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Meiofauna Community Structure in Maludam River, Sarawak
Muhammad Nur Arif Bin Othman (31434)
Bachelor of Science with Honours
Aquatic Resource Science and Management
2014
DECLARATION
I declare this thesis was based on my original work in Maludam River, Sarawak except for
quotations and citations that had been acknowledged. I also declare that there were no
portions or parts of the work had been submitted for another application of degrees at
universities or institutions besides Universiti Malaysia Sarawak.
……………………………………..
(Muhammad Nur Arif Bin Othman)
Aquatic Resource Science and Management Programme
Faculty of Resource Science and Technology
Universiti Malaysia Sarawak.
Meiofauna Community Structure in Maludam River, Sarawak
Muhammad Nur Arif Bin Othman
This project is submitted in partial fulfilment of requirement for degree of Bachelor of
Science with Honours
(Aquatic Resource Science and Management)
Faculty Resource Science and Technology Universiti Malaysia Sarawak
12/5/2014
I
ACKNOWLEDGEMENT
First of all, I would like to thanks to Allah for helping me and giving me strength from the
beginning until I managed to finish my Final Year Project. Besides, I would like to thanks
my supervisor, Prof. Dr. Shabdin Mohd Long, a great man and teacher that have
continuously taught me, encourage and stimulate me with his words during my hard time. I
would like to thanks all my lecturers that have taught me. They really help me in finishing
the Final Year Project. Not forgetting my family that always encourage me not to give up.
I would like to thanks all my seniors, Mr. Chen Cheng Ann, Madam Zakirah, Madam
Athirah and especially Mr. Abang Azizil that have always helping and guide me in
laboratory and writing thesis. I would like to thanks the laboratory assistants that help me
during sampling and preparing the instruments, Mr. Richard Toh and Mr. Mohamad
Norazlan Bujang Belly. I am indebted to the boatman, Mr. Syahari and Mr. Harun for
helping me during sampling. I would also like to express my thanks to my labmates, Miss
Aina Syuhaida, Miss Aaqillah Amr, Miss Suhada and Miss Syuhaidah. Last and not
forgotten, I would like to thank all my friends and Universiti Malaysia Sarawak.
