Abstract
A preliminary ecological investigation of Wadi Hanifah Stream revealed the presence of a permanent stream flowing from north (Badiah) to south (south-east of Al-Hair city) covering a distance of about 50 km. The main sources of stream water are sewage effluents, agricultural runoff and pumped shallow ground water from Arriyadh city. The effects of sewage pollution were apparent from sampling stations 10 to 13. Thereafter, the quality of stream water improved. A luxuriant growth of reed plant and Typha domingensis has taken place along the margin of the stream. Seven introduced fish species have established breeding populations in the stream. Three species of snails were recorded. Marsh frog was common. Other invertebrate fauna comprising insects, crustaceans, rotifers, annelid worms, free living nematodes and protozoans were poor. Twenty two species of migratory birds were recorded.