When liquid petroleum is released into the marine environment, the result is an oil spill. Spills range from chronic small leaks to catastrophic well blowouts and tanker accidents. The oil spreads across the surface, coats shorelines and animals, and can sink or form tar balls depending on its chemistry and the weather.

Immediate impacts include smothering of seabirds and marine mammals, toxic effects on fish and invertebrates, and fouling of coastal habitats. Longer-term effects depend on the type of oil, the effectiveness of response, and the sensitivity of the affected ecosystems. Cleanup methods include containment booms, skimmers, dispersants, controlled burning, and shoreline washing, each with its own trade-offs.

Prevention through better vessel design, operational practices, and regulation has reduced the frequency of major spills, yet the risk remains wherever oil is extracted or transported. Scientific studies of past spills continue to inform response strategies and to document recovery times that can stretch from years to decades.

• Release of petroleum into the ocean
• Harms wildlife and coastal habitats
• Response includes containment, recovery, and dispersants
• Prevention remains the most effective strategy