Uptake of metals by microphytoplankton provides entry for heavy metals into the marine food-chains thereby reaching the higher trophic level organisms, often used for human consumption. The present study focusses attention on the levels of heavy metals (Cu, Zn, Ni, Co, Cd, and Hg) in the marine phytoplankton of Nagapttinam and Tuticorin lying along the Coromaldel coast of India. Annual mean concentrations  of heavy metals in microphytoplankton varied spatially, as Cu, .Zn, Ni and Co  concentrations  were high at station 1 and Cd and Hg concentrations  were high at station 2 Range of concentration  Cu, Zn, Ni, Co, Cd and Hg was 0.80.166.20. 13.8@31o.Oa, ND-116.30, 0.067930, 0.01-17.50 pg $ dry wt ud 2.00-2680W pg g'l dry wt in microphytoplankton at both the stations and were high during the monsoon and postmonsoon seasons and low during the summer season at the study areas . High concentrations of these metals in micro-phytoplankton coincided with their higher concentrations in the ambient medium, facilitating metals uptake by micro- phytoplankton this is substantiated by a higher significant positive correlation between  the
concentrations of heavy metals in micro-phytoplankton and seawater.  Moreover, high CFs were exhibited by microplankton indicating their differential bioconcentration capability for different heavy metals.

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