II
Table of Contents
Contain Page
Acknowledgement…………………………………………………………………… I
Table of Contents……………………………………………………………………. II
List of Abbreviations…………………………………………………………........... IV
List of Figures……………...………………………………………………………… V
List of Tables………………………………………………………………………… VI
Abstract……….……………………………………………………………………… VII
1.0 Introduction…………………………………………………………………….... 1
2.0 Literature Review………………………………………………………………... 4
2.1 Marine Meiofauna………….………..……………………………………….. 4
2.2 Freshwater Meiofauna……....…………...…………………………………… 4
2.3 Water Parameters…..………………………………………………………..... 5
2.3.1 Temperature………….…….…………………………………………..... 5
2.3.2 Salinity………….……………………………………………………….. 5
2.3.3 pH ………………………………………………………………………. 5
2.3.4 Dissolved Oxygen………………………………………………………. 6
2.3.5 Type of Particle Sizes.…………………………..………………………. 6
2.4 Feeding Habits…………………………………...…………………………… 7
2.5 Meiofauna as Pollution Indicators..………………………………...………… 7
2.6 Meiofauna in Sarawak and Sabah………………..…..……………………..... 8
3.0 Materials and Methods …………………………………………………………..
9
3.1 Sampling Sites………..………………………………………………………. 9
3.2 Field Sampling……...………………………………………………………… 11
3.2.1 Sediment Sampling……….……….…….………………………………. 11
3.2.2 Water Parameters……………….……………………………………….. 11
3.3 Laboratory Works……………………..……………...…………………......... 12
3.3.1 Particle size analysis…………………………………………………….. 12
3.3.2 Total Organic Matter……………………………………………………. 12
3.3.3 Chlorophyll a…………….……………………………………………… 13
3.3.4 Sorting of Meiofauna……………………………………………………. 14
3.3.5 Slide Preparation………………………………………………………... 14
3.4 Identification of Meiofauna…………………………………………………... 14
3.5 Data Analysis…………………………………………………...…………...... 15
3.5.1 Shannon-Wiener Index (H’)…………………………………………….. 15
3.5.2 Pielou’s Evenness Index (J’)………………………………………...….. 15
3.5.3 Species Richness (Df)………………………………………….…........... 16
3.5.4 One-Way Analysis of Variance (ANOVA) ……………………..……… 16
3.5.5 Correlation and Linear Regression……………………………………… 16
4.0 Results…………………………………………………………………………… 17
III
4.1 pH……….……………………………………………………………….......... 17
4.2 Temperature…….………………………………...…………………………… 17
4.3 Turbidity……………….……………………………...………………………. 18
4.4 Salinity……………………….……………………………...………………… 18
4.5 Dissolved Oxygen………………….……………………………...………….. 18
4.6 Depth…………………………………….……………………………….…… 19
4.7 Transparency………………………………….………………………………. 19
4.8 Particle Size Analysis…………………………………………………………. 26
4.9 Total Organic Matter and Chlorophyll a…………………………………………… 28
4.10 Species Composition….……………………………………………………... 29
4.11 Species Density……………………………………………………………. 30
4.12 Species Density (A), Species Diversity (H’), Species Evenness (J) and
Species Richness (Df)………………………………………………………………...
32
4.13 Correlation between Water Parameters and species Diversity, Species
Evenness, Species Richness and Species Density……………………………………
35
4.14 Linear Regression……………………………………………………………. 37
5.0 Discussion………………………………………………………………………...
41
5.1 Meiofauna Composition………………………………………………………. 41
5.2 Correlation between Water Parameters and Meiofauna Community…………. 42
6.0 Conclusion………..…...…………………………………………………………. 47
7.0 References……………………………………………………………………….. 48
8.0 Appendix………...………………………………………………………………. 52
IV
List of Abbreviations
Abbreviations Description
µm Micrometre
TOM Total organic matter
km Kilometre
% Percentage
cm Centrimetre
DO Dissolved oxygen
°C Degree celcius
rpm Round per million
nm Nanometre
m Metre
mg/m3 Milligram per metre cubic
mg/L Milligram per litre
PSU Practical salinity unit
FNU Formazin nephelometric unit
SD Standard deviation
V
List of Figures Pages
Figure 1 Location of six sampling sites in Maludam River,
Sarawak
10
Figure 2 Comparison mean and standard deviation of pH for six
stations (low tide and high tide)
22
Figure 3 Comparison mean and standard deviation of temperature
for six stations (low tide and high tide)
22
Figure 4 Comparison mean and standard deviation of turbidity for
six stations (low tide and high tide)
23
Figure 5 Comparison mean and standard deviation of salinity for
six stations (low tide and high tide)
23
Figure 6 Comparison mean and standard deviation of dissolved
oxygen for six stations (low tide and high tide)
24
Figure 7 Comparison mean and standard deviation of depth for six
stations (low tide and high tide)
24
Figure 8 Comparison mean and standard deviation of transparency
for six stations (low tide and high tide)
25
Figure 9 Comparison mean and standard deviation of surface
water current for six stations (low tide and high tide)
25
Figure 10 The percentage of sediment particle size for 6 stations
(1000 µm: very coarse sand, 500 µm: coarse sand, 250
µm: medium sand, 125 µm: fine sand, 63 µm: very fine
sand, >15.6 µm, >3.9 µm, <3.9 µm: silt and clay)
27
