A tracer study in an Alaskan gravel beach and its implications on the persistence of the Exxon Valdez oil

► An elegantly designed tracer study on two transects of an oil-spilled gravel beach. ► Successful 2-dimensional numerical modelling of the tracer transport in the beach. ► Explanation for the oil-persistence occurred along the right transect. ► Effects of nutrient application for bioremediation along the right transect. ► Implication of the lack of dissolved oxygen in pore water along the right transect.