Over the course of just one year, the Northern Sea Route (NSR) has turned into an illicit corridor for the Russian dark fleet. If in 2024 there were seven oil tankers and six LNG tankers identified as so-called “shadow” ships sailing along the Northern Sea Route (NSR), in 2025 there were a hundred such ships under international sanctions—or nearly a third of the cargo ships sailing the route. They belong to a shadow or dark fleet of vessels that sail under compromised flags, carry poor insurance, and often switch off their transponders to cloak their location—all of which boosts the risk of accidents in the vulnerable Arctic environment.

By December this year, 38 oil and oil products-hauling tankers sailed along the NSR fell under international sanctions for violating oil price caps or being linked to sanctioned industrial projects. The average age of the tankers is 13.4 years old, with 21 of them being older than 15 years. Thirteen tankers have either no or only low ice class certification.

The Mires vessel (IMO 9299771, flag – Sierra Leone) has no ice class. This 20-year-old tanker sailed through NSR once this year in September from China to St. Petersburg. The ship didn’t engage an ice breaker escort, despite being extremely vulnerable to being caught in ice, and evidently simply hoped for a favorable ice conditions on the route. Miraculously its voyage ended without accidents.

Another no ice class tanker Lynx (IMO 9412347, flag – Oman, 14-years-old) was not so fortunate and became trapped in ice a few days after Mires completed its voyage. The ship also lacked an icebreaker escort, was loaded with 150,000 tons of oil en route from Murmansk to China, and had to wait several days for assistance. Moreover, Lynx was not in the public records of the NSR administration at all. If other shadow fleet ships had received official permission to sail along the NSR, there are no records regarding the Lynx in the public registry.

Rosatom, Russia’s powerful nuclear corporation and official operator of the Northern Sea Route, has a tendency to hide information from public view. As such, the NSR administrators this year ceased publishing information about the current location of ships on the NSR, as well as a yearly summary of accidents and incidents along the route.

Three tankers of Ice2 class— the Prisma, Hyperion, and Sakhalin—undertook voyages through the NSR during the summer-autumn navigation period. Each vessel changed flags at least two times during past two years and have gaps in the transmission of their Automatic Identification Systems (AIS), making them invisible during many voyages.

Alongside oil tankers, Russia’s Northern shadow fleet additionally consists of 13 LNG tankers, 39 cargo ships, 5 research vessels and 5 service vessels. But for five LNG tankers, all have recently changed flags and now sail under the Russian flag. Fifteen of these have no or low ice class, including five LNG tankers. A no-ice-class LNG tanker Arctic Metagas was transporting a batch of liquefied natural gas from the Arctic LNG-2 project to China. The vessel became stuck in the East Siberian Sea as early as August 29 and had to wait more than a week for rescue. It had not booked an icebreaker escort.

Three LNG tankers—the Valera, Perle, and Arctic Mulan—received permission to enter the NSR but did not sail in 2025. LNG tanker La Perouse sailed twice from the Arctic LNG 2 facility to China through the western part of the NSR.

Another 49 sanctioned vessels sailing along the NSR are comprised of 39 assorted cargo vessels, five research vessels, and five service vessels. Most of the cargo vessels are included in the sanctions list because they have transported cargo for military purposes. They have also sailed in the NSR over the past several years. Other cargo vessels, research, and service vessels were involved in construction of sanctioned Russian industrial facilities in the Arctic.

Two thirds of NSR shadow fleet vessels worked on the route in 2024 as well, which means that they are likely to have appropriate certification, comply with the Polar code requirements and have experience in navigating in Arctic waters. But half of the oil and oil products tankers were new to the Arctic route, and almost all of those have low ice class and were not initially built for sailing in Arctic waters.

This increases the risk of accidents with extremely harmful consequences to the environment and safety of crews. As we wrote in the Bellona report and our article about safety infrastructure, there is absolutely zero rescue capacity along the NSR meant to deal with accidents at sea timely, and there is no technology to clean up oil spills in Arctic sea conditions. There are only 11 rescue centers along the whole of Russia’s Arctic coast, with seven of them located along the NSR. But they have very limited capacity and only operate a few months out of the year. During the winter navigation period, only one rescue center, in Dikson, is in operation on the NSR.

The recent accident of the Russian shadow oil tanker Kairos (IMO: 9236004) in the Black Sea shows that Russia has no intention of helping its shadow ships. After the Kairos allegedly was struck by Ukrainian drone on November 28 in the Black Sea’s Turkish exclusive economic zone, a Turkish tugboat dragged it to Bulgarian waters and left it there due to severe weather conditions. Fortunately, the tanker had unloaded its oil before the accident and does not pose a major risk for the environment. But it turned out that ten people of the crew were left aboard the tanker without a captain or a first mate and with only limited food, water and energy supply. Bulgaria commenced rescue operations on December 7, while the Russian side made no effort at all to assist the crew and the ship.

Another example of oil tanker accidents comes from the Kerch Strait in December of 2024, when a significant oil spill showed how ill-equipped Russian emergency services are even when trying to stem mishaps in favorable climactic conditions and close to shore. Such a stumbling response shows that any rescue operations mounted along the Arctic waters of the Northern Sea Route could be even slower and less efficient.

Lack of progress in ending of Russia’s unlawful war in Ukraine means that the situation on the NSR could deteriorate further. More ships could be added to sanctions lists, less information will be available to monitor shipping activities along the route, and the risk of accidents will increase. The international community should direct efforts toward limiting this risk by taking measures to reduce shipping activity along the Northern Sea Route.