Using the SeaCras’s Coastal Intelligence system, which integrates artificial intelligence (AI) and satellite technologies, a thin layer petroleum derivative (fuel) slick was detected in the wider port area of Hvar, including part of the adjacent coastal waters. Here’s more about the recent Hvar oil spill in the article below.
According to the criteria outlined in Annex I of the MARPOL Convention (International Convention for the Prevention of Pollution from Ships, IMO), the identified pollution event qualifies as an accidental oil spill in the coastal zone.
In accordance with the Maritime Domain and Seaports Act (Official Gazette 83/23) and the Environmental Protection Act (Official Gazette 80/13, 153/13, 78/15, 12/18, 118/18), such an incident constitutes environmental degradation and mandates an appropriate assessment and response.
Note: This study refers exclusively to an internal study conducted by SEA CRAS d.o.o. The results will be published by the company’s scientific team in the form of a peer-reviewed scientific paper. The goal of this activity is to contribute to the conservation of the marine environment and ecosystem of the Republic of Croatia, and to enhance preparedness for future incidents, which, given the maritime traffic density of the Adriatic Sea, are likely.
Through the use of SeaCras proprietary technology, it was established that the spill consists of a petroleum derivative dispersed in an extremely thin surface film. The oil slick was observed on April 24, 2025, at 12:05 PM local time, in the area between the islet of Gališnik and the island of Hvar.
Croatia and many of EU Member states still lack adequate monitoring capabilities for sudden pollution events affecting its territorial sea and internal waters
In the context of globally documented cases, it is important to emphasize that oil slicks of such small surface area are nearly undetectable using conventional monitoring methods. Specifically, the CleanSeaNet program of the European Commission, based on Sentinel-1 satellite radar (SAR) data, is incapable of detecting such phenomena for several reasons:
- The spatial resolution of the available SAR data is insufficient – results are often too coarse for precise detection.
- The use of Sentinel-1 radar imagery is not effective in enclosed, highly indented coastal zones, such as the waters around the Port of Hvar.
Complex coastlines like Croatia’s are characterised by diverse bathymetric and benthic properties and are full of small bays, narrow channels, and rocks in the sea, all of which hinder the use of traditional or most existing solutions available on the market.
Through the application of its proprietary technology, based on ultra-high spatial resolution satellite imagery analysis and AI-driven algorithms, SeaCras successfully detected petroleum derivative pollution in the form of an extremely thin surface film, covering a relatively small area compared to typical large-scale oil spills.
Nevertheless, even such a small detected slick constitutes an ecological incident with potentially long-term impacts on the marine environment of the area.
The SeaCras scientific team will continue with a detailed analysis of this incident and will propose mitigation and response measures aimed at protecting the wider affected marine area.