A Study of Coral Reef Fishes along a Gradient of Disturbance in the Langkawi Archipelago, Malaysia
Karin Andersson
Arbetsgruppen för Tropisk Ekologi Minor Field Study 83 Committee of Tropical Ecology Uppsala University, Sweden November 2002 Uppsala A Study of Coral Reef Fishes along a Gradient of Disturbance in the Langkawi Archipelago, Malaysia
Karin Andersson
Undergraduate Thesis in Biology Examensarbete i biologi, 20 poäng HT 2002 Department of Animal Ecology, Uppsala University, Sweden Supervisors: Prof. Göran Milbrink and Dr. Bo Tallmark, Uppsala University Mr Muhamad Nasir Abdul Salam, World Wide Fund for Nature, Malaysia ABSTRACT
The coral reefs in the Langkawi archipelago, Malaysia, are threatened by human disturbance, mainly sediment run-off from land and fishing. The coral reefs are important as many organisms, among them the coral reef fishes, are depending on them for survival. They are also economically important as a tourist attraction and as a breeding ground for commercially important fishes. My aims were to investigate if there are any differences in the fish communities between sites with different human disturbance and to see which substrate variables that are best correlated with the fish community. I also looked at the possibility to use butterflyfishes as indicator organisms of the health of the coral reefs in the area. At four sites with different levels of human disturbance, an inventory study of the coral reef fishes, using the Fish Visual Census method, as well as their substratum, using the Line Intercept Transect method, was carried out. There are significant differences between sites with low and high disturbance concerning both fish abundance and number of fish families. The abundance of fish and the number of families were significantly correlated with the live coral cover. The fishes are dependent on the live coral cover for food and shelter. No correlation was found between the fishes and the substrate diversity or the cover of the branching coral Acropora, which is probably because of the very sparse distribution of this genus in the area. The abundance of butterflyfish and the number of species were higher at the sites with little disturbance and the abundance of butterflyfish was also correlated to the live coral cover. This makes them useful as bioindicators in the area. The reefs at the Langkawi archipelago are threatened by the intensive human activities in the area. The live coral cover decreases with increasing disturbance, mostly sedimentation from construction work on the main island. The degradation of the corals affects the coral reef fishes negatively. If nothing is done to minimise the flow of sediment into the sea, this will lead to even more damaged reefs in the area in the future.
Keywords: Langkawi, Pulau Payar marine park, coral reef, coral reef fish, butterflyfish, Chaetodontidae, bio-indicators
2 FOREWORD
This study is part of the project “Vision of a blue environment, conservation planning for the Langkawi archipelago” and is initiated by the World Wide Fund for Nature, Malaysia (WWFM). The aim is to conduct a survey and a research study of the area, especially the marine and coastal zone, and to encourage integrated planning and responsible actions for the overall conservation of the Langkawi archipelago.
The fieldwork was carried out together with Dagmar Jonsson who has also written a report on the data we collected (Jonsson, 2002). Her report is focused on the coral community, while this study focus on the coral reef fishes and their response to the human disturbance.
3 TABLE OF CONTENTS
Introduction...... 5 Coral reefs...... 5 Coral reef fishes...... 5 Marine reserves...... 6 Factors affecting reef fish communities ...... 6 Butterflyfishes as indicator organisms...... 6 Description of the area...... 7 Aim ...... 8 Methods...... 8 Site descriptions...... 8 Pulau Payar...... 8 Pulau Singa Besar...... 9 Teluk Datai ...... 9 Pulau Rebak Besar...... 9 Field methods...... 9 Data analysis...... 11 ANOVA-tests ...... 11 Multivariate analysis ...... 12 Correlation tests...... 12 Results ...... 12 Comparison of fish families between sites ...... 12 Abundance...... 13 Number of families...... 15 Diversity ...... 16 Comparison of butterflyfishes between sites...... 17 Abundance...... 18 Number of species ...... 19 Feeding categories...... 20 Multivariate analysis of fish families ...... 22 Correlation tests...... 23 Correlation between fishes and substrate ...... 23 Correlation between fishes and weather and water conditions ...... 24 Discussion ...... 24 Differences between and within sites ...... 24 Comparisons with previous studies ...... 25 Marine reserves...... 25 Correlations between fish communities and the coral reef...... 26 Butterflyfishes as indicator organisms...... 27 Conclusions...... 28 Acknowledgement...... 29 References...... 30 Appendix I ...... 33 Appendix II...... 37
4 INTRODUCTION
Coral reefs have existed on the planet for hundreds of millions of years. They have the greatest diversity per unit area of any marine ecosystem. Many animals depend on the reefs for food and shelter and the coral reefs are among the most productive systems in the marine environment. The corals are sensitive to a number of natural and human induced disturbances that today seem to be challenging their continued survival.
Coral reefs The coral reef is primarily built up of hermatypic i.e. reef building corals. The coral animal belongs to the phylum Cnidaria and the class Anthozoa. They secrete an external skeleton consisting of calcium carbonate and each individual animal is occupying a cup or corallite in the massive skeleton. Around the mouth of each individual there is a series of tentacles with nematocysts that the animal uses for capturing zooplankton for food. The coral animal lives in symbiosis with zooxantellae, a dinoflagellate, which live in its tissue. The zooxantellae provide the coral with carbon compounds through photosynthesis (Nybakken, 2001). Coral reefs have been estimated to occupy 1 500 000 km2 or 0.17% of the total area of the planet. They are distributed in all the tropical seas but their distribution is limited since they have specific requirements of the environment in which they occur. The corals need a temperature of 23-25 °C and a salinity of 32-35 psu. The light needed for photosynthesis limits their downward growth and most coral reefs grow at a depth of 25 m or less. The upward growth is limited by air exposure as corals can be exposed for short time periods only. The lowest tide often marks the upper limit of the reef (Nybakken, 2001). Coral reefs do not only consist of coral animals. A wide variety of animals and plants also live in this ecosystem. They include algae, sponges, clams, polychaetes, sea cucumbers, sea urchins, soft corals, and fishes (Nybakken, 2001).
There are several reasons why a study of the status of the coral reefs in the Langkawi archipelago in Malaysia should be carried out. Pollution and overfishing, especially by destructive fishing methods, is damaging the reefs in the Andaman Sea (Chou et al., 1994). The major stresses to coral reefs result directly from human activities such as excessive nutrient and sedimentation run-off from the land into the sea (Wilkinson & Ridzwan, 1994). The coral reefs are economically important to Malaysia for two reasons: fishing and tourism. Fish productivity is much higher on coral reefs than anywhere else. Studies have shown that 10-30% of the fish catches from coastal waters in Malaysia are coral reef associated (Wan Portiah, 1990). Income from tourism in Asia has been growing by more than 18% per year with beaches and coral reefs being a major attraction (Chou et al., 1994).
Coral reef fishes Coral reefs harbour more species and more diverse fish communities than any other environment on earth. One of the reasons for the high diversity is the great variety of habitats that exists on reefs. Coral reefs encompass different zones of coral species progressing across the reef but also areas of sand, caves and algae. There is also a difference in fish composition between day and night where the nocturnal fishes can have the same ecological niche as the diurnal ones, thus permitting a greater number of species on the reef (Nybakken, 2001). The most abundant fish feeding types on reefs are the carnivores, which may constitute 50-70% of the fish species, and most of these carnivores are opportunistic. Herbivores and coral grazers make up the second largest group, about 15%. The remainder of the fishes are generally classified as omnivores (Goldman & Talbot, 1976). Many fishes spend all their lives on the reefs, but the coral reef also serves as a breeding and nursery ground for many other fishes (Polunin & Roberts, 1993).
5 Marine reserves Fishing causes a change in fish community structure caused by the removal of fishes, the destruction of habitat and because some fishing methods force fishes to move to another area of the reef (Russ & Alcala, 1989). Especially target species favoured by fishermen, mostly large predatory fishes, are decreasing (Grigg, 1994; Russ & Alcala, 1989). There are four main functions of marine reserves: (1) to maintain species diversity and abundance within the area, (2) to provide undisturbed breeding sites for the fishes, (3) to export fish biomass through migration of adults and (4) to export fish biomass through larval dispersal (Alcala, 1988; Russ & Alcala, 1989; Polunin & Roberts, 1993).
Factors affecting reef fish communities The coral reef is important for the fishes that live there. Among other things it provides food and shelter. The factors of the reef that are the most important to the coral reef fishes have been widely discussed. Some studies claim that live coral cover is most important (Bell & Galzin, 1984; Hourigan et al., 1988), especially for coral feeders (Sano et al., 1984 and 1987; Öhman & Rajasuriya, 1998). Other studies have found that substratum diversity affects the fishes the most (Roberts & Ormond, 1987; McCormick, 1994). The third factor which has an effect on the coral reef fishes is the structural diversity (Luckhurst & Luckhurst, 1978; McClanahan, 1994; McCormick, 1994; Grigg, 1994; Gladfelter et al., 1980).
Butterflyfishes as indicator organisms The butterflyfish family (Chaetodontidae) contains 114 species in 10 genera distributed in all the tropical seas (Lieske & Myers, 2001). Many of the species are obligate coral feeders and have coevolved with the corals they feed on (Hourigan et al., 1988). This makes them good candidates for serving as indicators of disturbance in coral reefs (Reese, 1981; Hourigan et al., 1988; Crosby & Reese, 1996). Since butterflyfishes are large, conspicuous and diurnal it makes them relatively easy to monitor compared to the coral substratum. Fishes are motile and may leave the reef if it detoriates as habitat (Reese, 1981; Hourigan et al., 1988). Especially corallivorous specialists are considered to be good indicators as they are expected to migrate rather than change their diets if their food source disappears (Reese, 1981; Hourigan et al., 1988; Öhman et al., 1998).
