Document Type: Original Article


1 MSc.Student, Filed of Natural Resources-Environment, University of Tehran, Iran

2 MSc.Student, Faculty Environment & Energy, Islamic Azad University, Tehran, Iran

3 Assistant Professor, Faculty of Agriculture, University of Birjand, Iran


All aquatic organisms are directly or indirectly affected by the physical characteristics of their environment, especially the chemical composition of the water. The high concentration levels, damage tissues and interfere with the normal growth and proliferation. The aim of this research was to Investigation acute toxicity of ZnSO4 and CuCl2 to Gambusia holbrooki by static bioassays at different water hardness. The acute toxicity of selected heavy metals to fish was determined in soft, hard and very hard water, respectively (25, 125 and 350 mg/L as CaCO3). Results showed that water hardness had a significant effect in terms of Cu and Zn toxicity in fish. The toxicity of Cu and Zn increased with decreasing water hardness. Results indicated that an increase in water hardness (from 25 to 350 mg/L as a CaCO3) substantially reduced the toxicity of Cu (up to 38-fold) and Zn (up to 264-fold) to fish at 96 hours exposure. The 96 hours LC50 values for fish were higher in the hard and very hard water compared to the soft water. Water hardness had a much smaller effect on the acute toxicity of Cu than the Zn in fish. Cu toxicity in all water types was higher than Zn toxicity for fish. In polluted areas, it is recommended to expand the aquaculture activities in the water resources that their hardness is higher than the average water hardness in the environment. The toxicity effect of other heavy metals on more diverse aquatic animals should be investigated in the future research.


Alkarkhi, A.F., Norli, M., Ahmad, I. and Easa, A.M. (2009). Analysis of heavy metal concentrations in sediments of selected estuaries of Malaysia- a statistical assessment. Environ Monit Assess, 153:179–185.

Dural Meltem, M. Z.,  Goksu, L., Ozak, A. A. and Derici, B. (2006). Bioaccumulation of some heavy metals in different tissues of Cicentrarchus labrax L., 1758, Sparus aurata L.,158 and Mugli cephalus L., 1758 from the Camlik Lagoon of the eastern coast of Mediterranean. Environmental Monitoring and Assessment, 118: 65-74.

Ebrahimpour, M., Mosavisefat, M. and Mohabbati, R. (2010 a). Acute toxicity bioassay of mercuric chloride: an alien fish from a river. Toxicological & Environmental Chemistry, 92(1): 169-173.

Ebrahimpour, M., Alipour, H. and Rakhshah, S. (2010 b). Influence of water hardness on acute toxicity of copper and zinc on fish. Toxicology and Industrial Health, 26: 361-365.

EPA. (2009). Probit Analysis, Version 1.5, Available from: /stat2.htm.

Garcia, R. and Huffaker, C. B. (1979).  Ecosystem management for suppression of vectors of human malaria and schistosomiasis.  Journal of Agro-Ecosystems, 5: 295-315.

Gillis, P. L., Mitchell, R. J., Schwalb, A. N., McNichols, K. A., Mackie, G. L., Wood, C. M. and Ackerman, J. D. ( 2008).  Sensitivity of the glochidia (larvae) of freshwater mussels to copper: Assessing the effect of water hardness and dissolved organic carbon on the sensitivity of endangered species. Aquatic Toxicology, 88: 137–145.

Harmon, S. M., King, J.K., Gladden, J.B., Chandler, G.T. and Newman. L .A. (2005). Mercury body burdens in Gambusia holbrooki and Erimyzon sucetta in a wetland mesocosm amended with sulfate. Journal of Chemosphere, 59 (2): 227-233.

Javid, A., Javed, M. and Abdullah, S. (2007). Nickel bio-accumulation in the bodies of Catla

catla, Labeo rohita and Cirrhina mrigala during 96-hr LC50 exposures. International Journal of Agriculture and Biology. 9: 139–142.

Kamrin, M. A. (2000). Basic concepts in toxicology and environmental chemistry. Pesticide profiles (Toxicity, Environmental Impact and Fate), Lewis Publishers: New York, 676 pp.

Kim, S. D; Gu, M. B; Allen, H. E; Cha, D. (2001). Physiochemical factors affecting the sensitivity of Ceriodaphnia bulba to copper. Environmental Monitoring and Assessment. 70:105–116.

Leyse, K. E; Lawler S. P. and Strange T. (2004). Effects of an alien fish, Gambusia affinis, on an endemic California fairy shrimp, Linderiella occidentalis: Implications for conservation of diversity in fishless waters. Biological Conservation, 118: 57–65.

Markich, S .J., King, A. R. and Wilson, S. P. (2006). Non-effect of water hardness on the accumulation and toxicity of copper in a freshwater macrophyte (Ceratophyllum demersum): How useful are hardness-modified copper guidelines for protecting freshwater biota?.  Chemosphere, 65: 1791–1800.

Martins, R. J. E., Pardob, R. and Boaventura, R. A. R. (2004). Cadmium (II) and zinc (II) adsorption by the aquatic moss Fontinalis antipyretica: effect of temperature, pH and water hardness. Water Research, 38: 693–699.

OECD. (1992). OECD guideline for testing of chemicals, Fish, acute toxicity test, 203:1-9.

Perschbacher, P.W. and Wurts, W. A. (1999). Effects of calcium and magnesium hardness on acute copper toxicity to juvenile channel catfish Ictalurus punctatus.Aquaculture, 172: 275-280.

Penttinen, S., Kostamo, A. and Kukkonen, J. V. K.(1998). Combined effects of dissolved organic material and water hardness on toxicity of cadmium to Daphnia magna. Environmental Toxicology and Chemistry,17: 2498–2503.

Pyle, G. G., Swanson, S. M. and Lehmkuht, D. M. (2002). The influence of water hardness, pH, and suspended solids on nickel toxicity to larva fathead minnows (Pimephales promelas). Water, Air, and Soil Pollution, 133: 215–226.

Rathore, R. S. and Khangarot, B. S. (2003). Effects of water hardness and metal concentration on a freshwater Tubifex tubifex muller. Water, Air, and Soil Pollution, 142: 341–356.

Straus, D. L. (2003). The acute toxicity of copper to blue tilapia in dilutions of settled pond water. Aquaculture, 219: 233–240.

Tabibzadeh, I., Behbehani, G. and Nakhai, R. (1970). Use of Gambusia fish in the malaria eradication program of Iran. Bulletin of the World Health Organization, 43: 623-626.

TRC. (1984). OECD Guideline for Testing of Chemicals, Section2: Effect on biotic systems, 1-39.

Vedamanikam, V. J. and Shazilli N. A. M. (2008). Comparative toxicity of nine metals to two Malaysian aquatic Dipterian larvae with reference to temperature variation. Bull Environ Contam Toxicol, 80:516–520.