Seasonal variations in the biochemical composition and bio accumulation of metals in selected fishes of Chirackal, Ernakulam district, Kerala

Abstract

Aims: Quantification of metabolites and heavy metals in fish samples obtained in the coastal region of Chirackal on seasonal basis. Methods: The proximate chemical composition was assessed using Spectrophotometer and the quantification of heavy metals using ICP-AES.Key Findings: Proximate composition was found to change with the seasons, with the best body composition being recorded in pre monsoon and post monsoon seasons Highest levels of proteins (70.42 mg/g in P. indicus), carbohydrates (71.06 mg/g, M. seenghala) and fat (51.17 mg/g, G. giuris) were noted. The concentration of heavy metals in fish muscles varied significantly with the seasons. The highest content of Fe and Cu (73.13µg/g, 51.04 µg/g) in P. indicus during post and pre monsoon seasons, Zn and Co (24.06 µg/g, 27.39 µg/g) was recorded in A. testudineus during post monsoon and highest Ni (28.43 µg/g) and Cr (7.17 µg/g) were observed in P. indicus and M. seenghala during pre and post monsoon respectively.Significance: Fish muscle is a valuable food of high quality protein and well balanced carbohydrate and fat for promoting health, prevention and healing of diseases in human body. The samples proved resistant to heavy metals and showed a high bioaccumulation rate. Thus, they can be used as a bio indicator of heavy metals.