Kottila Veettil DHANEESH^1*, Kunnamgalam Mohammed NOUSHAD², Appukuttannair BIJU KUMAR¹, Elavumkudi Paulose NOBI³ & Alikunhi M NABEEL^4
1*Department of Aquatic Biology and Fisheries, University of Kerala, Kariavattom, Thiruvananthapuram, Kerala, India, E-mail: dhanee121@gmail.com
²Department of Aquaculture and Fishery Microbiology, MES College, Ponnani, Kerala, India
³Ministry of Environment and Forests, New Delhi, India
⁴Coastal and Marine Resources Core Lab, King Abdulla University of Science and Technology, Thuwal, Kingdom of Saudi Arabia

HEAVY METAL CONTENT IN YELLOWFIN TUNA THUNNUS ALBACARES (BONNATERRE) OF LAKSHADWEEP SEA

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Tissue samples of fresh, dried and canned Yellowfin Tuna (Thunnus albacares) from Agatti Island of Lakshadweep were subjected to analysis of metals (cadmium, cobalt, chromium, nickel, lead, aluminium and mercury) using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) and Mercury analyser. Analysis revealed that the metals have different levels of accumulation - Cd: 0.007-0.387 μg g^-1, Co: 0.007-0.173 μg g^-1, Cr: 0.166-0.373 μg g^-1, Ni: 0.014-0.081 μg g^-1, Pb: 0.042-0.346 μg g^-1, Al: 10.69-24.29 μg g^-1 and Hg: 0.109-0.471 μg g^-1. The concentration of Co, Cr, Ni and Pb were comparatively higher in smoked and canned tuna rather than in fresh tuna. During processing of tuna, mercury content decreases while the content of other metals increases. Concentration of toxic metal such as Cr in all samples was well above the permissible limits (0.1-0.15 μg g^-1) proposed by the World Health Organization, while remaining metals were below the limits. Due to the high accumulation of all heavy metals, it is advisable to avoid liver and gill of tuna from consumption.