Oil spills in Europe’s seas (Signal)

Oil spills are one of the most concerning sources of marine pollution, as they are difficult to clean up and can last for a long time in the marine environment. They can severely pollute marine and coastal habitats, causing damage to the natural environment and the economy. Oil spills can originate from deliberate operational discharges, negligence — such as poor equipment maintenance — or the consequences of an accident or incident, such as a vessel collision or grounding, or a pipeline rupture (EEA and EMSA, 2021). 

In 2023, the European Maritime Safety Agency’s (EMSA) CleanSeaNet service detected 7,513 possible oil spills (see Figure). The analysis of CleanSeaNet data reveals a decreasing trend in potential pollution incidents detected per million km² from 2008 to 2015. This trend is likely due to increased awareness and better port reception facilities across the EU (UNCTAD, 2011). Between 2015 and 2018, the number of detected incidents rose, possibly because of improved satellite surveillance capabilities. A downward trend resumed from 2019 to 2022, with a 12% reduction in detections from 2021 to 2022. However, in 2023, there was a significant increase of over 58% in potential pollution detections, attributed to the enhanced ability of high-resolution satellite imagery to identify smaller spills. 

The analysis of the geographic distribution of the potential spills suggests a higher incidence in the North Sea and Mediterranean Sea compared to other areas. This is attributed to the heavy maritime traffic in these areas, where a significant number of ships transit daily, heightening the risk of illegal discharges and accidental spills.  

Furthermore, the North Sea is one of the largest offshore oil and gas production regions in the world. The region is populated with numerous platforms and drilling rigs, which may increase the occurrences of accidental and operational spills in the area, contributing to the high volume of detections by CleanSeaNet.  

The Mediterranean Sea’s highly industrialised nature, characterised by the many extensive ports, refineries and petrochemical plants along its coastlines, amplifies the potential for pollution incidents. For example, research studies indicate that approximately 35% of oil entering the sea originates from routine shipping operations. Meanwhile, around 45% derives from land-based sources, including municipal and industrial effluents and regular oil rig operations. Accidents involving oil tankers account for 10% and natural seepages for 5%. The origins of the remaining 5% remain undefined (World Ocean Review, 2014). 

In addition to identifying potential oil spills, CleanSeaNet promptly alerts the relevant Member State, typically within 20 minutes following detection by satellite. This enables responsible authorities to initiate follow-up actions, including on-site checks by patrol boats, aerial surveillance monitoring and other measures such as port inspections. 

In 2023, 2,464 potential pollution incidents within exclusive economic zone (EEZ) areas were verified on-site, accounting for 41% of detections. Among these, 133 (5%) were confirmed as ‘mineral oil’, 399 (16%) as ‘other substance’, 377 (15%) as ‘unknown feature’ and 65 (3%) as ‘natural phenomena’. Notably, 60% (1,490 detections) of the follow-up activities were reported as ‘nothing observed’. 

Despite the steady decrease in potential pollution incidents detected by CleanSeaNet in Europe and the increased surveillance and enforcement efforts, illegal discharges of oil and other polluting substances persist in Europe’s seas. From the limited data available, the legal follow-up and penalties remain relatively low, despite the dissuasive effect of the CleanSeaNet service and other surveillance systems in place (EC, 2023).  

Please consult the relevant indicators and signals below for a more comprehensive overview on the topic.