Post on 28-Mar-2019
UNIVERSITI PUTRA MALAYSIA
CONCENTRATIONS OF HEAVY METALS IN THE SOFT TISSUES OF MUDFLAT SNAILS (TELESCOPIUM TELESCOPIUM) FROM THE
INTERTIDAL AREAS OF PENINSULAR MALAYSIA
NOORHAIDAH BT ARIFIN
FS 2008 7
CONCENTRATIONS OF HEAVY METALS IN THE SOFT TISSUES OF MUDFLAT SNAILS (TELESCOPIUM TELESCOPIUM) FROM THE
INTERTIDAL AREAS OF PENINSULAR MALAYSIA
By
NOORHAIDAH BT ARIFIN
Thesis submitted to the School of Graduate Studies, Universiti Putra Malaysia, in fulfillment of the Requirements for the degree of Masters of Science
July 2008
Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfillment of the requirement for the degree of Master of Science
CONCENTRATIONS OF HEAVY METALS IN THE SOFT TISSUES OF MUDFLAT SNAILS (TELESCOPIUM TELESCOPIUM) FROM THE
INTERTIDAL AREAS OF PENINSULAR MALAYSIA
By
NOORHAIDAH BT ARIFIN
July 2008 Chairman: Yap Chee Kong, PhD Faculty: Faculty of Science
ABSTRACT The main aim of this study is to establish mudflat snail Telescopium telescopium as a
biomonitor of heavy metals for the intertidal area of Peninsular Malaysia. From this
study, the concentrations of heavy metals in the different parts of soft tissues and
shells were determined in T. telescopium collected from 16 geographical sites along
the west coast and one site from the east coast (Tumpat, Kelantan) of Peninsular
Malaysia. Based on the 17 populations, the mean concentrations of heavy metals in
the total soft tissues of T. telescopium varied widely from 53.59 – 187.07 µg/g dry
weight for Cu, 65.11 – 155.38 µg/g dry weight for Zn, 5.59 – 17.66 µg/g dry weight
for Pb, 0.40 – 1.52 µg/g dry weight for Cd, 4.63 – 17.29 µg/g dry weight for Ni and
304.06 – 1062.19 µg/g dry weight for Fe.
The soft tissues of snail T. telescopium were dissected, separated and pooled into
seven parts namely foot, cephalic tentacle, mantle, muscle, gill, remaining soft
tissues and digestive caecum and the concentrations of heavy metals in these tissues
were measured. In the study of the relationship between different soft tissues of T.
ii
telescopium with its environment represented by sediment samples, the Pearson’s
correlation coefficients results showed positive significant correlation (p< 0.05) were
observed between Cd, Cu, Fe, Ni, Pb and Zn in the different soft tissues and
geochemical fraction of 6 metals studied in the sediment. The Pearson correlation
coefficients suggested that some soft tissues can be good biomonitoring organs (Cu:
mantle and remaining soft tissues; Fe: mantle, remaining soft tissues and foot; Ni:
gill and remaining soft tissues; Pb: gill, remaining soft tissues and digestive caecum;
Zn: gill and remaining soft tissues). It is noted that particular organ may be more
effective tool than the total soft tissues to monitor heavy metal contamination in the
intertidal zone. The study on the ratio of metals in the shell to the metals in the
different soft tissues shows that shell has higher degrees of variability for Cd, Ni and
Pb than in the different soft tissues of T. telescopium. Therefore, the results indicated
lower degrees of variability of Fe, Cu and Zn in the shells of T. telescopium than in
the different soft tissues of T. telescopium.
In conclusion, the metal distributions in the different soft tissues of T. telescopium
indicated that a particular organ is more useful and accurate to monitor a particular
metal contaminations in the intertidal area. The shells and soft tissues of T.
telescopium are found as potential biomonitor of Cd, Cu, Fe, Ni, Pb and Zn while the
usefulness of the shells need further studies.
iii
ABSTRAK
KEPEKATAN LOGAM-LOGAM BERAT DI DALAM BEBERAPA TISU LEMBUT SIPUT MUDFLAT Telescopium telescopium (Linnaeus) DARI
KAWASAN PASANG SURUT SEMANANJUNG MALAYSIA
Oleh
NOORHAIDAH BT ARIFIN
Julai 2008 Pengerusi: Yap Chee Kong, PhD Fakulti: Fakulti Sains
Tujuan utama kajian ini adalah untuk mencadangkan dan menggunakan siput
lumpur Telescopium telescopium sebagai agen penunjuk biologi logam-logam berat
bagi kawasan pasang surut Semenanjung Malaysia. Lokasi kajian adalah meliputi 16
lokasi sampel di sepanjang perairan Pantai Barat Semenanjung Malaysia dan satu
lokasi sampel dari perairan timur (Tumpat, Kelantan) Semenanjung Malaysia.
