IMPACT OF WATER QUALITY ON SEAGRASS MEADOW AT TANJUNG
KUPANG
SHAIKHAH BINTI SABRI
A project report submitted in partial fulfillment of the
requirements for the award the degree of the
Master of Engineering (Civil-Environmental Management)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
November, 2009
iii
To my beloved family and friends
Thank you for everything
“Today we are nobody but tomorrow we will be somebody”
iv
ACKNOWLEDGEMENTS
First of all, a very grateful to Allah gives me the ability to finish up my final
master project. I would like to express my deep gratitude to Assoc. Prof. Dr. Mohd
Ismid Mohd Said as final project’s supervisor for his valuable time, guidance, advice
and critics in fulfill the study. Also a million thanks to my co-supervisor Dr. Shamila
Azman for her encouragement, guidance and friendship throughout the course of this
study. Not forgetful my friends and colleagues for their patience and cooperation
during the entire study making process.
I am also would like to thank to staffs and technicians of Universiti Teknologi
Malaysia’s Environmental Laboratory who provided assistance and shared the
information that I needed.
Last but not least, my appreciative to all my family members for their support
and encouraging me to finish up my study.
v
ABSTRACT
Seagrasses which colonize near shore ecosystem may be used as indicator of
environmental health since it is vulnerable to the changes of water and environmental
quality. Six species of seagrasses were found at Tanjung Kupang, Johor which are
identified as Halophila ovalis, Halophila minor, Halophila spinulosa, Enhalus
acoroides, Halodule pinifolia and Thalassia hemprichii. Meanwhile three species
were found at Teluk Buih, Mersing identified as Enhalus acoroides, Halodule
pinifolia and Cymodocea rotundata. Heavy metals (As, Cd, Cr, Cu, Pb and Hg) were
analyzed using ICPMS and Halophila minor have the highest accumulation of heavy
metal among the species. Thalassia hemprichii turned out to be strongest
accumulator for Cd (0.016 mg/g dry weight) and Halophila ovalis for Hg (0.044
mg/g dry weight). The results obtained for water quality analysis exceeded the
Interim Marine Water Quality Standard except for Pb (0.0014 to 0.0066 mg/L) and
Total Cr (0.1486 to 0.105 mg/L). Dredging activities for land reclamation could be a
possible release of heavy metals to the seawater since the concentration of heavy
metal decrease in the following order: sediment > water > seagrass leaves. Therefore,
Halophila minor has the potential to be used as bioindicator since it accumulates
higher concentration of heavy metal compared to other species. Two rivers, Sungai
Pok Besar and Sungai Pok Kecil, situated near the seagrass bed is classified as Class
III based on Water Quality Index.
vi
ABSTRAK
Rumput laut yang tumbuh di kawasan perairan di pesisir pantai boleh
digunakan sebagai petunjuk kepada tahap pencemaran kerana hidupan ini sangat
sensitif terhadap perubahan kualiti air dan persekitaran. Enam spesies rumput laut
yang dijumpai di Tanjung Kupang, Johor dikenalpasti sebagai Halophila ovalis,
Halophila minor, Halophila spinulosa, Enhalus acoroides, Halodule pinifolia dan
Thalassia hemprichii. Sementara itu, tiga spesies yang dijumpai di Teluk Buih,
Mersing direkodkan sebagai Enhalus acoroides, Halodule pinifolia dan Cymodocea
rotundata. As, Cd, Cr, Cu, Pb dan Hg dianalisis menggunakan ICPMS dan Halophila
minor menunjukkan bacaan kandungan logam berat paling tinggi berbanding spesies
lain, Thalassia hemprichii pula mengumpulkan kandungan logam berat bagi Cd
(0.016 mg/g berat kering) dan Halophila ovalis untuk Hg (0.044 mg/g berat kering).
Keputusan yang didapati untuk analisis kualiti air melebihi Piawaian Interim Kualiti
Air Laut kecuali plumbum (0.0014 – 0.0066 mg/L) and Jumlah Kromium (0.1486 –
0.105 mg/L). Aktiviti pengorekkan untuk tebusguna tanah dikenalpasti sebagai
penyumbang kehadiran logam berat di dalam air laut kerana kandungan logam berat
berkurang mengikut aturan berikut: tanah > air > rumput laut. Oleh itu, Halophila
minor mempunyai potensi untuk digunakan sebagai penunjuk biologi kerana
mengumpul kandungan logam berat paling tinggi berbanding spesies rumput laut
lain. Dua buah sungai, Sungai Pok Besar dan Sungai Pok Kecil yang terletak
berhampiran dengan hamparan rumput laut dikenalpasti berada dalam Kelas III
berdasarkan Indeks Kualiti Air.
vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
TITLE
i
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xii
LIST OF SYMBOL
xiv
INTRODUCTION
1
1.1
Preface
1
1.2
Seagrass Distribution
2
1.3
Problem Statement
3
1.4
Objective of Study
4
1.5
Study Area
5
1.6
Scope of Study
7
LITERATURE REVIEW
8
2.1
Overview
8
2.2
Characteristics of Seagrass
9
2.2.1
12
Seaweeds
viii
2.3
Growth Requirements
12
2.4
The Significance of Seagrass
13
2.4.1
14
2.5
2.6
2.7
Threats to Seagrass
17
2.5.1
Natural Threats
17
2.5.2
Eutrophication
17
2.5.3
Dredging
18
2.5.4
Boating
19
Physical Water Quality Parameter
19
2.6.1
Total Suspended Solid
19
2.6.2
Turbidity
20
2.6.2
Temperature
21
Chemical Water Quality Parameter
21
2.7.1
Dissolved Oxygen
22
2.7.2
Biochemical Oxygen Demand
22
2.7.3
Chemical Oxygen Demand
23
2.7.4
pH
23
2.7.5
Nutrients
24
2.7.6
2.7.7
2.8
Marine Life Associated with Seagrass
2.7.5.1
Phosphorus
24
2.7.5.2
Ammoniacal Nitrogen
25
Heavy Metal
25
2.7.6.1
Arsenic (As)
26
2.7.6.2
Cadmium (Cd)
27
2.7.6.3
Total chromium
27
2.7.6.4
Copper (Cu)
28
2.7.6.5
Lead (Pb)
28
2.7.6.6
Mercury (Hg)
29
Oil and Grease
30
Marine Water Quality Standards
31
2.8.1 Malaysia Interim Marine Water Quality
Standards
2.8.2 Marine Water Quality Criteria for the
ASEAN Region
32
32
ix
2.8.3 Singapore Marine Water Quality Criteria
2.9
United Kingdom Interim Marine Sediment Quality
Guidelines (ISQG)
3
4
5
33
33
METHODOLOGY
35
3.1
Study Area
35
3.2
Sample Preparation
37
3.2.1 Water Sample
38
3.2.2 Seagrass Specimens and Sediment
40
3.3
Analysis of Samples
41
3.4
Chemical Analysis
42
RESULT AND ANALYSIS
43
4.1
Introduction
43
4.2
Specimen Identification
43
4.3
Marine Life at Tanjung Kupang
52
4.4
Water Quality Analysis
53
4.4.1 Oil and Grease
56
4.4.2 Total Suspended Solid
56
4.4.3 Ammoniacal Nitrogen and Phosphorus
57
4.5
Heavy Metals in Water
59
4.6
Heavy Metals in Sediment
63
4.7
Heavy Metals in Seagrass
64
4.8
Development Adjacent to the Seagrass Meadow
67
4.9
Overall Discussion
72
CONCLUSION AND RECOMMENDATION
75
5.1
Introduction
75
5.2
Recommendation
76
REFERENCES
77
x
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
The common seagrass species in Malaysia and their
identification features (Save Our Seahorse Handbook,
2006)
11
2.2
The differences between seagrass and marine algae
(Seagrass-Watch, 2008)
12
2.3
List of marine life supported by a seagrass bed
15
2.4
Malaysia Interim Marine Water Quality Standard
(Department of Environment (DOE) Malaysia, 2004)
31
2.5
Marine Water Quality Criterion for ASEAN region
(Association of Southeast Asian Nation, 2009)
32
2.6
Summary of criteria for site selection for floating netcage
farming (Singapore Fisheries and Aquaculture
Department, 2009)
33
2.7
Interim Marine Sediment Quality Guidelines (UK Marine
Special Areas of Conservation)
34
3.1
(a) Schedule of sampling at Tanjung Kupang
(b) Schedule of sampling at Teluk Buih, Mersing
Analytical procedures (Standard Method American
Public Health Association, 2005)
3.2
38
42
Specimen identification based on acknowledged species
by previous study at seagrass meadow Tanjung Kupang
and Teluk Buih, Mersing
45
4.2
List of marine life found during survey at seagrass
meadow
52
4.3
Water quality result of Sungai Pok Kecil and Sungai Pok
Besar
53
4.1
xi
4.4
Result of water quality parameter based on IMWQS and
AMWQC at Teluk Buih
54
4.5
Result of water quality parameter based on IMWQS and
AMWQC at Tanjung Kupang
55
4.6
Heavy metal concentration at Sungai Pok Kecil and
Sungai Pok Besar
59
4.7
Heavy metal concentration and Teluk Buih
61
4.8
Heavy metal concentration at Tanjung Kupang
62
4.9
Concentration of metals (mg g-1 dry weight) in the
sediment which evaluate to United Kingdom interim
marine sediment quality guidelines (ISQG)
4.10
4.11
63
Concentration of metals (mg g-1 dry weight) in the
different species of seagrass
66
Land use in Tanjung Pelepas Zone (MBJBT, 2008)
68
xii
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Seagrass distribution at Malaysia (The Encyclopedia of
Malaysia, The Seas, 2001)
3
1.2
The position of study area that is near to Pulai River
estuary, Second Link Bridge and Singapore
5
1.3
Location of seagrass field and sampling location
6
3.1
Station 1 for water quality at Sungai Pok estuary. The
land is fully covered with riverbank vegetation especially
mangrove
35
3.2
Second station for water quality measurement at seagrass
bed
36
3.3
Merambong Island as the third sampling station; inhabits
a lot of unique species.
36
3.4
(a) Upstream of Sungai Pok Besar used as boat parking
bay by local fisherman and (b) is downstream of the
river.
37
3.5
(a) Upstream of Sungai Pok Kecil and (b) is downstream
of the river. The river is surrounding by palm oil
plantation.
37
3.6:
Multi-Parameter Analyzer-Consort 535 that has used to
measure the pH level on surface water
39
3.7
YSI probe to determine concentration of dissolved
oxygen
39
3.8
Secchi disk used to measure the depth of turbidity in the
water column at Merambong Island
40
3.9
Seagrass leaves ((a) Halophila ovalis and (b) Halophila
spinulosa) that have been preserved in formalin and
placed in glass bottles
41
xiii
3.10
Digestion process using open beaker technique on hot
plate
41
4.1
(a) Current condition of coastal line near seagrass
meadow while (b) is the future development which under
Tanjung Pelepas industrial region
69
4.2
Existing and future development of Port Tanjung Pelepas
with potential expansion up to 95 berths
71
4.3
Several creatures that can found from seagrass area
where (a) is Holothuria leucospilota, (b) is Stichodactyla
gigantean meanwhile (c) Sabella spallanzanii, (d) is
Protoreastar nodosus, (e) Purple Climber Crab and (f)
Hippocampus kuda.
74
xiv
LIST OF SYMBOLS
AMWQC
ASEAN Marine Water Quality Criteria
AN
Ammoniacal Nitrogen
As
Arsenic
BOD
Biochemical Oxygen Demand
Cd
Cadmium
COD
Chemical Oxygen Demand
Cr
Chromium
Cu
Copper
DO
Dissolved Oxygen
DOE
Department of Environment Malaysia
Hg
Mercury
IMWQS
Interim Marine Water Quality Standard
INWQS
Interim Water Quality Standard
Pb
Lead
SOS
Save Our Seahorse
UTM
Universiti Teknologi Malaysia
WQI
Water Quality Index
CHAPTER 1
INTRODUCTION
1.1
Preface
Increasing human populations associated with port expansion, urbanization,
industrial development and agricultural activities along the Johor Strait especially at
Pulai River have focused intention on the risk of those activities to the estuaries and
coastal. The largest seagrass bed in Peninsular Malaysia located in the coastal area
of Johor, situated between Merambong Island and Tanjung Kupang. The green
carpet in the sea could very well be a submerged is vegetation “bridge” connecting
southwest Johor to Tuas in Singapore, given its sheer size of 38ha (New Strait
Times, 2008). 60% of Malaysia’s natural wetlands are located in Johor including the
seagrass sites. It supports a rich biodiversity such as seaweeds, sea cucumbers and
fishes that are facing the competition between development and preservation of
natural ecosystem.
Generally, the seagrass meadow are very important ecosystems especially for
the fishing industry and therefore for food supplies, beside to ensure stabilisation of
the coast as an important characteristic in view of rising sea levels and protection
against coastal erosion. Moreover, the area also identified as habitat for rare marine
animals like seahorses, pipefish and dugongs. There are between 70-76 species of
fish in 41 families that have been observed in the seagrass beds and the adjacent
mangrove areas in Tanjung Adang-Merambong (Aziz et al., 2006). Even with its
importance role in food production, climate regulation, genetic resources and
recreations, there have been minimal attempt to conserve the seagrass. According to
2
Choo (2006) the disappearance of a huge tract of seagrass bed was due to
reclamation works by Port of Tanjung Pelepas (PTP), the Second Link project, a
coal-fired power plant and a petrochemical hub. However the results have not been
revealed.
Seagrass is identified as an aquatic flowering plant which lives completely
submerged under saline environment. These marine angiosperms include 12 genera,
which 7 are characteristic of the tropics; Halodule, Cymodocea, Syringodium,
Thalassondendron, Enhalus, Thalasia and Halophila.
Meanwhile 5 others are
confined to temperate waters which are Zostera, Phyllospadix, Heterozostera,
Posidonia, and Amphibolis (Mann, 2000).
1.2
Seagrass Distribution
Worldwide there are 60 described seagrass species and majority of species
are found in the Indo-Pacific region where most of them grow in silty or sandy
sediment (Choo, 2006). Australia was identified to have more seagrass species
compared to other continent where 30 species can found there. Meanwhile, in
Malaysia the occurrence of seagrass are scattered at 78 sites which involves
mangroves, coral reefs, shallow inter-tidals, semi-enclosed lagoons and shoals areas
(Japar et al., 2000). Along the west coast, mixed species of seagrass inhabit from
sandy mud of Tanjung Rhu, Langkawi Island to sand-covered corals at Teluk
Kemang, Negeri Sembilan and extend till Serimbun Island in Malacca. At depths of
2-2.7 m at Tanjung Kupang-Merambong area, the largest and highest numbers of
seagrass species grows on calcareous sandy mud sub-tidal shoals.
At the east coastline, there are several species of seagrass that can be found
which populate on substrates of fine sand along shallow inland coastal lagoons from
Pengkalan Nangka, Kelantan to Paka, Terengganu.
Meanwhile at Sibu Island,
Tengah Island, Besar Island, Tinggi Island, Redang Island, Tioman Island and
Perhentian Island, the seagrass communities occur in the water off-shore with
3
fringing coral reefs. In Sarawak, the presences of seagrass recorded at Bintulu River
and estuary area of Punang-Sari- Lawas. The substrates of sand, muddy-sand and
coral rubble of the inter-tidal region support the mixed species of seagrass along the
west and south-eastern coast of Sabah. Figure 1.1 shows the major location of
seagrass ecosystems in Malaysia.
Figure 1.1: Seagrass distribution at Malaysia (The Encyclopedia of Malaysia, The
Seas, 2001)
1.3
Problem Statement
Coastal environments are subjected to contamination especially metals
through inputs from point sources and diffuse sources which transported via river
discharge and atmospheric deposition. The pollution entering in coastal systems will
incorporated into biota and may interferences the chemical and biological processes
in the water column, sediments and biota. Meanwhile, seagrasses are the least
studied and least protected among marine habitat and they are very sensitive and
vulnerable to the changes of water and environmental quality. Hence, seagrasses
which colonize near coastal ecosystem have potential as indicator of environmental
4
health. Pulai River’s mangrove forest is the most extensive wetland site in Malaysia
and exposed to human activities at Pulai River catchment area. The lost of mangrove
which act as buffer zone may propel sediment loading and siltation to seagrass bed
located near the Pulai River estuary.
Port of Tanjung Pelepas (PTP) located at the mouth of Pulai River is included
under Iskandar Development Region (IDR) in order to enhance economic
achievement. It is a strategic location to develop a mega port since the Sungai Pulai
mouth is located at the southern tip of Peninsular Malaysia and the confluence of the
international trade lanes which go right into one of the world's busiest route, the
Straits of Malacca (BERNAMA, 2007). In the other hand, the largest privatized
coal-fires power plant located at Tanjung Bin is on the opposite bank. The latest
development is an integrated petrochemical facility on 40.5ha of reclaimed island at
the estuary and it is expected to handle annually 60 million tones of petroleum
products - industrial and marine fuel oils, diesel, jet fuel and biodiesel (The Star,