This theory has been tested in several areas. Some studies have shown a correlation between live coral cover and the abundance of butterflyfishes, especially for species that are obligate corallivores (Bell & Galzin, 1984; Bouchon-Navaro & Bouchon, 1989; Öhman et al., 1998). Others have demonstrated a correlation between coral complexity and butterflyfish abundance (Luckhurst & Luckhurst, 1978; Bouchon-Navaro & Bouchon, 1989; Öhman & Rajasuriya, 1998). The correlation between butterflyfishes and live coral cover and structural complexity is related to food availability (Öhman et al., 1998) and shelter (Bouchon-Navaro & Bouchon, 1989).
Other studies also show how butterflyfishes are affected by disturbance. Especially the coral specialists among the butterflyfishes, are most affected by the death of corals caused by Acanthaster planci infestation (Sano et al., 1984 and 1987). Russ & Alcala (1989) found that destructive fishing reduces butterflyfish density and species number. There is, however, some criticism to this idea. Roberts et al. (1992) found that butterflyfish distribution varies among reef types and habitats due to natural variation and types of disturbance. Roberts & Ormond (1987) and Cox (1994) found that butterflyfishes are only weakly correlated with live coral cover.
6 Description of the area The Langkawi archipelago is situated in the straits of Malacca in the northern part of the west coast of Peninsular Malaysia (06° 18' N, 99° 47' E) (Figure 1). It is one of the few coral-reef areas of the west coast of Peninsular Malaysia (Rashid, 1980). It consists of about 100 islands, with a total landmass of 47 847 hectares, out of which the main island (Pulau Langkawi) constitutes 32 000 hectares. The southernmost islands in the archipelago form the Pulau Payar Marine Park originally established in 1987 as “Fisheries protected area” and subsequently as a marine park in 1994 (Nickerson-Tietze, 2000).
Figure 1. The Langkawi archipelago is situated in the northwestern part of Peninsular Malaysia.
The Straits of Malacca receive pollutants from three main categories of sources: agricultural, industrial and domestic wastes from land-based activities (Dow, 1995). Langkawi is developing as a major tourist centre for the northern region of Peninsular Malaysia. It has been aggressively promoted overseas, mainly by the Langkawi Development Authority (LADA) (Lim, 1998). The water quality in the area is affected by land-based activities such as the infrastructure development on Langkawi for tourism, agricultural sources, industries, mining and growth of the local population (Nickerson-Tietze, 2000).
7 Aim The aims of this study are: (1) to see if there are any differences in the fish community between sites affected by different amounts of disturbance. (2) to see which substrate variables are best correlated with the fish community. (3) to see if there is a possibility to use butterflyfishes as indicator organisms of the health of the coral reef.
METHODS
Site descriptions I chose four areas with different amounts of human disturbance. Disturbances in this area are mainly of two kinds. One is fishing on and around the reefs, the other is siltation, i.e. sedimentation of fine material, mostly from land clearing and construction. The sites are presented in the order from the least disturbed to the most disturbed.
Pulau Payar This site is situated on the eastern side of Pulau Payar in Pulau Payar Marine Park 6° 3' N, 100° 2' E (Figure 2), 10 nautical miles south of Pulau Langkawi. The reef is facing eastwards and is approximately 250 x 30 m. The site was used as a control site in this study since human disturbance here is lower than in the rest of the Langkawi archipelago and the amount of sediment in the water is considerably lower. Pulau Payar Marine Park consists of four different islands where fishing is forbidden within 2 nautical miles from the islands. Many tourists visit the marine park, mainly recreational snorkellers and divers. In the year 2000 there were 110 000 people visiting the park. In order to avoid most of the disturbance, I chose the study site in a part of the marine park with very few snorkellers.
Figure 2. The four sites in the study in the Langkawi archipelago, Malaysia.
8 Pulau Singa Besar This site is situated in the middle part of a bay in the southern part of Pulau Singa Besar (6° 11' N, 99° 43' E) (Figure 2) and is facing southeast. The size of the reef is approximately 50 x 300 m. Pulau Singa Besar is considered to be the least disturbed site by human activity in my study. The island is situated some distance away from the main island, the sedimentation rate is low, and there are no buildings on the southern part of the island. The bay is fished from small boats, and there is also one fish trap on the reef. Outside the bay larger fishing boats are passing by, but the number is limited.
Teluk Datai This site is situated in Teluk Datai in the northern part of Pulau Langkawi, 6° 25’ N, 99° 40’E (Figure 2). The bay opens towards the north. The reef is situated in the eastern part of the bay and is approximately 600 m long and 100 m wide. Teluk Datai is considered to be the second most disturbed site by human activities with two hotels around the bay. There may be possible fertilisers and sediment runoff into the water east of the bay where a golf course is located. The amount of sediment, and how much of it that is flowing into Datai bay, is not known. There are several types of human activity on and around the reef with a limited amount of snorkelling, kayaking and sailing in the bay. Fishing in the area is conducted mostly from smaller fishing boats. There are also a few fish traps in the area. In the strait outside the bay there is some traffic with large cargo ships.
Pulau Rebak Besar This site is situated on the northwestern part of Pulau Rebak Besar 6° 17’ N, 99° 41’E (Figure 2). The reef is facing northwards and is approximately 40 x 300 m. Pulau Rebak Besar is considered to be the site most disturbed by human activity in this study. On the southern part of the island there is a hotel, a marina and a crystal factory. The airport is situated 1 km east of the island. The area around the airport is reclaimed land and with a wave-breaker which serves as a protective barrier. The island is also situated close to Pantai Chenang, an area with lots of hotels and restaurants. Several fishing boats can be seen around the reef.
Field methods Data were collected during December 2001 and January 2002. A Line Intercept Transect (LIT) method was used to investigate the substratum (English et al., 1997). 20-meter long measuring tapes were laid out on the reef, as close to the substratum as possible, to record the length (cm) of each component. The components recorded include live coral identified to the generic level and other substrates covering the reef (for further details, see Table 1). The corals were identified in accordance with Searle (1956), Richmond (1997) and Veron (1986).
9 Table 1. All coral genera and other substrate components recorded in the LIT measurements. Coral genera Other substrates Acropora Merulina Anemone Alveoproa Montastrea Dead coral with algae Asteropora Montipora Dead coral Cyphastrea Mycedium Dead coral rubble Diplosatrea Oxypora Dead coral covered with sediment Echinopora Pavona Other non-coral matter Euphyllia Pachyseris Sand or silt Favia Pectina Sponge Favites Platygyra Fungia Pleurogyra Galaxea Pocillophora Goniopora Porites Goniastrea Psammocora Halomitra Symphyllia Hydnopora Turbinaria Lobophyllia
The Fish Visual Census Method (English et al., 1997) was used to examine the fish fauna. The fish population was counted from the bottom to the surface, within 1 m of each side of a 20-m long line. Most of the fish were then identified to the family level except for the butterflyfish (Chaetodontidae), which were identified to the species level according to Lieske and Myers (2001). The fish censuses were conducted between 10.00 a.m. and 3.00 p.m. to minimise bias in fish abundance patterns caused by diurnal variation. To minimise the impact of human disturbance, the counts were initiated ten minutes after the line was laid out and if the Fish Visual Census and the LIT were carried out on the same day, the fish counts were conducted before the LIT.
32 transects were arranged on each site at four different distances from the shore (level 1-4). Each level had eight transects parallel to the shore. The innermost line of transects was placed on the inner part of the reef (level 1) and the outermost line of transects on the outer part of the reef -1 m below the reef crest (level 4). The levels in between were arranged with equal distances in between. Within each level the transects were spaced out along the whole width of the reef (Figure 3). We defined the border of a reef to be where 50% of the substratum consisted of coral structure (living coral, dead coral, dead coral covered with sediment or dead coral covered with algae).
Figure 3. Arrangement of the transects at each site.
10 For each transect the reef components and the fishes were recorded and the depth was approximated as well as the sea state, the wind and the cloud cover. The wind force was approximated using 5 categories and the sea state was approximated in accordance with English et al. (1997) using 5 categories shown in Table 2. Even though there are five categories for both wind and sea state, only categories 1-3 were recorded. In rough weather, conditions were not suitable for data collection. The sky was divided into eight equally sized parts and the number of units covered by clouds was then counted.
Table 2. The wind force categories and sea state criteria approximated during the fieldwork. From English et al. (1997). Category Wind (knots) Description Sea state Sea criteria 1 0-5 Light air Calm Mirror-like to small ripples 2 6-10 Gentle breeze Smooth Large wavelets, crests beginning to break 3 11-15 Moderate breeze Slight Small waves becoming longer 4 16-20 Fresh breeze Moderate Many white caps forming 5 21-25 Strong breeze Rough Large waves, extensive white caps
The temperature, salinity and dissolved oxygen in the water at a depth of 1 m below the ocean surface were recorded several times during the day using a YSI Model 85. This was done from a boat in Pulau Singa Besar and Pulau Rebak Besar and 10 m from the shore in Teluk Datai and Pulau Payar. The turbidity of the water in the area of the transects was also recorded several times during the day using a portable Turbidimeter Model 2100P. Three samples were taken, at the surface, in the middle of the water column and close to the bottom.
Data analysis ANOVA-tests In order to evaluate the differences within and between the sites I analysed the data with a two-way ANOVA. The following variables were analysed: the total abundance of fish, the fish diversity (the Shannon-Wiener diversity index) and the number of families. Fish of the families damselfishes (Pomacentridae) and fusiliers (Caesionidae) sometimes formed large schools that could make up two thirds of the total number of fish in a transect. Therefore the variable “abundance of fish except damselfishes and fusiliers ” was also tested.
To get an opinion of the butterflyfish family (Chaetodontidae) I analysed two variables, their abundance and the number of species. I also separated the butterflyfishes into three different feeding categories and analysed these categories. The feeding categories are; obligate coral feeders, omnivores and invertebrate feeders in accordance with Steene (1977), Allen (1979), Harmelin-Vivien (1989), Randall et al. (1990), and Lieske & Myers (2001).
In order to test the homogeneity of variance I carried out a Bartlet’s test. For the variables families, diversity indices, butterflyfish species, omnivores and invertebrate feeders no transformation was needed. The variables abundance of butterflyfish and obligate coral feeders had to be square root transformed and the variables total abundance and “abundance of fish except damselfishes and fusiliers ” had to be double square root transformed in order to perform an ANOVA-test.
