Oil Spills along the Shore

Oil spilled into the water, having been pushed by winds and currents, often reaches the shore. Oil may strand at the high tide line, leaving black lines or globs of oil on the beach as the tide recedes. Thick layers of oil may coat rocks, beaches, or plants. On waterlogged sediments such as on mudflats, oil will remain on the mud surface if left undisturbed, and be lifted again on the next tide. Where animals have burrowed into the mud, oil may penetrate the surface through these openings. Sun, wind, and waves will gradually weather oil that remains on the beach (cause it to change physically and chemically), forming a hard asphalt-like substance, and eventually causing it to break apart and disappear. In sheltered areas, oil may remain for a long time.

Shore creatures that are harmed by oil are either injured or killed outright. Some creatures that can hide may survive oiling, such as snails or clams that can withdraw into their shells. These animals may take up toxic parts of the oil into their bodies, through eating contaminated food. Birds that feed along the shoreline may get oil on their feathers, causing them to lose their ability to keep themselves warm, and will likely die.

For more information

Environmental Sensitivity Index (ESI) Maps How we map shorelines according to their sensitivity to oiling.

Our Monitoring Study NOAA's long-term studies of how shoreline plants and animals of Prince William Sound, Alaska, were affected by the Exxon Valdez oil spill.

Downloadable resources

Shoreline Assessment Job Aid This job aid, in PDF format, is a supplement to the Shoreline Assessment Manual. It contains visual examples of many of the terms you would use during shoreline assessments after an oil spill. (Document format: PDF, size: 3.0 M)

Shoreline Assessment Manual A manual outlining methods for conducting shoreline assessments and using the results to make cleanup decisions. (Document format: PDF, size: 3.8 M)

Related image galleries

Mearns Rock Time Series Try your hand at investigating how intertidal organisms are recovering from the Exxon Valdez oil spill. (19 images)

Other pages in this series

Oil Spills at the Water's Edges Return to the main page of this section.

Oil Spills at the Water Surface Learn how oil can affect marine life at the surface of the water.