Nonvolatile Hydrocarbons Along Tanker Routes of the Pacific Ocean

Approximately 350 water samples were collected along 17,000 miles of tanker routes in the Pacific Ocean. Analysis of these samples for nonvolatile hydrocarbons gave a median concentration of 1.6 parts per billion (ppb) for the surface and 0.9 ppb in the sub-surface at -10 m. Somewhat higher concentrations were observed for one voyage. The hydrocarbons were mixtures which seemed to be of both petroleum and biogenic origin. Data are presented for water along the routes: San Francisco/Cook Inlet, San Francisco/Vancouver/Panama Canal, and San Francisco/Singapore.