MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY JAMSHORO

Abstract

In view ol' the ever increasing threat of oil pollution and its possible danger to marine environinent and resources of' Pakistan ni,arine areas this study was undertaken. Although therc have been a number of overviews on status ol' marine pollution in Pakistan, however to my knowledge this study is first effort to quantify the level of oil pollution in the coastal environment of Karachi. The main purpose of the study was to measure the concentration of total oil and grease in sea water and sediment, however, owing to the in)portance of Poly Aromatic Hydrocarbons ( P APIs) in the marine environment, elTorts were made to get some preliminary information about PAHs too. The first chapter deals with general inforn)ation regarding marine pollution, current status ol' Inarine pollution in the vicinity of Karachi, the industrial and domestic wastes being discharged into the marine environment. In order to understand the fate of oil discharged in Pakistan coastal waters, general oceanographic conditions of Pakistan tnarine areas have also been discussed briefly in this chapter. In the second chapter the infornlation collected from the literature survey has been sum:narised. The sources, tite and impact of oil pollution in coastal and marine environment has been described in general as well as with particular reference to Karachi coastal areas. Due to to.xicity of certain components of oil, Public Health Risk has also been highlighted. In this chapter brief intörmation about spill control operation in coastal waters has beef provided In chapter three ruethodologies adopted in this study are discussed in detail. The area of study and sampling stations are also described. The procedures for sample collection, preservation, processing and analysis of various physical and chemical oceanographic parameters, total oil and grease in sea water and sediment and tar balls along Karachi coast are described. The procedure of general survey carried out during this study has also been sununarised. Results obtained för various study parameters have been discussed in chapter (bur. Based on the observations and information collected during field sampling and further analysis of saniples in the laboratory, the sources and extent of oil pollution in the coastal environment of Karachi have been summarised and presented in Tables 4. I — 4.2 on pages 43 and 45 respectively. Since physical and chemical oceanographic parameters play important role in distribution and dispersion of pollutants in the marine environment these were studied. The results of temperature, salinity, density, PI-I, dissolved oxygen, T.D.S„ Suspended load and organic matter in particulate carbon show that environnlental conditions of' Karachi I-larbour, Gizri Creek and Korangi Creek have deteriorated considerably. The highest concentration of' total oil and grease in sea water has been found in Chinna creek (91 5 Ing/l) and Manora Channel (49.7 Ing/l), whereas in seditnents the highest concentration is present in Manora Channel, Korangi Creek near Ibrahim Haidary and Chinna creek which are 1 15 mg/kg, 81 mg/kg and 79 mg/kg respectively. According to preliminary result of P Al-Is the highest concentration both in sea water (34. 153 mg") and sediment (226.06 mg/kg) have been found in samples collected from the Lyari River mouth which discharges industrial and domestic wastes of Karachi city in Karachi I-larbour. Tar balls were noticed on the beaches of Sandspit and Hawks bay only. The observations regarding impact of oil pollution has been briefly discussed. The finding of general survey are also summarised in this chapter. In chapter five conclusion and recommendations of the present study have been given. From this study it is concluded that Karachi Horbour, Manora Channel, Chinna Creek _ Karachi Fish I lorbour are severely polluted while the rest of the coastal environment is not under the stress of significant oil pollution. Pollution in the grossly polluted areas is due to oil discharges from heavy shipping traffic, fishing activities and industrial and dotnestic wastes. The itnpacts of two recent oil spills in port Qasinl area during November and December 1999, have also been discussed in this ehapter