Abstract
Shu'aiba Lagoon (lat. 20 deg 45 min N, long. 39 deg 28 min E) is located on the eastern coast of the Red Sea (Saudi Arabia). It is relatively shallow with an area of approximately 11.7 sq km. The inlet to the lagoon is narrow, with a cross-sectional area of about 245 sq m. This lagoon is a future site for mariculture development. With this objective in view, the flushing time scale of the lagoon was calculated, as flushing is an important abiotic factor in lagoon ecology. The average flushing time for the months February to June and September to November is about 20 days. Oceanic inputs play an important part in the process of fertilization of the lagoons. The marine environment in arid zone lagoons is under natural stress due to high temperatures and salinities. However, the flushing time scale of 20 days may not exert intolerable stress on the ecology of the Shu'aiba Lagoon. (Author 's abstract)