11 Multivariate analysis A multivariate analysis was carried out using the multivariate analysis program CANOCO 4.0 in order to see a pattern in how the fish families were distributed on the reef in comparison with other families and environmental variables. In this analysis all the 128 transects were included. Each transect contained the number of fish in each family and the environmental variables for that transect. The fish families found in fewer than four transects were not included in the data. The environmental variables included in the test were the rubble cover (Rubble), the sand cover (Sand), the dead coral cover (Dead), the live coral cover (Living), what reef (Reef) and at what distance to the beach (i.e. transect level) (distance to beach) the transect was recorded. The variable reef was given a numeric value (1 to 4) from the least disturbed site, Pulau Payar, to the most disturbed site, Pulau Rebak Besar. The model used to treat the data was principal component analysis (PCA). This is an indirect gradient analysis in which the environmental variables are not explaining all the variation in the data. The data are instead arranged optimally and the environmental variables are then arranged to maximise their fit. The environmental variables were expected to follow a linear gradient.
The results are plotted in an ordination diagram containing all the families as dots and the environmental variables as arrows. The length of an arrow indicates its importance. Species that occur close together were often recorded in the same transect. If the families are placed along an arrow it indicates the importance of the environmental variable for that fish family.
Correlation tests To test the relationship between the fish variables and the different habitat variables I used Spearman’s rank correlation. The fish variables are the same as for the ANOVA-test. The habitat variables which I used were: the live coral cover, the dead coral cover, the sediment covered coral cover, the depth, the distance level from the shore, the habitat diversity, the number of coral genera, the sand cover, the coral rubble cover, and the cover of the coral genus Acropora. I also analysed the correlation between the fish variables and the environmental variables: sea state, wind and cloud cover.
To calculate the habitat diversity index I used the Shannon-Wiener diversity index and used all substrate components. To calculate the depth of each site I used the approximate depth recorded during the fieldwork minus the height of the tide at the time of the recording in accordance with a tide-table. The height of the tide was given in m above the lowest spring tide.
RESULTS
Comparison of fish families between sites At each site, 1280 m2 of the reef were investigated, i.e. a total of 5120 m2 for all the four sites. In all the sites 12 712 fishes belonging to 27 families were recorded (Table 3). Ten families were found at all the sites. The most abundant family was the damselfishes (Pomacentridae) with 8 341 fishes, two thirds of the total number of fish. Other abundant families were wrasses (Labridae), fusiliers (Caesionidae) and parrot fishes (Scaridae). Even though many fusiliers were recorded they were only found in two of the sites, Pulau Payar and Pulau Singa Besar (Table 3).
12 Table 3. The number of fish recorded in each family at each site. Family English name Pulau Payar Pulau Singa Teluk Datai Pulau Rebak Total Besar Besar Pomacentridae Damselfishes 4 590 2 712 558 481 8 341 Labridae Wrasses 554 313 107 148 1 122 Caesionidae Fusiliers 834 10 - - 844 Scaridae Parrot fishes 346 302 89 3 740 Caetodontidae Butterflyfishes 142 214 61 24 441 Pempheridae Sweepers 131 47 36 1 215 Apogonidae Cardinal fishes 88 63 11 43 205 Siganidae Rabbitfishes 102 46 12 2 162 Gobiidae Gobies 19 48 38 30 135 Serranidae Groupers 53 19 31 29 132 Nemipteridae Monocle breams 9 99 5 12 125 Holocentridae Squirrel fishes 50 1 23 - 74 Lutjanidae Snappers 34 22 1 - 57 Zanclidae Moorish idols 23 14 - - 37 Pomacanthidae Angle fishes 13 - 2 - 15 Centriscidae Shrimpfishes - - - 15 15 Carangidae Trevallys 15 - - - 15 Blenniidae Blennies 11 - - - 11 Mugilidae Mullets 9 - - - 9 Muraenidae Moray eels - 2 - 2 4 Ostraciidae Trunk fishes 1 1 - 1 3 Mullidae Goat fishes - 1 2 - 3 Diodontidae Porqupine fishes 1 1 - - 2 Tetraodontidae Puffer fishes 2 - - - 2 Haemulidae Sweetlips - - 1 - 1 Carcharhinidae Sharks 1 - - - 1 Fistulariidae Cornet fishes 1 - - - 1 Total 7 029 3 915 977 791 12 712
Pulau Payar has the highest abundance of fish, i.e. 7 029 fishes in 23 families. Six of the families were only found at this site. The total abundance of fish was 549 fishes per 100 m2. Pulau Singa Besar had the second highest abundance of all the sites, i.e. 3 915 fishes in 18 families. The total abundance was 306 fishes per 100 m2. Teluk Datai had 977 fishes in 15 families. One family was only found at this site. The abundance of fish was 76 individuals per 100 m2. Pulau Rebak Besar had the lowest abundance of all sites with 791 fishes in 13 families. One family was only found at this site. The abundance was 61 fishes per 100 m2.
Abundance There is a highly significant difference in total abundance between sites (ANOVA, F=109.39, df=3, p<0.001). The total abundance of fish is highest in Pulau Payar and second highest is Pulau Singa Besar. Teluk Datai and Pulau Rebak Besar have both a low total abundance of fish (Figure 4 and Table 4). For the category “abundance of fish except damselfishes and fusiliers ” the pattern is the same (ANOVA, F= 53.98, df=3 p<0.001 and Table 5) but the numbers are lower (Figure 4).
13 300
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0 Pulau Payar Pulau Singa Besar Teluk Datai Pulau Rebak Besar Number of individuals per transect Figure 4. The means of the total abundance of coral reef fishes (dark bars) and the abundance of fish except damselfishes and fusiliers (grey bars) per transect at the four study sites. 32 observations were made per site. Error bars indicate standard errors.
Table 4. Results from Tukey’s pairwise comparison of the total abundance of coral reef fishes between the different sites. 32 observations were made per site. Pulau Singa Besar Teluk Datai Pulau Rebak Besar T p-value T p-value T p-value Pulau Payar -7.95 <0.001 -15.26 <0.001 -15.70 <0.001 Pulau Singa Besar - - -7.31 <0.001 -7.75 <0.001 Teluk Datai - - - - -0.43 0.973
Table 5. Results from Tukey’s pairwise comparison of abundance of coral reef fishes except the families damselfishes and fusiliers between the different sites. 32 observations were made per site. Pulau Singa Besar Teluk Datai Pulau Rebak Besar T p-value T p-value T p-value Pulau Payar -4.70 <0.001 -10.34 <0.001 -11.06 <0.001 Pulau Singa Besar - - -5.63 <0.001 -6.37 <0.001 Teluk Datai - - - - -0.72 0.888
For the total abundance of fishes there is a highly significant difference between the levels of distance from the beach (ANOVA, F=29.32, df=3, p<0.001). Within each site there is a trend where the transect level closest to the beach has the lowest abundance, and the transect level furthest away from the beach has the highest abundance (Figure 5). There is also a clear interaction effect (ANOVA, F= 7.90, df=9, p<0.001). As seen in Figure 5, the level furthest away from the beach at Pulau Singa Besar has higher abundance than the other levels.
450 400 350 300 250 200 150 100 50 0
Number of individuals per transect 1234
Figure 5. The means of the total abundance of coral reef fishes per transect for each level of distance at the four study sites Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
14 The same pattern can be seen for “the abundance except damselfishes and fusiliers ” even though the numbers are lower (Figure 6). There is a significant difference between the different levels of distance (ANOVA, F=8.57, df=3, p<0.001); there is also a clear interaction effect (ANOVA, F=5.98, df=9, p<0.001).
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Number of individuals per transect 1234
Figure 6. The means of the abundance of coral reef fishes except for the families damselfishes and fusiliers per transect for each level of distance at the four study sites Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
Number of families There is a highly significant difference between the number of fish families at the different sites (ANOVA, F= 82.02, df=3, p<0.001). Here again the abundance is highest in Pulau Payar, but it is hard to differentiate between Pulau Singa Besar, Teluk Datai and Pulau Rebak Besar all of which have lower numbers of families (Figure 7 and Table 6).
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Number of families per transect Pulau Payar Pulau Singa Teluk Datai Pulau Rebak Besar Besar
Figure 7. The means of numbers of families of coral reef fishes per transect at the four study sites. 32 observations were made per site. Error bars indicate standard errors.
Table 6. Results from Tukey’s pairwise comparison between sites of numbers of families of coral reef fishes per transect. 32 observations were made per site. Pulau Singa Besar Teluk Datai Pulau Rebak Besar T p-value T p-value T p-value Pulau Payar -9.76 <0.001 -12.64 <0.001 -14.32 <0.001 Pulau Singa Besar - - -2.88 0.024 -4.56 <0.001 Teluk Datai - - - - -1.68 0.339
15 There is a highly significant difference between the different levels of distance from the beach (ANOVA, F=13.95, df=3, p<0.001) and an interaction effect (ANOVA, F=3.39, df=9, p<0.001). For Pulau Payar and Pulau Singa Besar there is an increasing number of families with an increasing distance from the beach. Teluk Datai and Pulau Rebak Besar have similar numbers of families over the whole site (Figure 8).
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Figure 8. The means of the numbers of families of coral reef fishes per transect for each level of distance at the four study sites, Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
Diversity There is no significant difference between diversity indices at the different sites (ANOVA, F= 1.51, df=3, p=0.216). As seen in Figure 9 the diversity index is similar for the four sites.
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0.4
Diversity index (H') 0.2
0 Pulau Payar Pulau Singa Teluk Datai Pulau Rebak Besar Besar
Figure 9. The means of Shannon-Wiener diversity index (H’) of coral reef fish per transect at the four study sites. 32 observations were made per site. Error bars indicate standard errors.
There is no significant difference between the different levels of distance from the beach either (ANOVA, F=1.34, df=3, p=0.265), and no interaction effect (ANOVA, F=0.45, df=9, p=0.907) (Figure 10). The diversity index is similar for all the sites of the whole reef.
