Evidences of Rapid Environmental Evolution of Obhur Creek, Eastern Coast of Red Sea: Physical and Chemical Properties

Abstract

Fifteen surface water samples were collected from Obhur Creek to assess the water quality and environmental conditions. Hydrographical parameters indicated gradual increase in salinity from mouth to the head of Creek, whereas dissolved oxygen showed supersaturation in most stations. Average concentration of nutrient ions was found to be 0.79, 0.03, 0.51, 1.04, 0.103 µmol/l for ammonium, nitrite, nitrate, silicate, and phosphate ions, respectively. These data showed relative increase compared to the previous intensive study for Obhur Creek during 2008. The concentrations of organic nitrogen and organic phosphorus were found to be 6.79 and 1.72 µmol/l, respectively, which are higher than coastal values. The ratio of total inorganic nitrogen/phosphate for the Creek was calculated giving average value of 42, indicating phosphorus limitation for phytoplankton production. The data of nutrients suggests relative change in the trophic level of Obhur Creek from oligotrophic to mesotrophic, which consider as starting point for dramatic changes in this coastal area.