2007). With all the activities occurring in the area it seem that the country’s most
extensive seagrass meadow ecosystem is in danger of being destroyed and requires
more intention to preserve the unique bio-ecology system.
1.4
Objective of Study
The objective of the study is to assess the seagrass occurrence at Tanjung
Kupang via the following evaluation:
1. To identify the marine life include plants and animals associated with
seagrass
2. To determine water quality at the surrounding area of seagrass meadow
3. To determine heavy metal concentration in sediment at seagrass meadow
4. To assess possibility of seagrass as bio-indicator of heavy metal
concentration through extraction of its leaves
5
1.5
Study Area
The study area is located near the Pulai River estuary (illustrated in Figure
1.2). It emphasizes the seagrass bed, which lay between Merambong Island and
Tanjung Kupang in given size of 38ha.
Seagrass
meadow
Figure 1.2: The position of study area that is near to Pulai River estuary, Second
Link Bridge and Singapore
There are only a few villages located along the coastal area nearby to the
seagrass bed which includes Kampung Tanjung Adang, Kampung Pok Besar and
Kampung Pok Kechil.
Most of villagers are fisherman and some of them are
involved in agriculture and palm oil plantation. From Figure 1.3 several sampling
points have been chosen that is significant to the study located at the seagrass
meadow, Pok River and Pulai River estuary, Merambong Island, Tanjung Adang and
near the Second Link Bridge. Pok River is the nearest waterway which brings runoff
from inland waters. Therefore, water quality level at the river will also be taken into
consideration.
6
(a)
Expansion of PTP
Tanjung Bin
power plant
LEGEND:
Seagrass meadow
Water quality sampling point
point
(b)
Figure 1.3: Location of seagrass field and sampling location
7
Johor Port at Pasir Gudang have expanded rapidly since it commencing
operation 1977 and growth prediction showed that the port would suffer capacity
problems by 2000 (Renkema and Kinlan, 2000). On 1990 the Johor Port Authority
start a study to find a site for a new port that can cater all future demands for cargo
traffic. Based on a site selection study, Tanjung Pelepas was selected as the most
strategic location for Johor’s new port because it protected by a deep water bay.
Moreover, it amidst the world busiest international shipping lane which guarantees a
good opportunity for it to become a port of call for ships passing through these
waters (Johor Port Authority, 2008). Nowadays, PTP have been covered on 1935
acre of reclamation land growth rapidly and in the year 2000, it was awarded ‘Best
Emerging Container Terminal’ on Llods list for excellent throughout its operations
(Johor Port Authority, 2008). In order to achieve world class port and fulfil the future
demand, PTP plans to expand their port up to 95 berths with terminal handling
capacity of 72 million TEUs. This future expansion area is including seagrass area
and if the plan is continue, the meadow will disappear forever.
1.6
Scope of Study
The study emphasizes on the following methodology analysis, which are:
1. In-situ and Ex-situ test; Dissolved Oxygen (DO), Biochemical Oxygen
Demand (DO), Chemical Oxygen Demand (COD), pH, salinity, phosphorus,
nitrogen, Suspended Solid (SS) and Secchi disk depth
2. Rapid assessment using time search method and fisheries sampling for
marine life identification
3. Analysis of seagrass based on extraction of leaves and sediment
4. Using secondary data to assess the future and current development at the
nearby area (Tanjung Pelepas, Tanjung Bin, Tanjung Adang and Tanjung
Kupang coastal area)
CHAPTER 2
LITERATURE REVIEW
2.1
Overview
Sungai Pulai is the largest mangrove system in Johor State which associated
with seagrass beds, inter-tidal mudflats and inland freshwater riverine forest (The
Star, 2008). This area consists of a lowland tropical river basin which supports a rich
biodiversity of species that depends on it. Located in the same area is the largest
seagrass meadow in Peninsular Malaysia with a given size of 38 hectares located
between Tanjung Kupang and Merambong Island. The seagrass site support unique
ecosystem that include seahorses, dugong and pipefish.
However, since 1995
massive port development around Pulai River Estuary has destroyed large tracts of
seagrass meadows. Today, besides two major developments that have already been
completed which Port of Tanjung Pelepas and Power plant at Tanjung Bin there will
be another two new proposed large developments consists of man made island which
will be construct by Asia Petroleum Hub. Meanwhile, Seaport Worldwide Sdn.Bhd
plan to build Petrochemical and Maritime Industries involving 2,255 acres next to the
Tanjung Bin Power Plant.
The mangroves are also important as the breeding grounds of fishes. The
destruction of the mangroves as well as the deterioration of the water quality of the
Sg. Pulai estuary would directly affect the fish catches of the fishermen in the area
especially the coastal fishermen (Hillary, 2008). As a Ramsar site, the estuary has
experienced changes that lead to the loss and degradation of mangroves habitat from
human intervention such as port and industries developments, power transmission
9
line maintenance activity, and land reclamation and agriculture activities (Dol et al.,
2008).
Meanwhile the long seagrass called giant tropical eelgrass (Enhalus
acoroides) dominates the meadow.
Although not favoured by big herbivorous
creatures due to its tough texture, this seagrass, which can reach 1.5m, serves as a
wave-breaker (News Strait Times, 2008). The loss of mangrove areas which act as
bio-filter for sediment and nutrient from direct loading on seagrass bed become a
threat since high sedimentation will lead to algae blooms that will further impede
photosynthesis process (Choo, 2006).
2.2
Characteristics of Seagrass
In Malaysia, there are thirteen major species of seagrass which belongs to
eight genera, three families and two orders recorded which are Enhalus acoroides,
Halophila beccarii, H. decipiens, H. ovalis, H. minor, H. spinulosa, Halodule
pinifolia, H. uninervis, Cymodocearotundata, C. serrulata, Thalassia hemprichii,
Syringodium isoetifolium, Ruppia maritima and Thalassodendron ciliatum ( Aziz
Arsad et.al.,2006) as shown in Figure 2.1. As terrestrial plant, seagrass is different
from seaweeds (algae) where the seagrasses have internal veins which transport food,
nutrients and water around the plant which possess root system and produce flowers
and fruits. It also tends to live in places which have soft sediment accumulation. On
the other hand algae do not have veins in their leaves and their roots acts as holdfast
anchors to the surface of a substrate. Algae do not produce flowers, seeds or fruit
(McKenzie, 2008).
The seagrass leaves have no stomata (microscopic pores on the underside of
leaves) which other terrestrial flowering plant have such as salt-marsh plant have
aerial leaves with stomata where they take up carbon dioxide and lose water through
transpiration. The seagrass have thin cuticle in order to adopt water and nutrients via
their roots when it is completely submerged in saline medium. They derived carbon
dioxide from solution in the seawater and the seagrasses increase the concentration
of carbon dioxide at the leaf surface by releasing hydrogen ions which cause
bicarbonate in seawater to dissociate to form carbon dioxide and water (Mann,
10
2000).
Chloroplast within the leaves is used for photosynthesis process using
sunlight to convert carbon dioxide and water to generate oxygen and sugar. Seagrass
Roots and horizontal stems or rhizomes are buried in sand or mud and act as anchors,
carbohydrates storage and nutrient absorbent. The roots can be simple or in branch
and have fine hair in order to help in absorbing nutrients taking up. The rhizomes
may facilitate vegetative reproduction by spreading underground and by breaking off
and drifting away (Phillips and Menez, 1988).
Seagrasses have simplified structure flowers where the pollen is produced
and carried from anthers to stamens underwater. The pollen is dispersed from male
seagrass flowers to female seagrass flowers by tidal. This hydrophilic pollination
can occur by transportation action of pollen above the water surface such as Enhalus,
on water surface; Halodule and pollen transport beneath water surface like Thalassia
(McKenzie, 2008). Figure 2.1 below show the common seagrass species in Malaysia
and the identification features.
11
Table 2.1: The common seagrass species in Malaysia and their identification features
(Save Our Seahorse Handbook, 2006)
Species
Halophila ovalis
Characteristics
 12 or more
cross veins
 No hairs on
leaf surface
Species
Halophila minor
Characteristics
 Less than 12
pairs of cross
veins
 Small oval leaf
blade
Halophila isoetifolium
 Cylindrical in
cross section
 Leaf tip tapers
to a point
 Leaves 7 – 30
cm long
Halophila
decipiens
 Small oval leaf
blade 1-2.5 cm
long
 6-8 cross veins
 Leaf hairs on
both sides
Cymodocea rotundata
Thalassia
 Rounded leaf
hemprichii
tip
 Narrow leaf
blade (2-4 mm
wide)
 Leaves 7-15
cm long
 9-15
longitudinal
veins
 Well developed
leaf sheath
 Short black
bars of tannin
cells on leaf
 Thick rhizome
with scars
between shoots
 Leaves 10-40
cm long
Enhalus acoroides
 Very long
ribbon-like
leaves with
inrolled leaf
margins
 Thich rhizome
with long black
bristles
 Leaves 20-150
cm long
 Rounded leaf
tip
 1 central vein
 Usually pale
rhizome with
clean black leaf
scars
Halodule pinifolia
12
2.2.1
Seaweeds
Seaweed is a marine macroalgae that also inhabit the sea and are often
confused with seagrass. In Malaysia 240 species of seaweeds in Malaysia which
contribute greatly to the productivity of the sea, as well as provide feeding and
breeding grounds for marine life (Ong and Gong, 2001). Most of the species inhabit
on substrates from the coral reefs to rocky shores and sandy or muddy areas.
Seaweeds are algae, and although they are photosynthetic organisms, in contrast to
the terrestrial plants they are non-flowering and do not have roots, leafy shoots or
sophisticated tissues for transporting water, sugars and nutrients (Kaiser et al., 2005).
Table 2.2 simplifies the difference between marine algae and seagrass.
Table 2.2: The differences between seagrass and marine algae (Seagrass-Watch,
2008)
Seagrass
Complex root structure to anchor plant
Marine Algae
Simple holdfast to anchor on hard
in the sediment and to extract nutrients
substrate such as rocks or shells
and minerals.
Photosynthesis process restricted to
Photosynthesis process undertaken
cells in leaves
by all cells
Transport minerals and nutrient in
Uptake of minerals and nutrients
aerenchyma and the veins
from water column via diffusion
Reproduction via flowers, fruits and
Reproduction via spores
seeds.
2.3
Growth Requirements
Seagrasses requires plenty of sun, clean water, acceptable salinity,
temperature and pH to grow. In the same time, it physiologically adjusts to survival
in seawater which involves adjustment to live in saline medium and completely
submerged. Moreover, they have anchoring system to resist the effects of tidal
currents and wave actions (Mann, 2000). They can tolerate salinity between 4 to 65
13
parts per thousand and usually salinity of 35 parts per thousand is the best condition
to grow. Since seagrasses grow submerged in seawater, they more likely to be light
limited (Mann, 2000). They require 4.4 to 29 % of surface light in order to perform
photosynthesis process (McKenzie, 2008).
Water temperature controls the rate of seagrasses growth and health. The
efficiency of photosynthesis activities decrease when temperature increases up to
38°C. Seawater above 40°C will stress the seagrasses and at 45°C, it will die off.
The plants can survive in low salinity at low temperatures; however a combination of
high temperatures and low salinity could be lethal (Mann, 2000).
Other essential needs by seagrasses are inorganic carbon, nutrients; nitrogen
and phosphorus for growth. Higher nutrient necessitate during growing season and
become toxic at senescent season. The availability of nutrients depend on the quality
of sediment comprise on type and size of particle. Sediment quality, depth and
mobility are important factors for seagrass composition, growth and persistence
(McKenzie, 2008). Most of seagrasses live in sand or mud substrates where their
roots and rhizomes anchor the plant to the sea floor (Aziz Arsad et.al. 2006).
However, seagrasses are incapable to survive in sediments with high organic content.
Furthermore, tidal currents play important role especially for pollination
purposes and gases exchange from the water to the plant. Factors such as the
photosynthetic rate of seagrasses depend on the thickness of the diffusive
boundary layer that is determined by current flow, as is the sedimentation rate. Both
condition influence growth rates of seagrass, survival of seagrass species and overall
meadow morphology (Rasheed et .al, 2007).
2.4
The Significance of Seagrass
Seagrass beds are highly diverse and productive ecosystems and can shelter
hundreds of associated species for example fish, worms, hawksbill turtles, highly
14
endangered dugong as well as seahorse. The seagrass meadow also is a hot spot for
life, serving as nursery, breeding and feeding ground to marine animals. Only a few
species were originally considered to feed directly on seagrass leaves (partly because
of their low nutritional content) but scientific review have shown that seagrass is a
highly important link in food chain (Hemminga and Duarte, 2000).
Seagrasses are sometimes labeled as ecosystem engineers because they partly
create their own habitat, the leaves slow down water currents which increasing
sedimentation and the seagrass roots and rhizomes stabilize the sea bed. As results,
seagrasses provide coastal zones with a numbers of goods ecosystem services
especially for fishing grounds, wave protection, oxygen production and protection
against coastal erosion.
Within seagrass communities, a single acre of seagrass can produce over 10
tonnes of leaves per years and may support as many as 40, 000 fish and 50 millions
small invertrabrates (Phillips and Menez, 1988). Since seagrasses support such high
biodiversity and sensitive to changes in water quality, it is recognized that seagrasses
are important indicator that reflect the overall health of a coastal ecosystem.
Seagrasses also perform a variety of functions within ecosystems and have both
economic and ecological value. The high level of productivity and biodiversity in
seagrass beds has been described by the seagrass communities as a marine
environment which is equivalent to tropical rainforests. As conclusion, seagrass
meadows help to reduce the effects of strong currents, providing protection to fish
and preventing scouring of bottom areas.
2.4.1
Marine Life Associated with Seagrass
Seagrass beds have an important role as a nursery ground for the juveniles of
commercially important fish species (Jafar et al., 2000).
For some species the
physical habitat is a key shelter from predators but other fish are attracted to seagrass
beds due to their supply of food in form of invertebrates (Kaiser et al., 2005). Table
15
2.3 below show the list of species of marine life that have been discovered by former
researcher associated with seagrass meadow.
Table 2.3: List of marine life supported by a seagrass bed
Year
2009
Author
Assoc. Prof. Dr.
Mohd Ismid Mohd
Said
Location
Merambong
Island
Unpublished report
Marine Life
Common Name
Species
 Black
 Holothuria
cucumber
leucospilota
 Carpet
 Stichodactyla
anemone
gigantean
 Sea grapes
 Caulerpa
lentillifera
 Fan worm
 Sabella
spanllanzanii
 Barbour’s
 Hippocampus
seahorse
barboure
 Violet Vinegar
crab
 Knobbly
seastars
 The pinkfingered
vinegar crab
 Orange
signaler crab
 Shen crab
 Crevice crab
 Mangrove
porcelain crab
 Sentinel crab
2009
Aziz Arsad, Mohd
Hanafi Idris,
Japar Sidik Bujang,
Mazlan Abd.
Ghaffar, Siti
Khadijah Daud
Idris, M.H.,Arsad,
A., Bujang, J.S.,
Ghaffar, M.A.,
Daud, S.K.
(2009).
Merambong
shoal
Tanjung
Adang shoal
 Star barnacles
 Mudskipper
 Stone/thunder
crab
 Pen Shells



