Coral Reef Diversity of the Talang-Talang Islands

Hwong Yie Hahn (23620)

Bachelor of Science with Honours

Aquatic Science and Resource Management

2012

Acknowledgements

I would like to express my heartfelt thanks to my supervisor, Dr.Aazani Mujahid

for her guidance and wealth of knowledge in the preparation of this report. I would also

like to thank my co-supervisor, Assoc. Prof. Dr. Lee Nyanti for his support and help during

the preparation of this report.

I would like to thank my colleagues Ng Chiew Tyiin, Nurin Teoh bt Ali Teoh, and

Lee Xue Li for their help and support during the field work and in sharing their knowledge

and data to make this report a success.

Not to forget, the staff and personnel from Blueventures and the Tioman Dive

Centre for providing me with the basic scientific field training and the necessary dive

experience to successfully complete this report.

Finally I would like to thank my parents and my friends for their unwavering

support and words of encouragement.

Declaration

I hereby declare that this report consists entirely of my original work with the exception of

external references, figures, tables and data in which I have properly acknowledged the

original creators and cited them in my work. I also declare that this report has not been

submitted as a prerequisite for any other under-graduate degree or other qualifications in

UNIMAS, Malaysia and any other institute of higher learning.

.............................................................

HWONG YIE HAHN

Aquatic Science and Resource Management

Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

iii

Table of Contents

List of Abbreviations............................................................................................... I

List of Tables and Figures...................................................................................... II

Abstract..................................................................................................................... V