Kepekatan purata logam-logam berat dalam keseluruhan tisu lembut T. telescopium
berubah daripada 53.59 – 187.07 µg/g berat kering untuk Cu, 65.11 – 155.38 µg/g
berat kering untuk Zn, 5.59 – 17.66 µg/g berat kerng untuk Pb, 0.40 – 1.52 µg/g
berat kering untuk Cd, 4.63 – 17.29 µg/g berat kering untuk Ni dan 304.06 – 1062.19
µg/g berat kering untuk Fe.
Siput T. telescopium yang telah disampel dari setiap satu lokasi telah dibedah dan
diasingkan kepada tujuh bahagian iaitu kaki, tentakel sefalik, mantel, otot, insang,
lebihan tisu lembut dan sekum pencerna. Kepekatan logam-logam berat dalam semua
tisu ini diukur. Kajian ini juga menjalankan analisis bagi hubungan antara beberapa
tisu lembut T. telescopium dengan persekitaran (iaitu sedimen), keputusan
menunjukkan korelasi positif yang signifikan (p < 0.05) antara kadmium, kuprum,
iv
besi, nikel, plumbum and zink dalam beberapa tisu lembut dan fraksi geokimia enam
logam berat yang dikaji. Pemalar korelasi yang diperolehi mencadangkan beberapa
tisu lembut berpotensi untuk digunakan sebagai organ penunjuk biologi (kuprum:
mantel dan lebihan tisu lembut; besi: mantel, lebihan tisu lembut dan kaki; nikel:
insang dan lebihan tisu lembut; plumbum: insang, lebihan tisu lembut dan sekum
pencerna; zink: insang dan lebihan tisu lembut). Di dapati organ-organ tertentu
dalam siput T. telescopium lebih berkesan untuk dijadikan agen penunjuk biologi
daripada menggunakan keseluruhan tisu lembut untuk mengetahui aras kepekatan
logam-logam yang dikaji di kawasan intertidal. Kajian yang dibuat untuk
menentukan kadar logam dalam cengkerang kepada logam dalam tisu lembut
menunjukkan cengkerang mempunyai darjah berubah-ubah yang tinggi terhadap
kadmium, nikel dan plumbum berbanding bahagian tisu lembut T. telescopium. Oleh
itu keputusan kajian menunjukkan cengkerang T. telescopium mempunyai darjah
berubah-ubah yang rendah bagi besi, kuprum dan zink berbanding tisu-tisu lembut T.
telescopium.
Kesimpulannya, taburan logam-logam dalam tisu-tisu lembut T. telescopium
menunjukkan bahawa organ tertentu lebih berguna dan tepat sebagai penunjuk
biologi bagi pencemaran logam-logam tertentu dalam kawasan intertidal.
Cengkerang dan tisu lembut T. telescopium didapati sebagai agen penunjuk biologi
yang berpotensi untuk logam kadmium, kuprum, besi, nikel, plumbum dan zink,
manakala penggunaan cengkerang memerlukan kajian yang lebih lanjut.
v
ACKNOWLEDGEMENTS
First, greatly thanks to Our Almighty and Prosperous God for giving me strength and
confidence to finish my study and face all over the difficulties
I most owe a favor to my supervisor, Dr Yap Chee Kong for his guidance and given
me a lot of valuable and incalculable comments, advice and ideas. He is certainly
part of my successful completion on my project. I certainly could not achieve until
this stage without his unfailing inputs and consistent guides. Thank you very much.
Hope God will bless you for the rest of your life.
I also would like to express my profound gratitude to my co-supervisor Dr Abdul
Rahim Ismail and Dr Nor Azwady Abdul Aziz for their helpful advice, commenting
and advising on my statistical analysis. They have co-supervised me to the best of
their abilities.
Special thanks are also given to Mr Cheng Wan Hee and Mr Franklin Berandah who
helped me a lot during the field trip and also in the laboratory. To all my friends of
the Department of Biology, thank you very much.
