Observations of petroleum hydrocarbons and some water quality parameters during oil spill , near Madras Harbour

Abstract

<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Status of water quality and accumulation of petroleum hydrocarbons (PHC) in intertidal sediment of the area affected by oil spill were studied. PHC concentration in water was 11-139 μg.l^-1 with higher concentrations at southern stations, away from the actual location of the oil spill. The PHC level in the intertidal sediment varied widely from 4-11,059 mg.kg^-1 having presence of oil patches at middle stations. Dissolved oxygen (DO) varied from 0.582-6.098 mg.l^-1 with higher concentrations at northern stations. Nitrite was very low (BDL-0.919 μg-at Nl^-1). Nitrate content was BDL-9.234 μg-at N l^-1 that was lower as compared with the baseline values. The lower values of nitrate at southern stations of the study area may be due to utilization of the species in absence of sufficient oxygen. The high phosphate content (1.832-8.850 μg-at P l^-1) may possibly originate through sewage discharge in the estuaries. Oxidation and microbial degradation of oil by bacteria utilizing DO and nitrate as a source leads to poor physico-chemical condition of the coastal ecosystem severely affecting the biota in this region.</span>