1.0 Introduction................................................................................................... . 1

2.0 Literature Review ......................................................................................... 3

2.1 Coral Reefs........................................................................................ . 3

2.1.1 Coral Taxonomy.................................................................... 3

2.1.2 Coral Anatomy....................................................................... 3

2.1.3 Coral Ecology ....................................................................... . 4

2.2 Coral Environment ........................................................................... . 5

2.2.1 Optimal Conditions ................................................................. 5

2.2.2 Coral Bleaching ...................................................................... 5

2.3 Importance of Coral Reefs ................................................................. 6

2.4 Threats Facing Coral Reefs ................................................................ 7

2.4.1 Human Activities ................................................................... 7

2.4.2 Global Warming ..................................................................... 7

2.5 Coral Rate of Growth and Recovery ................................................. 7

2.6 Coral Reef Sampling Techniques ...................................................... 8

2.7 Coral Reef Diversity in Malaysia and Around the World ................. 8

2.7.1 Malaysia ................................................................................. 8

2.7.2 Southeast Asia ....................................................................... .. 9

2.7.3 Global ........................................................................ ............ 10

3.0 Materials and Methods ................................................................................` 11

3.1 Survey Sites ..................................................................................... 11

3.2 Coral Cover Survey ......................................................................... 13

3.3 Coral Diversity Survey .................................................................... 14

3.4 Coral Identification .......................................................................... 15

iv

3.5 Survey Methodology ....................................................................... 16

3.6 Data Analysis ................................................................................. 17

3.6.1 Diversity Indices ................................................................ 17

3.6.2 List of Indices ..................................................................... 19

3.7 Statistical Analysis ..................................................................... 20

4.0 Results ......................................................................................................... 21

4.1 Percentage Coral Cover .................................................................. 21

4.1.1 Previous Studies .................................................................. 23

4.2 Coral Diversity ................................................................................ 24

4.4 Fish Diversity .................................................................................... 34

4.5 Invertebrate Diversity ....................................................................... 40

4.6 Rate of Sedimentation ....................................................................... 41

5.0 Discussion

5.1 Coral Cover ........................................................................... ........... 44

5.1.1 Current Status ....................................................................... 44

5.1.2 Comparison with Previous Studies ....................................... 46

5.2 Diversity ............................................................................................ 47

5.2.1 Coral Diversity ....................................................................... 47

5.2.2 Invertebrate Diversity ............................................................ 48

5.3 Correlation between Coral Diversity and Fish Diversity ................... 49

6.0 Conclusion .................................................................................................... . 50

7.0 References ..................................................................................................... 51

Appendices

I

List of Abbreviations

ANOVA: Analysis of Variance

ENS: Effective Number of Species

GPS: Global Positioning System

PIT: Point Intercept Transect

PTBE: Pulau Talang Besar East

PTBW: Pulau Talang Besar West

TSNP: Talang-Satang National Park

TTI: Talang-Talang Islands

II

List of Tables and Figures

List of Figures

Figure Description Page

3.1 Location of the Talang-Talang Islands, with (a) Pulau Talang Besar,

(b) Pulau Talang Kecil and (c) Batu Penyu. Sample sites are located

North of Sematan, Sarawak, Malaysia.

11

3.2 Map of (a) Pulau Talang Besar (Station 1, & 2); (b) Batu Penyu

(Station 3).

12

3.3 The Point Intercept Transect Method used to survey coral cover.

Transect was divided into 4 sample stations with a gap of 5m in

between each sample station in which no data was collected.

13

3.4 Example of methodology used in collecting Coral Diversity Data. Each

data point is set at 0.5 metre intervals along the transect line with the

width set at 0.5 metres from the transect line on both sides. Coral

abundance is determined as the occurrence of a coral genus in a data

point (DP). In this case Coral Genus A is counted as (DP 1= 1, DP 2=

1, DP 3= 1) and Coral Genus B as (DP1= 1, DP 2= 0, DP 3= 1) . The

total occurrence of Coral A across the 3 data points for Coral Genus A

is 3 while for Coral Genus B it equals to 2.

14

3.5 Flowchart of the survey methodology used during coral sampling 16

4.1 Graph of percentage cover of hard coral sampled in the survey sites

22

III

4.2 Proportion (%) of the top 5 coral families found at different sites

around the Talang-Talang Islands. From top left clockwise, (a) Pulau

Talang Besar West, (b) Pulau Talang Besar East, (c) Talang-Talang

Islands and (d) Batu Penyu

27

4.3 Diversity Indices used to determine coral diversity. (a) Total

Abundance, (b) Species Richness, (c) Shannon-Weiner Diversity Index

(Exp H’), (d) Simpson Diversity Index (1/ λ), (e) Berger-Parker

Dominance Index (1/ DBP) and (f) Pielou’s Evenness Index (J)

32

4.4 Hill Numbers plot of coral Diversity. Where No= Shannon Weiner

Diversity Index, N1= Species Richness, N2= Simpson Diversity Index

and NINF= Berger-Parker Index of Dominance.

33

4.5 Diversity Indices used to determine fish diversity. (a) Total

Abundance, (b) Species Richness, (c) Shannon-Weiner Diversity Index

(Exp H’), (d) Simpson Diversity Index (1/ λ), (e) Berger-Parker

Dominance Index (1/ DBP) and (f) Pielou’s Evenness Index (J)

37

4.6 Scatter chart of effective number of coral species vs. effective number

of fish species by station.

38

4.7 Scatter chart of effective number of coral species vs. effective number

of fish species with a slope of R2 = 0.9258

38

4.8 Pie chart of invertebrate proportions at different sampling stations

around the Talang-Talang islands. (a) Pulau Talang Besar East and (b)

Batu Penyu.

40

4.9 Bar chart of the Rate of Sedimentation (mg/cm2/day) of each sample

station around the Talang-Talang Islands.

41

IV

4.10 Scatter chart of graph of Rate of Sedimentation vs. Occurrence Coral

Genera with Massive Growth Forms with R2=0.9482

43

List of Tables

3.1 GPS coordinates of sampling stations around the Talang-Talang

Islands.

12

4.1 Results from a coral cover survey conducted at Pulau Talang Besar in

2003

23

4.2 Results from coral cover survey conducted at Pulau Talang Besar in

2011

23

4.3 Table showing the coral reef genera sampled from several stations

around the Talang-Talang Islands comprising Pulau Talang Besar

West (PTBW), Pulau Talang Besar East (PTBE) and Batu Penyu.

25

4.4 Coral Diversity Indices for each sample station and the Talang-Talang

Islands.

