Tracks of surface drifters from a major fairway to marine protected areas in the Gulf of Finland

Pollution caused by shipping accidents or by intentional discharge of harmful materials can be transported by currents to locations far from the source, and therefore poses a potential risk to marine protected areas (MPAs). The risk of current-driven pollution to MPAs in the Gulf of Finland is assessed by analysing the paths from 23 surface drifters crossing a major fairway in the western and central parts of the Gulf of Finland. About 2/3 of the drifters entered into one of the MPAs. The majority of drifters reached the Ekenäs Archipelago near the western coast of Finland. The travel time from the fairway to the MPAs ranged from 1.3 days to 36.1 days, suggesting that different processes may be influencing the surface circulation patterns and that the drifters can travel long distances before reaching a MPA.