The heavy metal content of copper (Cu) and protein in nile tilapia (Oreochromis niloticus) in floating net cage of Gajah Mungkur reservoir, Wonogiri, Central Java

Abstract

Abstract. Novebrianto MA, Sunarto, Setyono P. 2011. The heavy metal content of copper (Cu) and protein in nile tilapia (Oreochromis niloticus) in floating net cage of Gajah Mungkur reservoir, Wonogiri, Central Java. Bonorowo Wetlands 1: 70-79. Reservoir Gajah Mungkur of Wonogiri is an artificially aquatic environment with susceptibility to heavy metal contamination, so through the process of bioaccumulation, the fish tissue can be contaminated. This research was to identify the concentration of heavy metals copper (Cu) and protein in the tissue of tilapia (Oreochromis niloticus Linn.), bred in floating cage breeders at the reservoir Gajah Mungkur. It was also tended to observe the relationship between heavy metal concentrations of Cu with a protein content of tilapia tissue. Determination of sampling points was applied by a purposive sampling method. The concentration of both heavy metal and the measured protein was done descriptively, by comparing data obtained with freshwater quality standards according to PPRI No. 82 years 2001 and Decree DG POM No. 03725/B/SK/VII/89. Relations were analyzed by both correlations. The result showed that the concentration of Cu in the waters of reservoir Gajah Mungkur on a scale of 0.0108 mg/L was still below the threshold of freshwater quality standards. The parameters of temperature, pH, and DO on the results of the research were still in the range of values recommended for aquaculture activities. Cu concentration within tilapia tissues samples at 2.746 mg/kg was above the threshold of metal contamination in foods, especially processed meat, while the average protein content of tilapia value amounted to 18.07%. The higher the Cu content within the tissue, the lower the protein content of fish meat (r = ­0.780).