294 P-ISSN: 2305-6622; E-ISSN: 2306-3599 International Journal of Agriculture and Biosciences www.ijagbio.com; editor@ijagbio.com Research Article Regression of Heavy Metal Bioaccumulation on Age and Body Weight of Fishes in Ameka Dam of Ebonyi State, Nigeria Nwabunike MO 1 and Igwe GVC 2 Department of Fisheries and Aquaculture, Faculty of Agriculture and Natural Resource Management, Ebonyi State University, Abakialiki, Ebonyi State, Nigeria *Corresponding author: ojobaokanya@gmail.com; igwegodwinvcdozie@gmail.com Article History: Received: February 21, 2019 Revised: July 24, 2019 Accepted: September 01, 2019 ABSTRACT Heavy metals studied include: Cadmium (Ca), Nickel (Ni), Mercury (Hg), Chromium (Cr), Lead (Pb) and Arsenic (As). Experimental data was collected from Ameka Dam. Data on the body weight and age of fish was collected for about 2 (two) years that is 24 (twenty four) months, result obtained were presented and interpreted in Tables 1 -5 on each of the water body studied. The result of simple regression on the effect of heavy metals on body weight and age of fishes in Ameka Dam showed that cadmium exerted negative influence on the age and body weight of the fishes as indicated by their negative co-efficients. The extent of influence was measured by the co-efficient of multiple determination R 2 of 46% and 3.9% for body weight and age respectively; which means that about 46% of the total variation that occurred in their body weight was caused by the presence of cadmium in the Dam. But, only 3.9% of the change in age was explained by cadmium availability. Significant impact of Cadmium on fish weight was observed at the second year of study, with Cadmium explaining 25% variations in the weight of fish. Nickel had no significant impact while the impact of mercury was seen in year one and two. In conclusion, it was observed that the presence of heavy metals like cadmium, nickel, mercury, chromium, lead and arsenic all exerted more positive influence on both the age and body weight of the fishes. The low values of the Durbin Watson constant in all the heavy metals signified the absence of autocorrelation in the regression model, showing that the model was well specified and no relevant variable was omitted. Key words: Regression, Age, Body weight, Fish, Heavy metals INTRODUCTION The biodiversity of inland aquatic ecosystem is increasingly threatened by a variety of factors all of which are related to humans (Gopal, 2005). Available data suggest that 30% of fish species are threatened by human activities (Reveque et al., 2005). Metals such as mercury, cadmium, copper and zinc form major types of toxic compounds that are released into many water courses by the mining industry (Mason, 2002). Both air emissions and wastewaters are sources of metal pollution. Ebonyi State being naturally endowed with several mineral resources which range from lead, gypsum, calcium carbonate, copper, zinc, mercury, etc is seen to be blessed by nature. These resources have as well attracted several investors in the area of mining. Heavy metals are components of the earth crust. They cannot be destroyed or degraded. To a small extent, they enter our bodies via food, drinking water, and air as trace elements. Same heavy metals eg. (copper, selenium and zinc) are essential to maintain the metabolism of the human body, However, at higher concentrations, they can lead to poisoning (Mason et al., 2000). Heavy metal poisoning could result, they tends to bioaccumulate. Bioaccumulation means an increase in the concentration of a chemical in a biological organism over time, compared to the chemical concentration in the environment. Compounds accumulate in living things anytime they are taken up and stored faster than they are broken down (metabolized) or excreted. Heavy metals can enter a water supply by quarrying, industrial waste, consumer waste and or even from acidic rain; breaking down soils and releasing heavy metals into streams, rivers, lakes and groundwater (Nadal et al., 2004). The deteriorating conditions of surface water resources by heavy metal pollution have led to the study of Ivo River in Ishiagu area of Ebonyi State Nigeria. Most pollutions result from uncontrolled discharge of untreated effluent from mining companies and industries in the area. Rashed (2001) and Vinikour et al. (1980) reported that Cite This Article as: Nwabunike MO and GVC Igwe, 2019. Regression of heavy metal bioaccumulation on age and body weight of fishes in ameka dam of ebonyi state, Nigeria. Inter J AgriBiosci, 8(6): 294-298. www.ijagbio.com (©2019 IJAB. All rights reserved)