Bioaccumulation of Some Heavy Metals in Fish Samples from River Benue in Vinikilang, Adamawa State, Nigeria

Abstract

This study was aim to determined the levels of some heavy metals in the gills, liver, stomach, kidney, bones and flesh of four fish species (Tilapia zilli, Clarias anguillaris, Synodentis budgetti and Oreochronmis niloticus) collected at River Benue in Vinikilang, Adamawa State, Nigeria for analysis of Cu, Zn, Co, Mn, Fe, Cr, Cd, Ni and Pb. These metals were chosen because at higher concentrations there might be toxic to the fish and by extension humans that depends on such fish as food. The concentrations of the metals were carried out using Flame Atomic Absorption Spectrophotometer (AAS, Unicam 969). Large differences in trace metal concentrations were observed between different tissues within each fish. The highest concentration of Fe (12.65 µg/g) was recorded in gill of Synodentis budgetti, while the lowest value of 0.68 µg/g was recorded in the flesh of Oreochronmis niloticus. The liver of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species; Fe and Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Cd and Co. The stomach of Synodentis budgetti accumulate significant higher levels of Fe than other species; Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Mn, Cr, Cu, Cd and Pb. Similarly, the bone of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species; Zn and Fe were highest in the bone of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Ni, and Co. The highest levels of Fe (12.65 µg/g) observed in this study was recorded in the gill of Synodentis budgetti and it was below the high residue concentrations of Fe (34 -107 ppm) in fish samples. Based on the above results, it can therefore be concluded that metals bioaccumulation in the entire fish species study did not exceeds the permissible limits set for heavy metals by FAO, FEPA and WHO.

The concentration of Lead in Periwinkle (Tympanotonosfuscatus) and River sediments in Eagle Island River, Port Harcourt, Rivers State Nigeria

“…The higher level of lead reported here, in the periwinkle may be explained by the mechanism of bioaccumulation within the food chain as the periwinkles feed on sea organisms that may have absorbed some quantity of the lead that have found its way into the water bodies, and also by the principle of bio concentration over a period of time, while the water body is not static but following, thereby washing away the heavy metals at any particular sediment site. This finding is in consonance with the report of several other researchers [3,13], who also reported increase in heavy metals in the body of marine animals found in polluted water at a concentration higher than the surrounding environment. This is expected because the heavy metals are not easily excreted from the body, but tend to bio accumulate over a long period of time.…”

Analysis of Heavy Metals Concentration in Tissues of Three Different Fish Species Included in Human Diet from Danube River

“…Gills, liver and kidneys accumulate heavy metals at higher concentration, while muscles contain lower quantities of heavy metal, what is in agreement with the vital function of these tissues. Since it is known that fi sh presents protein food all around the world, toxic effects of heavy metal presence in their body can result in hazardous effects on human health [11].…”

“…Metal pollutants present in water can accumulate in aquatic organisms from water, sediments or through the food chain [5][6][7][8][9][10]. Some metals like Cu, Zn or Fe are also important for many biochemical processes in living organisms and they are essential elements for aquatic plants and animals [11]. However, in the case of higher concentrations of those metals, they also become toxic and considered as pollutants.…”

Heavy Metals (Lead, Cadmium and Nickel) Concentration in Different Organs of Three Commonly Consumed Fishes in Bangladesh

“…Exposure of fish to elevated levels of HMs induces the synthesis of metallothioneine proteins (MT), which are metal binding proteins [17,18]. Fishes are known to possess the metallothioneine proteins [19]. Metallothioneine proteins have high affinities for HMs and in doing so, concentrate and regulate these metals in the liver.…”