Episesama
versicolo
Protoreaster
nodosus
Episesama
chentongense
 Metaplax elegans
 Shenius anomalum
 Baruna trigranulum
 Petrolisthes
kranjiensis
 Macrophthalmus
crinitus
 Periophtlalmus
gracilis
 Myomenippe
harwicki
 Pinna bicolor
 Pinna atropurpurea
 Pinna deltodes
 Pinna incurve
 Pinna muricata
 Atrina pectinata
 Atrina vexillum
16
Year
Author
Location
Local Name
Marine Life
Species
Morphological
Characteristics of
Pinna bicolor
Gmelin and Pinna
deltodes Menke
from the Seagrass
Bed of Sungai
Pulai, Johor,
Peninsular
Malaysia Sains
Malaysiana 38
(3), 333-339.
2006
Japar Sidik Bujang,
Muta Harah
Zakaria,
Aziz Arsad
Distribution and
Significance of
Seagrass
Ecosystems in
Malaysia. Aquatic
Ecosystems Health
and Management
Society, 9(2): 203214
2001
Prof. Dr. Ong Jing
Eong, Assoc. Prof.
Dr. Gong Wooi
Khoon
The Encyclopedia
of Malaysia, The
Seas (Volume
editors).
Singapore:
Edition Didier
Millet Pt Ltd
1. Tanjung
AdangMerambong,
Johor
 Fish
2. Pengkalan
Nangka,
Kelantan
3. Paka shoal,
Terengganu
Malaysia
 Dugong
 Neretid
 Putter fish




