Effects of northeast monsoon on trace metal distribution in the South China Sea off Peninsular Malaysia

Abstract

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.

Study of dissolved Copper(II) Speciation at Coastal Water of Peninsular Malaysia

“…Similar findings were recorded by Fortune and Mauraud 38 , where they found the highest DO values at high tide and lowest values at low tide. These findings were comparable to Adiana et al, 39 ; Suratman et al, 40 and the Malaysian Meteorological Data reports by Sang et al, 37 . The variations in DO indicated a temporal pattern since DO change with tides condition 38 for PP1 and PP2.…”

“…However, this study was done in a simulation laboratory, where the pH range was controlled. Previously, dissolved trace metals in seawater samples were done in Peninsular Malaysia by Adiana et al, 15 and Godon and Mohamed 16 , where their findings suggested comparable range of dissolved trace metals concentrations with effects from the Northeast monsoon in Terengganu coastal area. Unfortunately, no speciation data reported for both studies.The main concern about monsoon is that it could alter the physical-chemical parameters and affect the trace metal speciation.…”

“…In fact, there was a strong El Niño episode occurred in the area during the Northeast monsoon (NEM) 2015/16 period 59 during the PP1 sampling, but not in PP2. The El Niño caused the Northeast monsoon to be longer than 59 and in turn, affecting the water condition by releasing of some metals from the suspended particulate materials which led to re-suspension of surface sediment due to the strong current velocity 39 and influenced the metal remobilization in the water column 50 .…”

Sediment Sources and Dispersion on the Western Sunda Shelf, Malay Peninsula, Southern South China Sea

“…Recently, Shi et al (2015) [7] and [8] discussed clay mineral and elemental distributions, respectively, in the western Gulf of Thailand, which neighbours the study area to the northwest. Until now, limited work on sediment compositions, except for trace metal and rare earth elemental compositions, has been conducted in the WSSMP [9][10][11]. Multi-proxy studies from the land to the ocean are required to better understand the compositions and spatial distributions of sediments on the Sunda Shelf in the southern SCS.…”

Identification and profiling of microRNAs responsive to cadmium toxicity in hepatopancreas of the freshwater crab Sinopotamon henanense

“…Cadmium (Cd) is a serious environmental pollutant which occurs naturally, it could be released into environments by natural processes and human activities [1]. There exists certain amounts of Cd in different rivers and sea waters [2, 3]. In some developing countries, such as China, the Cd level is much higher in the severely polluted aquatic environments.…”