Oil spilled from the tanker Exxon Valdez in 1989 is still trapped in gravel beaches in Prince William Sound, Alaska, according to a research team.

In data, published in Nature Geoscience, the team reveal a ‘considerable amount’ of chemicals are still in the area which are harmful to wildlife and plants.

Remediation, following the disaster, stopped in 1992 because it was assumed the disappearance rate of oil was large enough to get rid of it within a few years.

However, researchers Michel Boufadel and Hailong Li discovered this was not the case as they investigated ‘groundwater dynamics’ of a beach on Eleanor Island, Alaska.

The research found the oil would appear cleared off the top layer of the gravel, but had actually become entrapped by ‘capillary forces’ in lower levels of the sand.

It also suggests ‘similar dynamics’ could mean sites with oils spills around the world could still be contaminated underneath the top layer.

Although, it would be particularly common ‘in mid- and high-latitude’ regions, which would according to the report have implications for any biological remediation work.

Luke Walsh

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