Creeper shell
Bivalve
Sea cucumber
Shrimp
 Black-lipped
conch
 Rabbit fish






Ilisha spp.
Stolephorus indicus
Thryssa hamiltoni
Hippocampus spp.
Lates calcarifer
Lutjanus
chrysotaenia
 Plotosus canius
 Apolynemus
sextarius
 Rastrelliger
kanaqurta
 Siganus guttatus
 S.javus
 Siganus sp.
 Epinephalus sp
 Therapon spp.
 Hippocampus kuda
 Metrix-meretrix
 Hiatula solida
 Modiolus senhausii
 Dugong dugon
 Clithon
oualaniensis
 Tetraodon
nigroviridis
 Batillia zonalis
 Paphia gallus
 Holothuria scabra
 Parapenaeopsis
tenella
 Strombus ureceus

Siganus guttatus
17
2.5
Threats to Seagrass
Generally, the disappearance of seagrasses bed has been identified due to
both natural and man-induced influences. Herbivores, cyclones, typhoons and tidal
waves are the examples of natural threats (McKenzie, 2008). Meanwhile, man-made
causes play a major contribution in decline of seagrasses by pollution through coastal
runoff and discharge of sewage. Other ways is through physical destruction such as
dredging, boat propeller and anchoring.
If only the leaves and above ground
vegetation are impacted, seagrasses are able to recover from damage within a few
weeks however when damage is done to the roots and rhizomes, the ability of the
plant to produce new growth is severely impacted and plants may never be able to
recover (Kaiser et al., 2005).
2.5.1
Natural Threats
Natural disturbances such as grazing, storms and ice scouring are an inherent
part of seagrass ecosystem. The changing environmental conditions is due to human
disturbance mostly eutrophication, mechanical destruction of habitat and over-fishing
(McKenzie, 2008). Storm can also cause widespread damage to established seagrass
meadows. Wind driven waves may break or uproot seagrasses. Species such as
crabs, fishes, skates and rays disturb rhizomes and roots, and can tear apart seagrass
leaves as they forage for concealed or buried prey (Mann, 2000).
2.5.2
Eutrophication
The health of seagrass communities obviously relies heavily on the amount of
sunlight that penetrates the water column to reach submerged blades. A moderate
amount of nutrient may increase the growth of seagrass.
The main nutrients
responsible for eutrophication are nitrogen, phosphorus and carbon. High nutrient
18
input; nitrogen and phosphorus lead to massive epiphyte growth as well as
phytoplankton blooms that reduce the water clarity by blocking the sunlight
penetration. Meanwhile carbon is rarely the limiting nutrient since nitrogen and
phosphorus are added to the water. Carbon dioxide from atmosphere converts to
organic carbon compounds through biotic carbon reduction and photosynthesis
(Kaiser et al., 2005).
Excessive presence of nutrients; nitrogen and phosphorus lead to massive
blooms of algae that reduce the water clarity by blocking the sunlight penetration.
During the progress of eutrophication, fast growing microalgal compete for nutrients
and light with benthic plants. As nutrients supply decrease lead to their death,
decomposition of these blooms will cause further deterioration of water quality
through depletion of dissolved oxygen level in water column. Soon the seagrasses
can die off as well as fish in the habitats.
2.5.3
Dredging
Dredging destroys seagrass habitat directly by digging and indirectly affects
it by suspending sediment. Storm water runoff drains both urban and agricultural
areas and carries household chemicals, oils, automotive chemicals, pesticides, animal
wastes and other debris. Under normal conditions, seagrasses maintain water clarity
by trapping silt, dirt and suspended sediment in the water column. However, when
excessive sediment loadings, turbidity in the water column increases and the
penetration of sunlight is inhibited ((Kaiser et al., 2005).
In extreme cases, excessive sediment can actually smother seagrasses.
Furthermore, increase of turbidity due to the dredging activities and erosion input of
fine-grained sediment will decrease the light level.
Thereby, the process of
photosynthesis is interfered and hence limits the range of depth suitable for seagrass
growth. This activity does not give huge impact to seagrass but if dredging affects
19
hydrodynamic properties of the area such as depth profile, current direction, or
current velocity, it may severely threaten the seagrass (McKenzie, 2008).
2.5.4
Boating
Boating and fishing activities involving anchoring and grounding boat on
seagrass bed. Boat anchors and the chains dig into seagrass and pull from the seabed
meanwhile propellers can chew off the leaves and unstable the rhizome mat. These
scared areas will take years for the seagrass to grow and if the damage is repeated,
the meadow may never completely recover. Furthermore, scrappy seagrass bed is
more exposed to effects of erosion and to suffocation by loose sand since the sand is
not being held in place by a root network (McKenzie, 2008).
2.6
Physical Water Quality Parameter
Physical parameters describe the water characteristics which respond to the
senses of sight, touch, taste or smell. Suspended solid, turbidity and temperature are
in this category.
2.6.1
Total Suspended Solid
Suspended solid in the marine environment may occur in inorganic, organic
or immiscible liquid. The natural sources of suspended solid are silt and detritus
which carried by rivers, atmospheric fall out, bioactivity, chemical reaction and resuspension of sediment from the sea bottom as a result of current and wave action
(Gross, 1972). Meanwhile anthropogenic sources of suspended solids mostly come
from activities that loosen soil and transported to the sea by runoff. The activities
20
involved dredging, deforestation, agriculture and mining operations (Deocadiz and
Montano, 1999).
Total Suspended Solid (TSS) is a measurement to measure water clarity for
water quality assessment. TSS includes all particles suspended in water that does not
pass through a filter. Suspended solids are an important indicator of water quality.
Increase of TSS directly reduced dissolved oxygen content in water, hence reducing
the ability of a water body to support life.
Marine ecosystems include coral reefs, mangroves, fish and seagrass
adversely affected by suspended solid since the suspended load will block the light
penetration and limit the photosynthesis process. Of all anthropogenic disturbances
of the estuarine and near shore environments, dredging and filling activities present
the greatest potential for damage to seagrass beds (Deocadiz and Montano, 1999).
For the guidance of concerned authorities in the ASEAN region, where coral reef
communities are not present (or to be protected) the maximum permissible increase
in TSS should be 10% of the seasonal average concentration, and where coral reef
communities are present (and to be protected) the maximum permissible increase in
TSS concentration should be that which would not have any adverse effects on the
coral reefs (Deocadiz and Montano, 1999). Meanwhile for human health protection
for recreational use, the recommended suspended solid is the same as for marine
aquatic life protection.
2.6.2
Turbidity
Turbidity is a measure of the extent to which light is either absorbed or
scattered by suspended material in water (Train, 1979). It related to the cleanliness
of the water. The water is transparent and less turbid with the low concentrations of
total suspended solids (TSS) compare with those which have high TSS
concentration. Most turbidity in surface water results from high concentrations of
21
biota like phytoplankton or by loading of colloidal matter such as clay, silt and
sediment.
Turbidity is important in aquatic systems since it may interfere with light
penetration thereby potentially affecting photosynthesis reaction and organism’s
distribution within the water column. Lowered rates of photosynthesis will lead to
decrease levels of dissolved oxygen in the water body, thus can adversely affect
larger populations such as fish.
2.6.3
Temperature
Temperature is a critical water quality and environmental parameter because
it governs the kind and types of aquatic life, regulates the maximum dissolved
oxygen concentration of the water, and influences the rate of chemical and biological
reactions. The organisms within an ecosystem have preferred temperature regimes
that change as a function of season, organism age or life stage, and other
environmental factors (Mann, 2000).
With respect to chemical and biological
reactions, the higher the water temperature causes the higher the rate of chemical and
metabolic reactions. The variations in water temperature may be caused by changes
in air temperature, meteorological events, and a number of physical aspects related to
the stream and watershed (Smith, 2004).
2.7
Chemical Water Quality Parameter
Chemical water quality parameters include biochemical oxygen demand
(BOD), chemical oxygen demand (COD), oil and grease (O&G), nutrient;
ammoniacal nitrogen and phosphorus.
Meanwhile evaluation on heavy metals
referring to Interim Marine Water Quality Standards (INWQS) involved arsenic
(As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and mercury (Hg).
22
2.7.1
Dissolved Oxygen (DO)
Dissolved oxygen (DO) is the amount of oxygen dissolved in water. The
amount varies directly in response to changes in atmospheric pressure and water
temperature (Train, 1979).
The higher atmospheric pressure result of high the
oxygen solubility in water causes increasing concentration of DO. The opposite is
true with temperature, the higher the temperature the lower the solubility and
saturation concentration of oxygen in water. DO is one of the major factors that
determine the type of biological communities that inhabit an aquatic system. The
addition of organic or inorganic material that exerts an oxygen demand through
respiration and biodegradation will lowers the DO concentration and can facilitate
the growth of nuisance organisms. If the water temperature is less than that, it may
actually have more oxygen dissolved in it. Dissolved oxygen level of 9-10 mg/L is
considered very good condition. At levels of 4 mg/L or less, some fish and macroinvertebrate populations such as bass and trout will begin to decline (Davis and
Masten, 2004).
2.7.2
Biochemical Oxygen Demand
Biochemical oxygen demand (BOD) is a measure of the quantity of oxygen
used by microorganisms in aerobic oxidation of organic matter. In rivers with high
BOD levels, aerobic bacteria, robbing other aquatic organisms of the oxygen they
need to live, consume much of the available dissolved oxygen. BOD measures the
rate of oxygen uptake by microorganisms in a sample of water at a temperature of
20°C and over an elapsed period of five days in the dark (Train, 1979). The sample
is kept at 20°C in the dark to prevent photosynthesis (and thereby the addition of
oxygen) for five days before the dissolved oxygen is measured again.
The oxygen consumption during aerobic decomposition is easily measured
since the greater amount of organic matter present the greater used of oxygen. The
BOD test is an indirect organic matter measurement because it only measures the
changes of dissolved oxygen concentration due to the degradation of organic by
23
microorganisms. Although not all organic matter is biodegradable and the actual test
procedures lack precision, the BOD test is still the most widely used method of
measuring organic matter because of the direct conceptual relationship between BOD
and oxygen depletion in receiving waters (Davis and Masten, 2004).
2.7.3
Chemical Oxygen Demand
Chemical oxygen demand (COD) test is commonly used to indirectly
measure the amount of organic compounds in water. Most applications of COD
determine the amount of organic pollutants found in surface water, making COD a
useful measure of water quality. Generally, the COD will be greater than the BOD
since there are more compounds can be oxidized chemically than can be biologically
oxidize.
The COD test is more sophisticated and has more advantages than the BOD5
test because the results are available within three hours instead of five days. The test
also has capability of measuring organic material which is resistant to biological
decay. In COD test, dichromate is used to oxidize inorganic substances and enhance
the visible organic content of the sample since some of the organic substance may be
toxic to the bacteria used in BOD test. According to Sarkar et al. (2005), the value
of COD in tropical coastal-wetland in Southern Mexico is high associated with
mangrove enriched organic matter.
2.7.4
pH
pH is an important factor in the chemical and biological systems of natural
waters where it is a measure of the acidity or basicity of a solution. Normally the pH
of water is 6.5 to 8.0. Water with a pH of less than 7 becomes increasingly acidic.
One of the most significant environmental impacts of pH is the affect that it has on
the solubility and thus the bioavailability of other substances. Changes in the pH
24
value of water are important to many organisms. As the pH falls (solution becomes
more acidic) many insoluble substances become more soluble and thus available for
absorption. Most organisms have adapted to life in water of a specific pH and may
die if it changes even slightly. Water with heavy algal growth often has pH value as
high as 9 to 10 (Train, 1979)
2.7.5
Nutrients
Nutrients are an important element for the growth and reproduction of plants
and animals. Aquatic species depend on the surrounding water to provide their
nutrients.
The most abundant nutrients required by aquatic species is carbon,
nitrogen and phosphorus. Carbon is readily available from many sources and its
limitation is usually important in low-salinity regions of estuary where the conditions
of high pH and low inorganic concentrations will occur due to depleted of carbonate
buffering. In most cases, nitrogen and phosphorus are nutrients that are the limiting
factors for aquatic plant growth (Davis and Masten, 2004).
2.7.5.1 Phosphorus
Phosphorus as phosphate is one of the major nutrients required for plant
nutrition and is essential for life (Train, 1979). Phosphorus may occur in water in
form of dissolved or particulate phase. Particulate phosphorus includes living and
dead plankton, phosphorus adsorbed to particulates, in mineral form as aluminium,
iron or calcium compound and incorporated in organic matter.
This form of
phosphorus can move into surface waters attached to soil and organic matter particles
through soil erosion (Chongprasith et al., 1999). The dissolved phosphorus exists
naturally in all soils in small amounts and phosphorus gets into water in both urban
and agricultural setting. Water runoff which contains dissolved phosphorus either
from the top layer of the soil and from recently applied fertilizer or manure still on
the soil surface moves into surface water bodies. However it can be quickly utilized
by aquatic organisms.
25
Discharges of phosphorus can come from many sources both from natural
and human which consist of soil and rocks, wastewater treatment plants, runoff from
fertilized lawns and cropland, failing septic systems, runoff from animal manure
storage areas, disturbed land areas, drained wetlands, water treatment, and
commercial cleaning preparations (Rasheed et al., 2007). Moreover the destruction
of mangroves though its conversion for agricultural or residential purposes give
serious problem to coastal area since the coastal swamps acts as natural filters for
fertilizers and sediments transported by river (Chongprasith et al., 1999). It will then
cause direct discharge of nutrient to coastal environments
2.7.5.2 Ammoniacal Nitrogen
Measurements of ammoniacal nitrogen specify the mass of nitrogen
contained in ammonia, rather than the total mass which includes the mass of the
hydrogen in the molecule. Ammonia (NH3) is an abundant of inorganic substance
that can be found on surface water, soil and easy to cater through decay of plant
tissue and compose of animal waste. In aerobic condition, the rich source of nitrogen
in ammonia is oxidized to nitrite (NO2-) and then to nitrate (NO3-) during nitrification
process. Surface water considered polluted when concentration of ammonia reach up
to 0.1 mg/L and at 2 mg/L the water is no longer considered safe to support aquatic
life due to the high toxicity. Higher concentration of ammonium will cause a sharp
decrease of dissolved oxygen and obvious toxicity on aquatic organisms. The main
contributors of ammonia are municipal sewage, industrial wastewater and
agricultural wastes or decomposed from organic nitrogen compounds in wastewater
and wastes.
2.7.6
Heavy Metal
Anthropogenic sources of metals which come from industrial and municipal
waste products, urban and agricultural runoff, fine sediments eroded from
catchments, atmospheric deposition increase metal concentrations to higher than
background levels.
Metals tend to accumulate in animals and plants including
26
mangrove vegetation and seagrasses (Prange and Dennison, 2000). The potential
impact of heavy metals on seagrasses is two-fold, firstly via uptake in to the plants
themselves, and secondly (and indirectly) where the inhibition of grazers impacted
by the toxic effects of the metals results in denser epiphyte growth (Wilkinson et al.,
2005).
2.7.6.1 Arsenic (As)
Arsenic occurs extensively in the environment in different chemical species
especially in natural water systems where it generally occurs in the oxidation states
As(Ill) and As(V) as well as in food chain in various other forms (Yusof et al., 1994).
It has become one of the most widely measured trace metals in environmental
programs due to its toxicity and possible carcinogenic effect. Principally, arsenic
occurs in natural waters as arsenate As (V) and lesser extent as arsenite As (III) and
methylated aesenicals. Arsenate will be more toxic in waters deplete with dissolved
oxygen and at lower pH.
Millions of tons of arsenic enter the environment from both natural and
anthropogenic sources. In the Asian region, arsenic is traceable to residuals from
mining activities and geothermal energy generation (Deocadiz, 1999). Moreover,
major sources of arsenic in surface waters of the ocean are riverine inputs carrying
arsenic-contaminated drainage from the land, and upwelling of deep ocean water
enriched in arsenic (Neff, 1997). Therefore, the concentration of arsenic is higher in
estuaries and coastal water compared to the open sea.
Marine mammals which ingest the heavy metals in food or absorption
through water will faced of bioaccumulation of these elements in their tissues. These
substances can become toxic and cause multiple symptomatic effects involve the
health and survival of animal in higher concentration. Arsenic is moderately toxic to
fish and aquatic invertebrates but highly toxic to some algal species (Deocadiz,
1999). For example, growth and survival of the microalgae Tetraselmis chui and
Hymenomonas carterae were not affected during exposure to arsenite or arsenate
concentrations as high as 1,000 µg/L (Neff, 1997), while communities of some
27
species of marine macroalgae (seaweed) may be eliminated at exposures of about 10
µg/L (IPCS/WHO,1992).
Interim marine ASEAN water quality suggested 120 µg/L of arsenic in
seawater for aquatic life protection purposes. Meanwhile, total arsenic content; 3.0
µg/L is recommended to protect human health from the toxic properties of arsenic
ingested via contaminated seafood and 60 µg/L for the protection of human health
for recreational activities in the marine environment.
2.7.6.2 Cadmium (Cd)
Cadmium is mainly used in metal plating and manufacturing of pigments in
plastics and batteries. Fertilizers produced from phosphate ores constitute a major
source of diffuse cadmium pollution (Fawell et al., 2004).
In natural waters,
cadmium is found mainly in bottom sediments and suspended particles. The factors
that govern the toxicity of cadmium includes salinity.
As salinity increases,
cadmium is less toxic however it has great toxicity at high temperature.
Cadmium enters the sea and ocean through contaminated agricultural soils,
mining wastes, mine waters, and industrial use of cadmium, municipal sewage
effluents and sludge may cause serious detrimental impacts on marine organisms and
public health.
In order to protect human health from adverse effects from
consumption of contaminated seafood, Asian marine water qualities has
recommended concentration of cadmium at 23µg/L and propose for recreational
activities 35.7µg/L in the marine environment.
2.7.6.3 Total Chromium
Chromium is an occurring element in rocks, animals, plants and soil and exist
in several different forms; chromium (III) and chromium (VI) depending on pH.
Trivalent chromium is a dietary requirement for some organisms however hexavalent
chromium is very toxic to flora and fauna. It is used widely in stainless steel, chrome
28
electroplating, dyes and pigments, leather tanning and wood preservation. Plants and
animals do not bioaccumulate chromium; therefore the potential impact of high
chromium levels in the environment is considered acute toxicity to plant and animals.
Natural sources of water contain very low concentrations of chromium since it is a
micronutrient or essential trace element (USEPA, 2009). Exposure at low level will
cause ulceration and skin irritation meanwhile long term exposure can cause kidney
and liver damage.
2.7.6.4 Copper (Cu)
Copper is an essential substance that occurs naturally in the environment and
