Geographic Information System-Based Source Estimation of Copper Pollution in Lake Itezhi-tezhi and Metal-Accumulation Profiles in Oreochromis spp. from Both Field and Laboratory Studies
- 445 Downloads
The Copperbelt region, upstream of the Kafue River, including Lake Itezhi-tezhi (ITT), in Zambia has extensive copper (Cu) mines. In our field study, geographic information system analysis in lake sediment indicated that the northern part of the lake, i.e., the Copperbelt region, could be the source of Cu pollution. Concentrations of Cu in stomach contents between fish species were not significantly different. However, Oreochromis spp. liver showed significantly greater Cu concentrations than those in other fish species. Log liver [Cu], standard length, and nitrogen stable isotope ratio were positively correlated only in Oreochromis spp. In the laboratory study, O. niloticus and O. latipes were exposed to Cu for 4 days, and recovery phases ≤28 days were examined. O. niloticus showed significantly greater concentrations of Cu compared with O. latipes at all sampling points. Significantly greater concentrations of Hg in Schilbe intermedius liver than for other fish species were observed, whereas O. macrochir showed significantly greater concentrations of cadmium. In conclusion, the northern part of the lake could be the source of Cu pollution in Lake ITT. Diet may not be the reason for high Cu accumulation in Oreochromis spp. Results from both field and laboratory studies imply that Oreochromis spp. contain high concentrations of Cu under normal physiological conditions.
This study was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan awarded to M. Ishizuka (Grant Nos. 24248056 and 24405004) and Y. Ikenaka (Grant No. 23710038); a Research Fellowship from the Japan Society for the Promotion of Science grant-in-aid awarded to S. Nakayama (Grant No. 2403000402); and the foundation of JSPS Core to Core Program (AA Science Platforms). We acknowledge the financial support from The Naito Foundation and Sompo Japan Environment Foundation. We gratefully acknowledge the assistance of Peter Mambwe Chiwala, district veterinary officer, and the Department of Fisheries for the Itezhei-tezhi district. We also thank A. Agui for assistance with stable isotope ratio analysis.
- Bowen SH (1980) Detrital nonprotein amino acids are the key to rapid growth of Tilapia in Lake Valencia. Venezuelan Sci 207:1216Google Scholar
- Forstner U (1981) Metal pollution assessment from sediment analysis. Metal pollution in the aquatic environment. Springer, Berlin, HeidelbergGoogle Scholar
- Ikenaka Y, Nakayama SMM, Muzandu K, Choongo K, Teraoka H, Mizuno N et al (2010) Heavy metal contamination of soil and sediment in Zambia. Afr J Environ Sci Technol 4:729–739Google Scholar
- Mbabazi D, Makanga B, Orach-Meza F, Hecky R, Balirwa J, Ogutu-Ohwayo R et al (2010) Intra-lake stable isotope ratio variation in selected fish species and their possible carbon sources in Lake Kyoga (Uganda): implications for aquatic food web studies. Afr J Ecol 48:667–675Google Scholar
- Nakayama SMM, Ikenaka Y, Muzandu K, Choongo K, Oroszlany B, Teraoka H et al (2010) Heavy metal accumulation in lake sediments, fish (Oreochromis niloticus and Serranochromis thumbergi), and crayfish (Cherax quadricarinatus) in Lake Itezhi-tezhi and Lake Kariba. Zamb Arch Environ Contam Toxicol 59(2):291–300CrossRefGoogle Scholar
- Skelton P (1993) A complete guide to the freshwater fishes of Southern Africa. Southern Book Publishers, Halfway House, pp 1–388Google Scholar
- World Health Organization (2004) Guidelines for drinking-water quality. WHO, Distribution and Sales, Geneva, SwitzerlandGoogle Scholar