Date of Award

1-1-2000

Thesis Type

Masters

Document Type

Thesis

Divisions

Institute for Advanced Studies

Department

-

Institution

Universiti Malaya

Abstract

The coral reef ecosystem at Cape Rachado, is the only remaining fringing coral reef along the west coast of Peninsular Malaysia. The reef represents an interesting ecosystem with diverse flora and fauna and possesses a critical geographical location at the Straits of Malacca. The reef ecosystem especially the associated seaweed flora, was shown to be sensitive to development when increased silt levels led to loss of sensitive species of seaweeds. As yet, no study of heavy metal distribution and bioaccumulation in the coral reef area has been done. This study was aimed to investigate the distribution and bioaccumulation of iron, copper, zinc and lead in seawater, sediment, seaweeds (Sargassum baccularia, Padina tetraslomalica and Turbinaria conoides), soft coral (Sinularia sp.) and sea cucumber (Holothuria atra). The effect of environmemal parameters on metal bioaccumulation in the different trophic and taxonomic levels was investigated. Seawater, sediment, three brown seaweed species (Sargassum baccularia, Padina tetrastomalica and Turbinaria conoides), soft coral (Sinularia sp.) and sea cucumber Holothuria atra were collected from the intertidal area at selected sites (B&C) of the Cape Rachado coral reef ecosystem over a period of 14 month s. Metals (dissolved) in seawater were preconcentrated using Chelex 100 resin at pH of .S .10 ±0.01 prior the instrumental analysis. Surface sediments (>2 mm size) were used for total metal concentrate ion measurement. The di solution of sediment samples was achieved with a mixture of nitric, perchloric and hydrofluoric acids in covered Teflon vessels. Reflux digestion technique was applied to achieve the complete digestion of biological samples using a mixture of nitric ac id and hydrogen peroxide. The concentration of iron, copper, zinc and lead in the various components of the Cape Rachado coral reef ecosystem were measured using the ICP-AES. No significant difference was observed in most of the environmental parameters and metal concentrations between the two study Sites B and C. Metal concentrations in various components of Cape Rachado showed temporal changes over the study period as a response to the short-term environmental changes over time. The concentration of iron in seawater over the study period was 0.0 128 ± 0.0036 μg ml"1 for Site Band 0.0176 ± 0.0144 μg ml"1 for Site C. Copper concentration in seawater over the study period was 0.00 10 ± 0.0003 μg ml" 1 for Site Band 0.0010 ± 0.0005 μgmr1 for Site C. Zinc concentration in seawater was 0.0098 ± 0.0059 μg mr1 for Site Band 0.0104 ± 0.0049 μg ml"1 for Site C. Lead concentration in seawater was 0.0048 ± 0.0025 μ g mr1 for Site Band 0.0047 ± 0.0023 μg m1"1 for Site C. The concentration of iron in sediment was 4560.0286 ± 1799.7433 μg g"1dry wt for Site Band 2137.9571 ± 401.0338 μg g·1dry wt for Site C. Copper concentration in sediment was 1.3991 ± 0.661 I μg g' 1dry wt for Site B and 0.2451 ± 0.0881 μg g'1dry wt for Site C. Zinc concentrat ion in sediment was 11.7215 ± 6.62 1 μg g" 1dry wt for Site B and 4.2484 ± 4.3578 μg g" 1dry wt for Site C. Lead concentrations in sediment were 4.8321 ±1.9908 μg g'1dry wt and 1.3347 ± 0.9287 μg g''dry wt, for Sites B and C respectively. The concentration of iron in Sargassum haccularia was 214 .07 14 ± 68. 7573 ~tg g·1 dry wt for Si te B and 207.257 1 ±84.3032 μg g'1dry wt for Site C. Copper concentration in S. haem/aria was 2.3228 ± 0.3845 μg g"1dry wt for Si te 8 and 2.4388 ± 0.4363 μg g·1dry wt for Site C. Zinc concentration in S. bacc:11/aria was 31 .3530 ± 10.3 130 μg g"1dry wt for Site B and 34.991 7 ± 17.4 516 μg g'1dry wt for Site C. Lead concentration in S. baccularia was 12.2906 ± 5. 11 82 ~tg g" 1dry wt for Site B and 13.48831 ± 4.9554 μg g" 1dry wt for Site C. The iron concentration in Padina letrastomatica was 1241.0000 ± 609.7023 μg g" 1dry wt for Site B and 1452.9286 ± 549.6211 μg g" 1dry wt for Site C. Copper concentration in P. letrastomatica was 4.2794 ± 0.6184 μg g·1dry wt for Site B and 4.6688 ± 0.338 I μg g" 1dry wt for Site C. Zinc concentration in P. tetrastomatica was 51.5467 ± 14.0208 μg g·'dry wt for Site B and 48.1943 ± 24. I 921 μg g·'dry wt for Site C. Lead concentration in P. tetrastomatica was 20.4077 ± 7.9308 μg g"1dry wt for Site Band 20.4003 ± 4.8775 μg g'1dry wt for Site C. The concentration of iron in Turbinaria conoides was 78.5914 ± 30.7812 μg g· 1 dry wt for Site B and 80. 