Not forgetting my lovely and understanding husband, Mr Azlan bin Ahmad and all
my sons, you all are the most source of inspiration and motivation. I could not make
it without you all. I love you all.
vi
This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment of the requirement for the degree of Master of Science. The members of the Supervisory Committee were as follows: Yap Chee Kong, PhD Faculty of Science Universiti Putra Malaysia (Chairman) Abdul Rahim Ismail, PhD Faculty of Science Universiti Putra Malaysia (Member) Nor Azwady Abdul Aziz, PhD Faculty of Science Universiti Putra Malaysia (Member)
AINI IDERIS, PhD Professor and Dean School of Graduate Studies Universiti Putra Malaysia
Date :
viii
Declaration I declare that the thesis is my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously, and is not concurrently submitted for any other degree at Universiti Putra Malaysia or at any other institutions.
NOORHAIDAH BT ARIFIN Date :
ix
TABLE OF CONTENTS Page ABSTRACT ii
ABSTRAK iv
ACKNOWLEDGEMENTS vi
APPROVAL viii
DECLARATION ix
LIST OF TABLES xiii
LIST OF FIGURES xvii
PLATE xviii
CHAPTER
1 INTRODUCTION
1
2 LITERATURE REVIEW 5 2.1. Biology of Telescopium telescopium (Linnaeus, 1758) 5 2.1.1.Taxonomy 5 2.1.2. Species description 5 2.1.3. Telescopium telescopium, Linnaeus, 1758 7 2.1.4. Distribution of T. telescopium 8 2.1.5. Ecology/ Way of Life 8 2.1.6. Human uses 9 2.2. Rational of Using Snail as a Biomonitor 10 2.3. Heavy Metal Contamination in The Intertidal Area 14 2.3.1.. Speciation of Heavy metals in the sediment 16 2.4. Environmental Chemistry of Heavy Metals and Their
Accumulation in Aquatic Organisms 17
2.4.1. Cadmium in Aquatic Snail 17 2.4.2. Copper in Aquatic Snail 18 2.4.3. Lead in Aquatic Snail 20 2.4.4. Nickel in Gastropods 22 2.4.5. Zinc in Gastropods 22 2.5. Past Studies of Snail as Biomonitors for Heavy Metals 23 2.6. The Role of Gastropod Shells 24 3 MATERIALS AND METHODS 26 3.1. Study Area 26 3.2. Sampling procedure 26 3.2.1. Telescopium telescopium 26 3.2.2. Sediment 26 3.3. Heavy metals analysis on Telescopium telescopium 29
x
3.3.1. Sample preparation for heavy metals analysis 29 3.3.2. Sample digestion 31 3.4. Heavy metals analysis on the sediment 32 3.4.1. Sample preparation 32 3.4.2. Sample digestion 32 3.4.3. Speciation of Cd, Cu, Fe, Ni, Pb and Zn in
sediment samples 32
3.5. Determination of heavy metals (Cd, Cu, Fe, Ni, Pb and Zn) for biological and sediment samples.
33
3.5.1. Quality Assurance/ Quality Control Activities 35 3.5.2. Cleaning procedures 32 3.5.3. Blank 35 3.5.4. Recovery test 35 3.6. Calculations 36 3.6.1. Allometric ratios 36 3.6.2. Bioconcentration factor 37 3.6.3. Coefficient of variation 38 3.6.4. Statistical Analytical Procedures 38 4 RESULTS 39 4.1. Heavy metals of intertidal sediments of Peninsular Malaysia 39 4.1.1. Geochemical fractions (EFLE, acid reducible,
oxidisable organic and resistant fraction of Cd, Cu, Fe, Ni, Pb and Zn
39
4.1.2. Percentage of non-resistant and resistant fraction of Cd, Cu, Fe, Ni, Pb and Zn
54
4.1.3. Total Concentration of Cd, Cu, Fe, Ni, Pb and Zn
54
4.2. Concentration of heavy metals in the different soft tissues of Telescopium telescopium from 17 different sampling locations
56
4.2.1. Correlation between heavy metals in different soft tissues and geochemical fraction of metals in the surface sediment.
