternon, Calotomus carolinus, Chaetodon auriga, Chlorurus sordidus, Lutjanus bohar, Scarus ghobban, and Zanclus cornutus [Dorenbosch et al., 2005b]. The same habitat preference could only be observed from Chaetodon auriga and Zanclus cornutus, but without a significant difference in all analysed samplings. The other five species were seen in both habitats, but Acanthurus leucosternon and Chlorurus sordidus showed a significantly higher abundance and biomass in the coral reef. 22 other species showed significant differences for the their habitat use of the coral reef

101 from which 17 species were counted in both habitats. To these species belonged three acanthurids, three chaetodontids, five labrids, Parupeneus macronemus, two pomacentrids and Scarus rubroviolaceus. Only Chaetodon trifasciatus and Plectroglyphidodon lacrymatus showed this significant preference in nearly all analysed samplings. Some species indicated only a significant difference for the coral reef during high tide at day, e.g. Chaetodon guttatissimus, and Halichoeres hortulanus. Others had only a significant habitat preferation during twilight samplings, e.g. Acanthurus nigrofuscus, Ctenochaetus striatus, Amblyglyphidodon leucogaster, and Scarus rubroviolaceus.

The fish community was also influenced by lunar cycles, tidal amplitudes and diel cycles. The lunar cycle had the least influence on the fish community composition in the coral reef. Only eight species revealed a significant difference for both lunar cycles, e.g. Ctenochaetus striatus, Thalassoma hebraicum, three pomacentrids, and Chlorurus sordidus. But every of these species had only one significant difference for both comparisons of lunar cycle samplings. Tha- lassoma hebraicum had significant differences in terms of abundance and biomass for the low tide in a neap cycle and a significant difference in terms of biomass for the high tide in a spring cycle. 16 species showed similarity in their habitat preference between both lunar cycles, e.g. three acanthurids, six labrids and four pomacentrids.

The tidal amplitude had a significant influence on the presence of eleven species in the coral reef. The tidal amplitude influenced the habitat use of the coral reef of the most species. Nine species revealed a significantly higher presence during high tide in terms of abundance or biomass, e.g. Chaetodon guttatissimus, Thalassoma hebraicum, and Scarus caudofasciatus. Nine species showed no influence of a tidal amplitude in their habitat use of the coral reef. To these species belonged Parupeneus macronemus, five pomacentrids, and Scarus niger. The influence of the tidal amplitude was stated as a manipulating factor on the habitat use of species in other studies [Castellanos-Galindo et al., 2010, Dorenbosch et al., 2004].

Nine species were significantly influenced in their habitat use of the coral reef in a diel cycle. The majority of eight species revealed a significantly higher presence in the coral reef during daytime, e.g. Halichoeres hortulanus, Pseudocheilinus hexataenia, and Chromis weberi. Tha- lassoma hebraicum and Stethojulis bandanensis indicated a significantly higher abundance or biomass during day in the analysis of both comparisons. Only Parupeneus macronemus showed a significantly higher abundance during sunset in the coral reef. Eight species indicated high consistences in their habitat use during day and twilight, e.g. two acanthurids, and three pomacentrids. Diel migrations were also investigated from Hobson et al. in 1973. It was assumed that diel migrations occur for feeding purposes and to avoid predation pressure [Hobson, 1973]. Warner et al. (1975) and Warner and Hoffman (1980) examined that spawn- ing was also an reason for diel migrations [Warner et al., 1975, Warner and Hoffman, 1980]. Scarids showed also diel migrations in other studies [Ogden and Buckman, 1973, Dubin and Baker, 1982].

102 Seagrass residents were Cheilio inermis, Leptoscarus vaigiensis, and Lethrinus obsoletus [Dorenbosch et al., 2005b]. This habitat preference was the same in this study for Cheilio inermis and Leptoscarus vaigiensis. Both indicated also significant differences in their preferred habitat in terms of abundance. Six other species revealed also significant difference in their habitat use of the seagrass bed. These were Plectorhinchus flavomaculatus, Labroides dimidiatus, Stethojulis bandanensis, Lethrinus mahsena, Chromis viridis, and Sphyraena flavicauda. All these species were counted in both habitats. Five species revealed significant differences for their habitat use during day and twilight. Only Plectorhinchus flavomaculatus (haemulid), Labroides dimidiatus and Leptoscarus vaigiensis showed a significantly higher habitat use of the seagrass bed during twilight. Twilight migrations of Haemulidae were also observed from other studies [Appeldoorn et al., 2009, Nagelkerken et al., 2000].