16 2.5
2
1.5
1
Diversity index (H') 0.5
0 1234
Figure 10. The means of Shannon-Wiener diversity indices (H’) of coral reef fishes per transect for each level of distance at the four study sites, Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
Comparison of butterflyfishes between sites At all the sites 441 butterflyfishes of 12 species were found. Only two species were found at all the sites, i.e. the Collared butterflyfish (Chaetodon collare) and the Eight-banded butterflyfish (Chaetodon octofasciatus). The Collared butterflyfish (C. collare) was the most common species - 275 fishes were found - making up more than half of the total numbers of butterflyfishes (Table 8). Obligate coral feeders was the dominant feeding category. There were 421 fishes of this category compared to 5 that were omnivores and 15 that were invertebrate feeders. What feeding category each fish belongs to can be seen in Table 7.
Most fish were found at the Pulau Singa Besar with 214 fishes belonging to nine species, three of those only found at this site. The abundance was 17 fishes per 100 m2. At the Pulau Payar 142 fishes were found belonging to 7 species. One species was only found at this site. The abundance was 11 fishes per 100 m2. At Teluk Datai 61 fishes belonging to 4 species were found. Two species were only found at this site. The abundance was 5 fishes per 100 m2. The Pulau Rebak Besar site had the lowest fish density, 24 fishes belonging to two species were found here. The abundance was 2 fishes per 100 m2.
Table 7. The species of butterflyfish (Chaetodontidae) that were seen at the four sites. The species are grouped into different feeding categories. Scientific name English name Feeding category Chaetodon collare Collared Butterflyfish Obligate coral feeder Chaetodon octofasciatus Eight-banded Butterflyfish Obligate coral feeder Chaetodon triangulum Triangular Butterflyfish Obligate coral feeder Heniochus singularis Singular Bannerfish Obligate coral feeder Chaetodon trifascialis Chevroned Butterflyfish Obligate coral feeder Chaetodon lineolatus Lined Butterflyfish Omnivores Chaetodon decussatus Indian Vagabond Butterflyfish Omnivores Chaetodon lunula Racoon Butterflyfish Omnivores Chaetodon vagabundus Vagabond Butterflyfish Omnivores Chaetodon rafflesi Latticed Butterflyfish Invertebrate feeder Heniochus acuminatus Longfin Bannerfish Invertebrate feeder Chelmon rostratus Copperbanded Butterflyfish Invertebrate feeder
17 Table 8. The number of butterflyfish (Chaetodontidae) found at each site Pulau Payar Pulau Singa Besar Teluk Datai Pulau Rebak Besar Total Chaetodon collare 65 156 39 15 275 Chaetodon octofasciatus 42 44 20 9 115 Chaetodon triangulum 22 2 0 0 24 Heniochus singularis 0 4 0 0 4 Chaetodon trifascialis 1 2 0 0 3 Chaetodon lineolatus 0 2 0 0 2 Chaetodon decussatus 0 1 0 0 1 Chaetodon lunula 0 0 1 0 1 Chaetodon vagabundus 0 0 1 0 1 Chaetodon rafflesi 6 2 0 0 8 Heniochus acuminatus 4 1 0 0 5 Chelmon rostratus 2 0 0 0 2 Total 142 214 61 24 441
Abundance There is a highly significant difference in the abundance of butterflyfishes between the sites (ANOVA, F= 14.89, df=3, p<0.001). There is no difference between the two sites with the highest abundance, i.e. Pulau Payar and Pulau Singa Besar and there is no difference between the two sites with the lowest abundance either, i.e. Teluk Datai and Pulau Rebak Besar. However, between a site with high abundance and a site with low abundance there is a significant difference (Table 9 and Figure 11).
10 9 8 7 6 5 4 3 2 1 0 Pulau Payar Pulau Singa Teluk Datai Pulau Rebak
Number of individuals per transect Besar Besar
Figure 11. The means of the total abundance of butterflyfishes per transect at the four study sites. 32 observations were made per site. Error bars indicate standard errors.
Table 9. Results from Tukey’s pairwise comparison of the total abundance of butterflyfishes between sites. 32 observations were made per site. Pulau Singa Besar Teluk Datai Pulau Rebak Besar T p-value T p-value T p-value Pulau Payar -1.29 0.573 -4.41 <0.001 -5.91 <0.001 Pulau Singa Besar - - -3.12 0.012 -4.62 <0.001 Teluk Datai - - - - -1.50 0.439
There is a highly significant difference between the different levels of distance from the beach (ANOVA, F=9.93, df=3, p<0.001). There is also an interaction effect (ANOVA, F=8.50, df=9, p<0.001). For Pulau Singa Besar the transect level furthest away from the beach has higher fish abundance than the levels closer to the beach. The other sites have similar abundance at all levels (Figure 12).
18 30
25
20
15
10
5
0
Number of individuals per transect 1234
Figure 12. The means of the total abundance of butterflyfishes per transect for each level of distance at the four study sites, Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
Number of species There is a highly significant difference between sites in the number of species (ANOVA, F= 19.00, df=3, p<0.001). Pulau Payar has the significantly highest number of species followed by the rest of the sites. There is no difference between Teluk Datai and Pulau Singa Besar or Pulau Rebak Besar, but there is a difference between Pulau Singa Besar and Pulau Rebak Besar (Table 10 and Figure 13).
2.5
2
1.5
1
0.5
0
Number of species per transect Pulau Payar Pulau Singa Teluk Datai Pulau Rebak Besar Besar
Figure 13. The means of the numbers of butterflyfish species per transect at the four study sites. 32 observations were made per site. Error bars indicate standard errors.
Table 10. Results from Tukey’s pairwise comparison of the number of butterflyfish species between sites. 32 observations were made per site. Pulau Singa Besar Teluk Datai Pulau Rebak Besar T p-value T p-value T p-value Pulau Payar -3.54 0.003 -5.67 <0.001 -7.09 <0.001 Pulau Singa Besar - - -2.13 0.151 -3.54 0.003 Teluk Datai - - - - -1.42 0.491
19 There is a highly significant difference between the different levels of distance from the beach (ANOVA, F=6,33, df=3, p=0,001). There is also an interaction effect (ANOVA, F=4,78, df=9, p<0.001). There is high variation between sites and within each site (Figure 14).
3.5
3
2.5 2
1.5 1
0.5
0 Number of species per transect 1234
Figure 14. The means of the numbers of butterflyfish species per transect for each level of distance at the four study sites, Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
Feeding categories Obligate coral feeders was the dominant feeding category. There were 421 fishes in this category compared to 5 omnivores and 15 invertebrate feeders (Figure 15). For the obligate corallivores there is a highly significant difference between sites (ANOVA, F= 14.15, df=3, p<0.001). Here again the abundance is highest in Pulau Payar and Pulau Singa Besar and lowest in Teluk Datai and Pulau Rebak Besar (Figure 16 and Table 11).
9 8 7 6 5 4 3 2 1 0
Number of individuals per transect Pulau Payar Pulau Singa Besar Teluk Datai Pulau Rebak Besar
Figure 15. The means of butterflyfishes per transect at the four study sites. The fishes are separated into three feeding categories, i.e. obligate corallivores (dark bars), omnivores (grey bars) and invertebrate feeders (white bars). 32 observations were made per site. Error bars indicate standard errors.
Table 11. Results from the Tukey’s pairwise comparison test of obligate corallivores between sites. 32 observations were made per site. Pulau Singa Besar Teluk Datai Pulau Rebak Besar T P-value T P-value T P-value Pulau Payar -1.09 0.697 -4.21 <0.001 -5.71 <0.001 Pulau Singa Besar - - -3.12 0.012 -4.63 <0.001 Teluk Datai - - - - -1.51 0.435
20 For obligate corallivores there is a highly significant difference between the different levels of distance from the beach (ANOVA, F=10.34, df=3, p<0.001). There is also an interaction effect (ANOVA, F=6.86, df=9, p<0.001). Pulau Singa Besar has higher abundance at the level furthest away from the shore. The other sites have similar abundance at all levels (Figure 16).
30
25
20
15
10
5
0 Number of individuals per transect 1234
Figure 16. The means of obligate corallivores of the family Chaetodontidae per transect for each level of distance at the four study sites, Pulau Payar (circles), Pulau Singa Besar (squares), Teluk Datai (triangles) and Pulau Rebak Besar (crosses). The levels indicate distance from the beach, where 1 is closest to the beach and 4 is furthest away. Eight observations have been made per level per site. Error bars indicate standard errors.
For the omnivores and the invertebrate feeders the number of fish was too low for statistical analyses. Omnivores were only found at Pulau Singa Besar and Teluk Datai, and invertebrate feeders were only found at Pulau Payar and Pulau Singa Besar (Figure 15).
21 Multivariate analysis of fish families
Caesionidae
Holocentridae
Pomacanthidae Ser ranidae Carangidae
Sand Rubble Pempheridae Reef Gobiidae distance to beach Siganidae
Dead Pomacentridae Muraenidae Apogonidae Living Lutjanidae Blenniidae Zanclidae
Scaridae Nemipteridae Labridae Caetodontidae
-1.0 +1.0 Figure 17. An ordination diagram showing the relationship between fish families and environmental variables.
All the families with one exception, Gobiidae, are positively correlated to the living coral (Figure 17). Among the environmental variables found in the live coral cover (positively correlated to axis 1) and on which reef the transect was recorded (negatively correlated to axis 1) were most important. The environmental variables “distance to beach” and “sand cover” are positively correlated to axis 1. The “dead coral cover” and “the rubble cover” are negatively correlated to axis 1. These variables are of less importance. The environmental variables explain 98.1% of the total variation found in the fish families (Table 12).