Figure 11 Scattered plot of linear regression graph between a)
species diversity (H’), b) species richness (Df) with
increasing of chlorophyll a (mg/m3)
37
Figure 12 Scattered plot of linear regression graph between species
evenness (J’) with increasing of pH
38
Figure 13 Scattered plot of linear regression graph between species
evenness (J’) with increasing of turbidity (FNU)
38
Figure 14 Scattered plot of linear regression graph between species
evenness (J’) with increasing salinity (PSU)
39
Figure 15 Scattered plot of linear regression graph between species
evenness (J’) with increasing of dissolved oxygen (mg/L)
39
Figure 16 Scattered plot of linear regression between species
evenness (J’) with increasing of surface current (cm/s)
40
Figure 17 Scattered plot of linear regression graph between species
evenness (J’) with increasing of temperature (°C)
40
VI
List of Tables Pages
Table 1 The location of sampling stations in Maludam River 9
Table 2 Mean and standard deviation for water parameters during
low tides
20
Table 3 Mean and standard deviation for water parameters during
high tides
21
Table 4 Percentage of sand, silt and clay content in each station 26
Table 5 Mean and standard deviation of total organic matter and
chlorophyll a in all stations
28
Table 6 Density (number of individuals/10 cm2) and percentage
(%) of meiofauna found in Maludam River
31
Table 7 Total species density (A), Species diversity (H’), species
evenness (J’) and species richness (Df) for each station in
Maludam River
32
Table 8 List of meiofauna found in Maludam River 33
Table 9 Pearson linear correlation (r) between water parameters
with species diversity, species evenness, species richness
and species density
36
VII
Meiofauna Community Structure in Maludam River, Sarawak
Muhammad Nur Arif Bin Othman
Aquatic Resource Science and Management Faculty of Resource Science and Technology
Universiti Malaysia Sarawak
Abstract
Maludam River is one of the rivers located in Sarawak and it is the habitat for many
aquatic animals and plants. The main objective of the study was to determine the
relationship between meiofauna community and environmental parameters. The sampling
was done on 24th
and 25th
August 2013. Six stations were selected which runs from
freshwater to estuarine regions. Eight taxa were recorded in Maludam River such as
Nematoda, Polychaeta, Oligochaeta, Tardigrada, Copepoda, Insecta, Gastropoda larvae and
Bivalvia larvae. Copepoda was the common meiofauna found in all stations. Station 6 had
recorded the highest species density (182.46 ind./10 cm2) while the lowest species density
was recorded in station 2 (10.61 ind./ 10 cm2). Chlorophyll a shows a strong positive
correlation with species diversity (r= 0.917, p= 0.005) and species richness (r= 0.883, p=
0.010). The data gathered from the study could be used as baseline data for future
management of Maludam River.
Key words: Meiofauna, environmental parameters, species diversity, species richness,
species evenness
Abstrak
Sungai Maludam adalah salah satu sungai yang terletak di Sarawak dan ia adalah habitat
pelbagai haiwan akuatik dan tumbuhan. Objektif utama kajian ini adalah untuk
menentukan hubungan antara komuniti meiofauna dan parameter persekitaran. Kajian
telah dilakukan pada 24 dan 25 Ogos 2013. Enam stesen telah dipilih sebagai kawasan
kajian dari air tawar ke muara sungai. Lapan taksa direkodkan di Sungai Maludam seperti
Nematoda, Polychaeta, Oligochaeta, Tardigrada, Copepoda, Insecta,larva Gastropoda
dan larva Bivalvia. Copepoda adalah meiofauna yang biasa ditemui di semua
stesen.Stesen 6 telah mencatatkan kepadatan spesies paling tinggi (182.46 ind./10 cm2)
manakala kepadatan spesies paling rendah adalah stesen 2 (10.61 ind./ 10 cm2). Klorofil
a telah menunjukkan hubungkait positif yang kuat dengan kepelbagaian spesies (r= 0.917,
p= 0.005) dan kekayaan spesies (r= 0.883, p= 0.010). Data yang diperolehi daripada
kajian ini boleh digunakan sebagai data asas bagi pengurusan masa depan Sungai
Maludam.
Kata kunci: Meiofauna, parameter persekitaran, kepelbagaian spesies, kekayaan spesies,
kesamarataan spesies
1
1.0 Introduction
The study of meiofauna has begun since the 18th
century. At the beginning, meiofauna
studies only focused on the discovery, identification and taxonomy of new species but
today meiofauna have been widely used as the important component in aquatic ecosystem
(Higgin & Thiel, 1988). Mare was the first human that used the term meiofauna in 1942
which comes from the Greek word means small. Generally, meiofauna are defined as
organisms with size smaller than macrofauna but have large size than microfauna. The
sizes of meiofauna are between 500 µm and 45 µm pore sizes (Armenteros et al., 2006).