The fish community composition in the seagrass bed was also influenced by lunar cycles, tidal amplitudes and the diel cycle. The lunar cycle influenced the fish community composition least in a comparison with the other temporal pattern. This was the same in the coral reef. Only three species indicated a significant difference in their biomass in the seagrass bed. These were Meiacanthus mossambicus, Cheilio inermis, and Stethojulis bandanensis. Meia- canthus mossambicus showed significantly higher habitat use of seagrass bed in a spring cycle, whereas Cheilio inermis and Stethojulis bandanensis revealed a significantly higher habitat use of seagrass bed in a neap cycle. Labroides dimidiatus, Parupeneus macronemus, Sphyraena flavicauda and Canthigaster valentini were not influenced by lunar cycles. All of them showed a similarity between their habitat use in both cycles.

The tidal amplitude had the biggest influence on the fish community composition in the seagrass bed. Eight species revealed a significant difference in their habitat use of the seagrass bed during both tides. Six of them indicated a significantly higher presence during high tide. These were Labroides dimidiatus, Stethojulis bandanensis, Thalassoma hebraicum, Lethrinus mahsena, Sphyraena flavicauda, and Canthigaster valentini. Out of these species all had a significant difference in terms of biomass except for Stethojulis bandanensis. The most species showed a significantly higher use of the seagrass bed during high tide. Six species were not influenced by the tidal amplitude and revealed similarities in their habitat use of the seagrass bed between both tides. Tidal patterns in the habitat use of the seagrass bed were also observed from other studies [Sogard et al., 1989, Unsworth et al., 2007].

The diel cycle significantly influenced the habitat use in the seagrass bed of five species. These were Ctenochaetus striatus, Pomacentrus trilineatus, Stethojulis bandanensis, Thalas- soma hebraicum, and Sphyraena flavicauda. Only Sphyraena flavicauda revealed a significantly higher habitat use during twilight, all other species had a significantly higher habitat use during high tide at day. Leptoscarus vaigiensis and Canthigaster valentini were not influenced by the diel cycle. Both indicated a similarity in their habitat use during day and twilight. Diel migrations in the seagrass feeding ground were also observed from Robblee and Zieman

103 [Robblee and Zieman, 1984].

There were also species which revealed different habitat preferences with the influence of different temporal pattern. These were Chromis atripectoralis, Pomacentrus trilineatus, and Siganus sutor. Chromis atripectoralis had a significantly higher habitat use during low tide in the seagrass bed and during sunset in the coral reef. Pomacentrus trilineatus showed a habitat use in contrary to Chromis atripectoralis. Siganus sutor revealed a significantly higher habitat use during all twilight samplings and low tide at day in terms of abundance, but in the analysis in terms of biomass appeared a significant difference during the sunrise sampling in the habitat use of the coral reef.

Also nine species showed high accordances between both habitat types during different analysed samplings. Five species revealed these similarities during daytime, e.g. Ctenochaetus striatus, Labroides dimidiatus, and Thalassoma hardwicke. Five species indicated also a high consistence in the twilight samplings, e.g. Cheilinus trilobatus, Cantherhines pardalis, and Amphiprion akallopisos. Cheilinus trilobatus was also classiﬁed as a generalist in the study of Dorenbosch et al. (2005b) [Dorenbosch et al., 2005b].

4.3. Difference between the analysis in terms of abundance and biomass

The fish community composition differed between both analyses. 61 species were analysed in terms of abundance and biomass and 14 species differed. There was the expectation that the analysis in terms of biomass will be obtaining more results than the analysis in terms of abundance. This was done due to the fact that the size classes were added in the calculation of biomass. For all significant results the analysis in terms of biomass indicated more species with a significant difference. For the comparison between the two habitat types 32 species were recorded with a significant difference in terms of biomass and 30 species in terms of abundance. For the comparison between the three influencing factors was it a relation of 30 species in terms of biomass to 25 species in terms of abundance. But also some species lost their significant difference.

