9 million tons of oil pass through the Öresund Strait and the Great Belt, based on Danish analysis. The amount of oil transiting Denmark and the Öresund coast has surged by 58 percent from 2021 to 2025, and traffic through these waterways has increased explosively since Russia's invasion of Ukraine, according to Danske Rederier. This dramatic rise reflects shifting global energy flows in response to the conflict.
The Swedish Coast Guard confirms a substantial increase in oil transports from Russian oil ports and into Baltic Sea ports of non-sanctioned oil. According to SVT Skåne, Mattias Lindholm, press chief at the Swedish Coast Guard, described that since the start of the Russian invasion of Ukraine, oil transports have changed patterns, departing primarily from oil ports in the Gulf of Finland and passing through the Great Belt on the way out. He also noted that because trade with Russian oil has ceased, more oil is being imported from elsewhere, leading to increased oil entering the Baltic Sea.
The Coast Guard can confirm a substantial increase in oil transports from Russian oil ports but also into Baltic Sea ports of non-sanctioned oil.
However, the Swedish Coast Guard has not made its own calculations of how much oil transports have increased, leaving precise figures uncertain. Ships from the Russian shadow fleet, often in fairly poor condition, frequently pass through Öresund and the Scanian south coast on their way back to Russia after being emptied of oil, according to the Swedish Coast Guard. Navigational challenges arise because Öresund is a much shallower passage than the Great Belt, so ships with a larger draft must use the Great Belt and Danish fairways, as Mattias Lindholm described to SVT Skåne.
This rerouting adds complexity to maritime traffic management in the region. With the increased amount of oil transports in the Baltic Sea, the risks of accidents with oil spills as a consequence also increase, the Swedish Coast Guard warns. According to SVT Skåne, Mattias Lindholm emphasized that the Baltic Sea is a sensitive and very vulnerable environment, where every liter of oil that gets out affects marine life.
Since the start of the Russian invasion of Ukraine, we have seen that oil transports have changed patterns.
These concerns highlight the heightened environmental stakes amid the traffic surge. Limitations in official data complicate monitoring of the oil transport surge, as the Swedish Coast Guard has not conducted its own calculations of the increase. This gap in information makes it difficult to assess the full scope and impact of the changes.
Authorities have not detailed specific measures being taken to mitigate the increased risks of oil spills in the Baltic Sea, and it remains unclear how much of the increased oil traffic is attributed to the Russian shadow fleet versus legitimate commercial transports. Additionally, whether there have been any recent incidents or near-misses involving oil tankers in the Öresund or Great Belt due to the increased traffic is not publicly known, leaving safety concerns partially unaddressed.
But when we no longer trade with Russian oil, we need to import oil from elsewhere, which means that more oil is also coming into the Baltic Sea than before.
Because Öresund is a much shallower passage than the Great Belt, ships with a larger draft must go through the Great Belt and the Danish fairways.
We have a sensitive sea that is very vulnerable. Every liter of oil that gets out affects marine life.