28

4.5 Checklist of all coral genera found around the Talang-Talang Islands

grouped by station.

31

4.6 Fish Diversity Indices for each sample station and the Talang-Talang

Islands.

36

4.7 List of number of Invertebrate Family in each station. 40

4.8 Table of coral genera with massive growth forms sampled in the

Talang-Talang Islands.

42

v

Coral reef diversity of the Talang-Talang Islands

Hwong Yie Hahn

Department of Aquatic Science and Resource Management

Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

ABSTRACT

Coral reefs are an important ecological resource which must be protected and conserved. Previous studies on

the coral reefs of the Talang-Talang Islands (TTI) have found the percentage coral cover to be low with the

reefs undernourished and underdeveloped. The objective of this study is to determine the present hard coral

percentage cover of the Talang-Talang Islands. It also seeks to determine the composition of coral genus as

well as the Genus Diversity of the TTI. This study also aims to find the correlation between the coral

diversity of the TTI with various ecological factors such as fish and invertebrate diversity and the rate of

sedimentation. The coral cover survey was carried out using the Point Intercept Transect Method (PIT) while

the Coral Genus Diversity survey was concluded using a modified PIT. The results were significant, with

71% average live coral cover. The results were compared with previous studies and were found to be

significantly different. A total of 27 coral Genera were sampled from 15 Families. Shannon-Weiner Diversity

Index= 2.90; Simpson Diversity Index= 0.07, Berger-parker Dominance Index= 0.17 and Pielou’s Evenness

Index= 0.88. Statistically significant correlation between coral diversity and fish diversity were found with r=

0.9622. Correlation between occurrences of massive growth forms was suspected but could not be correlated

due to small sample size. The coral reefs of the Talang-Talang islands are diverse but poorly understood.

More studies need to be conducted to better understand this important ecological resource.

Keywords: Coral Reef, Diversity, Ecology, Talang-Talang,

ABSTRAK

Terumbu karang adalah sumber ekologi yang amat penting yang perlu dilindungi dan dipulihara. Kajian

sebelum ini atas terumbu karang Pulau Talang-Talang(PTT) menunjukkan bahawa peratus litupan adalah

rendah dengan karang yang tidak sihat dan mundur. Objektif kajian ini adalah untuk menentukan peratus

litupan terumbu karang terkini, komposisi Genus dan Kepelbagaian Genus PTT. Kajian ini juga bertujuaan

untuk mencari kolerasi antara kepelbagaian terumbu dan factor ekologi lain seperti kepelbagaian ikan dan

invertebrata dan juga kadar sedimentasi. Kajian peratus litupan dilaksanakan mengunakan Transek

Pintasan Titik (TPT) dan kajian kepelbagaian genus terumbu dengan TPT yang dimodifikasi. Keputusan

dibandingkan dengan keputusan kajian sebelum ini dan didapati ketara perbezaanya. 27 Genus terumbu dari

15 Famili dijumpa. Index Kepelbagaian (IK) Shannon-Wiener= 2.09, IK Simpson= 0.07, Index Dominasi

Berger-Parker= 0.17 dan Index Kesamarataan Pielou= 0.88. Kolerasi yang ketara secara statistik dijumpai

antara kepelbagaian terumbu dengan kepelbagaian ikan dengan r=0.9622. Kolerasi antara kekerapan

ketumbuhan terumbu besar-besaran dengan kadar sedimentasi disyaki tetapi tidak dapat dikolerasi kerana

saiz sampel yang terlalu kecil. Terumbu karang PIT sangat berkepelbagaian namun tidak difahami. Lebih

banyak kajian perlu dilaksanakan untuk memahami sumber ekologi ini yang amat penting.

Kata Kunci:Terumbu Karang,Kepelbagaian,Ekologi, Talang-Talang

1

1.0 Introduction

The coral reef ecosystem is an economically and ecologically valuable resource

that needs to be monitored and protected. The biggest and most significant aggregation of

coral reefs near the Kuching area can be found around the Talang Satang National Park

(TSNP) (Awang et al., 2003).

