In order to follow-up the commitments on co-operation on aerial surveillance within the Baltic Sea area, and to provide an overview of the situation in the region, the HELCOM Secretariat compiles annually data on discharges observed in the Baltic Sea area during national and joint co-ordinated aerial surveillance activities. The Data can be viewed in HELCOM Map and Data Service.
The annual HELCOM reports focus on detected spills of mineral oil but has since 2014 also covered spills of other substances and unknown substances. The report covers detections from fixed-wing aircraft. Thus, the figures may differ from reports also taking into account detections from from i.a. helicopters or ships and other kinds of pollution. Since 2019 a separate section with data from other types of aerial surveillance such as helicopters and drones, has also been included in the report.