Petroleum-Derived Hydrocarbons in Gulf of Mexico Waters: ABSTRACT

Abstract

Petroleum-type hydrocarbons occur in waters of the Gulf of Mexico principally as particulate material floating on the surface of the water (tar balls) and as dissolved components in the water column. Gas-chromatographic, mass-spectrometric, and carbon isotopic analytical methods have been used to characterize the hydrocarbons in tar balls from western Gulf beaches. These analyses provide a fingerprint which indicates that the source of some of the tar ball materials is from seeps. Dissolved hydrocarbons have been measured both near producing platforms and in the open Gulf. The amounts of dissolved hydrocarbons in the water near producing platforms have been measured to provide basic data useful for interpreting the possible impact of oil production on marine ecology. Samples were taken approximately 20 ft below the surface to eliminate any effects of surface films, although none were visible at the time of sampling. Gaseous hydrocarbons (C1-C4) were less than 1 microgram/kg, light-liquid hydrocarbons (C5-C10) were less than 0.7 microgram/kg, and heavy hydrocarbons (C15+) were less than 5 micrograms/kg. These values are not different significantly from values measured on samples from the open Gulf. There does not appear to be an increase in dissolved hydrocarbons in the water near producing platforms. End_of_Article - Last_Page 1834------------