Seasonal Variation of Heavy Metals in Q. Quelea, C. Gariepenus, N. Septemfascia and T. Swinderianus in Gyawana Ecosystem, Adamawa State, Nigeria

Heavy metals are metallic elements that are toxic and have high density, specific gravity or atomic weight, they occur naturally in the ecosystem with large variations in their concentration. This study was conducted in Gyawana ecosystem, Adamawa State, Nigeria, to compare seasonal variation in the concentrations of heavy metals in the study animals [birds (Quelea quelea), catfish (Clarias gariepenus), grasshoppers (Nomadacris septemfascial) and cane rats (T. swinderianus)]. A total of four hundred and eighty (480) adult of each Q. quelea, C. gariepenus, and T. swinderianus were collected and a total of nine hundred and sixty (960) N. septemfascia were trapped from the wild. The organs of bird, fish, rat and the whole grasshopper were dried in a furnace at 105oC and ground. The ground samples temperature was gradually increased to a maximum of 550oC and then digested with tri-acid mixture (HNO3: HCO4: H2SO4) in the ratio of 10:4:1, respectively. Determination of the heavy metals was done directly on each final solution using a Buck Scientific 210A Model, Atomic Absorption Spectrophotometer (AAS) and the values obtained were expressed in milligram per gram. The result shows that, the concentration of arsenic was higher during the dry season than wet season in all the animals studied. And statistically, there was no significant difference in the mean concentrations of arsenic in wet and dry season (p