A great advantage was the analysis in terms of biomass for the species with similarities. The amount of species in terms of abundance was 34 and in terms of biomass only 19 species revealed consistences. Due to the analysis in terms of biomass the most species under sus- picion for spatial pseudoreplication could be relieved except from Chromis dimidiata. This species showed similarities in the analysis in terms of abundance and biomass. So it is assumed that this species was counted several times in the same quadrat during different samplings because it is living there.

4.4. Discussion of bias

The observer bias was reduced to a minimum. Both observers trained the size estimation and species identiﬁcation until both observers were accurate and at the same level.

104 The problem of spatial pseudoreplication was solved by observing all species with high similarities during the analysis and comparison of all their results. It showed that only one species showed spatial pseudoreplication. It was Chromis dimidiata in the coral reef. The species was excluded in the discussion of the results.

Another problem occurred during the statistical analysis. The p-values for the comparison between two samplings showed for some species not expected results. These were analyses in which species with high amounts of counted ﬁsh were compared with zero counts. It seemed that the chosen statistical methods could not cope with this situation, but it was stated other- wise [Crawley, 2007]. Maybe a multivariate analysis with the program Primer-E will lead to a solution to this problem. For this analysis all data are processed in similarity-matrices. For me the time for this type of analysis was to short. When I heard about this possibility, I had to less time left to calculate all of these similarity-matrices and get used to the program.

Also during the statistical analysis occurred that many species showed outliers in their comparison between different samplings. These was due to the fact that at maximum six replicates could be compared. In an analysis of few replicates outlier have a higher inﬂuence on calculated means. All species which showed outlier were excluded in the discussion.

4.5. Conclusions

1. The ﬁsh community composition surveyed in this study is typical for East African tropical waters. These was assumed after a comparison with other studies carried out in this area.

2. The ﬁsh community composition differed between the seagrass bed and the coral reef. Out of 139 observed species, 72 species were only seen in the coral reef and 14 species were only seen in the seagrass bed. 53 species occurred in both habitats and could show differences in their habitat use.

3. The ﬁsh community composition differed also between the coral reef and the seagrass bed for different times. 63 species were present during daytime and twilight. 19 species could be only counted during daytime and 20 species were only seen during twilight. 8 species were present during daytime and sunrise and 29 species were counted during daytime and sunset.

4. The fish community composition was influenced by the analysed temporal pattern (lunar cycles, tidal amplitudes and diel cycle), but to a different extent in both habitats. The tidal amplitude had in both habitats the biggest influence on the species composition. The diel cycle had a higher influence than the lunar cycle.

5. The analysis in terms of biomass revealed more results because the size of the ﬁsh is included in the analysed parameter. The ﬁsh community composition differed between

105 analyses in terms of abundance and biomass. 14 species were different in both analyses.

6. The problem of spatial pseudoreplication could be solved with the monitoring of species with similarities. The statistical analysis seemed to have failures for some species when swarms occur and were compared with zero counts.

4.6. Outlook

The data of this study will be used as one basis in a multi-species individual based model (IBM). Such a model can help to understand the habitat use of ﬁsh species in reaction to different scenarios. Also a development over time can be calculated.

For a better understanding of the habitat use of coral reef ﬁsh assemblages and improve- ment of the management of marine protected areas further analysis is needed. This could be studies with tagging and resighting experiments as done from Dorenbosch in 2004 or with implemented sensors and recording of ﬁsh migrations.

For more results for species of special interest with a value for the ecosystem and commercial ﬁsheries an additional study with more replicates and concentration in these species could be done.

106 List of abbreviations

COR ...... corallivor CR ...... coral reef D ...... day FT ...... feeding type GLM ...... Generalized Linear Model H ...... herbivor HC ...... hard coral HN ...... high neap HS ...... high spring INV ...... invertebrates LN ...... low neap LS ...... low spring MA ...... macroalgae MPA ...... marine protected area NK ...... Not known OMNI ...... omnivor OT ...... others P ...... planktivor PIS ...... piscivor PVC ...... Polyvinylchlorid RB ...... rubble RC ...... rock RKC ...... recently killed coral SB ...... seagrass bed SD ...... sand SG ...... seagrass SI ...... species of special interest SP ...... sponge SR ...... sunrise SS ...... sunset TA ...... turf algae TW ...... twilight

107 References

[Allen, 2009] Allen, G. R. (2009): Field guide to marine ﬁshes of tropical Australia and South- east Asia. 4th Edition. Western Australian Museum. Welshpool, Western Australia.