According to Pilcher and Cabanban (2000), coral cover around the Talang-Talang

islands are sparse and under-developed. This is due to the input of highly silted waters

from numerous rivers. The island reefs grow on granodiorite rock with the sea bed mostly

sandy with rock and dead coral boulders covered with sediment and macroalgae and large

scattered patterns of reef.

Awang et al. (2003) found that there was no significant difference in the coral

coverage between the coral reefs found in Pulau Talang Besar and Pulau Talang Kecil.

This was the first quantitative study done on the coral cover and composition around the

Talang-Talang islands.

They found the percentage coral cover around the Talang-Talang Islands to be low.

The percentage of live coral surveyed in selected sites around Pulau Talang Kecil was

24.33% while the percentage of dead coral was 40.33% .The percentage of live coral cover

surveyed in Pulau Talang Besar was higher with 38.12% live coral and 23.95% dead coral.

From the data obtained, they also classified the reefs around the Talang-Talang

islands as fringing reefs. Visibility in both islands was very low, ranging from 3 to 5

meters. There were signs of minimal stress except for anchor damage.

2

Since the last study conducted by Awang et al. (2003), there has been no recent

data on the status of coral reefs around the Talang-Talang Islands. Second, there is a need

for more comprehensive and quantitative data such as species richness, evenness and

diversity of hard corals in order to assess the status of hard corals around the Talang-

Talang Islands.

Accurate and adequate data on the status of coral cover and composition as well as

diversity is crucial in determining the health and status of coral reefs. As coral reefs form

complex and dynamic ecosystems, coral data can be compared to fish and invertebrate data

to form a better overall picture on the coral reef ecosystem being studied.

. The objective of this study is to determine the current cover of hard coral in

selected sites around the Talang-Talang Islands and to compare it with previous studies

done to monitor the growth and status of the corals found around the Talang-Talang

Islands.

It also seeks to obtain more detailed diversity data on the types of genus present to

serve as baseline data for future coral studies. From this data, benchmarks such as species

richness, diversity and evenness can be calculated and compared with other coral reefs in

Malaysia, regionally and around the world.

Finally this study also seeks to find the correlation between coral diversity and

other environmental factors. The data obtained will also be correlated with fish,

invertebrate, and sedimentation data to further understand the dynamics of the coral

ecosystems found around the Talang-Talang Islands. This data can also be used for

management purposes in conserving and managing the Talang-Talang Islands as a marine

park as well as a tourist destination.

3

2.0 Literature Review

2.1 Coral Reefs

2.1.1 Coral Taxonomy

Coral reefs are formed by underwater structures made from calcium carbonate.

Corals consist of polyps that cluster in groups. These polyps secrete calcium carbonate

which support and protect the coral. Corals grow best in clear, warm, shallow waters that

are exposed to high light intensity. Coralline algae also produce limestone skeletons and

help to build and consolidate coral reefs (Harmelin & Stoddart, 1985).

Reef building or hermatypic corals have a symbiotic relationship with

photosynthetic zooxanthellae. These organisms live within the coral polyp and provide

nutrients to the coral. Corals gain 90% of their nutrients from this symbiotic relationship

and without it, are unable to grow fast enough to form significant reef structures (Marshall

& Schuttenberg, 2006). Scleractinia constitutes as the largest order which contains

hermatypic reef building corals. Other orders which include hermatypic corals are orders

Helioporacea and Anthoathecata (Stolarski & Roniewicz, 2001).

Ahermatypic corals or non reef-building corals have no photosynthetic

zooxanthellae. Unlike hermatypic corals, the skeletons of ahermatypic are not made from

aragonite, a natural crystal formation of Calcium Carbonate (CaCO3). Instead, their

skeletons are proteinaceous rather than calcarus (Schuhmacher & Zibrowius, 2006).

