HEAVY METALS IN WATER, SEDIMENT AND IN SOME SELECTEDFISH SPECIES OF THE ENNORE AND CHENNAI FISHERIESHARBOUR, CHENNAI, TAMIL NADUHEMASANKARI PALANI, P. KALADHARAN, VASANTH KRIPA,R. NARAYANA KUMAR AND A. GOPALAKRISHNAN
Mercury and arsenic are the toxic heavy metals found in water, sediment and in different speciesof fish tissue, Rastrelligerkanagurta(Indian Mackerel), Nemipterus spp., (threadfin beam),ParapenaeopsisMaxillipedo (shrimp), Metapenaeusdobsoni (shrimp), Perna sp. (bivalve), Sepiasp.(Cephalopod-cuttlefish) and Loligo sp.(Cephalopodâsquid) of the Chennai, Ennore estuary. Thewater, sediment and fish tissues were analysed for mercury and arsenic using standard procedurein Atomic Absorption Spectrophotometry. The maximum mercury concentration in water is0.02ppbÂ±0.01, in sediment is 0.30 ppbÂ±0.01 and in different fish tissue species in RastrelligerKanagurta, 0.25ppbÂ±0.06, Nemipterus spp., 0.54ppbÂ±0.06, ParapenaeopsisMaxilliâpedo0.58ppbÂ±0.06, Metapenaeusdobsoni, 0.34 ppbÂ±0.06, Perna sp., 0.61ppbÂ±0.06 and Sepia sp.0.72ppbÂ±0.06 and Loligo sp.,Cephalopod-squid, 0.38 ppbÂ±0.06 in the first quarter. Among the fishspecies selected for the study during Apr-Juneâ09, the lowest mercury content is in Rastrelligerkanagurta (Indian Mackerel), 0.35ppbÂ±0.11 followed by Metapenaeusdobsoni,0.68ppbÂ±0.11, Sepiaspp., 0.76ppbÂ±0.11, Loligosp. (Cephalopod squid), 0.78 ppbÂ±0.11 and Nemipterusspp. (threadfinbream), 1.29ppbÂ±0.11 during second quarter. The percentage increase in mercury during firstquarter is 64.67% from lowest to highest. The percentage increase in mercury during secondquarter is 55.99% from lowest to highest. The percentage increase in mercury content in Î¼g/g (ppb)was 80.27% from lowest to highest. The metal concentration in tissues Î¼g/g (ppb) ranged between0.26-1.29Î¼g/g (ppb) in mercury. Among the fish species selected for study for arsenic during Jan-Marâ09, the lowest arsenic content is in RastrelligerKanagurta (Indian Mack erel), 3.85ppbÂ±8.22followed by Nemipterusspp. (threadfin bream), 6.10ppbÂ±8.22, Loligo sp., 26.09ppbÂ±8.22,MetapenaeopsisMaxillipedo (shrimp), 34.72 ppbÂ±8.22, Parapenaeopsis Maxi -millipedo (shrimp),43.84ppbÂ±8.22, Sepia spp., 52.09ppbÂ±8.22 and Perna sp. (bivalve) 60.13 ppbÂ±8.22 in the first quarter.Among the fish species selected for the study during Apr-Juneâ09, the lowest arsenic content is inRastrelligerkanagurta(Indrai Mackerel), 4.35ppbÂ±7.88 followed by Nemipterusspp. (threadfinbream), 13.12ppbÂ±7.88, Metapenaeusdobsoni (shrimp) 14.92 ppbÂ± 7.88, Sepia sp., (Cephalopodcuttlefish), 18.74ppbÂ±7.88 and Loligo sp. (Cephalopod âsquid) 45.09 ppbÂ±7.88 in the second quarter.The percentage increase in arsenic during first quarter is 93.58%. The percentage increase in arsenicduring second quarter is 90.34%. The percentage increase in arsenic content value in Î¼g/g(ppb) was93.58%. The metal concentration in tissues, Î¼g/g (ppb) ranged between 3.85-60.13Î¼g/g(ppb). Thelowest mercury in tissue was found in the species RastrelligerKanagurtawas 0.25Î¼g/g (ppb)Â±0.06and in arsenic it was 3.85Î¼g/g, (ppb) Â±8.22 the highest mercury in tissue was found in theNemipterus sp., 1.29Î¼g/g(ppb)Â±0.11, the highest arsenic was found in 60.13Î¼g/g (ppb)Â±7.88 in Pernasp.(bivalve).