Total concentrations of Zn in the sediments of the offshore and intertidal areas of the west coast of Peninsular Malaysia were recently reported in the literaturs. However, total concentrations of metals in the sedime...Total concentrations of Zn in the sediments of the offshore and intertidal areas of the west coast of Peninsular Malaysia were recently reported in the literaturs. However, total concentrations of metals in the sediment samples do not reflect the portion or carrier phase which is attributable to anthropogenic activities and those of natural origins. In this work, geochemical fraction of Zn in the sediments of the same areas was studied and the potential use of CV as an indicator of Zn pollution was determined. The geochemical study by using sequential extraction technique revealed that nonresistant fraction of the offshore and intertidal sediments (summation of ‘easily or freely leachable and exhangeable (EFLE)’, ‘acid-reducible’ and ‘oxidisable-organic’) covered about 30% and 48% of total zinc concentrations, respectively, in the sediments while most of the total zinc concentrations (offshore: 70%; intertidal: 52%) found in the sediments could be mostly due to natural origins (nonresistant fraction). Thus, the Zn levels in the Straits of Malacca should not pose a risk to the living organisms. Based on Spearman’s correlation coefficients, the source of Zn contamination in the Straits of Malacca was mainly contributed by the intertidal coastal area rather than offshore area. The present study also indicated the coefficient of variation can be used as a potential indicator of total summation of geochemical Zn concentrations in the coastal sediment but of different geochemical of Zn needs further validation.展开更多
The concentrations of Cd,Cu,Pb,Zn,Ni and Fe were determined in the surface sediment and marine gastropod Nerita lineata collected in May 2005 from the intertidal zone of Dumai,Sumatera,Indonesia and Johor,Peninsular M...The concentrations of Cd,Cu,Pb,Zn,Ni and Fe were determined in the surface sediment and marine gastropod Nerita lineata collected in May 2005 from the intertidal zone of Dumai,Sumatera,Indonesia and Johor,Peninsular Malaysia.The results showed that metal concentrations in sediment and the soft tissue of N.lineata varied at different sampling stations.Mean heavy metal concentrations were 0.92 μg/g(Cd);6.40 μg/g(Cu);32.77 μg/g(Pb);54.41 μg/g(Zn);11.56 μg/g(Ni) and 2.97%(Fe) in sediment from Dumai and 1.15 μg/g(Cd);26.73 μg/g(Cu);53.45 μg/g(Pb);130.77 μg/g(Zn);20.79 μg/g(Ni) and 2.72%(Fe) in sediment from Johor.Concentrations of metals in gastropod N.lineata were 0.71 μg/g(Cd);15.16 μg/g(Cu);9.35 μg/g(Pb);94.69 μg/g(Zn);5.08 μg/g(Ni) and 397.97 μg/g(Fe) in samples from Dumai and 1.24 μg/g(Cd);18.02 μg/g(Cu);19.75 μg/g(Pb);95.09 μg/g(Zn);5.57 μg/g(Ni) and 473.56 μg/g(Fe) in samples from Johor.Although they were not statistically significant(p>0.05),heavy metal concentrations in N.lineata were correlated with the concentrations of respective metals in sediment in both samples from Dumai and Johor.In general,samples of sediment and gastropod from Johor accumulated significantly higher heavy metal concentrations when compared to samples from Dumai(p<0.05).Higher concentrations of metals were recorded in samples collected from the stations close to the industrial and anthropogenic activities in both Dumai and Johor areas.However,most of the concentrations were still comparable to the previous reported studies from other geographical areas.展开更多
The Strait of Malacca （SoM）, the world＇s busiest sea-route, is increasingly polluted as the rapid develop- ment of world trades, affecting phytoplankton primary productivity therein. The variations of surface phy- ...The Strait of Malacca （SoM）, the world＇s busiest sea-route, is increasingly polluted as the rapid develop- ment of world trades, affecting phytoplankton primary productivity therein. The variations of surface phy- toplankton biomass, size-structure and carbon fixation were investigated across the SoM during the spring period （May 4 to 9, 2011）. Chlorophyll a concentration increased from 0.12 ptg/L at the northwest entrance of the SoM to a maximal 0.63 #g/L at narrowest section, and decreased to 0.10/.tg/L at the southeast entrance. Photosynthetic carbon fixation by phytoplankton coincided well with Chl a biomass, and increased from 10.8 to 22.3 pg C/（L.d）, then decreased to 9.21/zg C/（L.d）; while the carbon fixation rate showed an inverse pattern to the changes of Chl a, and decreased from 87.1 to 35.5 #g C/（#g Chl a.d） and increased thereafter to 95.3 btg C/（/2g Chl a.d）. Picophytoplankton cells （〈3/2m） contributed to more than 60% and 50% of the total Chl a and carbon fixation at both the entry waters; while the contributions of pico-cells decreased sharply to the minimum of 18.3% and 27.5% at the narrowest part of the SoM. In particular, our results showed that the silicate concentration positively regulated Chl a biomass and carbon fixation, reflecting that the higher silicate favoured the growth of phytoplankton and thus led to higher primary production in this strait.展开更多
文摘Total concentrations of Zn in the sediments of the offshore and intertidal areas of the west coast of Peninsular Malaysia were recently reported in the literaturs. However, total concentrations of metals in the sediment samples do not reflect the portion or carrier phase which is attributable to anthropogenic activities and those of natural origins. In this work, geochemical fraction of Zn in the sediments of the same areas was studied and the potential use of CV as an indicator of Zn pollution was determined. The geochemical study by using sequential extraction technique revealed that nonresistant fraction of the offshore and intertidal sediments (summation of ‘easily or freely leachable and exhangeable (EFLE)’, ‘acid-reducible’ and ‘oxidisable-organic’) covered about 30% and 48% of total zinc concentrations, respectively, in the sediments while most of the total zinc concentrations (offshore: 70%; intertidal: 52%) found in the sediments could be mostly due to natural origins (nonresistant fraction). Thus, the Zn levels in the Straits of Malacca should not pose a risk to the living organisms. Based on Spearman’s correlation coefficients, the source of Zn contamination in the Straits of Malacca was mainly contributed by the intertidal coastal area rather than offshore area. The present study also indicated the coefficient of variation can be used as a potential indicator of total summation of geochemical Zn concentrations in the coastal sediment but of different geochemical of Zn needs further validation.