Table 12. Summary of the cumulative percentage variance in species data and species environment relationships explained by the four axes in the fish family ordination diagram. Axes 1 2 3 4 Cumulative percentage variance of species data 69.3 80.4 84.5 88.2 Cumulative percentage variance of family-environment relationships 95.8 96.5 97.3 98.1
22 Correlation tests Correlation between fishes and substrate Table 13 shows the results from the correlation tests between the fish variables and the substrate variables. Two correlations are stronger than the rest - a positive correlation between the total abundance of fish and the live coral cover and a negative correlation between the number of fish families and the corals covered by sediment. The live coral cover and the dead coral cover are positively but weakly correlated with the fish variables, and the coral covered by sediment show a significant but weak negative correlation with the fish variables. The correlations between the substrate variables “substrate diversity”, “coral genera”, “level of distance”, “sand”, “rubble” and “Acropora” and the fish variables are either not significant or if they are significant, they are very weak. The variable “fish diversity”- with two exceptions - shows no significant correlation with the substrate variables.
Table 13. The results from the Spearman’s rank correlations between fish variables and substrate variables. * p<0.05, ** p<0.01, ***p<0.001 Fish families Butterflyfish Total Abundance except Families Fish Abundance Number of Obligate abundance damselfishes and diversity species coral feeders fusiliers Living coral 0.61 0.51 0.48 -0.13 0.43 0.46 0.44 *** *** *** ns *** *** *** Dead coral -0.44 -0.43 -0.50 -0.11 -0.39 -0.40 -0.38 *** *** *** ns *** *** *** Sediment -0.54 -0.53 -0.61 -0.16 -0.44 -0.47 -0.44 covered coral *** *** *** ns *** *** *** Depth 0.48 0.35 0.46 -0.04 0.40 0.38 0.42 *** *** *** ns *** *** *** Level of 0.36 0.23 0.26 -0.16 0.25 0.25 0.25 distance *** ** ** ns ** ** *** Substrate 0.08 0.01 -0.05 -0.12 0.13 0.16 0.12 diversity ns ns ns ns ns ns ns Coral genera -0.05 -0.15 -0.19 -0.25 0.02 0.02 0.02 ns ns * ** ns ns ns Acropora -0.01 -0.13 -0.13 -0.23 -0.09 -0.08 -0.09 ns ns ns ** ns ns ns Sand 0.07 0.05 0.18 0.05 0.10 0.10 0.09 ns ns * ns ns ns ns Rubble -0.30 -0.20 -0.22 0.10 -0.26 -0.26 -0.26 *** * * ns ** ** **
23 Correlation between fishes and weather and water conditions Table 14 shows the results from the correlation tests between the fish variables and the weather conditions. These correlations are significant. The only exception is fish diversity. Even though the correlations are significant they are very weak. The highest correlation factor is 0.31.
Table 14. The results from the Spearman’s rank correlations between fish variables and weather conditions. * p<0.05, ** p<0.01, ***p<0.001 Fish families Butterflyfish Total Abundance except Families Fish Abundance Number of Obligate abundance damselfishes and fusiliers diversity species coral feeders Sea state 0.29 0.26 0.24 -0.05 0.31 0.31 0.31 *** ** ** ns *** *** *** Wind -0.23 -0.20 -0.21 0.16 -0.22 -0.23 -0.22 ** * * ns * ** * Cloud 0.21 0.25 0.23 0.15 0.26 0.27 0.26 * ** ** ns ** ** **
The only water quality variable that deviates from the rest is the turbidity at Pulau Payar (Table 15), which is lower here than at the other sites. This can be compared with the water visibility, which is greater here than at the other sites.
Table 15. The means of the water quality data at each site during the study. Pulau Payar Pulau Singa Besar Teluk Datai Pulau Rebak Besar Temperature (°C) 28.8 28.1 28.0 27.3 Salinity (psu) 32.4 32.6 32.8 33.0 Dissolved oxygen (mg/l) 6.2 5.9 6.3 5.7 Turbidity 0.5 1.9 1.6 1.5
DISCUSSION
Differences between and within sites Pulau Payar is the richest site for fish according to all the variables tested except diversity, which shows no difference between any of the sites. The fishes are more evenly distributed here than at the other sites. Even the inner part of the reef has a high abundance of fish. Pulau Singa Besar has the second highest abundance, but here the outer part of the reef shows a high abundance and variety of fish and the inner part shows a low abundance and variety. Teluk Datai and Pulau Rebak Besar do not differ from each other and have the lowest abundances of fish. Another general trend is that there are more fishes in more families in the outer part of the reef than in the inner part. This is particularly evident in Pulau Singa Besar and Teluk Datai.
There is no difference in the Shannon-Wiener diversity index (H') between the sites. This probably depends upon the fact that the fishes were only recorded to the family level and not to the species level. The family level is not detailed enough to allow diversity index comparisons
The same trends can be seen in the coral study by Jonsson (2002). She found that Pulau Payar had the highest coverage of living coral and the lowest coverage of dead coral and coral covered by sediment. Pulau Singa Besar has the second highest abundance of live coral cover. There is no difference between Teluk Datai and Pulau Rebak Besar in this respect, and these two sites have the lowest coverage of living coral. However, with respect to the numbers of genera and the diversity she found no differences between Pulau Singa Besar, Teluk Datai and
24 Pulau Rebak Besar. Only Pulau Payar differed and had a lower diversity. She also found a general trend with more living coral and more genera at the outer part of the reef. The only exception is Pulau Payar, which had a more even distribution.
In summary all our data show the same result: The corals and the coral reef fishes are less abundant and diverse in areas with high human disturbance.
Comparisons with previous studies Few previous fish studies have been made in the area. In 1982 the WWW conducted a study of the coral reefs in Pulau Payar Marine Park (de Silva & Ridzwan, 1982). They recorded 25 different families, out of which 16 were found in our study. In addition five families were found in our study but not in theirs. Since their study was qualitative and not quantitative it is difficult to make any further comparisons. In the year of 2000 a quantitative study of the coral reefs and the coral reef fishes were made in all the major sites in the Langkawi archipelago (Pulau Payar Marine Park not included) (Hendry & McWilliams, unpubl.). The fish communities they recorded were very similar to those in the present study with dominance of the three families Pomacentridae, Labridae and Scaridae. At Teluk Datai they recorded an average of 69 fishes per 100 m2 compared to 76 in this study. Similarly, in Pulau Singa Besar they recorded an average of 260 fishes per m2 compared to 306. They found more families than in this study, i.e. 24 compared to 15 at Teluk Datai and 22 compared to 18 at Pulau Singa Besar. These differences can be explained by the fact that their transects covered a much larger area than ours did.
Marine reserves One of the reasons why Pulau Payar contains more fishes is because it is an area protected from fishing. Fishing causes a decrease in species richness and density of all coral reef fishes (Russ & Alcala, 1989; McClanahan, 1994). Some species favoured by fishermen, so called target species, are even more affected (Russ & Alcala, 1989; Polunin & Roberts, 1993). Studies have provided strong evidence that marine reserves enhances the abundance and size of target species within the reserve boundaries (Alcala, 1988; Russ & Alcala, 1989; Grigg, 1994). In a comparison between a protected area and a non-protected area made by Polunin & Roberts (1993) target species showed 2 times higher biomass in the protected area.
Table 16. Fish families found on coral reefs that are Table 16 shows the coral reef fish families commercially important in Western Malaysia. From Rashid (1980). + indicates fish families found in this that are commercially important in Western study, - indicates families not found Malaysia. One family (Carangidae) was only found in Pulau Payar. Six of the Fish families families were found on several sites but the Carangidae + abundance was higher in Pulau Payar than Serranidae + on the other sites. Only one family, Lutjanidae + Caesionidae + Nemipteridae, had higher abundance in Labridae + Pulau Singa Besar than in Pulau Payar. Five Siganidae + of the families were not found in our study Nemipteridae + at all. In this study many other variables Pomadascyidae - may have had an impact on the fish Sillaginidae - Scomridae - communities, and therefore it is impossible Dasyatidae - to draw any definite conclusions from these Balistidae - results. It clearly indicates, however, that protection from fishing affects the target species positively.
25 Marine parks also function as a breeding ground for non-obligate coral reef fishes. Such parks can act as a source of fish larvae for recruitment into fish communities outside the park. The park can also enhance fisheries when post settlement juveniles or adults emigrate to areas outside the park (Roberts & Polunin, 1991). The establishment of a marine reserve may therefore be important for the fishing community in the area. Between 10 and 30 % of the fish landings in Western Malaysia are associated with coral reefs (Wan Portiah, 1990, Rashid, 1980). Before the marine park was established the fishermen in the area did not approve of it and felt that their catches would be negatively affected by the marine park (Nickerson-Tietze, 2000). There are some findings, however, indicating that the coral reefs of Pulau Payar export fishes to the surrounding areas. In the area around Pulau Payar Marine Park the fish catches per unit effort (kg/boat/day) have increased both for the target fish and the non-target fish (Alias & Mohd, 1997). It is assumed that these fishes use the marine park habitat for feeding, spawning, protection of larval stages and other critical activities, and that the park therefore contributes to recruitment and survival. 31% of the fishermen have reported improvement in fish stocks (Nickerson-Tietze, 2000).
Correlations between fish communities and the coral reef The strongest positive correlation is found between the total abundance of fish and the live coral coverage, and a negative correlation is found between the number of fish families and the sediment covered coral (Table 13). According to Jonsson (2002) the coverage of sediment covered coral and dead coral is negatively correlated with the coverage of living coral. These findings, together with the conclusions drawn from the ordination diagram (Figure 17), imply that the most important factor for the fish communities is living coral. Coral reefs provide food for the fishes, not only for the obligate coral feeders but also for other fishes whose prey is dependent on living coral (Bell & Galzin, 1984). It also provides shelter for the fishes (Öhman & Rajasuriya, 1998). Sano et al. (1984 and 1987) found that on dead reefs with intact structure, only the coral feeding fishes had disappeared. On coral rubble sites few fishes were living there due to the lack of shelter. Correlations between living coral and fish communities are also found in other studies (Bell & Galzin 1984; Hourigan, 1988), especially the coral feeders (Öhman & Rajasuriya, 1998). There are also studies that have demonstrated that no such correlation between fish and live coral cover exists (Luckhurst & Luckhurst, 1978; Syms, 1998).