62
4.2.2. Concentration of Cd, Cu, Fe, Ni, P and Zn in the shell of T.telescopium
64
4.2.3. Bioconcentration Factors (BCF) 77 5 DISCUSSION 81 5.1. Geochemical fraction of metals in the sediment 81 5.1.1. Cadmium (Cd) 81 5.1.2. Copper (Cu) 82 5.1.3. Iron (Fe) 83 5.1.4. Nickel (Ni) 84 5.1.5. Lead (Pb) 84 5.1.6. Zinc (Zn) 85 5.2. Overall distributions of the geochemical fractions of Cd, Cu,
Fe, Ni, Pb and Zn 86
5.3 Studies on correlation on geochemical fraction of Cd, Cu, Fe Ni, Pb and Zn
88
xi
5.4. Concentration of heavy metals in the different soft tissues and the shell of Telescopium telescopium
92
5.4.1. Concentration of heavy metals in the different soft tissues of Telescopium telescopium from 17 different sampling locations
92
5.4.2. Correlation between heavy metals in different soft tissues and geochemical fraction of metals in the surface sediment.
98
5.4.3. Concentration of Cd, Cu, Fe, Ni, P and Zn in the shell of T.telescopium
102
5.4.4. Correlation coefficients of metals in the shell and geochemical fraction in the surface sediment
105
5.4.5. Comparison between the accumulation of metals in the total shell and different soft tissues of T. telescopium
107
5.4.6. Bioconcentration Factor 109 6 CONCLUSION 111 REFERENCES 114 BIODATA OF STUDENT 134 LIST OF PUBLICATIONS 135
xii
LIST OF TABLES
Table Page 2.1 Heavy metals concentrations in field collections of selected
species of mollusk (Values shown are in mg/kg or ppm fresh weight [FW], dry weight [DW] or ash weight [AW].
25
3.1 Positions (Global positioning system), sampling dates, for the intertidal sediments collected along the west coast of Peninsular Malaysia
27
3.2 Mean of shell width, shell height and volume of the shell of T. telescopium analyzed and descriptions of sampling sites in the intertidal area of Peninsular Malaysia
28
3.3 Correlation coefficients and comparative results of analyses of the direct aqua-regia and sequential extraction procedures on the sediment samples (n = 51) based on the log10 transformed (µg/g dry weight of Cu, Zn, Pb, Ni and Cd
35
3.4 Comparison of heavy metal concentrations between measured and certified values of Certified Reference Materials (CRM) of DOLT-3 Dogfish liver (National Research Council Canada) and Soil-5 (International Atomic Energy Agency, Soil-5, Vienna, Austria).
35
4.1 The Cd percentage of EFLE, acid reducible, oxidisable organic and resistant fraction (mean concentration ± SE in µg/g dry weight) and total Cd concentration (min-max in μg/g dryweight) of intertidal sediment collected from 17 sampling locations
43
4.2 The Cu percentage of EFLE, acid reducible, oxidisable organic and resistant fraction (mean concentration ± SE in µg/g dry weight) and total Cu concentration (min-max in μg/g dryweight) of intertidal sediment collected from 17 sampling locations
44
4.3 The Fe percentage of EFLE, acid reducible, oxidisable organic and resistant fraction (mean concentration ± SE in µg/g dry weight) and total Fe concentration (min-max in μg/g dryweight) of intertidal sediment collected from 17 sampling locations
45
4.4 The Ni percentage of EFLE, acid reducible, oxidisable organic and resistant fraction (mean concentration ± SE in µg/g dry weight) and total Ni concentration (min-max in μg/g dryweight) of intertidal sediment collected from 17 sampling location
46
xiii
4.5 The Pb percentage of EFLE, acid reducible, oxidisable organic and resistant fraction (mean concentration ± SE in µg/g dry weight) and total Pb concentration (min-max in μg/g dryweight) of intertidal sediment collected from 17 sampling locations.
