Seashore water characteristics in the vicinity of Tripoli, Libya

Abstract EN

This study was conducted for the purpose of establishing a data base system of chemical and physical properties of seawater as a part of an environmental monitoring program for the Libyan coastal water, and to ass's pollution effect on the marine environment in the vicinity of the coast of Tripoli, Libya.

Two study sites were selected namely, Gargarch (exposed to sewage discharge) and Ghot-Elrromman (away from any discharge) at the western part of the Libyan coast.

Surface water samples were collected monthly from July 2004 to June 2005.

Samples were analyzed for the surface distribution of hydrographical conditions (water temperature, salinity, DO, BOD, pH and TSS), nutrients (P04+ NH4+, N02 / NO, and Si04").

Temperature, salinity, pH, BOD and DO were (13.0-26.5°C), (35.4-38.8 % o), (7.59-8.43), (1.04-4.47 mg / 1) and (3.12-7.99 mg / 1) respectively, for Gargarch site (polluted), and were (12.5-25.6°C), (37.2-39.5 % o), (8.11-8.28), (1.03-2.70 mg / 1) and (5.95-8.02 mg / 1) respectively, for Ghot-Elrromman site (considered unpolluted).

The nutrients concentration ranges for Gargarch site were (0.029-1.609 mg / 1) for phosphate, (0.003-0.044 mg / 1) for nitrite, (0.117-0.799 mg / 1) for nitrate, (0.017-2.299 mg / 1) for ammonia and (0.010-1.931 mg / 1) for silicate, The nutrients concentration ranges for Ghot-Elrromman site were (0.013-0.090 mg / 1) for phosphate, (0.002-0.023 mg / 1) for nitrite, (0.129-0.383 mg / 1) for nitrate, (0.028-0.109 mg / l) for ammonia and (0.098-0.440 mg / 1) for silicate.

TSS was (0.008-0.038 g / 1) for Gargarch site and (0.007-0.022 g / 1) for Ghot-Elrromman site.

The concentrations of different dissolved inorganic nitrogen forms at polluted Gargarch site were mainly in the order NH4' > N03" > N02", confirming the increasing rate of NH4 production as a result of decomposition of organic matter as consequence of sewage discharge to this site., and in the order N03' > NH4' > N02" for unpolluted Ghot-Elrromman site reflecting normal situations which characterized by the increasing rate of nitrification.