Assessing the effects of aquaculture farms on water quality of Haraz and Tajan rivers

Document Type : Ecology

Authors

1 Department of Fisheries, Marine Sciences Faculty, Tarbiat Modares University, Noor, Iran

2 Office of Basic Water Resources Studies, Mazandaran Regional Water Authority, Sari, Iran

Abstract

Constructing cold-water fish farms along Haraz and Tajan rivers is done without any scientific investigations. Little attention has been paid to the distances between farms. Moreover, the farms lack wastewater treatment facilities, and untreated effluents are easily discharged into the surrounding rivers. In the present study, we have investigated the impacts of aquaculture farms on water quality parameters in Haraz and Tajan rivers. We have analyzed quantitative and qualitative effects of farms effluents on water physicochemical parameters of these two rivers. Three different farms in each river were selected. For each farm, samples were collected from before farm inlet (control station), and two other stations, one at 50-100 m (where the farm effluent enters the river) and one at 1.5-2 km (to assess the self-purification potential) downstream of the farm. In total, 9 stations in Haraz river and 5 stations in Tajan river were selected. The results showed that both Haraz and Tajan rivers have the potential of purifying the effluents discharged by aquaculture farms. However, increasing the number of these farms in the future and also releasing untreated effluents may cause important problems for these rivers. It seems, according to the present study, that self-purifying potential at 1.5-2 km downstream of the farms is considerable. Therefore, considering this distance in the construction of aquaculture farms can help in maintaining the health of the river ecosystem. In addition, owners of the farms should be asked to use some facilities for treating the effluents.

Keywords


  1. Amirkolaie, A.K., 2008. Environmental impact of nutrient discharged by Aquaculture waste water on the Haraz River. Journal of Fisheries and Aquatic Sciences.Vol. 3, No. 5, pp: 275-279.
  2. APHA. 1998. Standard method for examination of water and wastewater. American Public Health Association.
  3. Costa-Pierce, B.A., 2002. Ecological Aquaculture: The Evolution of the Blue Revolution Blackwell Science. Oxford, UK. pp: 17-20.
  4. Food and Agriculture Organization of the United Nations (FAO). 2010. Fisheries and Aquaculture Information and Statistics Service, FAO Year Book, Aquaculture Production 1950-2008. Rome, Italy. pp: 28-40.
  5. Loch, D.D.; West, J.L. and Perlmutter, D.G., 1996. The effect of trout farm effluent on the taxa richness of benthic macroinvertebrates. Aquaculture. Vol. 147, pp: 37-55.
  6. Phillips, M.J.; Beveridge, M.C.M. and Muir, J.G., 1985. Waste output and environmental effects of rainbow trout culture. ICES CM 1985/F: 21.
  7. Rennert, B., 1994. Water pollution by a land-based trout farm. Journal of Applied Ichthyology. Vol. 16, pp: 373-378.
  8. Selong, J.H. and Helfrich, L.A., 1998. Impact of trout culture effluent on water quality and biotic communities in Virginia Headwater streams. The progressive fish culturist. Vol. 76, pp: 247-262.