In this study no or weak correlation between the fish and the substrate diversity and the number of coral genera was found (Table 13). Similar results have been found in other studies as well (Luckhurst & Luckhurst, 1978; Öhman & Rajasuriya, 1998). Other studies, on the other hand have demonstrated positive correlations between substrate diversity and coral reef fishes (Roberts & Ormond, 1987; McCormick, 1994; Grigg, 1994).
Most of the corals in our study were massively growing (e.g. Porites, Goniastrea and Goniopora) and only a few of them were branching. The branching corals are more sensitive to physical disturbance than the massive ones (see Jonsson, 2002, for further discussion). Less than one per cent of the substratum consisted of Acropora, and on Pulau Payar it was lacking completely. There has formerly been more Acropora at Pulau Payar but much of it died during the ENSO event in 1998 (Yusuf & Ali, 2001). Many studies have shown a correlation between the structural complexity of the reef and the abundance and diversity of the fishes (Luckhurst & Luckhurst, 1978; Grigg, 1994; McCormick, 1994; McClanahan, 1994; Öhman & Rajasuriya, 1998). Several fishes, especially species of damselfish, Pomacentridae, are dependent on Acropora (Booth, 1992; Öhman & Rajasuriya, 1998). The lack of Acropora and other branching corals may have affected the fish communities negatively.
26 Sand and rubble had weak or no correlations with the fish variables. These findings were supported by the results obtained from the ordination diagram where only one family (Gobiidae) is depending on the rubble and six families (Caesionidae, Holocentridae, Pomacanthidae, Serranidae, Carangidae and Pemheridae) are depending on sand. These families are found mostly on the Pulau Payar site which has got more sand than the other sites. This might explain why these fishes correlate with the sand in the ordination diagram but not in the correlation test.
There is only a weak correlation between the fish variables and the weather and water conditions (Table 14). This indicates that weather conditions, if not too extreme, do not affect the fish community much.
At Pulau Payar the water contained less sediment than at the other sites. The turbidity was lower (Table 15), the water visibility was much greater, and the sediment covered corals cover was lower at Pulau Payar. This is probably the most important factor to why there are more living corals (see Jonsson, 2002 for further discussion) and thus more fish at Pulau Payar.
Butterflyfishes as indicator organisms Pulau Payar and Pulau Singa Besar have a higher total abundance and a higher abundance of obligate corallivores of the butterflyfish family (Chaetodontidae) than Teluk Datai and Pulau Rebak Besar. The high mean value of the abundance of butterflyfish at Pulau Singa Besar is due to the extremely high abundance in the outer part of the reef. Pulau Payar has the highest number of species compared with the other sites. The omnivores are only found at Pulau Singa Besar and Teluk Datai, and the invertebrate feeders are only found at Pulau Payar and Pulau Singa Besar. Together these results indicate that Pulau Payar and the outer part of the reef at Pulau Singa Besar have the highest abundance and most species of butterflyfishes. These are also the areas with the highest cover of living coral (Jonsson, 2002).
As for the fish families, live coral cover is the most important factor affecting the abundance of butterflyfishes, which is in accordance with other studies (Bell & Galzin, 1984; Findely & Findely, 1985; Bouchon-Navaro & Bouchon, 1989; Öhman et al., 1998).
Many of the butterflyfish species are strongly correlated with Acropora. Some obligate corallivores feed only on species of this genus. Other studies have shown a positive correlation between butterflyfishes and Acropora (Bouchon-Navaro & Bouchon 1989; Öhman et al., 1998) and between butterflyfishes and the substratum complexity (Luckhurst & Luckhurst, 1978; Bouchon-Navaro & Bouchon, 1989; Öhman & Rajasuriya, 1998). In this study no correlations between butterflyfishes and Acropora were found. The best way to explain the lack of correlations in my study is the extremely low coverage of Acropora (less than one per cent). Few fish that were obligate Acropora feeders (e.g. Chaetodon trifascialis) were found in this study. Accordingly the two most common butterflyfishes in this study (Chaetodon collare and Chaetodon octofascicatus) were not obligate Acropora feeders.
There have been very few omnivores (5 specimen) and invertebrate feeders (15 specimen) recorded in this study of totally 441 specimen observed. Other studies have also shown that corallivorous butterflyfishes dominate on coral reefs (Anderson et al., 1981; Öhman et al., 1998). According to Hourigan et al. (1988) and Reese (1981), obligate coral feeders would be the best indicators of the health of the reef because they can not change their diets and are expected to emigrate if the preferred corals deteriorate. Another theory is that since
27 specialists only respond to the changes in abundance of the preferred corals, an overall stress would be indicated by an emigration by the generalists (Hourigan et al., 1988). The results of this study could fit into both theories as the best sites Pulau Payar and Pulau Singa Besar had more obligate corallivores as well as most of the omnivores and invertebrate feeders.
The conclusion of this census of the butterflyfishes is that in this area they can be used as indicators of the health of a coral reef, since they correlate well with live coral cover, and most of the butterflyfishes are found in the least disturbed sites.
CONCLUSIONS
The reefs in the Langkawi archipelago are affected by human disturbance. This disturbance consists mainly of eutrophication and sedimentation from land-based activities such as infrastructure development for tourism, agricultural sources, industries and domestic wastes. The consequences are a decrease in live coral cover and in diversity of the corals. The health of the corals is important for the coral reef fishes. Most important is the live coral cover, which serves as food and protection for the fish. This means that if the corals are affected, so are the fishes.
If the high impact of eutrophication and sedimentation in the Langkawi archipelago continues this will strongly affect the coral reefs and their inhabitants. Many tourists come to the area to experience the coral reefs, but if the degradation of the reefs continues the reefs will loose their attraction and the tourism will decrease. Since many people in the area are depending on tourism this will have an economic impact on the society in Langkawi. The degradation of the coral reef will also affect the fishes that use the reefs as breeding grounds and for juvenile feeding. Many of these fishes are commercially important. It is therefore important to minimise the human disturbance in the area, not only to protect what is left of the rich biological life in the sea, but also from a pure economic perspective.
28 ACKNOWLEDGEMENT
First of all I would like to thank Mr Muhamad Nasir Abdul Salam at the World Wide Fund for Nature, Malaysia (WWFM) who gave me the opportunity to come to Malaysia and work on his project. I would also like to thank my supervisors Dr. Bo Tallmark and Prof. Göran Milbrink at Uppsala University for good advice and interesting discussions during the course of this work.
During my stay in Malaysia I shared everything and all my time with one person, Dagmar Jonsson. Thank you for being a good friend, for all good ideas and for all the hard work. I will always remember our adventures.
This study would not have been possible without the economic support form the Swedish International Development Cooperation Agency (Sida) through the Committee of Tropical Ecology at Uppsala University or WWFM who let us borrow lot of essential equipment. I would also like to thank the fisheries department in Malaysia for letting us stay and work in the Pulau Payar Marine Park.
All the staff at WWFM has been really friendly and has always had the time to listen to me and has tried their very best to help us. Thank you so much. A special thank to: Hymeir Kamarudin who arranged many practical details for us in Langkawi, Mr Fong Oon Ng at the office in KL, Julia Ng who helped us find articles and translate some of them, as well as being a great friend supporting us during the whole stay and Gan Sien Ban our field assistant who is helped us out when we needed it the most.
Many persons has helped us during our stay in Langkawi. Among those, I would especially like to thank Mr Irshad Mobarak at The Datai and Mr Mohd Firdaus Dev at The Andaman, Datai Bay for helping out with practical arrangements in Datai bay, Mr Wicky Sundram and the staff at the Royal Langkawi Yacht Club for letting us keep the boat in the marina, and Mr Danny Lim and his staff at the East Marine Dive Club for helping us with transport to Pulau Payar.
I would also like to thank friends and neighbours in Langkawi, and all the friendly staff at the Andaman and the Datai hotel in Datai bay for making my stay in Langkawi enjoyable and memorable.
Last but not least I would like to thank everybody who has come with ideas about how to improve the report and all my friends and family who has supported me during the periods when I couldn't see an end to all the work.
29 REFERENCES
Alcala, A. C., 1988. Effects of marine reserves on coral fish abundances and yields of Philippine coral reefs. Ambio 17:194-199. Alias, M. & Mohd, S. I. 1997. Status and trends of key target fisheries species of Pulau Payar. In Report and proceedings of the DOFM/FAO BOBP Integrated Coastal Management workshop. Alor Setar, Malaysia, 20-220 October, 1997. Allen, G. R. 1979. Fjärils och kejsarfiskar, Band 2. Tidskriften Akvariet. Göteborg. Anderson, G. R. V., Erlich, A. H., Ehrlish, P. R., Roughgarden, J. D., Russel, B. C. & Talbot, F. H. 1981. The community structure in coral reef fishes. American Naturalist 117:476-495. Bell, J. D. & Galzin, R. 1984. Influence of live coral cover on coral reef-fish communities. Marine Ecology Progress Series 15: 265-274. Booth, D. J. 1992. Larval settlement patterns and preferences by domino damselfish Dascyllus albisella Gill. Journal of Experimental Marine Biology and Ecology. 155:85-104. Bouchon-Navaro, Y. & Bouchon, C. 1989. Correlations between chaetodontid fishes and coral communities of the Gulf of Aqaba (Red Sea). Environmental Biology of Fishes 25:47-60. Chou, L.M., Wilkinson, C., Gomez, E. and Sudara, S. 1994. Status of coral reefs in the Asean region. In: Wilkinson, C.R. 1994. Living coastal resources of Southeast Asia: status and management. Report of the consultative forum Third ASEAN – Australia Symposium on living coastal resources. Chulalongkorn University, Thailand. Australia Institute of Science. Cox, E. F. 1994. Resource use by corallivourous butterflyfishes (Family Chaetodontidae) in Hawaii. Bulletin of Marine Science 54:535-545. Dow, K. M. 1995. An overview of pollution issues in the Straits of Malacca. Maritime institute of Malaysia (MIMA) Issue paper no 5/95 English, S., Wilkinson, C. & Baker, V. (eds). 1997. Survey manual for tropical marine resources, 2nd edition. Australian Institute of Marine Science. Townsville. Findley, J. S. & Findley, M. T. 1985. A search for pattern in butterflyfish communities. American Naturalist. 126:800-816. Gladfelter, W. B., Ogden, J. C. & Gladfelter, E. H. 1980. Similarity and diversity among coral reef fish communities: a comparison between tropical western Atlantic (Virgin Islands) and tropical central Pacific (Marshall Islands) patch reefs. Ecology 61: 1156- 1168. Goldman, B. & Talbot, F. H. 1976. Aspects of the ecology of reef fishes. In Jones, O. A. & Endean, R. (eds), Biology and Ecology of coral reefs. Vol. 3, pp. 125-164. Academic Press. New York, USA. Grigg, R. W. 1994. Effects of sewage discharge, fishing pressure and habitat complexity on coral ecosystems and reef fishes in Hawaii. Marine Ecology Progress Series 103:25- 34. Harmelin-Vivien, M. L.1989. Implications of feeding specialization on the recruitment processes and community structure of butterflyfishes. Environmental biology of fishes 25:101-110. Hendry, H. J. & McWilliams, J. P. Assessment of the coastal marine resources of the Langkawi archipelago, to be published Hourigan, T. F., Tricas, T. C. &. Reese, E. S. 1988. Coral reef fishes as indicators of environmental stress in coral reefs. In: Soule, D. F. & Keppel, G. S. (eds) Marine Organisms as Indicators. pp. 107-136. Springer-Verlag. New York.
