When oil enters the sea as a result of an oil spill it causes both immediate and long-term changes in the biotic and abiotic environments. This publication is the first uniform Finnish national plan of action in the case of large-scale oil pollution incidents. For this report, a working group comprising researchers, experts and authorities has compiled essential current information on the impact of oil on marine ecology as well as guidelines on how to conduct research and sampling. Furthermore, the areas of research responsibilities have been clearly defined. The focus of this report is on the impact of mineral oils.

It has been found in connection with earlier oil spills that the impacts of petroleum hydrocarbons on living organisms extend beyond the visibly polluted area. This action plan therefore provides instructions on how to survey the ecological impacts of oil irrespective of the extent of the oil spill, and covering areas beyond the main affected area. In addition to acute-stage research, monitoring of long-term effects and oil levels is also necessary.