Concentrations of trace metals in the South China Sea (SCS) were determined off the coast of Terengganu during the months of May and November 2007. The concentrations of dissolved and particulate metals were in the range of 0.019-0.194 μg/L and 50-365 μg/g, respectively, for cadmium (Cd), 0.05-0.45 μg/L and 38-3,570 μg/g for chromium (Cr), 0.05-3.54 μg/L and 21-1,947 μg/g for manganese (Mn), and 0.03-0.49 μg/L and 2-56,982 μg/g for lead (Pb). The order of mean log K D found was Cd > Cr > Pb > Mn. The study suggests that the primary sources of these metals are discharges from the rivers which drain into the SCS, in particular the Dungun River, which flows in close proximity to agricultural areas and petrochemical industries. During the northeast monsoon, levels of particulate metals in the bottom water samples near the shore were found to be much higher than during the dry season, the probable result of re-suspension of the metals from the bottom sediments.
The present study aims to define the possible sources that contribute to the level of Pb into the Brunei Bay, Borneo. The cluster analysis has classified the bay into the northern part with heavy and agriculture-related industries; the southern area with a moderate rural human settlement as well as the southwestern area with a more pristine environment and a low level of human settlement. The score plot of spatial discriminant analysis verified a significant influence of the river system toward the estuary, whereas the temporal discriminant analysis has discriminated the seasonal changes. In comparison to elsewhere, the stable Pb isotopic ratios in Brunei Bay showed a fingerprint similar to coal-related sources and of aerosol input. Briefly, even though Pb in the Brunei Bay ecosystem proved to be at a low level, the stable Pb isotopic ratios showed that human and industrial activities are slowly contributing Pb into the bay ecosystem.
Metals are natural elements existed in the environment. However, due to the rapid development of urbanisation and economic, high content of anthropogenic metals are being perceived in polluting the environment. The oceans are known to be a part of the sinking basin for anthropogenic metals ends. Dataset provided is purposely to give an overview of dissolved metals spatial distribution in the South China Sea off the east Peninsular of Malaysia during the pre-, post- and Northeast (NE) Monsoon period. Seawater samples were collected in a grid of 18 stations at 3 different water depth. Dissolved metals were pre-concentrated on-board ship using Chelex-100 resin and analysed using Inductively Coupled Plasma Mass Spectrophotometry (ICPMS). The dataset shows the effect of NE Monsoon on dissolved metals spatial distribution mainly at the area closer to the land. Therefore, this dataset could reveal the past information on anthropogenic metals intrusion in the South China Sea, since Terengganu state was recently pointed to be one of the Malaysian waterfront city. Additionally, this dataset also could help in studying the cycle of metals in the southern South China Sea waters.
Brunei Bay is a unique ecosystem which offers a vast biodiversity. This study was carried out to define the source of metals in the surface sediment of Brunei Bay to ensure the bay's health. The secondary data were analysed using chemometrics analysis to verify the possible factors that influence metals distribution in Brunei Bay sediment. Samples were collected several times during 2013 to 2014 using Ponar grab at 16 stations within the bay. Samples were then dried, pre-treated, digested and analysed using Inductively Coupled Plasma Mass Spectrometry (ICPMS) in the laboratory. Overall, the mean concentration of metal, sediment pH and clay fraction were significantly changed during different sampling periods, as the changes were presumed affected by seasonal changes. The Pearson correlation has pointed that metals were dominantly derived by natural input; however, the total organic carbon was proven to be derived by anthropogenic sources. Moreover, the principal component analysis has verified that the distribution of metals in the bay's sediment was dominantly influenced by natural processes. However, the utilization and manipulation of marine resources are slightly affecting the bay's ecosystem which may deteriorate the ecosystem health soon.
Pulau Kapas is tropical island which dominantly depends on land-supplied and groundwater for freshwater sources. The groundwater quality was monitored monthly, to identify the possible factors effecting the groundwater quality throughout May to October 2022. Physico-chemical parameters were in-situ measured and groundwater were collected for nutrients analysis in the laboratory. The concentration of ammonium, phosphate, nitrite, and nitrate were in the range of 0.07-1.08 mg/L, 0.00-0.06 mg/L, BDL-18 × 10-4 mg/L and 0.01-0.19 mg/L, respectively. The cluster and principal component analysis unveiled the seawater intrusion for freshwater needs was the dominant factor affecting the groundwater. Followed by the dissolution of soil particles surrounds the groundwater table, and the surface run-off by rainfall. In conclusion, the groundwater was affected by geogenic factors as it was not extensively extracted due to movement control order of Covid-19 event. This has provided significant insight for a better management plan in sustaining the groundwater of Pulau Kapas.
Heavy metal pollution in aquatic ecosystems can lead to harmful accumulation in organisms like stingrays, posing potential health risks to humans. To assess this risk, 45 stingrays were sampled from Johor Waters (Pontian, Muar, and Batu Pahat) and analyzed for heavy metal content using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The average concentrations of Cu, Zn, As, Cd, Pb, and Hg in the fillets were 0.982±0.637, 31.3±5.93, 93.57±24.5, 0.039±0.047, 0.158±0.036, and 0.592±0.424 μg/g dw, respectively. Arsenic (As) was found at the highest concentration. The study indicates that fish size does not directly influence heavy metal accumulation and that metal levels vary by location. Calculated consumption limits for different metals are crucial for human safety. This data is valuable for evaluating contamination risks and guiding future research to protect marine ecosystems in Johor Waters.