human used widely especially in the industries and agriculture. Wind blown dust,
decaying vegetation, forest fires and sea spray are the example of natural sources of
cuprum released into the environment. Meanwhile human activities such as mining,
metal production, wood production and phosphate fertilizer production can
contribute copper to the surrounding. Furthermore, it is often found near mines,
industrial settings, landfills and waste disposal (Lenntech, 2008).
Copper strongly attach to organic matter and mineral when ends up in soil
because it does not break down. It will accumulate in plants and only limited
number of plants that can survive on copper-rich soils.
2.7.6.5 Lead (Pb)
Accumulation of lead in the bodies of water organisms will induce health
effects from lead poisoning.
The body functions of phytoplankton which is
important source of oxygen production in the seas and food for many animals will be
disturb when lead interferes.
Soil functions are disturbed by lead intervention
especially near highway and farmland, where extreme concentrations may be present
(Mance, 1987). The significant releases of lead due to natural processes such as soil
weathering and erosion, volcanoes and forest rarely result elevated concentrations in
the environment.
29
The natural concentration of lead in sea water is 0.015 mg/L and most of the
concentrations found in environment are consequence of human activities.
The
plumbum salts such as chlorine, bromines and oxides as result of lead burned in car
engines entering the environment through the exhaust. The larger particles will drop
to the ground immediately and pollute soils or surface water meanwhile the smaller
particles will travel long distances through air and remain in the atmosphere and
during rain, it will fall back on earth (Lenntech, 2008). Moreover, the major sources
of lead are from lead mining, smelting and refining operations, battery manufacture,
and industrial and municipal effluent. Batteries, tin cans and other products that
contain lead winds up in landfills and incinerators, and enter the atmosphere and
aquatic systems.
2.7.6.6 Mercury (Hg)
Mercury is a highly toxic element which can be found in various forms
including elemental mercury, inorganic mercury compounds and organic mercury
compound such as methyl mercury that is the most toxic form. It is considered
persistent pollutants that exist naturally in the environment but the levels have risen
due to human activities and pollution. Particularly, exposure to methyl mercury are
usually via ingestion and will affects the immune system, alters genetic and enzyme
systems, and damages the nervous system including coordination and the senses of
touch, taste and sight (US Geological Survey, 2000).
Accumulation of mercury in the food chain can harm human health which
consumes seafood. Mercury cannot be eliminate through cooked out of consumable
game fish since it concentrates in the muscles tissues of fish where the older and
larger fish have higher concentrations of mercury than younger within the same
water body. There are many cases of death which were directly related to mercury
contamination and the most popular is the Minimata disease which happened in
Japan where hundreds of people died due to the mercury effluent from a vinyl
processing plant (Eisler, 2006). .
30
In aquatic environments, mercury present with low concentration except in
the surrounding of anthropogenic or natural mercury sources and the speciation of
mercury in water influenced by redox, pH and ligands (Eisler, 2006). Meanwhile
particulate and reactive mercury in the atmosphere travels in short distances, usually
less than 50 km and has a residence time of about one year (Mason et al., 1994).
2.7.7
Oil and Grease
Oil and grease is an important parameter for water quality and safety. The
term ‘oil and grease’ encompasses a broad family of chemical compounds such as
fatty material of biogenic origin, or petroleum hydrocarbon constituents. These
compounds can cause environmental degradation and induce related public health
risks when discharged in surface or ground water (Tong et al., 1999).
The sources of oil pollution are mainly from offshore production and
petroleum (crude oil) or its fractions derive from transportation as from tanker
operations, dry-docking, discharged oils, oil losses from tanker and other vessel
accident. Beside that, land-based sources such as municipal and industrial wastes,
urban run-off, and automotive sources are also causes of oil pollution. Examples of
natural sources are from marine seeps and erosion of sediments. Additionally, oil
gets deposited from incomplete combustion processes (motor vehicles, incineration
and open burning) and palm oil mills, refineries and oleo-chemical plants (Tong et
al., 1999). All of the sources of oil and grease can be distinguish via the chemical
composition.
Interim ASEAN marine water quality criteria have proposed a limit of 0.14
mg/L of oil and grease in order to protect aquatic life. However, water quality
criteria for human health protection from consumption of contaminated seafood and
recreational activities were not derived for the Asian marine environment.
31
2.8
Marine Water Quality Standards
Marine water quality plays an important component particularly in marine
resources conservation that contributes to the stability of marine ecosystem. Sources
of land-based pollution as well as from the sea can be a threat to precious resources.
Each country has their own interpretations regarding water quality standard but the
main purpose is to protect human health and preserve the environment.
2.8.1
Malaysia Interim Marine Water Quality Standards
Since 1978 the Interim Marine Water Quality Standards (INWQS) have been
used for marine monitoring program at Peninsular Malaysia and in 1985 at Sabah
and Sarawak. Table 2.4 below shows the parameter involved in IMWQS.
Table 2.4: Malaysia Interim Marine Water Quality Standard (Department of
Environment (DOE) Malaysia, 2004)
Parameter
Escherichia coli (E.coli)
Oil and Grease (O & G)
Total Suspended Solid (TSS)
Arsenic (As)
Cadmium (Cd)
Chromium (Cr) Total
Copper (Cu)
Lead (Pb)
Mercury (Hg)
Unit
MPN/100ml
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Interim Standards
100
0
50
0.1
0.1
0.5
0.1
0.1
0.001
According to DOE (2004), causes of contaminant of total suspended solid are
from agriculture activities, tourism development, coastal reclamation, logging and
road construction. Meanwhile discharge from vessels, tank clearing; de-ballasting,
bilges, leakages and disposal of engine oil from ferries and boat and bunkering are
the possible sources of oil and grease pollutant. Industrial development and landbased sources contribute contaminant of heavy metal to marine environment.
32
2.8.2
Marine Water Quality Criteria for the ASEAN Region
Asian has coastline of 173,000 km, marine fish production is about 14% of
world total, has 35% of the world’s mangrove forests and about 30% of the coral
reefs (Association of Southeast Asian Nation (ASEAN), 2009). For that reason it is
very important and high priority should be given for ASEAN to sustain and manage
the coastal and marine resources as well as maintain its quality. Therefore, the
Marine Water Quality Criteria have been initially set with 17 water qualities
parameters in order to protect aquatic life and human health. Apart from that, these
criteria would ensure concerted the action at national level to protect the shared
marine waters of ASEAN. The criteria has been expanded and implemented during
10th ASEAN Summit in Vientiane, Lao PDR in 2004 (Source: Association of
Southeast Asian Nation, 2009). Table 2.5 illustrates the parameters involved in
Marine Water Quality Criteria for ASEAN region.
Table 2.5: Marine Water Quality Criterion for ASEAN region (Association of
Southeast Asian Nation, 2009)
Parameter
Ammonia (NH3-N)
Dissolved Oxygen (DO)
Escherichia coli (E.coli)
Nitrate (NO3-N)
Nitrite (NO2-N)
Oil and Grease (O & G)
Phosphorus (P)
Temperature
Unit
mg/L
mg/L
MPN/100ml
mg/L
mg/L
mg/L
mg/L
o
C
Total Suspended Solid (TSS)
Tributyltin
Arsenic (As)
Cadmium (Cd)
Chromium (Cr) VI
Copper (Cu)
Cyanide
Lead (Pb)
Mercury (Hg)
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Criteria Values
0.07
4
100
0.06
0.055
0.14
0.015 (Coastal)
0.045 (Estuarine)
Increase not more than
2oC above the maximum
ambient temperature
Permissible 10%
maximum increase over
seasonal average
Concentration
10
0.12
0.01
0.05
0.008
0.007
0.0085
0.00016
33
2.8.3
Singapore Marine Water Quality Criteria
Singapore Fisheries and Aquaculture Department have set criterion for
marine water quality particularly for site selection of marine finfish netcage culture
in Singapore. The site of floating fish farm should be in an area with good water
quality in order to protect human health. High concentration of heavy metals in
water would render cultured fish unsuitable for human consumption since it can
accumulate with the fish. The important heavy metals and the acceptable safe limits
in water are given in Table 2.6. Standard for heavy metals is based on Japanese
standard for fisheries.
Table 2.6: Summary of criteria for site selection for floating netcage farming
(Singapore Fisheries and Aquaculture Department, 2009)
Parameters
Ammonia Nitrogen(NH3N)
Dissolved Oxygen
pH
Salinity
Suspended Solid
Temperature
Aluminium (Al)
Cadmium (Cd)
Chromium (Cr)
Copper (Cu)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Tin (Sn)
Zinc (Zn)
2.9
Unit
mg/L
Acceptable Standard
< 0.5
mg/L
>4
7.8-8.5
26-31
< 10
27-31
< 0.1
< 0.03
< 1.0
< 0.01
< 1.0
< 0.1
< 1.0
< 0.004
< 0.1
< 0.1
%
mg/L
o
C
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
United Kingdom Interim Marine Sediment Quality Guidelines (ISQG)
Since Malaysia do not have specific guideline of heavy metal compound in
sediment, United Kingdom (UK) sediment standard has been refer which produce by
34
UK Marine Special Areas of Conservation.
Table 2.7 present the standard for
inorganic substance in marine sediment.
Table 2.7: Interim Marine Sediment Quality Guidelines (UK Marine Special Areas
of Conservation)
Substance
Arsenic
Cadmium
Chromium
Lead
Mercury
Zinc
Unit
mg/g dry weight
mg/g dry weight
mg/g dry weight
mg/g dry weight
mg/g dry weight
mg/g dry weight
ISQG
0.00724
0.0007
0.0523
0.0302
0.00013
0.124
CHAPTER 3
METHODOLOGY
3.1
Study Area
Water samples and seagrass specimens were collected from November 2008
and Jun 2009 during low tide at three station located at seagrass bed (N 1o 19’ 50.9”,
E 103o 35’ 51.6”), Pok River estuary (N 1o 20’ 26.7”, E 103o 35’ 31.5”), Merambong
Island (N 1o 19’ 1.1”, E 103o 36’ 25.5”). Samples were also collected from Teluk
Buih, Air Papan, Mersing (N 02o 30’ 11.7”, E 103o 50’ 26.1”) for comparison
purposes. Meanwhile water samples was also collected from the nearest rivers i.e.;
Sungai Pok Besar and Sungai Pok Kecil which carried runoff from inland that might
contribute significant impact to the seagrass meadow. Figure 3.1, 3.2, and 3.3 below
show the locations of sampling area for water quality at the coastal area.
Figure 3.1: Station 1 for water quality at Sungai Pok estuary. The land is fully
covered with riverbank vegetation especially mangrove
36
Sungai Pok estuary has a wide coverage of mangrove area which it closely
linked to estuary, where the seawater mixes with fresh water to form brackish water;
an environment of varying salinities. Mangrove swamps are habitats for salt-loving
shrubs or trees as well as nursery for most of marine life species for fishes, crabs and
prawns.
Figure 3.2: Second station for water quality measurement at seagrass bed
Figure 3.3: Merambong Island as the third sampling station; inhabits a lot of unique
species.
According to Majlis Bandaraya Johor Bahru Tengah (MBJBT), the catchment
area of both Sungai Pok is within Tanjung Pelepas Zone.
The coastal line of
Kampung Pok, Kampung Tanjung Kupang and Kampung Tanjung Adang which is
near the seagrass meadow will be developed as an industrial region of Tanjung
Pelepas consisting of light and medium industries, housing area and agriculture
purposes. All the projects at the area are under Iskandar Development Region (IDR)
37
carried out to enhance an economic achievement. Figure 3.4 and 3.5 below present
the
nearest
river
which
bring
runoff
(a)
from
inland
to
seagrass
area.
(b)
Figure 3.4: (a) Upstream of Sungai Pok Besar used as boat parking bay by local
fisherman and (b) is downstream of the river.
(a)
(b)
Figure 3.5: (a) Upstream of Sungai Pok Kecil and (b) is downstream of the river.
The river is surrounding by palm oil plantation.
3.2
Sample Preparation
Seagrass specimens were only sampled during low tide where the area is
almost 0 m. Due to the time constraint all the work must be planned and carried out
38
quickly.
Tide times for the study area was referred to Singapore National
Environment Agency website and Jabatan Laut Johor for Mersing area. Table 3.1(a)
and (b) shows the schedule of sampling at Tanjung Kupang and Mersing respictively.
Table 3.1 (a): Schedule of sampling at Tanjung Kupang
Date
15/11/2008
1/5/2009
29/5/2009
26/6/2009
Time
5.00 p.m
9.46 a.m
8.45 a.m
9.30 a.m
Height/m
0
0.2
0
-0.1
Table 3.1 (b): Schedule of sampling at Teluk Buih, Mersing
Date
24/7/2009
3.2.1
Time
4.43 a.m
Height/m
0
Water Sample
The actual Geographical Positioning System (GPS) Extrex Summit model
was applied in order to estimate the size of seagrass meadow at Tanjung Kupang. It
also been used to determine the coordinate of water quality station. Meanwhile
insitu measurements consist of pH, dissolved oxygen, salinity, turbidity, temperature
and Secchi disk depth. Measuring of pH value was via Consort 535 Analyzer
(Figure 3.6) and YSI 55 probe (Figure 3.7) used for dissolved oxygen, and
temperature.
39
Figure 3.6: Multi-Parameter Analyzer-Consort 535 that has used to measure the pH
level on surface water
Figure 3.7: YSI probe to determine concentration of dissolved oxygen
The probe was rinsed using distilled water after being dipped into seawater to
protect the accuracy of the equipments. Water samples at 3 sampling points using
polyethylene bottles (1 liter) and amber glass bottles for oil and grease test which
was cleaned according to Standard Method (APHA, 2000). The sampling bottles
were rinsed twice with seawater and the water samples were preserved by adding
hydrochloric acid (HCl) 50% before stored at 4oC. Sample preservation will lower
activities and metabolism of bacteria present in the water samples thus qualities of
samples can be maintained.
Secchi disk depth measurement was carried out using a disk of 18 cm
diameter with alternating black and white quadrants which is lowered into water
column till it can no longer be observed from the surface. The depth where the disk
40
is no longer visible was recorded. Then, the reading when the disk is rising up until
it just become visible was also taken into account. Average of both depths is used to
get the Secchi depth.
Figure 3.8: Secchi disk used to measure the depth of turbidity in the water column at
Merambong Island
3.2.2
Seagrass Specimens and Sediment
Seagrasses and sediment were hand picked to examine their characteristic in
order to identify the species.
The seagrasses were then digested in aqua-regia
solution for heavy metal analysis. Mature seagrass leaves without sign of infection
or injury were collected underwater and stored in bottles for laboratory analysis as
well as sediment.
After collection, the plants were rinsed vigorously with distilled water and
preserved in formalin solution. Formalin is a saturated solution of formaldehyde and
in typical form it is 37% formaldehyde by weight (40% by volume), 6-13% methanol
and the rest is water. Formaldehyde provides the disinfectant and bactericide effect
of formalin meanwhile methanol stabilizes the unstable chemical condition of
formaldehyde compound.
Figure 3.9 shows the seagrass which preserved with
formalin before extraction and analysis.
41
(a)
(b)
Figure 3.9: Seagrass leaves ((a) Halophila ovalis and (b) Halophila spinulosa) that
have been preserved in formalin and placed in glass bottles
3.3
Analysis of Samples
The seagrass specimens from each sampling station were dried in an oven at
65°C for a period of 24 hour. After the drying stage, the seagrass leave were
weighted (1 g) and transferred to a glass beaker (200 mL). The sample was then
digested using an open beaker digestion technique on hot plate for 2 hours with aqua
regia solution. During digestion the sample was not let to dry. The same procedure
was adopted for sediment analysis. The extraction reagents used in the study is aqua
regia method which involved 20% of nitric acid (HNO3) and hydrochloric acid (HCl)
in the proportion of 1:3. The extract were then filter into clean bottles with a filter
paper Whatman type GF/C (0.7µm). The concentration of As, Cd, Cr, Cu, Pb and
Hg were then measured by inductively coupled plasma mass spectroscopy (ICP-MS).
Figure 3.10: Digestion process using open beaker technique on hot plate
42
3.4
Chemical Analysis
Most of the water quality analysis parameters were determined at the
Environmental Engineering Laboratory of Faculty of Civil Engineering, Universiti
Teknologi Malaysia (UTM).
Parameters such as phosphorus, total phosphorus,
ammonia nitrogen, total nitrogen and COD analyzed using HACH DR 5000
Spectrophotometer adapted Standard Method American Public Health Association
(APHA, 2000). Meanwhile heavy metals were measured by inductively coupled
plasma mass spectroscopy (ICPMS). Table 3.2 summarized the standard method
used to analyze each parameter.
Table 3.2: Analytical procedures (Standard Method American Public Health
Association, 2005)
Experiments
Arsenic
Biochemical Oxygen Demand, BOD5 at 20oC
Cadmium
Chromium
Cuprum
COD
Mercury
Nitrogen Ammonia
Oil and Grease
Oxygen (Dissolved)
pH
Phosphorus
Plumbum
Suspended Solid
Temperature
Method
ICPMS
5210-B
ICPMS
ICPMS
ICPMS
5220-C
ICPMS
4500-NH3-BC
5520
4500-O
4500-H+
4500-P
ICPMS
2540-D
2550
CHAPTER 4
RESULT AND DISCUSSION
4.1
Introduction
Seagrasses are marine plants that belong to the subclass Monocotyledoneae
also known as Angiosperm and have the capability to live fully submerged in a saline
environment. They play an important role as habitat for many marine life, sediment
trap and assist coastal stability through acting as buffers against wave action. Based
on all the benefits, destruction of seagrass meadow can lead to a serious
environmental consequence. This chapter will discuss data analysis obtained from
in-situ and laboratory test.
Discussion covers seagrass specimen identification,
which based on literature review, water quality analysis using Interim Marine Water
Quality Standard and ASEAN Marine Water Quality Criteria. Moreover analysis on
heavy metal concentration in the seagrass leaves and sediment will also be discussed.
It is important to identify the water quality status and condition of seagrass as it can
serve as an indicator of marine environmental health. Seagrass can absorb nutrients
and minerals accumulate in the tissues and revealed in their physiological, biological
and morphological characteristics.
4.2
Specimen Identification
According to Aziz Arsad et al., (2006) there are 10 species of seagrasses that
inhabits at the calcareous sandy-mud sub-tidal shoals of Tanjung KupangMerambong. It is considered the highest species number for any locality in Malaysia.
44
The occurrence of seagrasses were observed from November 2008 to July
2009 during low tide at Tanjung Kupang-Merambong and Mersing. The identity of
the seagrasses were ascertained with reference to McKenzie (2008), Save Our
Seahorses (SOS) Handbook (2006) and The Encyclopedia of Malaysia: The Sea
(2001). However, in this study only six species of seagrass have been collected at
the site.
The water at seagrass meadow have very small variation in salinity, from
28.0 to 29.6 ppt and temperature ranging from 29.6°C to 31.4°C with six species of
seagrass collected. At Teluk Buih, Air Papan, Mersing three seagrass species were
collected with salinity at 30.3 ppt and temperature at 26.5°C. Six species discovered
were common species recorded in Malaysia, i.e Enhalus acoroides, Thalassia
hemprichii, Halophila spinulosa, Halophila ovalis, Halodule pinifolia and Halophila
minor. The specimens from Teluk Buih were recognized as Enhalus acoroides,
Halophila pinifolia and Cymodocea rotundata.
Table 4.1 summarizes the
comparison of seagrasses characteristic that were collected during sampling with
documented species.
In Tanjung Kupang seagrasess grow and form dense communities (meadow)
with a size of 38 ha compared to seagrasses at Teluk Buih, which grow sparsely near
the shoreline. Through literature, the species of Enhalus acoroides and Halophila
ovalis are predominantly at seagrass meadow (Choo, 2006). Moreover, leaves of
Enhalus acoroides at Tanjung Kupang was longer compared to leaves at Teluk Buih,
this is due to difference in depth of water in order for the leaves to reach sunlight for
photosynthesis process.
On the other hand, the length of H. pinifolia’s leaves
collected at Teluk Buih was longer, however the number of species is less.
Therefore, the competition to survive is less compared to H. pinifolia at Tanjung
Kupang.
Table 4.1: Specimen identification based on acknowledged species by previous study at seagrass meadow Tanjung Kupang and Teluk Buih,
Mersing
Species
Enhalus
acoroides
Documented Species