Nematoda, Rotifera, Copepoda, Ostracoda, Turbellaria and Tardigrada are examples of
permanent meiofauna (Higgin & Thiel, 1988). Permanent meiofauna mean that the
organisms are meiobenthos throughout their life cycles. Some of them are temporary
meiofauna such as Oligochaeta, Mollusca and insect larvae. They are usually larvae of
macrofauna and only become part of meiofauna during juvenile stages. In lake, meiofauna
consists of three groups which are permanent meiofauna, temporary meiofauna and bottom
resting stages of planktonic Cyclopoida (Kurashov, 2002).
The definition of community based on Solomon et al. (2008) is the combination of various
populations that live in the same place at the same time where they interact with each other
to survive. According to Mouawad et al. (2009), meiofauna communities are made up from
organisms with small size and no planktonic larval stage.
Mangrove is defined as a tree, shrub, palm or ground fern where generally the height of the
plant species exceeding one metre and occupy large areas in subtropical and temperate
zones (Armenteros et al., 2006). Mostly the mangroves grow in the intertidal zone of
coastal environments or estuarine margins (Robertson & Alongi, 1992). In term of
2
mangrove ecosystem, the species that live there interact with each other and have
adaptations to survive under such harsh environmental conditions. Mangrove is a home for
variety of aquatic animals including meiofauna.
Sarawak is the largest state in Malaysia where it has coastline over 800 km along the
northwest coast of Borneo (Norliana et al., 2013). About 1.4 % of the Sarawak land is
covered by mangrove forest. Sarawak mangrove forest is located along the sheltered shores
and estuarine where they occupied 60 % of Sarawak coastline. The major mangrove part
can be seen in Kuching, Sri Aman, Limbang Divisions and Rejang Delta. Sarawak
mangrove forest is a habitat for various animals and plants. Malaysian mangrove had
recorded the higher nematode species richness with value of 107 species (Somerfield et al.,
1998; Netto & Gallucci, 2003).
Maludam River runs from freshwater to estuarine regions. Some parts of Maludam River
are inside the Maludam National Park. There is water plant treatment near the river where
it supplies water to residential areas. Iban longhouses are found in Maludam River located
at entrance of Maludam National Park. Malay villages and fish market also can be seen in
Maludam River. Some of mangrove plant species that can be found in Maludam River are
Avicennia, Rhizopora and Nypa.
From the previous studies, meiofauna are more focused at Peninsular Malaysia
(Sasekumar, 1994; Zaleha, 2009). In Sarawak, meiofauna were studied by (Shabdin &
Abang, 1999; Shabdin & Chen, 2010). The past studies of meiofauna in Sarawak are more
focused on the zonation pattern, their roles as food for higher trophic levels and responses
to perturbations (Shabdin & Chen, 2010). However, there are still less information on
meiofauna community structure in Maludam River, Sarawak. The aim of this research is to
3
collect, examine and identify the existing meiofauna species in the Maludam River. The
research questions are: (i) what is the meiofauna that can be found in Maludam River?; (ii)
What are the parameters that influence the meiofauna community along Maludam River?;
(iii) What are the potential values of Maludam River in the future?
The objectives of this study are: 1) to determine the species density of meiofauna in
Maludam River, Sarawak; 2) to determine the species composition of meiofauna in
Maludam River; 3) to determine the species diversity of meiofauna in Maludam River; 4)
to determine the water parameters that influences the meiofauna community structure.
4
2.0 Literature Review
2.1 Marine Meiofauna
Meiofauna is a term used to describe organisms with size between 500 µm and 45 µm
where they are usually found at the upper two cm of the sediment (Higgins & Thiel, 1988).
According to Shabdin and Othman (1999), nematodes species can be found up until 30 cm
depth depend on the ability of the species to tolerate sulphides. Marine meiofauna are more
abundance in intertidal muddy estuarine areas and less abundance in deep water. The
distributions of meiofauna in marine habitat are affected by the type of sediments with
influence of other environmental factors such as dissolved oxygen, salinity, pH,
availability of food, temperature and water movement (Higgins & Thiel, 1988). Nematodes
and copepods are the two major groups of meiofauna that inhibit marine habitat (Shabdin
& Othman, 1999). Nematodes are the largest meiofauna species found in marine habitat.
Study done in estuary of Ratones River, Santa Catarina, South Brazil showed almost 90 %
of meiofauna found are composed of nematodes species follow by halacarids and
oligochaetes (Netto & Gallucci, 2003).