[Almany et al., 2002] Almany, G. R. , Berumen, M. L., Thorrold, S. R., Planes, S. and Jones, G. P. (2002): Local replenishment of coral reef ﬁsh populations in a marine reserve. Science 316: 742 – 744.

[Appeldoorn et al., 2009] Appeldoorn, R. S., Aguilar-Perera, A., Bouwmeester, B. L. K., Den- nis, G. D., Hill, R. L., Merten, W., Recksiek, C. W., and Williams, S. J. (2009): Movement of ﬁshes (Grunts: Haemulidae) across the coral reef seascape: A review of scales, patterns and processes. Caribbean Journal of Science 45: 304 – 316.

[Beck et al., 2001] Beck, M. W., Heck, K. L., Able, K. W., Childers, D. L., Eggleston, D. B., Gillanders, B. M., Halpern, B., Hays, C. G., Hoshino, K., Minello, T. J., Orth, R. J., Sheri- dan, P. F. and Weinstein, M. P. (2001): The identiﬁcation, conservation, and management of estuarine and marine nurseries for ﬁsh and invertebrates. BioScience 51: 633 – 641

[Bergman et al., 2000] Bergman, K. C., Öhman, M. C. and Svensson, S. (2000): Inﬂuence of habitat structure on Pomacentrus sulfureus, a western Indian Ocean reef ﬁsh. Environ- mental Biology of Fishes 59: 243 – 252

[Bergman et al., 2001] Bergman, K. C., Svensson, S. and Öhman, M. C. (2001): Inﬂuence of algal farming on ﬁsh assemblages. Marine Pollution Bulletin Vol 42: 1379 – 1389

[Castellanos-Galindo et al., 2010] Castellanos-Galindo, G. A., Krumme, U., and Willis, T. J. (2010): Tidal influences on fish distributions on tropical eastern Pacific rocky shores (Colombia). Marine Ecology Progress Series 416: 241 – 254.

[Crawley, 2005] Crawley, M. J. (2005): Statistics: An introduction using R. Reprinted. John Wiley and Sons Ltd. West Sussex, England.

[Crawley, 2007] Crawley, M. J. (2007): The R book. Reprinted. John Wiley and Sons Ltd. West Sussex, England.

[Debelius, 1996] Debelius, H. (1996): Fisch Führer Indischer Ozean. Rotes Meer bis Thai- land. 2Te überarbeitete Auﬂage. Tetra-Verlag. Melle, Germany.

[Dorenbosch et al., 2004] Dorenbosch, M., Verweij, M. C., Nagelkerken, I., Jiddawi, N. and van der Velde, G. (2004): Homing and daytime movements of juvenile snappers (Lut- janidae) between shallow-water nursery habitats in Zanzibar, western Indian Ocean. En- vironmental Biology of Fishes 70: 203 – 209.

[Dorenbosch et al., 2005a] Dorenbosch, M., Grol, M. G. G., Christianen, M. J. A., Nagelk- erken, I. and van der Velde, G. (2005a): Indo-Paciﬁc seagrass beds and mangroves contribute to ﬁsh density and diversity on adjacent coral reefs. Marine Ecology Progress Series 302: 63 – 76.

108 [Dorenbosch et al., 2005b] Dorenbosch, M., Grol, M. G. G., Nagelkerken, I. and van der Velde, G. (2005b): Distribution of coral reef ﬁshes along a coral reef - seagrass gradient: edge effects and habitat segregation. Marine Ecology Progress Series 299: 277 – 288.

[Dorenbosch et al., 2006] Dorenbosch, M., Grol, M. G. G., Nagelkerken, I. and van der Welde, G. (2006): Different surrounding landscapes may result in different ﬁsh assemblages in East African seagrass beds. Hydrobiologica 563: 45 – 60

[Dubin and Baker, 1982] Dubin, R. E., and Baker, J. D. (1982): Two types of coverseeking be- havior at sunset by the princess parrotﬁsh Scarus taeniopterus at Barbados, West Indies. Bulletin of Marine Science 32: 572 – 583.

