Turkey, Bulgaria and Romania announced on Thursday January 11 the creation of an alliance to combat floating mines in the Black Sea, the stated aim of which is in particular to secure the transport of Ukrainian grain in this strategic commercial region. This initiative by the three countries of the Atlantic Alliance aims to eliminate sea mines likely to drift from Russian and Ukrainian shores. Here is what we know about this threat.

Most of the mines laid by Russia and Ukraine in the Black Sea are line mines, which include a float containing the explosive charge and are weighted by a cable, which keeps them on the surface or between two waters, at height boat hulls. Drifting mines, which wander with the currents, have also been spotted. These two types of mines are triggered automatically when they hit the hull of a boat.

Hundreds, if not thousands, of mines may have been planted by Russia and Ukraine, but the exact number remains unknown.

Oren mines primarily have a defensive aim. At the start of the conflict, Ukraine mined its coastal zone between Odessa and the Dnieper estuary to prevent a Russian landing on its coasts and protect its ports, particularly around Odessa, a strategic point for Ukrainian trade. For its part, Russia has mined the western coast of Crimea. The belligerents also lined the banks of the Dnieper River with mines, which had become a decisive front line between Russia and Ukraine since kyiv’s counter-offensive.

However, “with time and storms, it is common for the cable [which weights the mines] to break and for the mines to drift towards the coast, and they can then hit ships,” notes Pascal Ausseur, director of the Foundation Mediterranean of strategic studies. After the destruction of the Kakhovka hydroelectric dam in June 2023, many mines laid by the Russians along the left bank of the Dnieper were also carried away by the current towards the Black Sea. “These mines today pose a residual threat,” analyzes Mr. Ausseur.

Drifting mines are dropped for offensive purposes to hit the coasts or enemy ships depending on the currents.

“These mines mainly pose a commercial danger,” explains Pascal Ausseur. Although Russia did not renew, in July 2023, the agreement which made it possible to secure the export of Ukrainian cereals via the Black Sea, it remains a major commercial shipping route. Ships regularly bypass the Russian maritime blockade, in particular thanks to the new corridor set up by Ukraine in August to reach ports in the Odessa region.

The igniting of sea mines, when they come into contact with the hull of a boat, can damage or even sink the ship. But “it is unlikely that these mines will be able to explode large merchant ships, such as grain ships, which have a modern structure with double hulls,” notes Mr. Ausseur. They can nevertheless damage them, and pose a risk for the crew.

Numerous collisions with sea mines have been reported since the start of the conflict – two, notably, in October 2023, when a Turkish tanker carrying oil and then a Liberian bulk carrier were damaged within days of each other. , injuring a sailor. In the latest incident, a Panamanian cargo ship was hit at the end of December while traveling to a Ukrainian port to load grain, injuring two crew members.

“The simple fact that this could happen causes the insurance prices for these journeys to rise very sharply,” notes Mr. Ausseur, recalling “the economic impact on commercial traffic” of these mines.

Since March 2022, numerous drifting mines have already been spotted and recovered without damage off the Turkish, Bulgarian and Romanian coasts. The Turkish navy also carries out “non-stop mine surveillance”, said the Turkish defense minister, who restricted the mine countermeasure initiative to the three coastal countries, thus excluding the intervention of NATO ships .

“These are a priori basic mines, easy to “pétarté” [detonate], explained a French military source to Le Monde in June 2022. Turkey has minesweepers to free up access to Ukrainian ports. » Minesweepers are warships equipped with a tow, which can shear the orins of contact mines to bring them to the surface and destroy them with a light cannon or rifle.

The objective is to “patrol specific routes, to clear a channel and ensure a mine-free route for commercial ships,” adds Pascal Ausseur, who specifies that this requires “regularly repeating the operation, to ensure that new mines have not drifted into the area.” Due to drifting mines and currents, completely demining the Black Sea could take years.