Ecological and Health Risk from Heavy Metal Exposure to Fish


Ecological and Health Risk from Heavy Metal Exposure to Fish

This study is very interesting and it is presented by Olawusi-Peters OO et al. from the Department of Fisheries and Aquaculture Technology, Federal University of Technology, Akure, Nigeria.

Fisheries are the most important element in the economy of many nations as they have been a stable item and a good protein source in the diet of many people. Fishes are bio-monitors of aquatic ecosystems especially in estimating pollution of heavy metals. Heavy metals pollution in the aquatic environment is a globally increasing problem because they are highly persistent, indestructible and possess the ability to bio-accumulate.

Fishes are suitable indicators of heavy metal contamination and are extensively used to evaluate the health of aquatic ecosystem since they are of different sizes and occupy different trophic levels. Since fishes are at the end of the aquatic food chain they reflect the water quality and are indicators of pollution. Metals in the aquatic environment accumulate in the food chain and lead to ecological damage as well as human health risks after eating such aquatic organism. Hence, monitoring the contamination of fish tissue is important as early warning indicator of water quality contaminations and helps taking rights actions in the interest of public health and the environment.

According to this study Heavy metals in the gills and muscles of Sarotherodon galilaeus, Coptodon zilli, Heterobranchus isopterus and Clarias isherensis of Awara Reservoir, Ikare-Akoko Ondo State, Nigeria were assessed from February to May, 2016 using 210VGP Atomic Absorption Spectrophotometer after digestion and the values were subjected to Health Risk Index and Ecological Risk Quotient. Results revealed that the observed concentration of heavy metals was generally below the permissible limit.

The conclusion of the study is the concentration of all the heavy metals in the examined fish species was generally below the permissible limit set by WHO, FEPA and FAO in fish even though all the six metals analyzed were found. This study also established that gills bioaccumulated more metals than muscle in the four examined fish species. Similarly C. zilli and S. galilaeus (Cichlidae) bioaccumulated more metals than C. isherensis and H. isopterus (Claridae). Findings also showed that no health risk was observed for the consumption of the four fish species but ecological risk was recorded for Mn in S. galilaeus and H. isopterus. Therefore, anthropogenic activities in the area should be regulated to the barest minimum and the fisheries of the area must be constantly checked to improve the fish yield as well as diversity and to ensure healthy fish food for human consumption.

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With Regards,

Anna D Parker

Editorial Assistant

Journal of Fisheries Research