[English et al., 1997] English, S., Wilkinson, C. and Baker, V. (1997): Survey Manual for Trop- ical Marine Resources. 2nd Ed. Australian Institute of Marine Science, Townsville

[Friedlander et al., 2007] Friedlander, A. M., Brown, E. K. and Monaco, M. E. (2007): Cou- pling ecology and GIS to evaluate efﬁcacy of marine protected areas in Hawaii. Ecological Applications 17: 715 – 730.

[Froese and Pauly, 2012] Froese, R. and Pauly, D. Editors. (2012): FishBase. World wide web electronic publication. www.ﬁshbase.org, version (02/2012 identiﬁcation) and (05/2012 biomass calculation).

[Hobson, 1973] Hobson, E. S. (1973): Diel feeding migrations of tropical reef ﬁshes. Hel- golander Wissenschaftliche Meeresuntersuchungen 24: 361 – 370.

[Lieske and Myers, 1999] Lieske, E. and Myers, R. (1999): Coral reef fishes, Caribbean, In- dian Ocean, and Pacific Ocean. Including Red Sea. Second printing and first paperback printing. Princeton University Press, New Jersey.

[Lokrantz et al., 2010] Lokrantz, J., Nyström, M., Norström, A. V., Folke, C. and Cinner, J. E. (2010): Impacts of artisanal ﬁshing on key functional groups and the potential vulnerability of coral reefs. Environmental Conservation 36: 327 – 337.

[Lugendo et al., 2007] Lugendo, B. R., Nagelkerken, I., Jiddawi, N., Mgaya, Y. D. and van der Velde, G. (2007): Fish community composition of a tropical nonestuarine embayment in Zanzibar, Tanzania. Fisheries Science 73: 1213 – 1223.

[Mumby, 2006] Mumby, P. J. (2006): Connectivity of reef ﬁsh between mangroves and coral reefs: Algorithms for the design of marine reserves at seascape scales. Biological Con- servation 128: 215 – 222.

[Nagelkerken et al., 2000] Nagelkerken, I., Dorenbosch, M., Verberk, W. C. E. P., Cocheret de la Morinière, E., and van der Velde, G. (2000): Day-night shifts of ﬁshes between shallow-water biotopes of a Caribbean bay, with emphasis on the nocturnal feeding of Haemulidae and Lutjanidae. Marine Ecology Progress Series 194: 55 – 64.

109 [Nagelkerken et al., 2008] Nagelkerken, I., Bothwell, J., Nemeth, R. S., Pitt, J. M. and van der Velde, G. (2008): Interlinkage between Caribbean coral reefs and seagrass beds through feeding migrations by grunts (Haemulidae) depends on habitat accessibility. Marine Ecol- ogy Progress Series 368: 155 – 164

[Ogden and Buckman, 1973] Ogden, J. C. and Buckman, N. S. (1973): Movements, foraging groups, and diurnal migrations of the striped parrotﬁsh Scarus croicensis Bloch (Scari- dae). Ecology 54: 589 – 596.

[Polunin and Roberts, 1993] Polunin, N. V. C. and Roberts, M. C. (1993): Greater biomass and value of target coral-reef ﬁshes in two small Caribbean marine reserves. Marine Ecology Progress Series 100: 167 – 176

[Randall et al., 1997] Randall, J. E., Allen, G. R. and Steene, R. C. (1997): Fishes of the Great Barrier Reef and coral sea. Reviewed and expanded edition. Crawford House Publishing Pty Ltd. Bathurst, Australia.

[Robblee and Zieman, 1984] Robblee, M. B., and Zieman, J. C. (1984): Diel variation in the ﬁsh fauna of a tropical seagrass feeding ground. Bulletin of Marine Science 34: 335 – 345.

[Roberts, 1997] Roberts, C. M. (1997): Connectivity and management of Caribbean marine reserves. Science 278: 1454 – 1457

[Sogard et al., 1989] Sogard, S. M., Powell, G. V. N., and Holmquist, J. G. (1989): Utilization by ﬁshes of shallow, seagrass-covered banks in Florida Bay: 2. Diel and tidal patterns. Environmental Biology of ﬁshes 24: 81 – 92.

