Searching Relationships between Tissue Elemental Concentrations and Geographical Distribution of Bigeye Tuna(Thunnus Obesus) from the South Atlantic Ocean

Abstract

Abstract:Tunas are at the top of the food chains and have high metabolism and feeding rates, leading to increased metal accumulation in their tissues. Several tools using biological, biochemical and chemical measurements have been used to identify populations, geographic distributions and migrations of fish species in different environments. Elemental composition (V, Cr, Co, Ni, Cu, Zn, As, Se, Cd and Pb) was determined in muscle and liver tissues of bigeye tuna (Thunnus obesus) caught in three areas of the south Atlantic Ocean. Concentrations in liver (V, Co, Cu, Zn, As, Cd and Pb) point to increased values in specimens captured near the South Africa and South America relatively to the open-ocean areas. The obtained results showed that tissue elemental concentrations in T. obesus from the south Atlantic areas can be used as a natural tag. Due to its role, liver seems to be the best indicator tissue.

Bioaccumulation Levels and Potential Health Risks of Mercury, Cadmium, and Lead in Albacore (Thunnus alalunga, Bonnaterre, 1788) from The Aegean Sea, Greece

“…Tuna fish, like other marine fish species, is very important in the human diet and represents the main source of protein, polyunsaturated fatty acids (PUFAs), vitamins and a wide range of other important nutrients [ 7 , 8 , 9 , 10 , 11 ]. However, large predators, such as albacore tuna, are at the top of the aquatic food chain, and hence they can bioaccumulate large amounts of toxicants, such as the heavy metals mercury (Hg), cadmium (Cd) and lead (Pb) [ 12 , 13 , 14 , 15 ]. In addition, albacore tuna is a high-performance fish with very high metabolitic rates, which contributes to the enhanced bioaccumulation of such metals [ 16 ].…”