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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.