[Unsworth et al., 2007] Unsworth, R. K. F., Bell, J. J., and Smith, D. J. (2007): Tidal ﬁsh connectivity of reef and sea grass habitats in the Indo-Paciﬁc. Journal of the Marine Biological Association of the United Kingdom 87: 1287 – 1296.

[Warner et al., 1975] Warner, R. R., Robertson, D. R., and Leigh, E. G. (1975): Sex change and sexual selection. Science 170: 633 – 638.

[Warner and Hoffman, 1980] Warner, R. R., and Hoffman, S. G. (1980): Population density and the economics of territorial defense in a coral reef ﬁsh. Ecology 61: 772 – 780.

[Watson and Quinn, 1997] Watson, R. A. and Quinn, J. T. (1997): Performance of transect and point count underwater visual census methods. Ecological Modelling 104: 103 – 112

[www.chumbeisland.com, 2012] www.chumbeisland.com, 14.03.2012, 16:19

110 Acknowledgements

I would like to thank my both supervisors, Dr. Christopher A. Muhando and Dr. Hauke Reuter, for their help, support and organisation during my thesis and ﬁeld work. I also want to thank the staff at Chumbe Island and the management for the opportunity to work on their island and their support during my ﬁeld work. Thanks also to the whole staff at the Institute of Marine Science on Zanzibar, who helped me with their assistance.

Thanks to Prof. Dr. Kai Bischof for joining the committee for my thesis defense.

A special thank to Phd. candidate Maren Kruse. We did the field work and fish identification together and overcame every obstacle.

Thanks to the Zanzibar team of my fellow masterstudents, Kristin, Marisol and John. It was a great time together with you!

Thanks to my family. They supported me during all the time.

Last I would like to say thank you to Oliver, my life partner. He supported me also during his holidays on the island and lend us a hand during our ﬁeld work. He also solved my computer problems, especially with LaTex. A. Abundance boxplots

(a) Acanthurus leucosternon (b) Chaetodon trifasciatus

(e) Thalassoma hebraicum (f) Lethrinus mahsena

Figure A.1: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during high tide in a neap cycle.

112 (a) Centropyge multispinis (b) Plectroglyphidodon lacrymatus

Figure A.2: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during high tide in a neap cycle.

113 (a) Chaetodon trifasciatus (b) Gomphosus caeruleus

(e) Chromis viridis (f) Plectroglyphidodon lacrymatus

Figure A.3: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during high tide in a spring cycle.

114 (a) Siganus sutor

Figure A.4: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during high tide in a spring cycle.

(a) Chromis viridis

Figure A.5: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both cycles during high tide in the coral reef.

115 (a) Chaetodon trifasciatus (b) Gomphosus caeruleus

(e) Chromis viridis (f) Plectroglyphidodon lacrymatus

Figure A.6: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during low tide in a neap cycle.

116 (a) Siganus sutor

Figure A.7: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during low tide in a neap cycle.

117 (a) Cheilio inermis (b) Thalassoma hebraicum

(e) Chlorurus sordidus (f) Sphyraena ﬂavicauda

Figure A.8: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during low tide in a spring cycle.

118 (a) Canthigaster valentini

Figure A.9: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during low tide in a spring cycle.

119 (a) Acanthurus leucosternon (b) Ctenochaetus binotatus

(e) Stethojulis bandanensis (f) Thalassoma hebraicum

Figure A.10: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both cycles during low tide in the coral reef.

120 (a) Centropyge multispinis (b) Chromis atripectoralis

(e) Chlorurus sordidus (f) Scarus niger

Figure A.11: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both cycles during low tide in the coral reef.

121 (a) Canthigaster valentini

Figure A.12: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both cycles during low tide in the coral reef.

(a) Stethojulis bandanensis (b) Pomacentrus trilineatus

Figure A.13: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both cycles during low tide in the seagrass bed.

122 (a) Oxymonacanthus longirostris (b) Chromis atripectoralis

Figure A.14: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both tides in a neap cycle in the coral reef.

123 (a) Chaetodon trifascialis (b) Gomphosus caeruleus

(e) Chromis viridis (f) Plectroglyphidodon lacrymatus

Figure A.15: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both tides in a spring cycle in the coral reef.

