Recurrent discharges of non-petroleum substances from chemical tankers in Swedish marine Natura 2000 sites are against the aims of EU Directives.

The transport of non-petroleum substances such as vegetable oils, other bio-based oils and their refined products by chemical tankers is increasing worldwide. The majority of the non-petroleum substances carried by chemical tankers will have detrimental effects on the marine environment if accidentally spilled or discharged during tank washing procedures. Swedish Coast Guard aircrafts detected 233 discharges of floating non-petroleum substances in the Swedish territorial sea and Swedish Exclusive Economic Zone (EEZ) between 2020 and 2023. The majority of the discharges, 84%, were detected in the EEZ. About 14% of the discharges were detected within protected marine Natura 2000 sites. Together, the detected discharges covered 1071 km of sea surface. Discharges in marine Natura 2000 sites covered 228 km. We conclude that the regulations in the IMO MARPOL Annex II convention are not strict enough to meet the objectives of EU nature legislation regarding protection of sensitive seas areas.