2.2 Freshwater Meiofauna
According to Radwell and Brown (2008), the studies of freshwater meiofauna are less
focused compare to macrofauna due to lack collection of sample. This has causes
insignificant data and misunderstanding that assume meiofauna are not abundant in
freshwater. Researchers in meiofauna taxa have demonstrated the abundant of meiofauna
in freshwater ecosystem and the roles of them in ecological aspects although they
acknowledge it is still unclear (Radwell & Brown, 2008). Kurashov (2002) has shown that
more studies need to be done for meiofauna in freshwater ecosystem to show the
abundance and their roles in freshwater ecosystem.
5
2.3 Water Parameters
2.3.1 Temperature
Temperature plays an important role in distribution of meiofauna by affecting their
reproductive system. Nematodes are abundant in sediment with high temperature because
it affects their reproductive system (Armenteros et al., 2006). Based on study done by
Chen et al. (2012), nematodes density is greater in intertidal zone compare to subtidal zone
due to high temperature.
2.3.2 Salinity
Natural phenomena such as tide, rain and seasonal monsoon can change the salinity of the
water and influence the distribution of meiofauna (Sasekumar, 1994). According to
Sasekumar (1994), meiofauna have ability to burrowing deeper into sediment where the
salinity is suitable for their survival. Each of the meiofauna species has different tolerant to
change of salinity (Warmick & Gee, 1984; Higgins & Thiel, 1988). Warmick and Gee
(1984) showed that nematodes distributions have no correlation with salinity but copepods
are affected by change of salinity.
2.3.3 pH
pH is one of the factors that influence the species density and diversity of meiofauna in an
area. Study done by Chen et al. (2012) showed that each of nematodes species have
different density with change of pH. pH of water can be affected by chemical discharge
where it created a harmful environment for meiofauna (Mouawad et al., 2009).
6
2.3.4 Dissolved Oxygen
Concentration of dissolved oxygen is very important in distribution of meiofauna. Zaleha
(2009) showed that meiofauna had decreased in Muar River, Johor, Malaysia due to
discharge of waste water from industrial plants. Sewages, oil and waste products have a
tendency to reduce the absorption of oxygen into water because of their chemical contents.
Besides, the concentration of oxygen in sediment is related to type of substrate. Sandy
substrates have more dissolved oxygen compare to muds due to availability of them to
retain more water (Sasekumar, 1994). Shabdin and Othman (1999) showed that
hydrodynamism such as tidal current give a greater influence to concentration of oxygen in
sediment.
2.3.5 Type of particle sizes
Sediment grain size is one of the important factors that affect the abundance and
composition of meiofauna. According to Higgins and Thiel (1988), different in sediment
grain size will determine the porosity, permeability and salinity gradients. Interstitial space
between the sediment particle determine the amount of dissolved oxygen, water content
and the meiofauna species that can occupied the space (Radwell & Brown, 2008).
Substrate that is composed of silt and clay has lower diversity of meiofauna compare to
sandy structure due to availability of space (Sasekumar, 1994; Chen et al., 2012). Each of
the meiofauna organisms has difference level accessibility toward sediment grain size such
example burrowing meiofauna are likely to occupied grain size below 125 µm (Higgins &
Thiel, 1988).
7
2.4 Feeding Habits
Meiofauna have variety way of feeding. Due to their small sizes, meiofauna transfer the
energy from algae, bacteria, detritus and small protozoans to higher trophic levels.
Rotifera obtain foods by scraping on substrate or prey upon other small organisms (Rundle
et al., 2002). Based on Daiber (1982), oligochaetes are more attract and concentrate at
sediment with high detritus. Some of meiofauna such as nematodes, polychaetes and
Foraminifera have unique feeding habit. They choose their food and only feed on particular
bacteria and algae. There are also meiofauna that have different sizes of buccal cavity.
Meiofauna with large buccal cavity ingest more algae compare to meiofauna with small
mouth opening. Daiber (1982) suggest that the meiofauna with selective digestion process
and selective feeding can help reduce interspecific competition between meiofauna. These
enable large number of meiofauna species to live and survive in an area with limited
source of food.
