This book provides a synthesis of the current understanding of the fate and effects of oil in freshwater. Its objectives are to provide a compilation, summary and critical evaluation of the available scientific literature on the impact of petroleum on freshwater organisms; to review procedures for the cleanup of petroleum from freshwater habits and to examine restoration and recovery rates; to provide background information on the chemistry and fate of petroleum in freshwater; and to identify gaps in the information on the effects of petroleum related contamination on freshwater. The book provides a source of data for the preparation of environmental impact statements predicting the effects of petroleum contaminated freshwater spills, and presents an introduction to methods of cleanup which are currently applied to the accidental release of petroleum.

The Fate and effects of oil in freshwater

Six oceanographic moorings were maintained in 1993 and 1994 and provided data on the water circulation and the flushing characteristics of the Gulf of Thailand. The concentration of dissolved and dispersed petroleum hydrocarbons (DDPH) was measured at 78 sites in 1994 and 1995 in coastal waters of the Gulf. The water circulation was sluggish and the Gulf was poorly flushed; the mean currents were generally 40 μg l-1), superimposed 25% of the time upon chronic pollution (DDPH≈4 μg l-1) due to limited flushing of the Inner Gulf and the Eastern Sea Board, and the presence of slightly contaminated water elsewhere (DDPH

Seasonal dispersion of petroleum contaminants in the Gulf of Thailand

A study was carried out at some selected coastal areas of Malaysia to determine the present status of hydrocarbon pollution. Five sites were chosen and these include Pulau Langkawi and Pulau Ketam in the west coast, Tanjung Piai in the south, and Pulau Tioman and Kemaman in the east coast of Peninsular Malaysia. The levels of total hydrocarbon in the sediments are found to vary from 18.2 to 847.4 mg kg-1 with sediments from Pulau Langkawi and Tanjung Piai recorded the highest values (691.2 to 847.4 mg kg-1) while Kemaman and Pulau Ketam recorded the lowest values (18.2 to 59.8 mg kg-1). It was noted that these values are related not only to possible sources of hydrocarbon but also to the physical characteristics of the sediments analysed. Sandy sediment generally contains less hydrocarbon than clayey sediment. Further analyses of the sediment extracts indicate that the sources of the hydrocarbon pollution are predominantly petrogenic with significant contribution from biogenic hydrocarbon.

Hydrocarbon Pollution in the Sediment of Some Malaysian Coastal Areas

With its rapid economic growth in the past three decades, Thailand is encountering serious environmental problems. Among these, the issue of environmental pollution caused by oil has become increasingly important because their usage in large quantities have resulted in negative impacts on marine and coastal ecosystems including health effects on wildlife. Major oil spills are of public concern and usually under control of pollution authorities. However, small oil spills occurring in offshore areas due to ship operations are usually uncontrolled, unaccounted in oil spill balance and have smaller public concern. A re- view is presented of the database generated to the present concerning petroleum hydrocarbons in waters and sediments of the Gulf of Thailand. Historical changes in the extent of contamination are discussed and assessed by comparison to data produced elsewhere. In general, the level of petroleum contamination in the Thai waters is low to medium level compared with more ur- banized and industrialized countries. Nevertheless, continuous monitoring and investigations on the level of petroleum con- tamination are still needed in Thailand.

Petroleum pollution in the Gulf of Thailand: A historical review

Detailed GC/MS based chemical analyses of organic concentrates from the Chao Phraya River obtained from a water sample collected in the Bangkok metropolitan area indicated that hydrocarbons of petroleum or combustion sources may be minor constituents of the dissolved lipophilic fraction relative to biogenic hydrocarbons and industrial chemicals. Using published data on river discharge and the concentrations measured in an integrated sample, tentative input rates into the Upper Gulf of Thailand for characterized chemicals are calculated.

Kinuko Saito

Papers

Characterization and determination of lipophilic hydrocarbons in the chao phraya, bang pakong and tha-chin rivers and the upper gulf of Thailand