Onshore clean-up operations conducted following an oil spill can sometimes be more harmful for the environment than the pollutant itself. "Doing nothing" and leaving the environment to self-clean may be a conceivable option.
An experimental protocol to answer this question
In order to assess this option, an original protocol was developed. Plates representing the given substrate (granite, concrete, limestone, wood, etc.) are artificially polluted before being installed at the study site. They are regularly sampled and send to the laboratory. Chemical and biological analyses are conducted on the samples to assess the substance's persistence, degradation kinetics over time as well as its impact on species that naturally colonise the environment.