Condition factor, heavy metals and polychlorinated biphenyls (PCBs) in the muscle of fishes harvested in, and imported into Lagos, Nigeria

Oyelowo Oluwakemi,Awobajo Funmileyi,Mofolorunso Adekunle,Sogbesan Teniola,Fayiga Adewale,Samuel Titilola

doi:10.13170/ajas.5.1.14995

Abstract

Fish is an important part of the human diet, are at the top of the aquatic food chain with a high propensity to accumulating contaminants like heavy metals and polychlorinated biphenyls (PCBs) which are toxic to humans. The objective of this study was to evaluate the relationship between condition factor (physiologic wellbeing) of the fishes, PCBs, and heavy metal accumulation.Ten adult fish species three each of Chrysichthys nigrodigitatus, Trachinotus teraia, Liza dumerilli, Tilapia guieensis, Pseudotolithus elongatus, Pomadasys jubelini, Polydactylus quadrifilis, Caranx hippos, Sphyreana barracuda, Arius heudoloti,were acquired at Epe Lagoon. Ten adult fish species three each of Argentina silus, Gadus chalcogrammus, Gadus morhua, Atlantic mackerel, Micropogonias undulatus, Urophycis sp., Chrysichthys nigrodigitatus, Oreochromis niloticus, Clupea harengus, Trachurus trachurus, imported into Lagos were purchased. The fish species’ condition factor was determined. The heavy metals were determined using AAS while PCB level was determined using GC-MS. Iron, mercury, zinc, arsenic, nickel and copper levels correlated positively with the condition factor in the local fishes while in the imported fishes, cadmium, iron, zinc, nickel, copper and lead levels correlated positively to the condition factor. The levels of PCBs in both the local and imported fishes were non-detectable. It is concluded that the lead, copper, arsenic, zinc, mercury and cadmium in both the imported and local fishes were within permissible limits compared with the FAO/WHO maximum permissible limits. The positive correlation of some heavy metals to the fishes’ condition factor infers that these metals might be altering physiologic activities in the fishes. Keywords: Condition factor; Heavy metals; Polychlorinated biphenyl; Fish

Highlights

Condition factor defines the physiological welfare of fishes (Voight, 2003; Muchlisin et al, 2010)
The main objective of this study is to determine the condition factor, heavy metal content and polychlorinated biphenyl levels in fish species found in Epe Lagoon as well as in those imported into Lagos state
The lead, copper, arsenic, zinc, mercury and cadmium in both the imported and local fishes were within permissible limits compared with the FAO/WHO maximum permissible limits while nickel and iron had levels higher than the FAO/WHO maximum permissible limits (Table 1)

Summary

Introduction

Condition factor defines the physiological welfare of fishes (Voight, 2003; Muchlisin et al, 2010) These physiological conditions take into cognizance the feeding, length, weight, and general well-being, as well as the build-up of metals in fishes, resulting from the pollution in the aquatic environments (Voight, 2003; Sfakianakis et al, 2015; Muchlisin et al, 2017). The aquatic ecosystem as with other biospheres experiences pollution as a result of rapid urbanization, industrialization which affects the food chain. These persistent particles in the environment such as metals, dioxins and polychlorinated biphenyls (PCBs) and other contaminants would move into filter-feeding organisms and other invertebrates and will eventually reach higher trophic levels. There have been reports of human contact to PCBs due to the eating of fish (Faroon and Ruiz, 2016)

Objectives

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Results

Discussion

Conclusion