124 (a) Chaetodon trifascialis (b) Canthigaster valentini

Figure A.16: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both tides in a spring cycle in the coral reef.

(a) Stethojulis bandanensis

Figure A.17: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both tides in a neap cycle in the seagrass bed.

125 (a) Lethrinus mahsena (b) Pomacentrus trilineatus

Figure A.18: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both tides in a neap cycle in the seagrass bed.

126 (a) Acanthurus nigrofuscus (b) Ctenochaetus binotatus

(e) Chaetodon trifasciatus (f) Cheilio inermis

Figure A.19: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunset in a neap cycle.

127 (a) Gomphosus caeruleus (b) Thalassoma hebraicum

(e) Chlorurus sordidus (f) Siganus sutor

Figure A.20: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunset in a neap cycle.

128 (a) Stethojulis bandanensis (b) Thalassoma hebraicum

(e) Chromis viridis (f) Scarus niger

Figure A.21: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both times in a neap cycle in the coral reef.

129 (a) Stethojulis bandanensis (b) Lethrinus mahsena

Figure A.22: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both times in a neap cycle in the seagrass bed.

130 (a) Acanthurus leucosternon (b) Platax teira

(e) Thalassoma hebraicum (f) Lethrinus mahsena

Figure A.23: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunset in a spring cycle.

131 (a) Amblyglyphidodon leucogaster (b) Chromis atripectoralis

(e) Pomacentrus trilineatus (f) Leptoscarus vaigiensis

Figure A.24: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunset in a spring cycle.

132 (a) Cephalopholis boenak (b) Siganus sutor

Figure A.25: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunset in a spring cycle.

(a) Halichoeres hortulanus (b) Stethojulis bandanensis

Figure A.26: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both times in a spring cycle in the coral reef.

133 (a) Ctenochaetus striatus (b) Stethojulis bandanensis

Figure A.27: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both times in a spring cycle in the seagrass bed.

134 (a) Chaetodon trifasciatus (b) Stethojulis bandanensis

(e) Siganus sutor

Figure A.28: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunrise in a neap cycle.

135 (a) Chaetodon trifasciatus (b) Meiacanthus mossambicus

(e) Chromis viridis (f) Plectroglyphidodon lacrymatus

Figure A.29: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunrise in a spring cycle.

136 (a) Siganus sutor

Figure A.30: Boxplots of the species with a signiﬁcant difference in terms of abundance for the comparison between both habitat types during sunrise in a spring cycle.

137 B. Biomass boxplots

(a) Chaetodon guttatissimus (b) Chaetodon trifasciatus

(e) Lethrinus mahsena (f) Parupeneus macronemus

Figure B.1: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during high tide in a neap cycle.

138 (a) Chaetodon trifascialis (b) Chaetodon trifasciatus

(e) Pseudocheilinus hexataenia (f) Thalassoma hebraicum

Figure B.2: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during high tide in a spring cycle. (a) Parupeneus macronemus (b) Chromis viridis

Figure B.3: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during high tide in a spring cycle.

140 (a) Thalassoma hebraicum (b) Chromis viridis

Figure B.4: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both cycles during high tide in the coral reef.

(a) Meiacanthus mossambicus (b) Cheilio inermis

Figure B.5: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both cycles during high tide in the seagrass bed.

141 (a) Ctenochaetus binotatus (b) Chaetodon trifasciatus

(e) Parupeneus macronemus (f) Chromis viridis

Figure B.6: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during low tide in a neap cycle.

142 (a) Plectroglyphidodon lacrymatus (b) Chlorurus sordidus

Figure B.7: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during low tide in a neap cycle.

143 (a) Acanthurus leucosternon (b) Thalassoma hardwicke

(e) Canthigaster valentini

Figure B.8: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during low tide in a spring cycle.

144 (a) Acanthurus leucosternon (b) Ctenochaetus binotatus

(e) Chaetodon trifascialis (f) Stethojulis bandanensis

Figure B.9: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both cycles during low tide in the coral reef.

145 (a) Thalassoma hebraicum (b) Cantherhines pardalis

(e) Plectroglyphidodon lacrymatus

Figure B.10: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both cycles during low tide in the coral reef.

146 (a) Cheilio inermis (b) Pomacentrus trilineatus

Figure B.11: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both cycles during low tide in the seagrass bed.