47
4.6 The Zn percentage of EFLE, acid reducible, oxidisable organic and resistant fraction (mean concentration ± SE in µg/g dry weight) and total Zn concentration (min-max in μg/g dryweight) of intertidal sediment collected from 17 sampling locations
48
4.7 Pearson’s correlation coefficients of dependent variables (Total aqua-regia (TOT), non-resistant (NR) and Resistant (R) of Cu, Zn, Pb, Ni and Cd) based on their log10(X + 1) transformed concentrations in µg/g in the intertidal sediments of Peninsular Malaysia
49
4.8 A comparison of total concentrations of Cu Zn, Pb, Ni and Cd in the sediments of Malaysian studies (µg/g dry weight)
55
4.9 Increasing order of Cd concentrations in the different soft tissues of T. telescopium (µg/g dryweight) from each sampling location
56
4.10 Increasing order of Cu concentrations in the different soft tissues of T. telescopium (µg/g dryweight) from each sampling location
57
4.11 Increasing order of Fe concentrations in the different soft tissues of T. telescopium (µg/g dryweight) from each sampling location
58
4.12 Increasing order of Ni concentrations in the different soft tissues of T. telescopium (µg/g dryweight) from each sampling location
59
4.13 Increasing order of Pb concentrations in the different soft tissues of T. telescopium (µg/g dryweight) from each sampling location
60
4.14 Increasing order of Zn concentrations in the different soft tissues of T. telescopium (µg/g dryweight) from each sampling location
61
4.15 Mean concentrations (µg/g dry weight ± SE) of Cd, Cu, Fe, Ni, Pb and Zn from 17 sampling locations in the different soft tissues of T. telescopium
62
xiv
4.16 Results of Pearson’s Correlation Analysis, relationships between Cd concentration in the different soft tissues, different parts of shell, total shell and geochemical fraction in the sediment
62
4.17 Results of Pearson’s Correlation Analysis, relationships between Cu concentration in the different soft tissues and geochemical fraction in the sediment
63
4.18 Results of Pearson’s Correlation Analysis, relationships between Fe concentration in the different soft tissues of T. telescopium and geochemical fraction in the sediment
63
4.19 Results of Pearson’s Correlation Analysis, relationships between Ni concentration in the different soft tissues of T. telescopium and geochemical fraction in the sediment
63
4.20 Results of Pearson’s Correlation Analysis, relationships between Pb concentration in the different soft tissues of T. telescopium and geochemical fraction in the sediment
64
4.21 Results of Pearson’s Correlation Analysis, relationships between Zn concentration in the different soft tissues of T. telescopium and geochemical fractions in the sediment
64
4.22 Comparisons of Cd, Cu, Fe, Ni, Pb and Zn (mean µg/g dry weight ± standard error) in the different parts of the shell of mudflat snail T. telescopium (n=17)
68
4.23 Overall mean concentration (mean µg/g dryweight ± standard error) of the average of metals in the three different parts of the shell
68
4.24 Range concentrations (µg/g dry weight) of Cd, Cu, Fe, Ni, Pb and Zn in the shell in some molluscs’ species in previous studies
68
4.25 Pearson’s Correlation Coefficients Analysis between Cd, Cu, Fe, Ni, Pb and Zn (log10 transformed) in the shell and geochemical fraction (EFLE, oxidisable organic, acid reducible, non-resistant, resistant and total concentrations) of the surface sediment
69
4.26 Comparison between coefficient of variation (%) of heavy metal concentrations in the different soft tissues and total shell of T. telescopium
69
4.27 The mean concentration of Cd, Cd, Fe, Ni, Pb and Zn in the total shells of Telescopium telescopium collected from 17 different sampling locations of intertidal area of
70
xv
Peninsular Malaysia (N=3)
4.28 Mean concentration (µg/g dry weight) of Cd, in the different soft tissues, total shell and ratio (shell/different soft issues) of T. telescopium collected from 17 sampling locations
71
4.29 Mean concentration (µg/g dry weight) of Cu, in the different soft tissues, total shell and ratio (shell/different soft issues) of T. telescopium collected from 17 sampling locations
72
4.30 Mean concentration (µg/g dry weight) of Fe, in the different soft tissues, total shell and ratio (shell/different soft issues) of T. telescopium collected from 17 sampling locations
73
4.31 Mean concentration (µg/g dry weight) of Ni, in the different soft tissues, total shell and ratio (shell/different soft issues) of T. telescopium collected from 17 sampling locations
74
4.32 Mean concentration (µg/g dry weight) of Pb, in the different soft tissues, total shell and ratio (shell/different soft issues) of T. telescopium collected from 17 sampling locations
75
4.33 Mean concentration (µg/g dry weight) of Zn in the different soft tissues, total shell and ratio (shell/different soft issues) of T. telescopium collected from 17 sampling locations
76
4.34 Macroconcentrators, microconcentrators and deconcentrators and BCF Values of the shell and different soft tissues of T. telescopium for Cd, Cu, Fe, Ni, Pb and Zn.