2.5 Meiofauna as Pollution Indicators
Previous studies show that meiofauna have high potential as indicator of pollution and
change in aquatic condition compare to macrofauna (Somerfield et al., 1994). According to
Gee et al. (1992), infauna benthic communities are more advantages as pollution indicator
compare to epibenthos because they are immobile and persistent. Small sample of
meiofauna for pollution study can be collected because they have small sizes, can be found
in high densities and more stable than macrofauna on seasonal (Gee et al., 1992;
Somerfield et al., 1994; Mouawad et al., 2009). Besides, Gee et al. (1992); Somerfield et
al. (1994) ; Mouawad et al. (2009) suggest that a few characteristics of meiofauna such as
shorter life times and absence of planktonic phase during life cycles make them more
sensitive and response faster to disturbance. Meiofauna also are not directly migrated when
8
meet stressful condition and many of them have high level of resistant again disturbance
and harmful chemical (Mouawad et al., 2009).
2.6 Meiofauna in Sarawak and Sabah
The studies of meiofauna in Sarawak were done by Shabdin and Abang (1999); Chen et al.
(2012a, 2012b); Norliana et al. (2013) while in Sabah, the studies were done by Shabdin
and Othman (1999); Shabdin and Othman (2008). The past studies of meiofauna in
Sarawak are more focused on the zonation pattern, their roles as food for higher trophic
levels and responses to perturbations (Shabdin & Chen, 2010). However, the studies of
meiofauna community structure are still lacking. In Sarawak, there are five common taxa
recorded in all published works which are Nematoda, Kinorhyncha, Polychaeta, Ostracoda
and Harpacticoida (Shabdin, 2006; Shabdin & Chen, 2010). Nematoda, Oligochaeta,
Copepoda, Rotifera and Ciliata are some of meiofauna found in rivers in Bario, Kelabit
Highlands, Sarawak (Shabdin & Abang, 1999).
9
3.0 Materials and Methods
3.1 Sampling Sites
The sampling was carried out in Maludam River, Sarawak on 24th
(low tide) and 25th
(high
tide) August 2013. Six different locations were selected as sampling site which runs from
freshwater to estuarine regions. The coordinate for each station was recorded by using
Global Positioning System (60 CSX, GARMIN). Station 1, 2, 3 and 4 were located inside
Maludam National Park, station 5 near the village and station 6 at the river mouth.
Table 1: The location of sampling stations in Maludam River
Station Coordinate River wide (m) Brief description
1 N 01° 37' 25.9"
E 111° 03' 13.6"
10 Station name: Sungai Bakong
Located inside Maludam National park.
The area was categorized as freshwater peat
swamp. Water colour was black.
2 N 01° 37' 27.7"
E 111° 03' 12.3"
15 Station name: Jalan Sami
Lot of detritus and dead leaves at the
bottom. Water colour was black.
Freshwater peat swamp.
3 N 01° 37' 40.5"
E 111° 02' 56.9"
26 Station name: Entrance of Maludam
National Park
Lot of detritus and dead leaves at the
bottom. Water colour was black.
Freshwater peat swamp.
4 N 01° 38' 22.4"
E 111° 02' 48.9"
10 Station name: Teluk Belanda
Located near water treatment plant. Water
colour was dark brown. Estuarine area.
5 N 01° 38' 36.6"
E 111° 02' 33.7"
28 Station name: Maludam Bridge
Located near the village. Dominated by
Nypa and Sonneratia trees. Lots of
mudskipper. Estuarine area.
6 N 01° 39' 50.7"
E 111° 01' 15.5"
40 Station name: -
Located at the river mouth. Dominated by
mangrove trees such as Avicennia,
Rhizopora and Nypa. Estuarine area.
10
Figure 1: Location of six sampling sites in Maludam River, Sarawak (Source: Maps from Department of Survey and Mapping Sarawak, 1994)
N
South China Sea
1 cm
100 km
1 cm
2 km
11
3.2 Field Sampling
3.2.1 Sediment Sampling
Replicate of 5 cm depth of sediments were collected by using Perspex tube at every
stations. The sediments were sieved by using sieve with mesh size of 500 µm on the top
and 45 µm beneath. The samples that retained at 45 µm were collected, labelled and fixed
with 5 % formalin. The samples were brought back to laboratory for further analysis.
