The shadow fleet in the Baltic Sea

The EU sanctions limit Russia’s ability to sell oil. As a result, a so-called shadow fleet is used to transport oil to countries that do not boycott Russia. It often consists of substandard tankers.

In many cases, these vessels are older than the industry standard. This can mean an increased risk of engine problems and weaknesses in the hulls.

Some of these vessels also do not have a double hull. A double hull is now a required standard to make oil spills more difficult and/or to prevent them, for example in the event of grounding or collision.

The vessels make long voyages, and they are operated and crewed by relatively new actors. The special conditions in the Baltic Sea add further uncertainty about safety.

Increased transport needs at sea along the Norrland coast

Industrial development along the Norrland coast has also increased transport at sea. This also means an increased risk of discharges.

Luleå, Skellefteå, Umeå and Gävle are ports that are undergoing extensive modernisation and adaptation for larger vessels and more sea traffic.

Over several years, a number of discharges of harmful substances have been identified. They are suspected to occur during tank cleaning.

Offshore wind power means an increased risk

The offshore wind farms being established in Swedish waters mean a higher risk of accidents. This is mainly because of narrower fairways, which increase the risk of grounding if there are engine problems.

The sea traffic needed to build and continuously service the wind farms also adds some risk, because this traffic crosses the fairways used by cargo traffic.

New types of vessel fuel worsen the risk picture

One change in the risk picture in recent years is the use of low-sulphur fuels and other alternative fuels. Changed international rules on reduced sulphur content in vessel fuel entered into force on 1 January 2020. They mean that shipping is being steered towards switching to other types of fuel.

Some of these new types of vessel fuel are known by the collective name hybrid oils.

Hybrid oils and marine diesel

There are a large number of hybrid oils. Depending on their composition and additives, they can behave differently in water. Another low-sulphur fuel that is widely used is marine diesel. It has low viscosity and quickly spreads over a large area in a thin layer.

This means that the technology and methods used to recover traditional heavy fuel oil from water can only partly be used, or cannot be used at all, for certain types of spill. This increases the risk of negative consequences.

Scrubbers and increased use of heavy fuel oil

Another way for shipping to handle the regulation of reduced emissions of sulphur and other hazardous substances is to install so-called scrubbers, while continuing to use traditional heavy fuel oil as fuel. These scrubbers remove the sulphur and other hazardous substances so that they are not released into the air after the oil is burned.

Sweden has introduced a ban on discharges of wash water from open vessel scrubbers in Swedish territorial waters. The ban took effect on 1 July 2025 under the Government’s decision.

GPS interference increases the risk of discharges

The GPS signal is central to both commercial shipping and the exercise of official authority at sea, not least for the Swedish Coast Guard. Our environmental rescue efforts depend on being able to locate, coordinate and act quickly, often with several vessels or aircraft at the same time. In a major oil spill or chemical leak, every minute is critical. If navigation systems are affected, there is a risk that operations will be delayed, which can make the environmental damage worse.

Interference with satellite-based navigation systems such as GPS has become more and more common, especially in our nearby areas. On several occasions, GPS signals have been observed to disappear completely, or vessel positions have been seen moving in unnatural patterns and at unnatural speeds.