Browsing by Author "Khawar Sultan"

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    The Changes of Sedimentological Characteristics in Kemaman Estuary, Terengganu, Malaysia
    (Middle-East Journal of Scientific Research, 2016) Nik Hani Shahira Nik Shirajuddin; Hasrizal Shaari; Khawar Sultan; Nur Sakinah Abdul Razak; Fathullah Abdullah; Rosnan Yaakob
    This study reports sedimentological properties of core sediments (length ~200 cm) from Kemaman Estuary, Malaysia and focuses on understanding depositional environment in a tropical estuarine setting by investigating grain size and morphological characteristic of the core sediment. The mean sediment size ranged from 4.97 to 7.22 Ø and is texturally classified as coarse silt to very fine silt (~55.84%). The cyclic trend in sediment grain size indicated a complex mix of marine and land based (riverine) processes under the influence of transportative and current action. The estuarine sediments are found to be poorly sorted and skewed pointing to the normal size distribution is influenced by finer grain sizes. Morphology of grain shape showed a dominant angular to sub-angular shape. This kind of grain angularity is mostly likely due to the shorter transport period (e.g. time and distance) and lack of maturity (i.e. sphericity and roundness). The dominance of silt and clay size fractions in the estuary can be attributed to depositional process under the influence of currents. Generally, the deposited sediments in the core sample seem to be dominantly from the terrestrial. This worked is important to report changes of depositional environment of the recent past in a tropical estuarine environment.
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    Status of heavy metals concentrations in oysters (Crassostrea sp.) from Setiu Wetlands, Terengganu, Malaysia
    (Sains Malaysiana, 2016) Hasrizal Bin Shaari; Bryan Raven; Khawar Sultan; Yuzwan Mohammad; Kamaruzzaman Yunus
    This study aimed at documenting the potentially toxic metal levels in oysters from the aquaculture area of the Peninsular Malaysia east coast. Concentrations of essential (Zn and Cu) and non-essential (Pb and Cd) heavy metals were analyzed in total soft tissue, different sex, selected organs and shells of Crassostrea sp. from cultured and wild area of Setiu Wetlands. The heavy metal contents among the sampling sites are statistically not significant (p>0.05) indicating no systematic and site-specific trend between cultured and wild environment. Zinc was the highest metal detected in total soft tissue, sex and shells with the mean concentration of 28.55±6.76, 30.55±3.89 and 8.22±2.98 μg/g, respectively. The analysed metals were highly accumulated in gills than other organs with the mean value of 74.11±13.03 μg/g of Zn, 4.82±0.82 μg/g of Cu, 0.61±0.06 μg/g of Pb and 0.45±0.1 μg/g of Cd. The varying metals content in the different soft tissues might be due to the different affinity of metals that bind with metallothioneins. The metal levels measured in oysters did not exceed the maximum permissible limits for Zn, Cu, Pb and Cd. The measured metal levels may represent baseline values reflecting background conditions that contain a certain degree of human impact