Replicate of 5 cm depth of sediments for Total Organic Matter were taken by using
Perspex tube at every stations. For Chlorophyll a analysis, four samples of 1 cm depth of
sediments were collected by using Perspex tube at each station. Five cm of sediment was
collected using Perspex tube at each station for particle size analysis. All the sediments
were kept in cooler box with ice and brought back to laboratory for further analysis.
3.2.2 Water Parameters
Physico-chemical parameters such as dissolved oxygen (DO), pH, turbidity, salinity and
temperature were measured in-situ. Dissolved oxygen and temperature were measured by
using Sper Scientific instrument (850048). pH and turbidity reading were recorded by
using Hanna instrument (HI 8424) and Eutech instrument (T 400) while salinity was
recorded by using Milwaukee instrument (MA 887). All water parameters reading were
taken three times.
Other parameters such as water transparency were taken by using secchi disk. Water depth
was measured using depth finder (Speedtech instrument, 65054). Surface current was
recorded by using simple own device where one metre thread was tied to the floating
object and stop watch was used to record the moving of floating object within one metre
distance. All water parameters were taken on 24th and 25
th August 2013.
12
3.3 Laboratory Works
3.3.1 Particle Size Analysis
Grade scale, a discrete series of increments was used to determine the size distribution of
sediment. Sediment particle size was analysed using methods proposed by Buchanan
(1984).
3.3.2 Total Organic Matter
Ash-free dry weight method (Higgins & Thiel, 1988) was used for total organic matter
(TOM) analysis. The sediment was heated inside the oven at 60 °C for 24 hours to remove
the water. After the drying process, the initial weight of the sediment was taken by
weighing on analytical balance. Then, the sediment was heated with high temperature (475
°C) inside the furnace for 7 to 12 hours. After heating, the sediment was weighed again as
final weight to determine the weight loss.
The equation involved is as follows:
F = (E-D)/E
Where:
F = Total organic content
E = Soil (60 ˚C, for 24 hours)
D = Soil (475 ˚C, for 7 to 12 hours)
13
3.3.3 Chlorophyll a
First, the sediment for chlorophyll a was grinded inside the mortar with 10 mL of 100 %
acetone (Higgins & Thiel, 1988). After grinding, the sediment was transferred into
centrifuge tube and left overnight for better pigment extraction. Then, the tube was
centrifuged at 4000 rpm for 30 minutes. After centrifuge, the supernatant was poured
inside cuvette and the reading for chlorophyll a at wavelength 665 nm was taken by using
spectrophotometer (Hach, DR 2010). The data was recorded to be used in the equations
below.
The crucible was labelled and weighed. The sediment was put into the crucible and
weighed. The crucible was heated inside the oven at 60 °C for 24 hours. After heat, the
crucible was weighed again. The weight of crucible with sediment was subtracted with
weight of crucible to calculate the weight of sediment only. The volume of sediment
sample (Vs) was measured by dividing the weight of sediment with density of sediment
(2.65 g/cm3). The volume of water content of sample was added with volume of acetone
use during grinding of sediment (V).
The equations involved were as follows:
Chl a = 26.7 (E0-Ea) x V
Vs x L
Where:
E0 = absorbance before acidification at 665 nm
Ea = absorbance after acidification at 665 nm
V = volume of water content of sample plus acetone (100 %) added
14
Vs= volume of sediment sample
L = path length (cm) of the spectrophotometer cell
3.3.4 Sorting of Meiofauna
A few drops of rose bengal was put into the sediment to stain the meiofauna. The sediment
was placed inside petri dish, observed under stereo microscope and wire loop was used to
collect the meiofauna.
3.3.5 Slide Preparation
The meiofauna was placed into cavity block with solution of 90% distilled water, 5%
glycerine and 5% pure ethanol. The cavity block was left in desiccator for a few days. A
clean slide and cover slip was prepared. Meiofauna was transferred to the slide with few
drop of pure glycerine. The cover slip was carefully dropped on the slide and sealed with
nail polish (Shabdin & Yasmin, 2013).
3.4 Identification of Meiofauna
The meiofauna were identified using Yule and Yong (2004). Nematode was identified
using Norliana (2011) while copepod was identified using Coull (1977). Brinkhurst (1982)
was used for identification of oligochaetes. The meiofauna were identified until genera
level.
