Chemical characteristics (nutrients, fecal sterols and polyaromatic hydrocarbons)‎ of the surface waters for Sharm Obhur, Jeddah, Eastern Coast of the Red Sea

الملخص EN

Jeddah is the second largest city in Saudi Arabia with a population of more than 2.5 million.

Its coastal area is under stress resulting from diverse human activities.

The levels of some hydrochemical parameters (salinity , pH and dissolved oxygen (DO), nutrients (nitrite (NO2–), nitrate (NO3–), ammonium (NH4+) andreactive phosphate (PO4–3)), fecal sterols and polycyclic aromatic hydrocarbons (PAHs) were measured in the surface water of Sharm Obhur, a coastal inlet north of Jeddah, during March and June 2008.

The distribution pattern of NO2–, NO3– and NH4+ showed a general increase of concentration with increasing distance from the entrance of the Sharm in both sampling periods.

In contrast, the hydrographic parameters and PO4–3 were decreased in concentrations with increasing distance from the entrance.

In the seawater in the vicinity of Faculty of Marine Sciences area, relatively high levels of nutrients were detected indicating a flow of nutrients through local effluent from an experimental fish farm.

The high values of NO2–, NO3– and NH4+ at the head of Sharm were attributed to restricted water circulation, shallowness and sediment water interaction.

However, the concentrations of nutrients in Sharm Obhur were in agreement with the values reported in the literature for the coastal and open Red Sea.

Concentrations of fecal sterols (coprostanol) and PAHs in Sharm Obhur were very low during both sampling periods indicating that the area is still far from being polluted when compared to other coastal lagoons such as Al-Arbaeen and Reayat Al-Shabab Lagoons.