EXTRACTABLE ORGANICS AND HYDROCARBONS IN THE MEDITERRANEAN SEA

The level of tanker shipments in the Mediterranean is relatively high, being approximately 8 million barrels per day in 1972 and 1975 (Lloyds, 1972, 1975). This represents an important proportion of world-wide shipments which in 1972-1975 were approximately 30 million barrels daily. Because of the tanker traffic and the Suez Canal opening in June 1975, there was particular interest in obtaining hydrocarbon baseline data prior to changed conditions caused by this event. In response, the present study was carried out in the latter half of 1975 when 0-1m and -5m samples were collected along the tanker routes; Augusta, Sicily/Gibraltar; Augusta/Alexandria, and Augusta/Tunis. Total dispersed extractable organics (lipids) and nonvolatile hydrocarbons (C14+) were measured. Hydrocarbons were found to be complex mixtures of normal and isoparaffins, cycloparaffins and aromatics. Surface water showed a persistent pattern of n-paraffins of carbon numbers 16, 17, 18, and 19, with a preponderance of the C17 and C19's. Presence of these compounds and low concentrations of aromatics indicate that an important proportion of the hydrocarbons were of biogenic origin. © 1979.