147 (a) Chaetodon guttatissimus (b) Amanses scopas

(e) Chromis weberi

Figure B.12: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both tides in a neap cycle in the coral reef.

148 (a) Acanthurus leucosternon (b) Chaetodon trifascialis

(e) Cantherhines pardalis (f) Parupeneus macronemus

Figure B.13: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both tides in a spring cycle in the coral reef.

149 (a) Pomacanthus semicirculatus (b) Chromis viridis

(e) Scarus frenatus (f) Canthigaster valentini

Figure B.14: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both tides in a spring cycle in the coral reef.

150 (a) Meiacanthus mossambicus (b) Cheilio inermis

Figure B.15: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both tides in a neap cycle in the seagrass bed.

151 (a) Acanthurus leucosternon (b) Labroides dimidiatus

(e) Pomacentrus trilineatus (f) Canthigaster valentini

Figure B.16: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both tides in a spring cycle in the seagrass bed.

152 (a) Acanthurus nigrofuscus (b) Ctenochaetus binotatus

(e) Chaetodon trifasciatus (f) Gomphosus caeruleus

Figure B.17: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunset in a neap cycle.

153 (a) Labroides dimidiatus (b) Thalassoma hebraicum

(e) Chlorurus sordidus (f) Siganus sutor

Figure B.18: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunset in a neap cycle.

154 (a) Meiacanthus mossambicus (b) Halichoeres hortulanus

(e) Amanses scopas (f) Centropyge multispinis

Figure B.19: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a neap cycle in the coral reef.

155 (a) Chromis viridis (b) Chromis weberi

Figure B.20: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a neap cycle in the coral reef.

156 (a) Stethojulis bandanensis (b) Pomacentrus trilineatus

(e) Sphyraena ﬂavicauda

Figure B.21: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a neap cycle in the seagrass bed.

157 (a) Acanthurus leucosternon (b) Meiacanthus mossambicus

(e) Thalassoma hebraicum (f) Amblyglyphidodon leucogaster

Figure B.22: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunset in a neap cycle.

158 (a) Chromis atripectoralis (b) Chromis viridis

(e) Scarus rubroviolaceus (f) Cephalopholis boenak

Figure B.23: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunset in a neap cycle.

159 (a) Siganus sutor (b) Sphyraena ﬂavicauda

Figure B.24: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunset in a neap cycle.

160 (a) Halichoeres hortulanus (b) Pseudocheilinus hexataenia

(e) Cantherhines pardalis (f) Scarus caudofasciatus

Figure B.25: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a spring cycle in the coral reef.

161 (a) Scarus frenatus (b) Canthigaster valentini

Figure B.26: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a spring cycle in the coral reef.

162 (a) Ctenochaetus striatus (b) Cheilio inermis

(e) Thalassoma hebraicum (f) Chromis viridis

Figure B.27: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a spring cycle in the seagrass bed.

163 (a) Pomacentrus trilineatus (b) Sphyraena ﬂavicauda

Figure B.28: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both times in a spring cycle in the seagrass bed.

164 (a) Meiacanthus mossambicus (b) Chaetodon trifasciatus

(e) Cantherhines pardalis (f) Plectroglyphidodon lacrymatus

Figure B.29: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunrise in a neap cycle.

165 (a) Siganus sutor

Figure B.30: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunrise in a neap cycle.

166 (a) Meiacanthus mossambicus (b) Chaetodon trifasciatus

(e) Parupeneus macronemus (f) Chromis viridis

Figure B.31: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunrise in a spring cycle.

167 (a) Plectroglyphidodon lacrymatus (b) Siganus sutor

Figure B.32: Boxplots of the species with a signiﬁcant difference in terms of biomass for the comparison between both habitat types during sunrise in a spring cycle.

168 Statement

Statement according to S6 (8) Prüfungsordnung der Universität Bremen für den Masterstudi- engang “International Studies in Aquatic Tropical Ecology” (ISATEC) vom 7. Januar 2002: Hereby I declare that I have written this Master’s Thesis by my own and without any assistance from third parties. Furthermore, I conﬁrm that no other sources and resources have been used than those indicated in the thesis itself and that all quotations are marked.

Bremen, 15.08.2012 / Melanie Klaus