30 Jonsson, D. 2002. An inventory of coral reefs in Langkawi Archipelago, Malaysia- assessment and impact study of sedimentation. Undergraduate Thesis, Uppsala University. Lieske, E. & Myers, R. 2001. Coral Reef Fishes, Indo-Pacific and Caribbean. Harper Collins Publishers. London. Lim, C. C. 1998. Carrying capacity assessment of Pulau Payar Marine Park, Malaysia BOBP/REP/79 Luckhurst, B. E. & Luckhurst, K. 1978. Analysis of the influence of substrate variables on coral reef fish communities. Marine Biology. 49:317-323 McClanahan, T. R. 1994. Kenyan coral reef lagoon fish: effects of fishing, substrate complexity and sea urchins. Coral Reefs. 13:231-241. McCormick, M. I. 1994. Comparison of field methods for measuring surface topography and their associations with a tropical reef fish assemblage. Marine Ecology Progress Series. 112:87-96. Nickerson-Tietze, D. J. 2000. Scientific characterization and monitoring : Its application to integrated coastal management in Malaysia. Ecological applications 10:386-396. Nybakken, J. W. 2001. Marine Biology, an ecological approach, 5th ed. Benjamin Cummings. San Fransisco Öhman, M. C. & Rajasuriya, A. 1998. Relationships between habitat structure and fish communities on coral and sandstone reefs. Environmental Biology of Fishes 53:19- 31. Öhman, M. C., Rajasuriya, A. & Svensson, S. 1998. The use of butterflyfish as bio-indicators of habitat structure and human disturbance. Ambio 27:708-716. Polunin, N. V. C. & Roberts, C. M. 1993. Greater biomass and value of target coral-reef fishes in two small Caribbean marine reserves. Marine Eclology Progress series. 100:167-176. Randall, J. E., Allen, G. R. & Steene, R. C. 1990. Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press. Honolulu. Hawaii Rashid, R. 1980. The Pulau Payar reef system, Malaysia Agricultural Journal 52:240-253. Reese, E. S., 1981. Predation on corals by fishes of the family Chaetodontidae, implications for conservation and management of coral reef ecosystems. Bulletin of Marine Science 31: 594-604. Richmond, M. D. (ed). 1997. A guide to the seashores of Eastern Africa and the western Indian Ocean islands. SIDA. Roberts, C.M. and Ormond, R.F.G. 1987. Habitat complexity and coral reef fish diversity and abundance on Red Sea fringing reefs. Marine Ecology Progress Series 41:1-8. Roberts, C. M., Shepherd, A. R. D. & Ormond, R .F. G. 1992. Large-scale variation in assemblage structure of Red Sea butterflyfishes and anglefishes. Journal of Biogeography 19:239-250. Russ, G. R. & Alcala, A. C. 1989. Effects of intense fishing pressure on an assemblage of coral reef fishes. Marine Ecology Progress Series 56:13-27. Sano, M., Shimizu, M. & Nose, Y. 1984. Changes in structure of coral reef fish communities by destruction of hermatypic corals: observational and experimental views. Pacific Science 38:51-79. Sano, M., Shimizu, M. & Nose, Y. 1987. Long term effects of destruction of hermatypic corals by Acanthaster planci infestation on reef fish communities at Iriomote Island, Japan. Marine Ecology Progress Series 37:191-199. Searle, A. G. 1956. The Malayan Nature Journal Vol II parts 1 & 2. An illustrated key to Malayan Hard corals. The Malayan Nature Society.
31 de Silva, M. W. R., & Ridzwan, A. R. 1982. Coral reef survey of Pulau Payar/Segantang group of islands, Kedah state, Malaysia: expedition report and recomendations for management. Report produced under WWF, project number MAL 41. Universiti Pertanian Malaysia, Serdang, Malaysia. Steene, R. C. 1977. Fjärils och kejsarfiskar, Band 1. Tidskriften Akvariet. Göteborg. Syms, C. 1998. Disturbance and the structure of coral reef fish communities on the reef slope. Journal of Experimental Marine Biology and Ecology. 230:151-167. Yusuf, Y.B. & Ali, A.B. 2001. Coral reef fish community: comparative study between marine park and non-protected area. Asian Wetland Symposium 2001, 27-30 August 2001, Penang, Malaysia Veron, J. E. N. 1986. Corals of Australia and the Indo-Pacific. University of Hawaii Press, Honolulu. 644 pp. Wan Portiah, W. H. 1990. Conservation of fisheries resources through the establishment of marine parks and artificially created habitats. In the status of nature conservation in Malaysia. Malayan Nature Society, Petaling Jaya. Wilkinson, C. and Ridzwan Abdul Rahman. 1994. Causes of coral reef degradation within Southeast Asia. In: Wilkinson, C.R. (Ed) 1994. Living coastal resources of Southeast Asia: status and management. Report of the consultative forum Third ASEAN – Australia Symposium on living coastal resources. Chulalongkorn University, Thailand. Australia Institute of Science.
32 APPENDIX I fish data
Pulau Payar Fish families 1234567891011121314151617181920212223242526272829303132 Pomacentridae 100 80 155 60 90 50 70 80 90 100 100 100 85 120 70 120 160 150 250 310 260 60 160 170 160 70 600 270 140 150 110 100 Labridae 25439 30145 272525201214192115251917121210142315- 8 10203 316 25 Caesionidae --80------502020-50170-2-80402502020302- Scaridae 30 24 3 12 9 22 12 10 7 6 9 5 12 7 2 15 8 14 8 4 8 12 12 11 12 12 25 7 3 8 9 8 Caetodontidae 11249344563- -2541017536857382-1545 Pempheridae --1------6--210-7301311-2-2-11217-3104- Apogonidae -----210--5--1--360-----2---1-2-2- Siganidae 101133- -3-5- - -321925155- -11646412- - Gobiidae ---5-1------332------5------Serranidae 2-312 4- -2- -2211651-3-3-351131-1 Nemipteridae ------1------1----1----12-1-11- Holocentridae ------121111- -2- -13102011-5- Lutjanidae - - -111121-12- -4-2- -2-321221-1211 Zanclidae 1- -111------1-1211-2-211-2-122 Pomacanthidae --1------11----1-21-1--311----- Centriscidae ------Carangidae --1---1--1------1---1--51-1-1-2- Blenniidae 23-1 1--21------1------Mugilidae ------6------3 Muraenidae ------Ostraciidae ------1------Mullidae ------Diodontidae ------1--- Tetraodontidae ------2------Haemulidae ------Carcharhinidae --1------Fistulariidae ------1------Butterflyfish Chaetodon collare 4- -111232- - -2228-53-5314151- -243 Chaetodon octofasciatus 1- -412224- - - -221-222124 211- -3-1 Chaetodon triangulum 522-11---3---1--1--1-3---1--1--- Heniochus singularis ------Chaetodon trifascialis 1------Chaetodon lineolatus ------Chaetodon decussatus ------Chaetodon lunula ------Chaetodon vagabundus ------Chaetodon rafflesi ---4 ------2------Heniochus acuminatus ------1------1-1-----1 Chelmon rostratus --2------
33 Pulau Singa Besar Fish Families 1234567891011121314151617181920212223242526272829303132 Pomacentridae 17 31 15 8 13 12 9 10 22 21 24 17 10 15 12 12 100 70 24 56 58 18 9 59 130 140 280 250 310 450 160 350 Labridae 386153-4157812444362832115913197151525121541 Caesionidae ------10----- Scaridae - 2 1 3 5 - 4 - - 1 2 - - 5133131- -325 411- 525304391570 Caetodontidae 21------2--2--1-78129--031182936203240 Pempheridae ------2--1---4--2034310 Apogonidae ------5520------303--- Siganidae 2------1------44310814 Gobiidae 34413742-42-104------Serranidae 4-1---1--1-----1122-111-111----- Nemipteridae ------111--1--222------115201025711 Holocentridae ----1------Lutjanidae ------13-2124 Zanclidae ------1--1-----5--142 Pomacanthidae ------Centriscidae ------Carangidae ------Blenniidae ------Mugilidae ------Muraenidae ------1-1----- Ostraciidae ------1 Mullidae -----1------Diodontidae ----1 ------Tetraodontidae ------Haemulidae ------Carcharhinidae ------Fistulariidae ------Butterflyfish Chaetodon collare -1------1----551-2-----172130142237 Chaetodon octofasciatus 2------2--1--1-11-27---21154572 Chaetodon triangulum ------2--- Heniochus singularis ------1-12- Chaetodon trifascialis ------1-----1- Chaetodon lineolatus ------1------1---- Chaetodon decussatus ------1---- Chaetodon lunula ------Chaetodon vagabundus ------Chaetodon rafflesi ------2------Heniochus acuminatus ------1 Chelmon rostratus ------