1329 ± 45.2190 μg g·'dry wt for Site C. Copper concentration in T. conoides was 1.7714 ± 0.8155 μg g'1dry wt for Site B and 1.7310 ± 0.3146 μg g· 1 dry wt for Site C. Zinc concentration in T. conoides was 17.4129 ± 5.1629 μg g" 1dry wt for Site Band 19.1961 ± ll.6552μg g·'dry wt for Site C. Lead concentration in T. conoides was 11 .4236 ± 4.4433 μg g" 1dry wt for Site B and 11 .463 1 ± 5.4325 μg g'1dry wt for Site C. The concentration of iron in Sirmlaria sp.was 22.2886 ± 6.2627 μg g"1dry wt for Site B and 28.5857 ± 11. 1942 μg g" 1dry wt for Site C. Copper concentration in Sinularia sp. was 7.7979 ± 0.5686 μg g" 1dry wt for Site 8 and 8. 1750 ± 0.8876 μg g"1dry wt for Site C. Zinc concentration in Simtlaria sp. was 23 .3129 ± 3.9785 ~tg g" 1dry wt for Site 8 and 25.8257 ± 9.1998 for Site C. Lead concentration in Si1111/aria sp. was 25.4300 ± 1.0982 μg g.idry wt for Site Band 25 .6629 ± 3.7704 ~lg g·1dry wt fo r Site C. The concentration of iron in Holoth11ria atra was 28.5433 ± 7.4755 ~lg g' 1dry wt for Site C. Copper concentration in H. atra was 2.7702 ± 0.8099 μg g" 1dry wt for Site C. Zinc concentration in H. alra was 37.2385 ± 29.0852 μg g· 1dry wt for Site C. Lead concentration in H. atra was 21.4335 ± 11.7456 μg g" 1dry wt for Site C. Metal concentrations in seawater and sediment were within the range of metal concentrations in areas with no history of metal contamination, suggesting that Cape Rachado is a relatively unpolluted area as far as Fe, Cu, Zn and Pb are concerned. All the four metals studied were ranked similarly in their distribution within the three seaweed species and proportional to seaweed thallus surface area as follows: P. telrastomatica > S. baccularia > T. conoides, indicating the role of seaweed surface area in metal accumulation. Bioconcentration factors for iron for all components ranged from 1622 to 89752. Bioconcentration factors for copper for all components ranged from 1751 to 7987. Bioconcentration factors for zinc for all components ranged from 1810 to 4947. Bioconcentration factors for lead for all components ranged from 2409 to 4560. Bioconcentration factors of the four metals in the three seaweed species were ranked similarly to the metal concentration ranks in the seaweed species and metal concentration ranking in seawater and sediment (Fe > Zn >Pb > Cu). The higher the ambient metal concentration the higher is the metal accumulation and bioconcentration factor in seaweeds. The bioconcentration factors obtained here are low reflecting the low ambient metal concentrations of the study area rather than the metal-species accumulation ability. For soft coral and sea cucumber, different ranking for the bioconcentration factors of the metals was obtained, with Cu > Pb > Zn > Fe in soft coral and Pb > Zn > Cu > Fe for sea cucumber. This suggests the presence of certain regulation processes in metal accumulation. Soft coral showed a particular affinity for Cu while sea cucumber showed higher affinity for Pb. Metal bioaccumulation was shown to be more affected by the past ambient environmental parameters including metal concentration rather than the concurrent or present parameters. The effect of environmental parameters on metal bioaccumulation is biotic species-metal specific. Synergistic interaction with the binding sites and the increase in metal binding affinity were also observed. Heavy metal contamination can be indicated by metal content in seaweeds. Seaweeds indicate concurrent and time-integrated responses (bioaccumulation) of metal concentration in the environment. The findings suggest the potential of using the two seaweed species: Sargas.mm baccularia and Padina letrastomatica as biomonitors for the heavy metals concerned

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Additional Information

Dissertation (M.A) -- Institute for Advanced Studies, Universiti Malaya, 2000

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