77
4.35 Pearson’s correlation coefficients of dependent variables (Total aqua-regia (TOT), non-resistant (NR) and Resistant (R) of Cu, Zn, Pb, Ni and Cd) based on their log10(X + 1) transformed concentrations in µg/g in the intertidal sediments of Peninsular Malaysia
78
xvi
LIST OF FIGURES
Figures Page 3.1 Map showing 17 sampling location (in numbers) of the
intertidal area of Peninsular Malaysia
29
3.2 Soft tissues of T. telescopium
30
3.3 Three parts of shell of T. telescopium
31
3.4 Sequential extraction procedure adopted from the modified method of Badri and Aston (1983)
34
4.1 Geochemical fraction of EFLE, Acid reducible, oxidisable organic and resistant (Cd, Cu and Fe) from 17 intertidal area of Peninsular Malaysia in percentage
52
4.2 Geochemical fraction of non-resistant and resistant (Ni, Pb and Zn) from 17 intertidal area of Peninsular Malaysia in percentage
49
4.3 Mean concentration of Cd and Cu (µg/g dryweight ± SE) of different parts of shell from 17 sampling locations (N=3)
65
4.4 Mean concentration of Fe and Ni (µg/g dry weight ± SE) of different parts of shell from 17 sampling locations (N=3)
66
4.5 Mean concentration of Pb and Zn (µg/g dry weight ± SE) of different parts of shell from 17 sampling locations (N=3)
67
xvii
xviii
Plate Page
Plate 1a and 1b The shell description of T. telescopium 6
Plate 2 The shell covered with barnacles 6
Plate 3 Multispiral operculum 6
Plate 4 Map of Indo Pacific Area 8
Plate 5 Foot of T. telescopium 5
Plate 6 Soft tissues of T. telescopium 30
CHAPTER 1
INTRODUCTION
It has become a common practice, in many monitoring programmes, to use aquatic
organisms as biomonitors because of temporal and spatial variability of the chemical
elements in dissolved and particulate phases of aqueous systems (Phillips and
Rainbow, 1993). Furthermore, all aquatic invertebrates accumulate trace metals in
their tissues, whether or not these metals are essential to metabolism (Rainbow,
2002). Some of the intertidal gastropods that inhabit rocky shores or sediments fulfill
most of the requirements of good biomonitors (Phillips and Rainbow, 1994);
however, it is important that they accumulate metals in proportion to metal
concentrations in the environment because only the bioavailability fraction of metals
in sediments can have an impact on metal toxicity and accumulation (Ying et al.,
1993) and also metal concentrations in sediments are high and relatively invariant
with time (Mastala et al., 1992). In addition to that, gastropods were employed as
biomonitors to determine the effect of marine pollution (Bu Olayan et al., 2001;
Ismail and Safahieh, 2004; Walsh et al., 1995; Ying et al., 1993). At the same time,
gastropod snail, Telescopium telescopium is used in this study because their direct
contact to the intertidal sediments. Moreover, intertidal sediments can accumulate
large amounts of organic matter and can act as an important reservoir of trace metals,
particularly in regions of intense shellfish culture activity where natural
sedimentation is enhanced by biodeposition (Sokolowski et al., 2005). On the other
hand, organisms often exhibit greater spatial variation in metal concentration
compared to sediments and are more reliable tool for identifying sources of
contamination (Thompson et al., 1983).
According to some authors (Marigomez and Ireland, 1989; Pip, 1992; Tessier et al.,
1994), gastropods also have the ability to concentrate the bioavailable heavy metals
from their ambient environment. On the other hand, the concentrations of heavy
metals in water may vary considerably depending on annual and seasonal
fluctuations (SCEP, 1971). Therefore, the measurement in the gastropods can
provide an integrated measurement of metal bioavailability of contaminant
(Rainbow, 1995). It has already been demonstrated (Langston and Zhou, 1987;
Marigomez and Ireland, 1989) that Littorina littorea is an excellent indicator species
for monitoring environmental with heavy metal contamination particularly cadmium.