Linear and dark green

leaves with many

parallel veins
The rhizomes are thick 
with long bristles and
cord-like roots.
Leaves 30-150 cm long
Characteristics
Seagrass Meadow
Leaves 92-140 cm long
Linear and dark green leaves with
parallel veins
Leaves width range from 1.0 to 2 cm
Teluk Buih



Leaves 60-112 cm long
Linear and dark green leaves with parallel
veins
Leaves 1.2-1.4 cm breadth
45
Table 4.1: Continued
Species
Halodule
pinifolia
Characteristics
Seagrass Meadow
Documented Species




Rounded leaf tip
Usually pale rhizome, with
clean black leaf scars
Leaves up to 20 cm long
Found on sand substrate,
sandy-mud and sub-tidal reef
flats




Leaves 11-12 cm long
0.1 cm width of leaf blade
Bright green leaf
Sediment is calcareous sandy-mud subtidal
Teluk Buih


Leaves 14-37 cm long
0.1 cm width of leaf blade
46
Table 4.1: Continued
Species
Thalassia
hemprichii
Characteristics
Seagrass Meadow
Documented Species



Leaves 10-40 cm long
Ribbon-like leaves with
slight curve laterally
Has a thick rhizome
prominently marked by
several shoot scars
between successive erect
shoots.


Leaves 10-15 cm long
Width leaf blade, 0.4-0.8 cm
Merambong Island


Leaves 9-14.2 cm long
Width leaf blade, 0.4-0.7 cm
47
Table 4.1: Continued
Characteristic
Species
Halophila
spinulosa
Documented Species
Seagrass meadow
Teluk Buih
Not found during
survey





Leaf margin serrated
Leaves arranged opposite in pairs
Erect shoot up to 15 cm long
Found at sub-tidal depths (>10m)
Each leaf comprises 10-23 pairs of oblong-linear
serrated leaflets arranged obliquely around the stalk.
 Fern like with dark green leaves
 Have 10-15 pairs of oblong-linear leaflets
48
Table 4.1: Continued
Characteristic
Species
Halophila
ovalis
Documented Species
Seagrass meadow
Teluk Buih
Not found during
survey



10 or more cross vein
Hairless on leaf
Has a pair of petiolate bright green oval to elliptical
leaves



12-15 pairs of cross vein at each leaf
Bigger than Halophila minor
Can be found widespread at seagrass bed
49
Table 4.1: Continued
Characteristic
Species
Documented Species
Seagrass meadow
Teluk Buih
Halophila minor
Not found during survey


Less than 12 pairs of cross veins
Small oval leaf blade with stalk

Each leaf has 6-8 pairs of cross veins
50
Table 4.1: Continued
Species
Cymodocea
rotundata
Documented Species
Characteristic
Seagrass meadow
Teluk Buih
Not found during
survey





Rounded and strap-like leaves with
narrow leaf blade 2-4 mm wide
Leaves 7-15 cm long
Smooth rhizome
9-15 longitudinal veins
Found on shallow reef flats



Leaf blade is 3-4 mm wide
Leaves 7.5-15 cm long
Rounded and smooth leaf tip
51
52
4.3
Marine Life at Tanjung Kupang
Table 4.2 below shows the list of species of marine life that has been
observed during sampling. The dense seagrass bed of Tanjung Kupang supports
abundant of vertebrates and provides an important refuge for many species. This
finding observed for a short duration (May to July 2009) matches the literature where
seagrass meadow at Tanjung Kupang posses the highest species number of seagrass
in Malaysia that highly diverse and productive ecosystems and can shelter hundreds
of associated species (Aziz Arsad et al., 2006).
Table 4.2: List of marine life found during survey at seagrass meadow
Marine Life
Common Name
Crustaceans
 Violet Vinegar crab
 The pink-fingered vinegar crab
 Orange signaler crab
 Shen crab
 Crevice crab
 Mangrove porcelain crab
 Sentinel crab
 Stone/thunder crab
 Mangrove tree-dwelling crabs
 Purple climber crabs
 Spider crabs










Bivalves
 Fan clam
 Star barnacles
 Pinna bicolor
 Cowrie Cypraea sp.
Plants
 Peacock anemones
 Sea squirt
 Sea grapes
 Carpet anemone
 Seagrass
Species