34 Teluk Datai Fish families 1234567891011121314151617181920212223242526272829303132 Pomacentridae 623235634461518132081110294099107714168226122318 Labridae 2- - -214114637-643912213134448975 Caesionidae ------Scaridae ------1----3---2-13-32-60-2--21--- Caetodontidae ------4--3163-831- -1- -41201122 Pempheridae ------4-3--721-----3-5---11 Apogonidae ------2----1-7------1 Siganidae ------2------712-- Gobiidae 12324553-1------2- - -262------Serranidae ----112--131111-1-1-4211---1-53- Nemipteridae ------1------13-- Holocentridae ------1-----1010-----1-1---- Lutjanidae ------1------Zanclidae ------Pomacanthidae ------1------1- Centriscidae ------Carangidae ------Blenniidae ------Mugilidae ------Muraenidae ------Ostraciidae ------Mullidae 1------1------Diodontidae ------Tetraodontidae ------Haemulidae ------1------Carcharhinidae ------Fistulariidae ------Butterflyfish Chaetodon collare ------4--2133-23- - -1- -2-17-- -1 Chaetodon octofasciatus ------1-3--6-1-----2111121 Chaetodon triangulum ------Heniochus singularis ------Chaetodon trifascialis ------Chaetodon lineolatus ------Chaetodon decussatus ------Chaetodon lunula ------1---- Chaetodon vagabundus ------1---- Chaetodon rafflesi ------Heniochus acuminatus ------Chelmon rostratus ------
35 Pulau Rebak Besar Fish families 1234567891011121314151617181920212223242526272829303132 Pomacentridae 10141188 1 4 7112091226202141261449 6826134638672323 Labridae 1010557354833932732135822852327533 Caesionidae ------Scaridae ------3------Caetodontidae 1122---7-2------22-12----11- Pempheridae ------1------Apogonidae --1------20------220 Siganidae ------2 Gobiidae 67--121-41-1--5------2---- Serranidae - - -11- - -2111-1- -21-112323121-1-1 Nemipteridae 1------21--1------1--11----22-- Holocentridae ------Lutjanidae ------Zanclidae ------Pomacanthidae ------Centriscidae ------15------Carangidae ------Blenniidae ------Mugilidae ------Muraenidae ------1------1------Ostraciidae ----1------Mullidae ------Diodontidae ------Tetraodontidae ------Haemulidae ------Carcharhinidae ------Fistulariidae ------Butterflyfish Chaetodon collare 1-12---7-1------1-----11- Chaetodon octofasciatus -11------1------22--2------Chaetodon triangulum ------Heniochus singularis ------Chaetodon trifascialis ------Chaetodon lineolatus ------Chaetodon decussatus ------Chaetodon lunula ------Chaetodon vagabundus ------Chaetodon rafflesi ------Heniochus acuminatus ------Chelmon rostratus ------
36 APPENDIX II coral data
Pulau Payar Transect 1234567891011121314151617181920212223242526272829303132 Living coral (%) 3764114248352142556255577430571446586943703150357459776567335718 Dead coral (%) 161111191929135198201529382749267111619271912682714431 Sediment covered coral (%) 0.9 0.5 0.0 0.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.8 0.0 0.0 0.0 0.0 0.0 1.3 0.0 0.0 0.0 2.5 1.10.00.00.00.00.00.00.00.00.0 Depth -0.5 -0.5 -1.0 -1.0 -1.0 -1.0 0.0 0.0 0.0 0.0 1.0 1.0 0.0 0.0 0.00.00.00.02.02.01.01.02.01.02.02.02.01.02.02.02.02.0 Level of distance 11111111222222223333333344444444 Substrate diversity 1.651.871.781.941.511.351.531.621.491.721.781.400.941.991.170.931.211.361.411.380.821.451.711.251.301.361.061.26 1.03 1.38 0.91 1.37 Coral genera 46655335543238413333136252453623 Acropora (%) 0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0 Sand (%) 0.9 8.1 8.4 10.1 7.1 10.0 21.9 31.1 0.6 2.5 1.2 17.5 11.2 27.2 4.0 59.8 5.0 13.1 19.4 39.1 14.1 41.5 19.2 39.1 4.1 27.7 3.6 23.0 19.1 52.7 38.3 48.9 Rubble (%) 1.94.60.04.71.72.08.14.03.22.89.22.30.012.50.60.00.00.04.56.50.08.61.76.810.15.18.110.56.90.00.61.9 Sea state 22222222222222222222222222222222 Wind 22111111221111112211111122111111 Cloud cover 88226666880066665500223655023333
Pulau Singa Besar Transect 1234567891011121314151617181920212223242526272829303132 Living coral (%) 4041122222141223261336232620393259673937504653287351596048635871 Dead coral (%) 3043334362311729222054296158216536242629474946362333383043363928 Sediment covered coral (%)3043164362301729222054296158206536242627464646362333383043363928 Depth -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 -0.5 -0.5 -0.5 -0.5 -0.5 -0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Level of distance 11111111222222223333333344444444 Substrate diversity 1.881.781.651.681.281.661.721.911.691.161.721.611.361.551.811.222.082.112.062.351.911.992.031.751.722.141.962.33 2.08 1.24 2.04 1.78 Coral genera 844643346844334311111111111112891411131271212 Acropora (%) 0.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.02.50.00.00.00.01.30.00.0 Sand (%) 6.0 10.2 41.3 17.2 2.4 17.7 28.6 23.5 4.8 1.3 2.0 7.8 10.7 9.0 12.7 3.0 3.5 9.2 15.7 21.4 0.0 0.0 0.0 2.0 4.5 11.5 3.5 5.7 6.2 0.0 2.4 0.0 Rubble (%) 24.0 5.8 4.0 18.0 13.8 30.9 21.2 17.6 47.3 65.6 7.4 40.6 2.2 13.2 28.1 0.0 0.0 0.0 6.8 6.5 0.0 4.3 7.1 34.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Sea state 22221111222222222222222222222222 Wind 11112222111122221122222211111111 Cloud cover 11110000111100001111111133333333
37 Teluk Datai Transect 1234567891011121314151617181920212223242526272829303132 Living coral (%) 14711511390353061421231731123318272849544779662644506148 Dead coral (%) 21 12 28 28 26 35 49 37 43 11 12 9 17 41 59 45 61 10 30 35 34 70 51 45 53 20 34 70 32 43 39 37 Sediment covered coral (%)2112282826354937431112914405945619 3035347051435320347032343936 Depth -0.5 -1.0 -1.0 -1.0 -0.5 -0.5 -0.5 -0.5 0.5 0.0 0.0 0.0 0.5 0.5 0.5 0.5 -1.0 1.0 0.5 0.5 -0.5 -0.5 -0.5 -0.5 0.5 0.5 0.5 1.0 0.0 0.0 0.0 0.0 Level of distance 11111111222222223333333344444444 Substrate diversity 1.191.320.721.721.291.451.641.141.960.830.781.031.491.961.751.601.911.822.162.032.181.051.341.861.182.192.081.58 2.04 1.81 0.87 2.49 Coral genera 853813219414266412912101186129111210107414 Acropora (%) 0.00.00.00.00.00.00.00.00.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.40.00.05.20.00.00.00.0 Sand (%) 63.2 43.7 26.3 18.9 31.0 9.4 13.2 6.0 9.8 10.1 11.6 14.9 52.3 28.7 12.8 20.7 6.4 27.0 6.8 11.5 29.5 2.1 0.0 0.0 0.0 0.0 0.0 4.1 24.1 0.0 0.0 10.5 Rubble (%) 2.0 37.6 71.0 38.1 42.8 42.8 27.1 56.8 3.3 75.5 76.5 70.2 16.2 8.3 4.9 16.8 0.0 31.4 26.1 31.8 3.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.5 0.0 1.7 Sea state 22222211222222222222222222222222 Wind 22222222222211112222111122212222 Cloud cover 11111111111122221444222211123333
Pulau Rebak Besar Transect 1234567891011121314151617181920212223242526272829303132 Living coral (%) 183838411598 15104323281612322517364038241223444317483529283832 Dead coral (%) 2546335625516381885774464653687569485745357877565769526571666268 Sediment covered coral (%)2540335625516381885768454653687569485745357877565769526571666166 Depth -1.0 -1.0 -1.0 -0.5 -0.5 -1.0 -1.0 -1.0 -0.5 -0.5 -0.5 -0.5 -0.5 -0.5 -1.0 -1.0 -0.5 -0.5 -0.5 -0.5 0.0 0.0 -0.5 -0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.0 0.0 Level of distance 11111111222222223333333344444444 Substrate diversity 1.381.711.741.551.521.411.310.940.521.881.551.621.491.331.601.111.531.861.971.861.841.451.451.871.621.531.521.45 1.31 1.70 1.98 1.95 Coral genera 255604746145555811105121110121114141010911131414 Acropora (%) 0.00.00.00.00.00.00.00.00.00.00.00.30.00.00.71.00.00.00.00.71.71.40.25.30.00.00.01.80.86.02.50.8 Sand (%) 1.5 3.9 0.0 0.0 12.2 14.0 0.6 0.0 0.0 0.0 3.3 8.8 16.3 10.3 0.0 0.0 9.6 0.4 0.0 15.2 28.6 3.6 0.0 0.0 0.0 9.6 0.0 0.0 0.0 4.8 0.0 0.0 Rubble (%) 41.6 12.2 2.4 1.2 0.0 22.6 28.4 2.1 2.0 0.0 0.0 3.2 22.2 24.7 0.0 0.0 4.3 15.8 0.0 1.4 10.7 5.3 0.0 0.0 0.0 4.3 0.0 0.0 0.0 0.0 0.0 0.0 Sea state 22222222222222221122222211112211 Wind 22111111222111111111222211112211 Cloud cover 66677111666711777777111177771177
38