Concentration and Biomagnification of Heavy Metals in Biota of the Coastal Marine Areas of Tanzania  

作　　者：Sharifa Omar Bungala, John Ferdinand Machiwa and Daniel Abel Shilla 

机构地区：Department of Aquatic Sciences and Fisheries, University of Dar es Salaam, Dares Salaam 35064, Tanzani

出　　处：《Journal of Environmental Science and Engineering(B)》2017年第8期406-424,共19页环境科学与工程（B）

摘　　要：The concentrations of heavy metals （As, Hg, Cr, Pb and Zn） were measured in the macroalgae, macrobenthos and fish from the Tanzanian coastal marine environment in order to ascertain the biomagnification using stable isotopes of C and N. Macroalgae samples from the central marine areas of the Tanzanian coast had higher mean concentrations of Hg （0.17 ± 0.01 μg/g） and Cr （23.7 ± 4.15 μg/g） compared to other locations. Higher concentration of Hg （0.06 ±0.02 μg/g） was detected in the Ulva fasciata close to the Msimbazi Creek in Dares Salaam, whereas the highest concentration of Cr （45.5 ± 6.83 μg/g） was found in Ulva petrusa near Dares Salaam port. The crab Portunus pelagicus collected from Pangani river estuary contained 411.5 ± 13.04 μg/g of Zn. The other metals were uniformly distributed in macrobenthos from the entire coast. Mercury and lead in the biota were found to biomagnify along the Arius dussumieri and Lethrinus lentjan food chains as suggested by the significant positive relationships between log-pollutant concentrations in fish muscle tissues vs. 615N signatures. Zinc in muscle tissues was found to be transferred along the food webs although no biomagnification was observed. Arsenic and chromium were found to decrease with the rise of the trophic position. Metal concentrations in macroalgae, macrobenthos and fish were compared with quality guidelines values by FAO （Food and Agricultural Organization） in 1983 and they all were below permissible limits for human consumption.δ

关 键 词：Heavy metals food chains BIOCONCENTRATION BIOMAGNIFICATION stable isotope ratios δ13C δ15N TL （Trophic Level）. 

分 类 号：P534.45[天文地球—古生物学与地层学] X703[天文地球—地质学]