文摘The concentrations of Cd,Cu,Pb,Zn,Ni and Fe were determined in the surface sediment and marine gastropod Nerita lineata collected in May 2005 from the intertidal zone of Dumai,Sumatera,Indonesia and Johor,Peninsular Malaysia.The results showed that metal concentrations in sediment and the soft tissue of N.lineata varied at different sampling stations.Mean heavy metal concentrations were 0.92 μg/g(Cd);6.40 μg/g(Cu);32.77 μg/g(Pb);54.41 μg/g(Zn);11.56 μg/g(Ni) and 2.97%(Fe) in sediment from Dumai and 1.15 μg/g(Cd);26.73 μg/g(Cu);53.45 μg/g(Pb);130.77 μg/g(Zn);20.79 μg/g(Ni) and 2.72%(Fe) in sediment from Johor.Concentrations of metals in gastropod N.lineata were 0.71 μg/g(Cd);15.16 μg/g(Cu);9.35 μg/g(Pb);94.69 μg/g(Zn);5.08 μg/g(Ni) and 397.97 μg/g(Fe) in samples from Dumai and 1.24 μg/g(Cd);18.02 μg/g(Cu);19.75 μg/g(Pb);95.09 μg/g(Zn);5.57 μg/g(Ni) and 473.56 μg/g(Fe) in samples from Johor.Although they were not statistically significant(p>0.05),heavy metal concentrations in N.lineata were correlated with the concentrations of respective metals in sediment in both samples from Dumai and Johor.In general,samples of sediment and gastropod from Johor accumulated significantly higher heavy metal concentrations when compared to samples from Dumai(p<0.05).Higher concentrations of metals were recorded in samples collected from the stations close to the industrial and anthropogenic activities in both Dumai and Johor areas.However,most of the concentrations were still comparable to the previous reported studies from other geographical areas.
基金The National Natural Science Foundation of China under contract Nos 41130855,41206132 and 41276162the Natural Science Foundation of Guangdong under contract No.S2011040000151+2 种基金CAS Knowledge Innovation Program under contract No.SQ201115National Project of Sciences and Technology under contract No.2008FY110100CAS Strategic Pilot Science and Technology under contract No.XDA05030403
文摘The Strait of Malacca （SoM）, the world＇s busiest sea-route, is increasingly polluted as the rapid develop- ment of world trades, affecting phytoplankton primary productivity therein. The variations of surface phy- toplankton biomass, size-structure and carbon fixation were investigated across the SoM during the spring period （May 4 to 9, 2011）. Chlorophyll a concentration increased from 0.12 ptg/L at the northwest entrance of the SoM to a maximal 0.63 #g/L at narrowest section, and decreased to 0.10/.tg/L at the southeast entrance. Photosynthetic carbon fixation by phytoplankton coincided well with Chl a biomass, and increased from 10.8 to 22.3 pg C/（L.d）, then decreased to 9.21/zg C/（L.d）; while the carbon fixation rate showed an inverse pattern to the changes of Chl a, and decreased from 87.1 to 35.5 #g C/（#g Chl a.d） and increased thereafter to 95.3 btg C/（/2g Chl a.d）. Picophytoplankton cells （〈3/2m） contributed to more than 60% and 50% of the total Chl a and carbon fixation at both the entry waters; while the contributions of pico-cells decreased sharply to the minimum of 18.3% and 27.5% at the narrowest part of the SoM. In particular, our results showed that the silicate concentration positively regulated Chl a biomass and carbon fixation, reflecting that the higher silicate favoured the growth of phytoplankton and thus led to higher primary production in this strait.
