The temporal variation of organic carbon during the pre-monsoon and post-monsoon seasons in Pahang river estuary, Pahang, Malaysia

The percentage of organic carbon contents of 62 bottom sediments in Pahang river- estuary were analyzed using the wet dichromate oxidation method. The sediments particle sizes at the same stations were also measured using the dry sieving and laser diffraction methods. In this study, the concentrations of organic carbon are relatively higher during pre-monsoon season and become much lower during the post-monsoon season. The average concentrations of organic carbon for both premonsoon and post-monsoon seasons are 1.61% and 0.88% respectively. This finding indicates that the annual seasonal changes that occur in Pahang river- estuary might probably have the important role in regulating the concentrations of organic carbon

Spatial and temporal bottom sediment characteristics of Pahang river estuary, Pahang, Malaysia

Bottom sediment samples from Pahang river- estuary were analyzed for the sediment characteristics in order to understand better sedimentation processes in the estuary. The mean, sorting,skewness and kurtosis values of each sample were determined by the Moment’s method. This study showed that the sediment characteristics were not significantly differ (p > 0.05) with the seasonal changes, except for sorting (p < 0.05). The sediment mean size becomes finer towards the estuarine area with the range of very coarse sand to fine silt. This indicates that the characteristics of deposited sediments at each station are much dependant upon the combination of physical forces such as freshwater run-off, tidal currents and waves

Determination of some heavy metal concentrations in razor clam (Solen brevis) from Tanjung Lumpur Coastal waters, Pahang, Malaysia

An effort to analyze selected heavy metal accumulation by the razor clam (Solen brevis) from Tanjung Lumpur was conducted on January to April 2010. A total of fifty individuals of Razor clam Solen brevis were sampled and metals such as Iron (Fe), Zinc (Zn), Copper (Cu), Manganase (Mn), Lead (Pb) and Cadmium (Cd) Concentrations were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Among the metals Fe occurred in elevated concentration in the soft tissue of razor clam followed by Zn. Cd was found to be in least concentration in the sample. Mean concentration of Fe, Zn, Mn, Cu, Cd and Pb in the soft tissue were 415.2±56.52, 87.74±11.85, 18.71±2.10, 8.64±1.75, 0.67±0.29 and 1.61±0.45 μg g-1 dw, respectively indicating that the bioaccumulation of essential metals in the soft tissue was greater than the non essential heavy metals. Metal accumulation in the soft tissue of razor clam followed Fe > Zn > Mn > Cu > Pb > Cd order in present study. The observed concentration of acute toxicity of metals in Solen brevis (Family: Solenidae) from Tanjung Lumpur Coastal waters was lower than the permissible limit recommended by National and international standards proved that this species could be utilized for human consumption

Physico-chemical characteristics and dissolved trace metals in the Pahang River Estuary, Malaysia

Water samples from Pahang River estuary were analysed for Cu, Pb, Zn and Cd at 63 stations during the monson and non-monsoon seasons. Concentrations ranges of dissolved metals in the Chukai estuary were relatively low compared with other estuaries and are not significantly influenced by seasonal changes. Concentration of Cu in both monsoons ranged from 0.57 – 1.01 μgl-1, Pb ranged 0.88 – 1.34 μgl-1, Zn ranged from 9.96 – 12.8 μgl-1 and Cd ranged from 0.09 – 0.18 μgl-1. On the whole, trace metal concentrations in the dissolved metals behave conservatively and are mostly controlled by the natural processes. The estuary remained marine dominated during non-monson seasons, whereas freshwater dominance prevailed during monsoon seasons. The temperatures of surface and bottom waters are almost uniform or even identical at times while pH has an inverse relationship with salinity

Accumulation and distribution of lead and copper in Avicennia marina and Rhizophora apiculata from Balok mangrove forest, Pahang, Malaysia

Bioaccumulation of lead and Copper in Avicennia marina and Rhizophora apiculata was studied. Samples of leaves, barks and roots were collected from Balok mangrove forest, Pahang. Pb and Cu accumulation was higher in Avicennia marina root tissue compared to bark and leaf but lower than surrounding sediment level. The average concentration of Pb in A. marina leaf, bark, root and sediment was observed to be 5.39 ppm, 3.63 ppm, 18.21 ppm and 23.13 ppm, and average Cu concentration was 4.13 ppm, 4.27 ppm, 4.81 ppm and 12.33 ppm, respectively. R. apiculata also showed higher concentration of Pb and Cu in root tissue compared to bark and leaf tissues but lower than surrounding sediment. The average concentration of Pb in R. apiculata leaf, bark, root and sediment was observed to be 4.30 ppm, 2.97 ppm, 22.45 ppm and 31.23 ppm, respectively. The average Cu concentration was 2.93 ppm, 4.71 ppm, 4.81 ppm and 15.52 ppm, respectively. Results of concentration factors (CF) showed that the accumulation of Pb and Cu was higher in A. marina than in R. apiculata