4

2.1.2 Coral Anatomy

Corals are made out of a group of individual yet genetically identical individual

multi-cellular organisms know as polyps which together form the coral colony. It has an

oral disk which has a coelenteron that opens up at one end at a mouth which is surrounded

by tentacles. The polyp lives in a cup like skeleton called a corallite. The polyps are

interconnected gastro vascular canals, forming the coral colony while allowing the sharing

of nutrients and symbiotes (Veron, 1995).

2.1.3 Coral Ecology

Corals are also capable of feeding and do not only depend on photosynthetic

zooxanthellae as their main source of nutrition. They feed on a variety of microscopic

organisms such as phytoplankton and zooplankton. The coral polyp immobilizes and

captures prey by using its tentacles which contain stinging cells known as nematocysts.

Once the prey is captured or immobilized, the tentacles retract, bringing the prey into the

stomach where it is ingested. After digestion, the stomach reopens; enabling the

elimination of waste by products and allowing the next hunting cycle to begin (Castro &

Huber, 2000).

Corals also form symbiotic relationships with photosynthetic zooxanthellae.

Zooxanthellae are endosymbiotic dinoflagellates from the genus Symbiodinium which

reside in the endoderm of hermatypic corals. They translocate nutrients from the by-

products of photosynthesis and in-turn receive essential inorganic nutrients from the host

(Blank & Trench, 1986).

5

Symbiodinium generally enter the host via phagocytosis and are ‘coccoid in

hospite’ in which it lives in the host polyp while being surrounded by a membrane which

originates from the host cell plasmalemma.

According to Blank and Trench (1986), the usage of the term zooxanthellae in

scientific literature should be discouraged due to the confusion caused by overly

generalizing taxonomically diverse symbiotic relationships. Instead the more correct term

Symbiodinium should be used instead.

2.2 Coral Environment

2.2.1 Optimal Conditions

Coral reefs are best adapted to grow in warm tropical waters between 26 to 27 °C.

Corals also thrive in shallow waters as this allows sufficient light penetration for the

zooxanthellae and other primary producers to photosynthesize. Corals also need very clear

and pollution free waters to thrive (Wells & Price, 1992).

2.2.2 Coral Bleaching

Fitt et al. (2001) state that coral bleaching occurs when the brown pigmentation of

the coral is lost due to disassociation of the coral and the symbiont or when chlorophyll

within the symbiont itself is lost. It commonly occurs due to sustained elevation of sea

surface temperatures that exceed the tolerance limit of the coral polyps, exposure to high

levels of irradiance such as ultraviolet rays from the sun or any other drastic changes to the

physio-chemical properties of its environment and disease (Donner et al., 2005).

6

Coral bleaching increases susceptibility to disease, reduced calcification levels and

if prolonged, may cause partial or total mortality (Brandt & McManus, 2009). Coral

bleaching is believed to be a mechanism derived to increase the chance of a coral surviving

short-term stress as the symbiont may start to place a strain on the coral host. The coral

host may then regain the Symbiodinium ejected, possibly of a different species at a

different time after the cause of the stressor resides (Toller et al., 2001).

2.3 Importance of Coral Reefs

According to Spalding et al. (2001) it has been estimated that coral reefs cover one

tenth of the surface area of the ocean (284,300 km²). South-east Asia alone accounts for

almost 32.3% of the world’s coral reefs. Malaysia has coral reefs on both the east and west

coasts of the Peninsula as well as in Sabah and Sarawak.

Markham et al. (1993) state that coral reefs are important as natural protection

between open seas and coastlines. They mentioned that corals act as wave breaks and

effectively prevent coastal erosion. According to them, coral reefs also help stem the

effects of predicted sea level rise such as storm flooding.

Castro and Huber (2000) state that Reefs are home to a large variety of organisms.

They also note that aside from humans, mammals are rare on coral reefs, with visiting

cetaceans such as dolphins being the main exception. A few of these varied species feed

directly on corals, while others graze on algae on the reef.

7

2.4 Threats Facing Coral Reefs

2.4.1 Human Activities

Kleypas et al. (2006) reported that there are various threats facing coral reefs

throughout the world. Brown and Dunne (1988) found that intensive coral mining caused

major damage to coral reef diversity. They found heavily mined areas often took an excess

of 50 years to recover. Guzman and Jimenez (1992) found high levels of heavy metals in

coral tissue, indicating high pollution levels in the region as a result of agriculture and

urban runoff.

