The indicator threshold value is based on estimated volumes of oil introduced to the Baltic Sea as illegal discharges of oil during a defined reference period. The volume of oil is considered to be the most relevant metric to evaluate the effect of oil spills on the marine environment.
Key message figure 1. Status assessment results based evaluation of the indicator 'operational oil spills from ships'. The assessment is carried out using HELCOM Scale 2 HELCOM assessment units (defined in the HELCOM Monitoring and Assessment Strategy Annex 4). Click here to access
interactive maps at the HELCOM Map and Data Service: Operational Oil Spills.
In the assessment period of 2011-2016 the estimated annual average volume of oil exceeded the threshold value in the Bothnian Bay, The Quark, The Bothnian Sea, The Åland Sea, the Eastern Gotland Basin, the Western Gotland Basin, the Great Belt and the Kattegat. The threshold value is defined based on a modern baseline using the reference period 2008-2013 when the estimated volume of oil was considered to be at a historically low level.
Both the number and the size of illegal oil spills detected in annual aerial surveillance show decreasing trends in all sub-basins. This shows that the measures implemented in recent years have been successful in decreasing the pressure on the environment caused by oil spills. Oil spills are principally detected along the main shipping routes.
Aerial surveys of oil spills have been carried out by Contracting Parties of HELCOM for several years with standardized methods, annually covering nearly the entire Baltic Sea. The confidence of the indicator evaluation is therefore considered to be high. However, decline in flight hours in recent years might have a negative effect on the confidence in the future.
Oil is an important commodity in the region, with large volumes being transported across the Baltic Sea, and constitutes the main fuel for the majority of ships in the region. Oil and other petroleum products end up in the marine environment through intentional introduction or due to negligence, often as oil in bilge water, via dumping of waste oil, or due to release during accidents. All oil spills pose a significant threat to water birds and other marine animals, both acute (death) and chronic toxic effects are known.
The indicator evaluates the sustainability of handling of oil and petroleum products in the Baltic Sea region, as sustainable activities should ensure minimal number of spills and volume of oil introduced to the marine environment.
Concentrations of hazardous substances close to natural levels.
Enforcement of international regulations – no illegal discharges.
D8 Concentrations of contaminants are at levels not giving rise to pollution effects.
D8C3 The spatial extent and duration of significant acute pollution events are minimized.
HELCOM, 2018. Operational oil spills from ships. HELCOM core indicator report. Online. [Date Viewed], [Web link].
Operational oil-spills from ships HELCOM core indicator 2018 (pdf)