Environmental impacts of shrimp farms on coastal waters in Tiab area, Hormozgan province, south of Iran

Abstract

Shrimp farming industry has rapidly expanded in the south of Iran and in particular in Honnozgan Province along the coastal line during the past decade. A survey was conducted for evaluation of environmental impacts of effluents from the shrimp farms during culture season (July-December 2003) of Tiab area in Hormozgan Province. The physico-chemical parameters such as air and water temperature, salinity, pH, dissolved oxygen, BOD5, nitrite, nitrate, total ammonia, inorganic phosphorus and total phosphorus were recorded monthly from 9 stations. The stations consisted of two inlets (stations 13 3), two outlets of effluents (stations 2, 4) and the remaining 5 stations were located along the coastal lines. The parameters were measured at 21-40°C, 22on39°C, 37-54ppt, 7.85-8.38, 4-8.1mg/L, 0.2-8.5mg/L, 0.11-0 .186mg/L, 0.001-0.029mg/L, 0- 0.016mg/L, Ome0.043mg/L and 0.014-1.4mg/L) respectively. The results showed that the range of most of the measured parameters such as water temperature, salinity, BOD5, ammonia, nitrate, phosphate and TP in the outflow waters (2, 4) were higher than inflow (1, 3) and coastal waters (5, 6, 7, 8 ,9). Statistical analysis of variance (ANOVA) demonstrated a significant difference between outlet effluent and other stations (P<0.05). We also concluded that the nutrients in the culture effluents are somewhat used by fauna of the Tiab creek, hence decreasing the pollutant load of the effluent.