Moslem Sharifinia - Department of Fishery, Faculty of Natural Resources, the University of Guilan, POB: 1144, Sowmehsara- Guilan
Zohreh Ramezanpour - International Sturgeon Research Institute, POB: 41635-3464, Rasht-Guilan,
Javid Imanpour - Department of Fishery, Faculty of Natural Resources, the University of Guilan, POB: 1144,Sowmehsara- Guilan,
Abbas Mahmoudifard - Department of Fishery, Faculty of Natural Resources, the University of Guilan, POB: 1144,Sowmehsara- Guilan,

The Zarivar Lake a freshwater lake in west of Kurdistan Province is home for large number of native plant and animal species therefore water quality and health of the lake are vital for conservation of these species. The present study aimed at evaluation of the Zarivar Lake using NSF- WQI as an indicator of water quality. WQI is a suitable tool to examine and classify spatial and temporal variations in water quality and pollution loads in a water body. Seven sites wereselected in different parts of the lake for sampling. Water samples were taken and placed in dark bottle, kept in ice box to prevent any change in chemical properties of samples prior totransportation to the lab for further analyses. Nitrite, Nitrate, Orthophosphate, NH4 +, NH3, Iron, salinity, Electron Conductivity (EC) and pH were measured in all sites. Electron Conductivity was 295- 426 μS.cm-1 and pH varied between 7.28- 8.35. Concentrations of examined chemicals were PO4 3-: 0.019-1.45 mg l-1، NO3-:0.6 mg l-1، NO2: 0.001-0.011 mg l-1، NH4+ :< 0.11-11.33 mg l-1 which indicated trophic status of the lake. Water quality assessment was carried out based on values obtained for nine factors including dissolved oxygen (DO), Fecal Coliform, BOD, pH, water temperature (oC), Phosphate, Nitrate, Total Suspended Solid (TSS) and turbidity. Thehighest value was recorded for Nitrate and lowest for fecal coliform. The study showed based on WQI indicator the Zarivar Lake is a low or slightly polluted basin with an average water quality.

Zarivar Lake, water pollution, water quality, NSF- WQI indicator