ABSTRACT Aberdeen University Research and Industrial Services (AURIS) undertook a joint industry pilot investigation on “Scientific Criteria for Optimizing Oil Spill Cleanup Operations and Effort” from October 1993 to March 1994. This project examined the worldwide scientific literature on the effects of oil spills, and experimental and natural clearances, on both rocky shores and salt marshes, to ascertain whether defensible scientific criteria could be used to establish the appropriate end point for oil spill cleanup operations. After exhaustive screening of the literature, the investigation found that ecological recovery of shore biota usually follows natural time scales of up to three years for rocky shores and five years for salt marshes, regardless of cleanup. Cleanup has a negative or marginal influence on these time scales, so there is little scientific justification for shore treatment. It may be justified, however, by socioeconomic factors relating to recreation, tourism, fisheries, aquaculture,...