Science / Medicine : Sea Life Off Eureka Said to Feed on Oil

Unusual mussels and gastropods that live on hydrogen sulfide, methane and other components of petroleum have been found off the California coast near Eureka. The unique organisms had previously been observed only in the Gulf of Mexico and at hydrothermal vents deep under the ocean’s surface.

The mussels and gastropods that live around oil seeps near Eureka have bacteria in their gills that convert hydrogen sulfide and methane into organic chemicals that are their sole source of energy, according to geochemists Mahlon C. Kennicutt II and Robert R. Bidigore of Texas A & M University.

The hydrogen sulfide and methane also serve as a secondary food source for fish, starfish and crabs that feed on similar free-living bacteria, Kennicutt said. The researchers found the unusual organisms in 1,500 to 1,800 feet of water about 10 to 15 miles off Eureka during dives in the Navy’s NR-1 research submarine and the Johnson Sealink submersible searching for new oil deposits. The discovery of marine organisms living on the petroleum suggests that oil drilling in such areas “may not be as deleterious as previously thought,” Kennicutt said.