2.4.2 Global Warming

Donner et al. (2005) states that elevated ocean temperatures can cause coral

bleaching to occur. He also noted that the effects of global climate change may increase the

frequency coral bleaching. The study indicates that bleaching could become an annual or

biannual event for the vast majority of the world's coral reefs in the next 30-50 years if

there are no concentrated efforts to stabilize greenhouse gas concentrations in the

atmosphere.

2.5 Coral Rate of Growth and Recovery

Acropora, which usually form branching, encrusting and plate growth forms, grows

at a rate of 5 - 10cm a year (Shinn, 1966). Porites, which usually form massive growth

forms, grows at a rate of 0.8 - 1.2cm per year (Supriharyono, 2004).

8

2.6 Coral Reef Sampling Techniques

Nadon and Stirling (2006) conducted a study on the cost effectiveness of different

coral reef survey methods. They stated that PIT provides a certain degree of randomness

during sampling. They concluded the Point Interact Transect (PIT) as the most cost

effective method in determining coral cover and diversity.

Beenaerts and Berghe (2005) also found the PIT method to be substantially faster

to use in comparison to line and belt transects. They also found no significant difference in

the precision and accuracy of different survey methods used. They concluded the PIT to

the most efficient coral survey method when faced with constraints in time and effort

2.7 Coral Reef Diversity in Malaysia and Around the World

2.7.1 Malaysia

Harborne et al. (2000) conducted a comprehensive survey on corals in the east

coast of Malaysia. They found 221 coral species comprising 66 genera. From this, 68

species not reported in any previous reports and journals were identified bringing the total

species of coral known to be found in Malaysia to 323, or roughly 40% of coral species

found worldwide. Mean coral cover was also average at around 42.2%.

Fenner (2001a) conducted a coral reef survey in 9 sites around Miri. He found 203

species and 66 genera of hard coral with number of species ranging between 41-108 at

each site. Fenner (2001b) also conducted another survey around Pulau Banggi, Sabah and

found 252 species of coral comprising 71 genera. Number of species sampled at each site

ranged between 44-132 with an average of 98 per site.

9

Comley et al. (2004) states that Redang Island, Malaysia has a high level of hard

coral species diversity with a Shannon Diversity Index ranging between 2.41 - 4.26.

Affendi et al. (2005) also conducted a survey in Kg.Tekek, Tioman Island and found 221

coral species from 14 families and concluded that coral diversity was high in the study

area.

2.7.2 Southeast Asia

Veron (1995) states that South-East Asia is located within the Coral Triangle which

is also recognized as the global centre of marine biodiversity. It covers 5.7 million square

kilometres of ocean waters and contains 605 coral species or 76% of total coral species

found worldwide. The site with the highest diversity sampled was the Bird’s Head

Peninsular located in Papua with over 574 coral species found (Hoegh-Guldberg et al.,

2009).

10

2.7.3 Global

It is estimated that there are more than 800 coral species which have been identified

and found worldwide found (Hoegh-Guldberg et al., 2009). In 2002, scientists around the

world grouped different coral hotspots around the world and ranked them by the threat

faced by the particular hotspot. The top ten coral ecosystems under threat are the

Philippines, Gulf of Guinea Islands (Papua New Guinea), Sunda Islands (Indonesia),

Southern Mascarene Islands (near Madagascar), Eastern South Africa, the Northern Indian

Ocean, Southern Japan, Taiwan and Southern China, Cape Verde Islands, the Western

Caribbean, the Red Sea and the Gulf of Aden (Robert et al., 2002).

Ammar (2011) conducted a study of coral biodiversity in the Gulf of Aqba, Egypt

and derived a Shannon Diversity Index (H’) of 0.74 - 0.94 over several sample sites with

live coral cover ranging from 18.77% - 42.06%.