Episesama versicolo
Episesama chentongense
Metaplax elegans
Shenius anomalum
Baruna trigranulum
Petrolisthes kranjiensis
Macrophthalmus crinitus
Periophtlalmus gracilis
Myomenippe harwicki
Selatium broclui
Caulerpa lentillifera
Stichodactyla gigantean
Halophila ovalis
Halophila minor
Halophila spinulosa
Enhalus acoroides
Halodule pinifolia
Thalassia hemprichii.
Halimeda discoidea
53
Table 4.2: Continued
Marine Life
Common Name
Species
Other
 Knobbly sea stars
 Fan worm
 Sea horse
 Sea cucumber
 Protoreaster nodosus
 Sabella spallonzanii
 Hippocampus sp.
 Holothuria scabra
 Holothuria leucospilota
 Pipefish
4.4
Water Quality Analysis
Table 4.3 shows the result of water quality from nearest rivers to the seagrass
bed, which are Sungai (Sg.) Pok Besar and Sungai (Sg.) Pok Kecil. Both of the
rivers are classified as Class III according to Water Quality Index (WQI) and Interim
National Water Quality Index (INWQS). From the survey, there was no aquatic life
living in both rivers. Dissolved oxygen (DO) at Sungai Pok Kecil was classified
under Class III and Sungai Pok Besar was Class IV according to WQI and INWQS.
Based on literature, a minimum of 2 mg/L of DO is needed to maintain higher life
form and fish needs 4 to 5 mg/L of DO to survive in a river (Davis and Masten,
2004).
Table 4.3: Water quality result of Sungai Pok Kecil and Sungai Pok Besar
Parameter
Dissolved oxygen
(mg/L)
pH
COD (mg/L)
BOD (mg/L)
Ammoniacal
nitrogen (mg/L)
Total Suspended
Solid (mg/L)
Oil and Grease
(mg/L)
WQI value
Sg. Pok
Kecil
WQI
INWQS
Class
Class
3.86
III (3-5)
III (3-5)
2.99
20
8.6
IV (<5)
II (10-25)
IV (6-12)
0.63
24
WQI
INWQS
Class
Class
2.8
IV
IV
II (25)
IV (12)
6.3
32
8.8
II
III
IV
III
III
IV
III (0.3-0.9)
III (0.9)
2.46
IV
IV
I (<25)
I (25)
20
I (<25)
I (25)
31.14
58.4
Sg. Pok
Besar
236
III
(51.9-76.5)
56.97
III
(51.9-76.5)
54
Meanwhile Table 4.4 and Table 4.5 show the result of seawater quality
obtained during sampling based on Interim Marine Water Quality Standard for
Malaysia (IMWQS) and Marine Water Quality Criteria for ASEAN Region
(AMWQC) at Tanjung Kupang and Teluk Buih.
Table 4.4: Result of water quality parameter based on IMWQS and AMWQC at
Teluk Buih
Parameter
Oil and Grease (mg/L)
Total Suspended Solid
(mg/L)
Ammoniacal
Nitrogen(mg/L)
Dissolved oxygen
(mg/L)
pH
Phosphorus (mg/L)
o
Temperature, ( C)
Salinity (ppt)
Secchi disk depth (m)
Teluk
Buih
NA
IMWQS
AMWQC
0
0.14
377
50
NA
NA
0.1
NA
4
NA
NA
0.06
NA
0.045
26.5
30.3
NA
NA
NA
NA
NA
NA
NA
2.5
6.83
7.53
Notes: NA-Not Available
During sampling, average of surface water temperatures ranged from 26.5 to
30.4ºC which is the typical temperature of tropical waters, whereas salinity ranged
from 27.6 to 30.3 ppt and pH was 7.28 to 8.07. Generally, salinity and pH value
were lower near shore as Sungai Pok estuary influence by freshwater river.
Freshwater generally has a lower salt content and pH than seawater (Bong and Lee,
2008). Meanwhile dissolved oxygen (DO) was higher at both seagrass area; seagrass
meadow (3.09 – 6.74 mg/L) and Teluk Buih (6.83 mg/L) due to photosynthesis
process by submerged aquatic vegetation and it is not under hypoxia state. Hypoxia
condition occur where DO concentration is from 0-2 mg/L resulting from large algal
blooms that sink to the bottom of the water column where bacteria breaks down the
algae, using oxygen during the process (Clement et al., 2001).
55
Table 4.5: Result of water quality parameter based on IMWQS and AMWQC at
Tanjung Kupang
Parameter
Oil and Grease,
mg/L
Total
Suspended
Solid, mg/L
Ammonia
Nitrogen, mg/L
Phosphorus,
mg/L
Secchi disk
depth, m
Sg. Pok
Estuary
Seagrass
Meadow
Merambong
Island
IMWQS
AMWQC
56
123
75
0
0.14
253
271
259
50
NA
0.628
2.43
1.825
NA
0.1
0.888
1.265
0.645
NA
0.045
0.92
0.52
0.13
NA
NA
Notes: NA-Not Available
56
4.4.1
Oil and Grease
By referring to Table 4.5 Sungai Pok estuary has the lowest concentration of
oil and grease at 53 mg/L compared to other station which is mainly used as boat
parking by the local fisherman and none of aquatic life were found live in the river.
Oil and grease concentration observed at all stations were higher compared to
IMWQS (standard = 0 mg/L). The highest oil and grease concentration was recorded
at seagrass meadow (123 mg/L) then followed by Merambong Island (75 mg/L). Oil
and grease contamination occur in the environment through leakage and disposal of
engine oil from boats. Free oil and grease are frequently visible as a rainbow colored
film on the surface water. It impedes re-oxygenation process and hence will decrease
dissolved oxygen in water. The result of dissolved oxygen (DO) concentration at
Sungai Pok Besar was classified as Class IV with the value of 2.8 mg/L and
biochemical oxygen demand (BOD) was 8.8 mg/L
The study areas were also located near Port of Tanjung Pelepas (PTP) and
restaurant that contribute to the oil and grease pollutant from sullage. Port contribute
oil and grease pollution from transportation activities i.e. from tanker operations
usually associated with the cleaning of cargo residues when the ship is ballasting and
cleaning its tank at the return voyage from the port of discharge (Tong et al., 1999).
Most of the oil have less density than water therefore; it will remain on the water
surface while the current and wind drifts it along to other place. Oil and grease value
increase as from Sungai Pok estuary > Merambong Island > seagrass meadow.
Moreover, seagrass meadow is the nearest station, which is located close to
restaurant and PTP.
4.3.2
Total Suspended Solid
Based on the report produced by Department of Environment on 2006, total
suspended solid remained a significant contaminant of marine water where Johor has
exceeded the IMWQS by 60 percent. The total suspended solid at Mersing at 377
mg/L have the highest reading due to presence of sand since sample was collected
57
near the beach.
Agriculture activities and coastal reclamation are also possible
sources of high content of suspended solid in seawater. Suspended solid at Sungai
Pok estuary, seagrass meadow and Merambong Island were high recorded at 332
mg/L, 324 mg/L and 386 mg/L respectively, which exceed the limit of IMWQS of 50
mg/L. Currently, Port of Tanjung Pelepas is under going expansion and will cover
1,362 hectares of reclaimed land and onshore land since the port is targeted to be
fully completed by 2020. This will lead to dredging activities, which will destroy
seagrass habitat directly by digging and indirectly by affecting the suspended
sediment. Excessive sediment smothers seagrasses where turbidity in the water
column will increases and interfere with sunlight penetration and eventually inhibits
photosynthesis process.
Other factor that contributes to high concentration of total suspended solid is
the presence of phytoplankton in seawater.
The rate of respiration and
bacterioplankton growth is high in most mangrove area (Alongi et al., 1998). In
rainy season, nutrients is supplied to estuaries and results in increase of
phytoplankton production while in dry season, it is otherwise due to low nutrient
supply and part of it is used to sustain the zooplankton biomass (Kitheka et al.,
1996). However, the abundance of plankton community and metabolism differs
between surface and near-bottom waters and between high and low tides where
heavy boat traffic and daily harvesting of mudflats cockles disturb and mix river bed
with overlaying waters and river banks erosion (Alongi et al., 2003).
4.4.3
Ammoniacal Nitrogen and Phosphorus
Ammoniacal nitrogen (NH3-N) and phosphorus exceeded the standard by
Asean Marine Water Quality meanwhile there are no criteria for NH3-N and
phosphorus stated in IMWQS. Water quality at the area where seagrass vegetate in
seagrass meadow have higher ammoniacal nitrogen with 4.0 mg/L followed by
Sungai Pok estuary at 3.3 mg/L, Merambong Island at 3.2 mg/L and Teluk Buih 2.5
mg/ L. Meanwhile, at seagrass meadow have highest dissolved phosphorus content
at 1.74 mg/L. Phosphorus in the form of phosphate occurs in environment via both
58
natural and anthropogenic sources, which mainly come from runoff from agriculture.
Moreover, rainfall and settling dust also contribute to nutrient inputs where it varies
from place to place (Kaiser et al., 2005).
Plants can take inorganic nitrogen in the atmosphere through conversion by
lightning and bacteria into nitrate or ammonia since they cannot use nitrogen
directly. Moreover, in sediments underlying the cover of sea-grass, silt-clay, organic
matter, exchangeable ammonium, ammonium dissolved in pore waters and total
nitrogen were larger than in unvegetated profiles (Kenworthy et al., 1982).
Ammonium is continuously transformed into ammonia and hydrogen ions and vice
versa, however ammonia is poisonous compared to ammonium (Ainon and Sapheri,
2008). In addition at pH of 7 or less only ammonium is present, at pH 8 around 5%
is ammonia and 95% ammonium, and at pH 9 then 50% is ammonia and 50% is
ammonium.
The nutrients concentration at the study areas are a possible result from loss
of mangrove at Sungai Pulai area where it cleared for development of a Petroleum
Hub and Bunkering Facility at Tanjung Bin and Iskandar Development Region.
Destruction of mangroves due to land reclamation results in the loss of biofilters, and
nutrients are often-discharged directly to coastal environments since it act as natural
filters for fertilizers and sediments transported by rivers (Dol et al., 2008). High
concentration of nutrients will lead to excessive growth of algae that will degrade
water quality.
Massive bloom of algae in long period will block sunlight to
submerged aquatic vegetation and induce low dissolved oxygen in water due to
increase in organic matter production. Nevertheless, the condition at the study area
does not indicate any sign of eutrophication which is widely known as one of the
threat to seagrass meadow.
59
4.5
Heavy Metals in Water
Table 4.6 shows the content of heavy metals in Sungai Pok Kecil and Sungai
Pok Besar which compare to Water Quality Index (WQI) and Interim National Water
Quality Index (INWQS). Sungai Pok Besar and Sungai Pok Kecil, located near the
seagrass meadow is classified as Class III according to WQI and INWQS for heavy
metal. Heavy metals are categorized as Class II in both rivers except for total
chromium and mercury, which is under Class V respectively. Therefore, both rivers
contribute to metal concentration especially at the seagrass meadow. The heavy
metals content at both rivers might be due to seawater that enter the river during high
tide, accumulate in the sediment, and release to the environment via soil erosion and
activities along the riverbank.
Table 4.6: Heavy metal concentration at Sungai Pok Kecil and Sungai Pok Besar
Parameter
Sg. Pok
Kecil
INWQS
Sg. Pok
Besar
Class
Arsenic (As),
mg/L
Cadmium (Cd),
mg/L
Chromium (Cr)
Total, mg/L
Copper (Cu)
mg/L
Lead (Pb), mg/L
Mercury (Hg),
mg/L
INWQS
Class
0.0123
II
0.0288
II
0.0027
II
0.0008
II
0.1657
V
0.1488
V
0.0567
IV
0.0503
IV
0.0522
II
0.0087
II
0.0768
V
0.0374
V
60
Refer to Table 4.7 and 4.8, the is not much difference in As concentration at
all sampling station except for Teluk Buih, Mersing. The concentration at Sungai
Pok estuary and Merambong Island exceeded standard of IMWQS. Sungai Pok
Besar have As concentration of 0.0288 mg/L and the estuary at 0.069 mg/L to 0.111
mg/L classified as Class II under INWQS. Arsenic are released into the environment
through pesticide used in agricultural activities and enter the watercourse via surface
run-off.
Pb and Cr concentration complies with IMWQS and AMWQC standards. Cd
only comply with IMWQS except for at Merambong Island with the value of 0.1244
mg/L which exceeds Malaysia’s interim. Coastal metal concentrations are often
significantly elevated due to nearby land-based pollution sources (Chongprasith et
al., 1999).
The highest values are usually from nearest drains and outfalls
(Hershelman et al., 1981). From geographical aspect, Merambong Island is near to
the industrial area of Jurong, Singapore which can be major contributor to Cd
pollution to the water from anthropogenic sources such as metal plating
manufacturing and pigments in plastics and batteries. The lowest measurements of
lead were detected at Merambong Island and Mersing, which is at 0.004 mg/L and
0.014 mg/L respectively. Lead is mainly present in the seawater from automobile
exhausts through direct atmospheric transport and during rainfall; the Pb particles
will fall back on earth. Since the third sampling point (Merambong Island) and
Mersing are quite far from the main road, the Pb concentration was lower compare to
seagrass meadow and Sungai Pok estuary area.
Mercury was the highest concentrations that exceed the standards compared
to other heavy metals. Hg can enter the environment via both natural and man made
activities. Natural process occurs from volcanoes, natural mercury deposit and ocean
volatization. Man related activities involved coal combustion, waste incineration and
metal processing.
However, that activities does not occur at the study area.
Therefore, the presence of Hg may come from the water which moves around or flow
as currents since the study area is near to the Malacca Strait. The Strait have been
polluted with industrial activities that have high levels of heavy metal include lead
and mercury contamination. Moreover, the areas also received flow from Sungai
61
Pulai and Tebrau Strait and the metals tend to accumulate especially in the sediment.
Atmospheric-borne mercury includes anthropogenic mercury, deposited everywhere,
including remote areas of the globe, hundreds of kilometers from nearest mercury
source, as evidenced by its presence in ancient lake sediment and glacial ice (Eisler,
2006). Based on the report produced by Department of Environment on 2006, the
concentration of Hg in Johor exceeded 10% of the IMWQS standard and most state
in the West Coast of Peninsular Malaysia exceeded the limit. In the other side of
Sungai Pulai estuary, which is Tanjung Bin, establish as the largest privatized coalfire power plant in Malaysia. The RM 7.8 billion cost project will cover over 41
hectares of land and generate 2,100MW electricity. As discovered by Sharma and
Pervez (2004), enrichment of toxic metals in respirable particulate matter emissions
from a coal-fired power plant in Central India documented that the concentration of
mercury was 4.8 times more the coal.
The Strait of Malacca is located between the east coast of Sumatera Island in
Indonesia and the west coast of Peninsular Malaysia, and linked with the Strait of
Singapore at its southeast end. According to Thiang-Eng et al., (2000) heavy metals,
primarily from the manufacturing sector, include cadmium, copper, lead, mercury
and nickel, all of which are reported in the coastal waters of West Malaysia,
particularly the coastal waters of Perak and Penang where most rivers of West
Malaysia contain concentrations of heavy metals that exceed standards.
Table 4.7: Heavy metal concentration at Teluk Buih
Parameter
Arsenic (As),
mg/L
Cadmium
(Cd), mg/L
Chromium
(Cr) Total,
mg/L
Copper (Cu),
mg/L
Lead (Pb),
mg/L
Mercury (Hg),
mg/L
Teluk
Buih
IMWQS
AMWQC
0.076
0.1
0.12
0.049
0.1
0.01
0.105
0.5
NA
0.138
0.1
0.008
0.014
0.1
0.0085
0.023
0.001
0.00016
62
Table 4.8: Heavy metal concentration at Tanjung Kupang
Parameter
Arsenic
(As), mg/L
Cadmium
(Cd), mg/L
Chromium
(Cr) Total,
mg/L
Cuprum
(Cu), mg/L
Plumbum
(Pb), mg/L
Mercury
(Hg), mg/L
Sg. Pok
Estuary
Seagrass
Meadow
Merambong
Island
IMWQS
AMWQC
0.1061
0.0998
0.1001
0.1
0.12
0.0060
0.0043
0.1244
0.1
0.01
0.1429
0.1377
0.1486
0.5
NA
0.1834
0.1889
0.1787
0.1
0.008
0.0066
0.0060
0.0046
0.1
0.0085
0.0396
0.0445
0.0459
0.001
0.00016
63
4.6
Heavy Metals in Sediment
Table 4.9 shows the concentration of metal in sediments collected on the
surface of the sediment bed. All parameter of heavy metal in sediment collected at
Sungai Pulai and seagrass meadow exceeded the limit. The highest heavy metal
found at Sungai Pulai was copper with a value of 0.6643 mg/L in dry weight and at
Tanjung Kupang, Chromium content was 0.4090 mg/L in dry weight. According to
Yap et al., (2003), the inter-tidal sediment of the Straits of Johor are enriched with
Cu, Ni, Pb and Zn. From the data, the value of Hg in sediment at seagrass meadow
was 0.0715 mg/L and Sungai Pulai estuary was 0.1151 mg/L were higher than Hg
concentration in the water at 0.0445 mg/L. The same condition applied to other
metal concentration in sediment where the values are higher in contrast with water.
As explained by Wiener et al. (2003), soils and sediments are the primary sink for
atmospherically derived mercury; however, these enriched pools are remobilized
through volatilization, leaching and erosion.
Table 4.9: Concentration of metals (mg g-1 dry weight) in the sediment which
evaluate to United Kingdom interim marine sediment quality guidelines (ISQG)
Sediment
Parameter
(mg/g dry weight)
Arsenic (As)
Cadmium (Cd), mg/L
Chromium (Cr) Total
Copper (Cu)
Lead (Pb)
Mercury (Hg)
Sungai
Pulai
0.1272
0.0680
0.1985
0.6643
0.3428
0.1151
Seagrass
meadow
0.2475
0.0208
0.4090
0.3997
0.2914
0.0715
Mersing
ISQG
0.001
0
0.001
0
0.002
0.017
0.00724
0.0007
0.0523
NA
0.0302
0.00013
The mercury concentration in sediment obtained in the study was higher
compared to the finding reported by Yap et al., (2003) at Tanjung Kupang in year
2000 which 0.000108 mg/g dry weight. They claim that the high level of Hg occur
in some sediment samples via hydrocarbon contamination because they have -S and
–O actives sites which can bind Hg.
In addition, Hg may also come from
manometers that contain elemental Hg, which are used at gas metering sites and at
64
refining gas plants. They made the conclusion since the present of Hg at west coast
of Peninsular Malaysia was not highly exposed to anthropogenic and regular
monitoring should be conduct since the industrial activities have rapidly increased
along the west part.
The same situation was observed for Cd concentration in sediment of
Tanjung Kupang. From this study the concentration was higher (0.0208 mg/g dry
weight) than the result obtained by Yap et al., (2003)in 2000 where the Cd value was
0.0017 mg/g dry weight. It appears that in 9 years, Cd content was elevated since the
area in progressive development.
Furthermore, previous studies have shown
increased levels of Cd and Zn in the coastal areas adjacent to industrial estates, urban
areas and ports in the area. According to the report by Department of the
Environment, Malaysia (DOE) on 1999, the sources of heavy metal inputs in the
west coast of Peninsular Malaysia include manufacturing industries, agro-based
industries and urbanization activities.
Meanwhile study carried by Ong and Kamaruzzaman, (2009) reported that
Mersing have an average of Pb and Cu concentration in sediment at 0.1377 mg/L dry
weight and 0.0085 mg/L dry weight respectively. The result were significantly high
compared to the result for Pb (0.002 mg/L dry weight) content and Cu which was not
detected. The result for metals in sediment ist considered not a threat to seagrass
where Syarifah Noormaisarah et al., (2004) discovered that when Halodule pinifolia
and Halophila minor were exposed to sediment with high concentration of cadmium
(0.288 mg/g dry weight) and copper (0.45149 mg/g dry weight) they die off after
week 4 and 5 respectively. Moreover, both species showed negative value in oxygen
production after week four.
4.7
Heavy Metals in Seagrass
Previous research on the interactions between metals and seagrasses are
focused on the accumulation of metals into seagrass and the use of seagrasses as
65
biological indicators of trace metal contamination (Prange and Dennison, 2000).
However, several studies showed that trace metal could interfere on seagrass
photosynthetic physiology (Kaiser et al., 2005 and Eisler 2006). On the other hand,
since seagrass ecosystems support important grazing and detritus food webs,
accumulation of metals in seagrass may be passed through to higher level consumers
including human due to uptake of seafood (Kaiser et al., 2005).
Heavy metals have been detected in all of the seagrass species at Tanjung
Kupang where Halophila minor exhibit the highest content of heavy metals in the
leaf except for cadmium and mercury. Thalassia hemprichii at Merambong Island
turned out to be strongest accumulator for Cd at 0.016 mg/g dry weight and
Halophila ovalis for Hg at 0.044 mg/g dry weight. Meanwhile at Teluk Buih,
species of Cymodocea rotundata accumulated higher heavy metals compared to the
other species. Table 4.10 show the mean concentrations of heavy metal in each
species of seagrass.
Table 4.10: Concentration of metals (mg g-1 dry weight) in the different species of seagrass
Parameter
(mg/g dry weight)
Arsenic (As)
Cadmium (Cd)
Chromium (Cr)
Total
Cuprum (Cu)
Plumbum (Pb)
Mercury (Hg)
Enhalus acoroides
Sungai
Seagrass
Mersing
Pulai
Meadow
0.0030
0.0012
0.0008
0.0010
0.0004
0.0000
0.0020
0.0010
0.0020
0.0320
0.0008
0.0004
0.0008
0.0055
0.0004
0.0004
0.0008
0.0034
Halophila
minor
Seagrass
Meadow
0.0128
0.0005
Halophila
spinulosa
Seagrass
Meadow
0.0018
0.0002
0.0116
0.0054
0.0081
0.0003
0.0019
0.0001
0.0001
0.0342
Species
Halophila
Thalassia hemprichii
ovalis
Seagrass Seagrass Merambong
Meadow
Meadow
Island
0.0111
0.0015
0.0006
0.0002
0.0001
0.0160
0.0045
0.0031
0.0035
0.0440
0.0018
0.0013
0.0014
0.0055
0.0009
0.0009
0.0009
0.0033
Halodule pinifolia
Seagrass
Meadow
0.0051
0.0003
Mersing
Cymodocea
rotundata
Mersing
0.0030
0.0045
0.0013
0.0013
0.0050
0.0038
0.0032
0.0380
0.0015
0.0015
0.0000
0.0056
0.0013
0.0013
0.0013
0.0011
66
67
Copper is considered a minor trace metal with 70% of the copper in leaves
contained in the chloroplasts of land plants. Ralph and Burchett (1998) suggested
that photosynthetic function is highly sensitive to Cu toxicity with Cu stress in the
seagrass H. ovalis detected at 1, 5 and 10 mg/L respectively. In addition, Prange and
Dennison (2000) discovered that the seagrasses H. ovalis and H. spinulosa (grazed
species) appear to have more readily uptake of trace metals than other seagrass
species, therefore these species are more prone to the toxicity effects linked with the
sequestering of trace metals from the environment and may provide a source of
contamination to seagrass consumers. The study also verified that increase in rainfall
and associated of run-off might serve to increase trace metal supply to seagrass
habitats, and localized developments can mobilize latent metal sources.
4.8
Development Adjacent to the Seagrass Meadow
The coastal zone of Johor that 64 km in length encompass under Iskandar
Development Region (IDR) to acceleration in growth of economy. Villages that
located nearby seagrass meadow will be develop as industrial area of Tanjung
Pelepas. Table 4.9 below shows the proportion of the various land use for Tanjung
Pelepas zone.
68
Table 4.11: Land use in Tanjung Pelepas Zone (MBJBT, 2008)
Types of Land use
Area (ha)
Percentage (%)
Saturated Land use
Residential
33.41
0.41
Commercial
2.34
0.03
280.61
3.47
-
-
Industrial
Institutional and Facility

