Assessment of monthly physico-chemical properties and fish yields of two micro dams of Tigray Region, Northern Ethiopia

Abstract

This study was conducted to assess some physico-chemical properties and yields of two micro dams (Korrir and Laelay Wukro) located in eastern zones of Tigray region (Northern Ethiopia). In each location, water samples and fish yield were examined from October 2013 to March 2014 once per month in each dams. The examined physico-chemical parameters were: Dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), water temperature, pH and transparency. The result showed that the monthly record values of DO, EC and TDS decreased while water temperature and transparency increased in studied months. Mean monthly pH value also fluctuated across months. The monthly mean value of DO, pH, temperature, EC, TDS and transparency were ranged: 3.20-7.70 mg/L, 8.23-9.14, 15.3-22.2°C, 284-353 µS/cm, 1.47-2.11 mg/L and 19.00-39.00 cm in Korrir dam while in Laelay Wukro were: 3.44-5.70 mg/L, 7.93-8.61, 19.4-24.2°C, 209-462 mg/L, 110-270 µS/cm and 18.00-40.20 cm, respectively. Fish yield was assessed by morphoedaphic index empirical models. There was no significant (p<0.05) difference in fish yield and the average estimated productivity of Korrir and Laelay Wukro dams were 13.99 and 14.47 quintal/ha/year respectively. Therefore physico-chemical properties of these micro dams were good for fish production and fish farmers should practice utilization of the micro dams through good management of the water bodies.    Key words: Physico-chemical properties, fish yields, micro dams, morphoedaphic index.