A study conducted by Sukumaran et al. (2008) on the coral reef diversity of the

Kilakarai group of Islands located in Gulf of Mannar, India found the live coral cover to

range between 25.0% - 40.1% with a H’ ranging between 1.72 - 2.53.

11

3.0 Materials and Methods

3.1 Survey Sites

The Talang-Satang National Park, in which the Talang-Talang Islands are located,

is the first national park in Sarawak to consist primarily as a marine protected area. Figure

3.1 shows the location of the Talang-Talang Islands comprising of Pulau Talang Besar,

Pulau Talang Kecil and Batu Penyu. Figure 3.2 shows the location of each station sampled.

Pulau Talang Besar West (Station 1), Pulau Talang Besar East (Station 2), and Batu Penyu

(Station 3). Pulau Talang Kecil was not sampled due time and logistical constraints. Table

3.1 lists down the Global Positioning System (GPS) coordinates of each station around the

Talang-Talang Islands.

Figure 3.1: Location of the Talang-Talang Islands, with (a) Pulau Talang Besar, (b) Pulau Talang Kecil and

(c) Batu Penyu. Sample sites are located North of Sematan, Sarawak, Malaysia.

12

Figure 3.2: Map of (a) Pulau Talang Besar (Station 1, & 2); (b) Batu Penyu (Station 3).

Table 3.1: GPS coordinates of sampling stations around the Talang-Talang Islands.

Station Coordinates

Station 1 1° 54’ 57.4’’ N, 109° 46’ 27.9’’ E

Station 2 1° 55’ 03.3’’ N, 109° 46’ 47.8’’ E

Station 3 1° 52’ 41.0’’ N, 109° 45’ 35.5’’ E

13

3.2 Coral Cover Survey

The point intercept transect method was used to assess hard coral cover in the reefs

of the Talang-Satang National Park. This method can be used to estimate the percentage

cover of coral life forms within a specified area (English et al., 1994).

The sample sites surveyed had a very narrow and shallow reef profile with depth

averaging at around 3 to 4 metres (Pilcher & Cabanban, 2000). Therefore the transect line

was laid out parellel to the shore while following the contours of the reef.

Figure 3.3: The Point Intercept Transect Method used to survey coral cover. Transect was divided into 4

sample stations with a gap of 5m in between each sample station in which no data was collected.

Figure 3.3 depicts the point intercept transect method. A 100 metre transect line

was deployed across the coral reef. The depth at which the transect line was placed did not

deviate more than 1 metre from the starting point (0 m). The transect line was then divided

into 4 sampling replicates each 20 metres long and separated from each other by a 5 metre

buffer in which no data was collected.

Once the transect line was laid, the observer recorded life forms found every 0.5

metres under the transect line on underwater slates. The same observer recorded all data in

each individual transect, at every station and in repeat surveys to ensure data

standardisation.

14

3.3 Coral Diversity Survey

A modified Point Intercept Transect (PIT) was used to identify the genus diversity

of the corals found around the Talang-Talang Islands. The standard methodology of the

PIT from the first survey had to be modified due to the fact that even though it enabled the

fast and rapid appraisal of coral genus diversity, the possibility of missing or non-detection

of different coral genera at a sample station was quite high, causing the under-

determination of the coral genus present (Beenaerts & Berghe, 2005).

A 100 metre transect line was laid parallel to the shore following the contour line of

the reef while ensuring that the depth did not deviate more than 1m from the starting point.

Figure 3.4 shows the methodology used in collecting the coral diversity data of the Talang-

Talang Islands.

Figure 3.4: Modified point intercept transect used in collecting Coral Diversity Data. Each data point is set at

0.5 metre intervals along the transect line with the width set at 0.5 metres from the transect line on both sides.

Coral abundance is determined as the occurrence of a coral genus in a data point (DP). In this case Coral

Genus A is counted as (DP 1= 1, DP 2= 1, DP 3= 1) and Coral Genus B as (DP1= 1, DP 2= 0, DP 3= 1) . The

total occurrence of Coral A across the 3 data points for Coral Genus A is 3 while for Coral Genus B it equals

to 2.