Institutional and Government use
5.18
0.06

Education Facilities
8.43
0.10

Health Facilities
1.01
0.01

Religion Facilities
1.41
0.02

Cemetery and Related Facilities
3.92
0.05

Area of Special use
971.66
12.02

Recreational and Open Areas
-
-
1307.97
16.17
288.13
3.56
6.46
0.08
294.59
3.64
Agriculture Areas
2575.59
31.85
Mangrove Areas
1493.77
18.47
Water Bodies
2414.68
29.86
8086.60
100.00
Sub-Total
Transportation, infrastructure and utilities reserve

Transportation and communication

Infrastructure and utilities
Sub-Total
TOTAL
69
(a)
(b)
Figure 4.1: (a) Current condition of coastal line near seagrass meadow while (b) is
the future development which under Tanjung Pelepas industrial region.
Figure 4.1 show the current condition of coastal line area near seagrass
meadow. From 1991 to 2005, the land cover of the river basin which consists of
inland freshwater riverine forest, intertidal mudflats and seagrass bed, functions
mainly as shoreline stabilization and severe flood prevention to adjacent land uses.
However this has changed gradually due to human intervention such as port and
industries developments, power transmission line maintenance activity, land
reclamation and agriculture activities (Dol et al., 2008). In addition, the mangrove
area declined from 5742 hectares to 5467 hectares which 5% of reduction. Figure 4.2
shows the expansion plan of Port Tanjung Pelepas (PTP) that is expected to be
complete on 2020 which involved five phases of development. According to PTP
(2009), first two phases will cater for container traffic while third, fourth and fifth
phases will have a combination of container, liquid and dry bulk cargo.
The
development will cover 1,362 hectares of reclaimed land and onshore land.
In the opposite of PTP, which is Tanjung Bin, is an establishment of a largest
privatized coal-fired power plant in Malaysia. The RM 7.8 billion cost project will
cover over 41 hectares of land and generate 2,100MW of electricity. There will be a
broad scale clearing of 2,255 acres of mangrove forest which can be approximated to
913 soccer field- this will disappear permanently from the global map (The Star,
2007). As discussed earlier Sharma and Pervez (2004) reported thst enrichment of
70
toxic metals in respirable particulate matter emissions from a coal-fired power plant
in Central India show that mercury was enriched 4.8 times over the coal.
With all the current and upcoming development nearby, the future of seagrass
meadow at Tanjung Kupang – Merambong shoal is still uncertain.
Massive
destruction of mangrove area will give major impact since it has close interaction
with seagrass bed especially as habitat for juvenile fish. Consequently, a significant
part of the connectivity between fish assemblages of seagrass beds, mangroves and
coral reefs is determined by a combination of three factors which are ability of fish
species to utilize the coral reef as alternative juvenile habitat besides seagrass bed
and mangroves; the distance between seagrass and mangrove habitats and coral reef
and the configuration of seagrass beds and mangroves in the marine landscape with
respect to accessibility to the coral reef (Dorenbosch, 2006).
72
4.8
Overall Discussion
From the result obtained, seagrass have a potential as bio-indicator since it
accumulates heavy metal in their system. Natural accumulation of heavy metals in
seagrass species consequently used as indicator organisms for heavy metal
contamination and bioavailability of the food chain in marine habitats. Generally,
biological indicators are any group of species where their function, population or
status can be use to determine and monitor the health of ecosystem or environment.
A good bioindicator will indicate the presence of pollutants and provide additional
information on the amount and intensity of the exposure.
Excluding seagrass, the use of bivalve or gastropods molluscs looks attractive
as these organisms take up metals from all environmental aspect, either from the
aqueous medium or through ingestion from food and inorganic particulate material
and heavily concentrate them (Phillips, 1977). Furthermore, they are suitable as
monitors in situ since they are sedentary or sessile and available all year long and
easy to collect. Study conducted by Storelli and Marcotrigiano, (2005) reported
using gastropod Patella caerulea since it is among the commonest inhabitants of
rocky shores in the whole Mediterranean basin. This small edible herbivorous
gastropod has already employed in campaigns evaluating pollution by metals (Lobel
et al., 1982).
However, the used of organisms are more complicated because their exposure
to trace elements is not limited to soluble metals in the aquatic medium where metal
uptake from food cannot be ignored (Campanella et al., 2001). Therefore, seagrass
appears as an interesting tool in setting up biomonitoring networks on the scale of the
Tanjung Kupang area. From this study, most of the species accumulate heavy metals
in their systems that possible through photosynthesis process and Halophila minor
exhibit the highest content of heavy metals in the leaf except for cadmium and
mercury.
From the result obtained, seagrass bed at Tanjung Kupang is still in good
condition and support a large diversity of marine life. The unique species such as
73
Holothuria leucospilota; black cucumber, Stichodactyla gigantean; Carpet anemone
and Sabella spallanzanii; fan worm inhabit in the area especially at Merambong
Island as shown at Figure 4.3. It is widely known that seagrass meadow serve as an
important fisheries habitat, nursery and feeding ground for associated fauna and algal
flora. In addition, the presence of seagrass bed in coastal area is significant in
stabilizing the sediments and regarded as an indicator of good water quality.
Land reclamation through dredging give a great environmental pressure to the
seagrass bed where some of the meadow has been smothered by sand from
construction site at Port Tanjung Pelepas. A volunteer called Save Our Seahorses
(SOS) is an active group that have aim to conserve the Pulai River Estuary in Johor
using the spotted seahorse, Hippocampus kuda, as a flagship species (The Star,
2008). Via the website, they made articles, comments, and petition that urged the
Johor’s government to stop the plan of build petrochemical and maritime industries
at the Pulai River estuary since the fragile ecosystems cannot tolerate a series of
heavy industries development (SOS, 2008).
On 27 August 2009, a memorandum to object the development at Tanjung
Bin was handed over by Ahli Jawatankuasa Bertindak Bantahan Projek Petrokimia
Mukim Tanjung Kupang to Johor State Menteri Besar, Datuk Abdul Ghani Othman.
913 ha of mangrove forest that has been cleared will cause the loss of almost RM 1
billion a year in fisheries industries and affect especially local fisherman. Moreover,
on February 2003 Sungai Pulai was gazetted as a Ramsar Site, which is an
intergovernmental treaty that provides the framework for national action and
international cooperation for the conservation and wise use of wetlands and their
resources (BERNAMA, 2008). Currently, there are five Ramsar sites in Malaysia
and according to Ramsar convention, there should not be any drastic changes in the
ecological character of our lands as a result of industrial development, pollution or
other human interference. If there is any obstruction Malaysia will be listed on the
Montreux Record which indicates that we have failed in preserving our wetland
heritage (The Star, 2007).
74
(a)
(c)
(e)
(b)
(d)
(f)
Figure 4.3: Several creatures that can found from seagrass area where (a) is
Holothuria leucospilota, (b) is Stichodactyla gigantean meanwhile (c) Sabella
spallanzanii, (d) is Protoreastar nodosus, (e) Purple Climber Crab and (f)
Hippocampus kuda.
CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1
Conclusion
The following conclusion can be drawn based on the findings from the study:
1. The study managed to identify six species of seagrass at Tanjung Kupang
which are Enhalus acoroides, Thalassia hemprichii, Halophila spinulosa,
Halophila ovalis, Halodule pinifolia and Halophila minor
2. Seagrass meadow at Tanjung Kupang support large number of marine
invertebrates
3. Water quality does not affect the seagrass distribution. Land reclamation for
port development post greater threat to seagrass then water quality
4. Heavy metals concentration in sediment are higher than in seagrass leaves
and water
5. Halophila minor has potential as bioindicator for heavy metals contamination
76
5.2
Recommendation
The use of seagrass as a bio-indicator of heavy metals first measurement in
the marine environment may be feasible tool in order to assess the potential
contamination of metals in the coastal ecosystem. Following recommendations
should be carried on to improve the study.
1. The analysis of metals in seagrass should be carried out separately involving
rhizome and leaf respectively since the uptake of metals via the roots from
sediment and through their leaves from water to indicate which way
contribute higher uptake.
2. Added water quality parameter such as chlorophyll-a to obtain information on
eutrophication process.
77
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