Years after an oil spill wreaks havoc on an area and well after vegetation may have been restored; the negative environmental effects can linger on - just below the surface.

A study by researchers at the Woods Hole Oceanographic Institution on an area affected by a fuel oil spill at Cape Cod nearly forty years ago show that  oil compounds are present in marsh sediment 3 to 8 inches below the surface.

The presence of these compounds has affected a number of species, including Burrowing fiddler crabs, who won't dig down more than several inches in order to avoid contact with the oil. When they do hit this oil affected sediment, they then burrow horizontally.

The crabs in affected areas also show significantly slower stimuli response times than their counterparts in non-affected areas; to the extent that one of the researchers stated; "It was as if they were drunk" . 

Numbers of crabs in the spill area were also half that of non-affected areas and these fiddler crabs also fed more slowly.

Fiddler crabs are also a food source for other species - the toxins concentrated in the crabs would likely have some affect on animals further up the food chain.

Read more of the study