karttatausta

Lauri Ojala: The volatile seascape in the Baltic Sea


Lauri Ojala
Professor 
University of Turku
Finland 

lauri.ojala@utu.fi


The Baltic Sea has been, is, and will remain a vital corridor for the transport of goods and passengers. Beneath its surface, it also serves as a crucial conduit for data and energy transmission for the countries surrounding it. Since early 2022, however, the region’s “business as usual” trajectory has deteriorated into a state of growing instability and unpredictability.

As the youngest sea on Earth, the Baltic Sea spans slightly less than 400,000 km², making it only marginally smaller than the Black Sea. It sees approximately 100,000 merchant vessel movements annually, with cargo volumes to, from, and within the Baltic accounting for about 10% of global maritime trade. Furthermore, with around 70 million cross-border passengers each year, the Baltic ranks among the busiest seas globally. Normally, it also accommodates millions of cruise passengers. 

Now the era of "normality" has ended, at least for the time being. Dissatisfied with the sanctions imposed by Western countries on itself and Belarus, Russia appears intent on reshaping the rules of maritime and shipping practices. For over 30 years, these rules were underpinned by peaceful coexistence and multilateral agreements, such as the globally recognized UNCLOS (United Nations Convention on the Law of the Sea). However, it has become evident that UNCLOS provisions did not anticipate a scenario where a major signatory—here, Russia—would deliberately seek to circumvent these rules. 

The reliance on the Baltic Sea for trade and transport varies significantly among the coastal states. This dependency relies on each country’s trade composition, trading partners, and geographical location. Geography plays a crucial role here, as it determines the availability of alternative transport routes.

After 2022, the volume of seaborne trade in all EU Member States along the Baltic Sea - par Poland - has diminished by 15-30%, while that of Russia and Poland has increased by 20-30%. For most EU Member States, this partly reflects diminishing trade demand, but the direct and indirect effects of sanctions on Russia are the main culprit for these reductions.

In 2023, Finnish and Swedish Baltic Sea ports each handled approximately 90 million tonnes (MT) of cargo. Latvian and Lithuanian seaports managed about 40 MT each, while Estonian ports handled 25 MT. Transit volumes of Russian raw materials have plummeted since 2022, dealing a particularly severe blow to the Baltic States and Finland. For instance, Estonian ports handled around 35 MT in 2022, with approximately 40% consisting of Russian transit cargo. By 2023, their total turnover had fallen to about 23 MT.

Among the Baltic Sea coastal states, Finland is the most reliant on maritime trade. In 2023 and 2024, over 95% of Finland’s trade by volume was transported by sea. Land connections through Sweden and Norway, located over 700 kilometres north of Finland’s primary seaports, cannot substitute maritime transport, nor do they possess the physical capacity to handle such volumes. Despite these challenges, Finnish businesses have shown exceptional resilience and adaptability in their trade logistics. Since 2022, nearly 30 MT of trade—roughly 30% of Finland’s total—have been rearranged or sourced from alternative suppliers.

The three Baltic States are also heavily dependent on maritime connections, though they benefit from direct road access to continental Europe, despite the rail gauge differing at the Polish border. Sweden, on the other hand, relies less on the Baltic Sea for its trade. Its primary port, Gothenburg, is located on the North Sea side and handled approximately 40 MT in 2023. Sweden also has land connections with Norway, a bridge linking it to Denmark, and several short-sea shipping routes with its major European trading partners. Overall, just over 50% of Sweden’s trade by volume is conducted via the Baltic Sea.

Poland’s sole coastline lies along the Baltic Sea, and its key port, Gdańsk, handles approximately 80 MT of cargo annually. Since 2022, Gdańsk has increased its volume by over 25%. Meanwhile, the combined ports of Gdynia and Szczecin-Świnoujście handle about 60 MT, though their throughput has slightly decreased. Poland’s robust land connections with its neighbours provide multiple trade options, supplementing its maritime capabilities. Denmark and Germany are the least reliant on the Baltic Sea among coastal states for trade connections, yet the Baltic remains an important linkage for both nations.

Despite sanctions and the price cap on its crude oil exports, Russia has managed to increase its fossil fuel shipments in recent years. An estimated 150 MT of Russian crude oil (about two-thirds of its total crude oil exports) were transported across the Baltic Sea in 2024, representing a critical revenue stream for a nation at war. Additionally, Russia relies heavily on the Baltic Sea for other major exports, such as non-sanctioned LNG, and for the majority of imports destined for western Russia, including Moscow, St. Petersburg, and surrounding regions. The strategic significance of the Baltic Sea is further highlighted by the fact that, aside from air transport, the only effective supply route between mainland Russia and Kaliningrad is via sea. This vital shipping line is operated by a company owned by Russia’s Ministry of Defence.

Given this context, it is perplexing that Russia appears willing to intensify uncertainty through its shipping practices, particularly by relying on the so-called shadow fleet on a large scale. These arrangements deliberately obscure the true ownership, operation, and beneficiaries of the vessels, routes, and cargoes. The actual insurance coverage for these vessels in the event of a maritime accident—along with the potential for widespread environmental damage—may effectively be non-existent. In addition, Russia extensively disrupts satellite navigation across the region, significantly impacting the safety of transport.

The repeated attacks on underwater telecommunications and energy infrastructure in the Baltic Sea since November 2023 can no longer be dismissed as mere accidents. These incidents have targeted telecom cables between Sweden and Estonia, as well as gas and telecom cables between Estonia and Finland. As is typical of asymmetrical hybrid operations, attribution is highly challenging, while denial remains remarkably simple. Even with evidence that goes beyond circumstantial, identifying the perpetrators or masterminds behind these acts is difficult—and holding them accountable is even more so.

One of the most recent incidents in this series occurred on Christmas Day 2024, when an electric cable between Finland and Estonia was severed by the MS Eagle S, a tanker under the Cook Islands flag. Finnish authorities boarded the vessel and brought it to a Finnish port, where prosecutors are now preparing criminal charges. During a Port State Control inspection, the vessel was found to have 32 deficiencies, three of which were so severe that it was deemed unfit to sail. The detention of the tanker and its cargo—approximately 35,000 tonnes of petrol valued at around €20 million—sends a strong message and serves as a measure to deter similar actions in the future.

On January 11, 2025, a tanker flagged in Panama and carrying approximately 99,000 tonnes of Russian crude oil lost power and steering. The vessel, part of Russia’s shadow fleet, was adrift in Germany’s coastal waters north of the island of Rügen. Three tugboats eventually secured the tanker, which was deemed incapable of manoeuvring. According to German authorities, no oil leaks has been detected.

NATO is intensifying its activities too. On January 14, 2025, a Baltic Sea NATO Allies Summit focused on bolstering regional security. As part of these efforts, NATO is enhancing vigilance in the region through initiatives such as Baltic Sentry. These measures are aimed to strengthen deterrence and prevent damage to critical infrastructure.

The operational environment and the safety and security of maritime trade and subsea infrastructure in the Baltic Sea are closely tied to the broader geopolitical climate. Russia’s ongoing war in Ukraine remains a key—though not the sole—factor shaping developments in the region. At the time of writing, it appears possible, and unfortunately even likely, that the situation could worsen before it improves.