It is known that both terrestrial and marine gastropod species accumulate heavy
metals; therefore they are suitable for detection of environmental heavy metal
pollution as biomonitors organisms (Coughtrey et al., 1977; Leatherland et al., 1973;
Navrot et al., 1970; Peden et al., 1973; Stenner and Nickless, 1975). T. telescopium
was chosen for this study not only because of their abundance but also because the
maesurement of metals levels in this organisms might give an idea of the level of
metal contamination which might be present in this intertidal area of Peninsular
Malaysia. T. telescopium is also commonly used as local food. The Telescope-shell
creeper is an abundant, gregarious, spiral mollusk that occurs on estuarine mudflats
(Nair and Saraswathy, 1971). According to Ismail and Safahieh (2004) T.
telescopium can be suggested as biomonitoring agent for assessing copper and zinc
in the river. Even though T. telescopium did not show positive correlation with the
levels of metals in surface sediments many other characters such as sessile and
sedentary which are representative of the study site, hardy and tolerating high
concentrations of pollutants and large ranges in salinity, abundant, easy to identify
2
and enough tissues for analysis contaminants, have made the T. telescopium a
potential biomonitoring agent (Ismail and Safahieh, 2004) since it fulfils many of the
selected criteria of an ideal biomonitor. However, future validation is required to test
its usefulness as a good biomonitor of heavy metal pollution. Uniquely, this study
used different soft parts of T. telescopium in order to gain some information on the
ecological distribution of T. telescopium along the west ccoast of Peninsular
Malaysia and redistribution of heavy metals in snail tissues. On the other hand,
accumulation of metals varies from organ to organ in invertebrates depending upon
the balance between uptake and elimination of metals (Soto et al., 1997). So far,
metal distribution in the different soft tissues of T. telescopium are not found in the
literature.
Since, metals accumulated in the total soft tissues could be affected by many biotic
and abiotic factors apart from pollution, therefore the selection of a particular
suitable tissue/organ therefore would increase the accuracy of the determination of
metal bioavailability and contamination (Yap et al., 2006). Furthermore, knowledge
on the distribution of metals in isolated organs/tissues of marine organisms is useful
in the identification of specific organs that may tend to accumulate higher levels of
heavy metals (Szefer and Szefer, 1990). This particular information has not been
reported yet in the literature for T. telescopium.
The west coast of Peninsular Malaysia was focused upon because there is no detailed
study of metals in this snail around this region. At the same time, comparisons of
contaminant levels in a biomonitoring agent collected from different geographical
3
sites will provide on the status of the pollutant contamination of coastal areas of
Peninsular Malaysia.
In a number of previous investigations on the metal pollution of coastal sites and
estuaries, various number of the indigenous biota have been engaged to evaluate the
bioavailability levels of metals in the marine environment (Cubadda et al., 2001).
The use of bivalve or gastropod molluscs looks attractive as these organisms
accumulate metals from all environmental compartments (i.e. from the aqueous
medium and through ingestion – from food and inorganic particulate material) and
heavily concentrate them (Phillips, 1978). In addition to that, sediment samples
cannot provide enough information on bioavailability, and then analysis of the snail
would give a better answer on the bioavailability of metal which is concerns.
The objectives of this study are:
a) To determine the heavy metal distribution in different parts of soft tissues and
shells of snail, T. telescopium
b) To study the relationship of metal concentrations between the snail and their
environmental surface sediment.
4
CHAPTER 2
LITERATURE REVIEW
2.1 Biology of Telescopium telescopium 2.1.1 Taxonomy Telescopium telescopium is classified into the Family Potamididae (Houbrick, 1991).
Below is the classification of T. telescopium.
Kingdom : Animalia
Phyllum : Mollusca (Linnaeus, 1758)
Class : Gastropoda (Courier, 1797)
Subclass : Prosobranchia
Order : Mesogastropoda
Superfamily : Cerithiacea
Family : Potamididae
Subfamily : Potamidinae
Genus : Telescopium (Montfort, 1810)
Species : Telescopium telescopium (Linnaeus,
1758)
2.1.2 Species description
The Telescope-shell Creeper has a very distinctive, large, telescope-shaped shell. It
grows up to 65-110 mm in length. Its shell is large and conical in shape, with a broad
and flat base. The shell sides are straight (Plate 1a and Plate 1b). The shell sculpture
consists of numerous flat-sided whorls and spiral grooves. The shell base has
concentric cords, and a deep channel around a short, twisted, columellar pillar. The
shell is beautifully patterned under the thick layer of mud that usually covers it. The
shell is also sometimes covered with barnacles and other encrusting animals (Plate 2)
and can remain out of water for long periods (7 days) (Tan and Chou, 2000).
5