Food partitioning among fishes in Pahang River-estuary, Malaysia

A study was conducted on the food resource partitioning among fish species in Pahang River-estuary from 2010-2013 during pre-monsoon and post-monsoon period. The area was divided in three strata (upstream, downstream and middle zone), based on environmental features. Stomach contents of all species present were analyzed. From 138 of total stomach analyzed, 24 of them were empty and 114 were with food. From the analysis of prey in the stomachs, various kinds of food items consumed by the different size of fishes included phytoplankton, zooplankton, unidentified materials, fish, fish parts, shrimp, shrimp parts, crab, crab parts, plant parts, mollusk and detritus. Detritus consisted of all types of biogenic materials in various stages of microbial decomposition. Different fishes consume different types of food and feeding habit of fishes varies from season to season. From the percentage of number and occurrence of food resources, zooplankton are important in their own right as a major component of fish diets and are especially important to small and young individuals, even for the detrivore. Nevertheless, it represents an important trophic resource for fish food web of Pahang River-estuary

Mineralogical study of Kemaman coastal sediments off Terengganu, Malaysia

The study was conducted to determine the mineral contents and the textural classes of the Kemaman coastal sediments. The samples were collected using Smith Mc Intyre grab on board KL PAUS ship owned by the Fishery Department, Malaysia. The sediments were collected from 12 stations and were analysed for mineral contents and textural classes of sediments. The result of X-ray Diffraction (XRD) analysis showed that quartz component was the dominant mineral in most of the stations, while other minerals, such as feldspar, illite, kaolinite, montmorillonite, chlorite and vermiculite, were found to be in trace amounts. For the textural class, two textural classes of the sediments were identified as sand and sandy loam. Sand texture was mostly found in the nearshore area while sandy loam was found in the offshore area

DNA barcoding of Arius species (Siluriformes: Ariidae) found in Peninsular Malaysia waters, using mitochondrial Cytochrome oxidase subunit I gene.

Ariid catfishes are widely distributed in tropical and temperate continental shelves all over the world, mainly inhabiting inshore waters and estuarine regions, or in some cases confined to freshwaters. Ariid catfishes, commonly known as the sea catfishes, belong to family Ariidae (order: Siluriformes). Ariids are one of the problematic groups for the identification using their morphological features. Furthermore, keys available for the identification are unclear and confusing. Thus, this study was done in order to determine the species in one of the problematic ariid’s genera, Arius, which found in Peninsular Malaysian waters using molecular approach. There were four species of Arius found in this study, Arius leptonotacanthus, Arius maculatus, Arius oetik and Arius spp. All the species were sequenced for 499-bp region of the mitochondrial cytochrome oxidase subunit I (COI) gene. Five sequences per species were amplified and a neighbour-joining phylogenetic tree using Tamura-3 parameter (T92+G) model was constructed. The results shows that Arius leptonotacanthus formed the base for other Arius species (A.maculatus, A.oetik and Arius spp.) supported by a moderate bootstrap value of 50%. Whereas, Arius maculatus formed a sister taxa to Arius spp. with 91% of bootstrap value. Overall, the phylogenetic tree shows that all the Arius species were grouped in separate clades according to the respective species with the support of high bootstrap values. Thus, this study revealed that this problematic Arius species can be clearly differentiated using the molecular marker

Diversity of juvenile decapods in Penor river estuaries in Pahang

Studies of decapods diversity are important to understand the species composition in a particular habitat. However, this information is very minute in Pahang estuaries area. This study was conducted to identify diversity and abundance of juvenile decapods in Penor River of Pahang. Specimens were collected from three different locations of the rivers using a traditional fish trap. The samples collected and identified into genus based on their morphological characteristics before analysed by using the Shannon-Wiener Diversity Index and Simpson’s Diversity Indices. The highest diversity of decapods found at Penor River at middle and inner rivermouth in the middle of the year respectively, while the lowest diversity of decapods recorded at this river is outer rivermouth in May. The result gives an impact on which months the decapods inhabit river estuaries