Aerial surveillance and regional cooperation remain key in detecting oil spills in the Baltic Sea


Over the years, the aerial surveillance activity in the countries has substantially improved. For example, the remote sensing equipment on board air­crafts and satellite surveillance is in good use to enable bigger area coverage and optimization of flights effectiveness. While in 2021, staff absence caused by covid-19 and technical reasons caused a dip in the annual flight hours, overall, the high number of annual flight hours has been maintained. Aerial surveys of oil spills have been carried out by Contracting Parties of HELCOM with standardized methods for several years, covering nearly the entire Baltic Sea. That is why it has been a substantial part of the HELCOM indicator on oil spills affecting the marine environment and, the confidence of the indicator evaluation has been considered high. The update of all HELCOM indicators will soon be finished as they form an elementary part of the next Holistic Assessment of the Baltic Sea (HOLAS 3), to be released in 2023. Collecting data on the frequency, size and nature of such spills is essential to understanding the environmental impacts of different kinds of substances on the Baltic Sea. Out of the 52 mineral oil spills identified in the Baltic Sea by air in 2021, the overwhelming majority (98%) were smaller than one cubic metre (1 m3) – small sizes of detected spills being another long-standing trend.


About aerial surveillance for spills in the Baltic Sea:
Currently coordinated by the HELCOM Informal Working Group on Aerial Surveillance (IWGAS), the surveillance of spills started in 1989 to detect spills of mineral oil. Since 2014, spills of other and unknown substances have been added to the reporting, among them garbage, litter and floating objects. Spills of unidentified chemical substances and novel fuel types warrant particular attention with regard to improving detection and response capabilities, especially in light of higher risks for accidents as a result of increased marine traffic and extreme weather conditions due to climate change.


The full article can be found at

The full HELCOM Annual report on discharges observed during aerial surveillance in the Baltic Sea 2021 can be found at

More information about the HELCOM Informal Working Group on Aerial Surveillance (IWGAS) can also be found at