Water quality assessment of pacific white shrimp (Litopenaeus vannamei) at villages in northern of Tiab district, Minab area, Hormozgan province

The present study was conducted to evaluate some of the physic-chemical parameters(Temperature, pH, Salinity, Dissolved Oxygen, nitrite, Hardness, Nitrite- Nitrogen, Ammonia , Transparency and clorophyll a) affecting the growth of Western Pacific shrimp (Litopenaeus vannamei) in 9 semi-intensive shrimp ponds (at the 3 farms) During a one period culture (six month) at villages in northern of Tiab, Minab area, Hormozgan province.The results showed that the ranged water temperature were (36.03 ± 0/07±  17.9 ± 1.59),pH (8.53 ±0.12-7.61± 0.01), salinity (51.04± 3.28± - 44.00± 0.5), dissolved oxygen (7.85 ± 0.73 mg .l -2.76± 0.07 mg .l),nitrite(36.9± 10.1μm.l-1.45±0.17μm.l ) Ammonia (0.06 ± 0.01-0.01± 0.001 mg.L), Transparency (67.92± 7.3-31.3 ±0.09 cm)  and chlorophyll a (156.2 ± 11.32 μg .l- 31.33± 1.22 μg.l l).The results of hierarchical cluster analysis showed that water quality in the second farm was far more unfavorable than the first and third farms. The Hierarchicalcluster analysis showed that the water quality in the second farm was much less favorable than the first and third farms.Based on PCA, chlorophyll a is affected by pH, transparency, dissolved oxygen and nitrate with high factor loading. As well as pH, oxygen, transparency and chlorophylla, as a differentiating factor between shrimp farms were identified. In this study, some of parameters such as water temperature, dissolved oxygen, salinity, transparency and chlorophyll a, were sometimes outside the ideal range for the cultivation of L.vannamei.