SEASONAL VARIATION OF IRON AND ZINC CONCENTRATION IN TISSUES OF SOME SELECTED FISH SPECIES FROM SHIRORO LAKE, NIGERIA

Abstract

Seasonal variation of iron and zinc concentration in tissues of some selected fish species (Clarias gariepinus,
Copton zilli, Lates niloticus and Bagrus bajad) and their bioaccumulation in the gills, liver and muscle tissues of
the four fish species from Shiroro Lake, were studied. Samples were stored and transported in ice chest to the
Laboratory for determination of iron and zinc. The target organs (gills, liver and muscle tissue) of each sample
were dissected and digested, heavy metal concentration in them were determined using atomic absorption
spectrophotometer (AAS). The results indicated that, there was a significant difference seasonally in the mean
value of iron and zinc accumulated. Rainy season had the highest while dry season had the least. Clarias
gariepinus liver contained the highest concentration of zinc and iron. While Copton zilli had the lowest. The
concentration of heavy metals in the target organs can be represented as; liver > gills > muscles for iron and
zinc. Heavy metals found in the target organs were within and some below the WHO (2011) recommended
permissible limits for consumption apart from iron found in the liver and gills of the fish species studied.
Anthropogenic activities within the vicinity of Shiroro lake should be monitored and regulated.