More than 300 merchant vessels are waiting to enter and exit the Black Sea amid Russia’s continued attack on Ukraine. There are 110 ships that have gathered outside the Bosphorus Strait in the Sea of Marmara, up from 50 vessels five days ago, according to VesselsValue data. “Vessels waiting at the southern entrance of the Bosphorus Strait destined for the Black Sea may fear consequences of transiting when the environment the other side remains hostile,” trade flow analyst Peter Williams told TradeWinds.

Turkey on Monday activated powers under an international treaty that allows it to effectively block Russian warships from crossing the Bosphorus. The move comes one day after Turkish foreign minister Meylut Cavusoglu formally labelled the Ukraine conflict as a war. More than 200 vessels — mostly small bulkers and tankers —wait at the mouth of Kerch Strait in the northern Black Sea, data showed, as Russian naval forces block the Sea of Azov from commercial vessels. Russia is letting ships leave the Sea of Azov and enter the Black Sea, according to insurer Gard. “Around 50% of these waiting vessels are reporting laden,” Gard said. Russia is also prohibiting vessel access to the Black Sea’s northwestern region, which is home to Odessa, Ukraine’s largest port. “There are reports of mines being laid in the northwestern part of the Black Sea near Ukrainian shores,” Gard said. Gard recommended that area vessels look out for the latest warnings on mined areas and contact local port authorities and ships agents for information.

All Russian ports are operating “in a routine manner”, but the International Maritime Organization has elevated its International Ship and Port Facility Security Code to level two. “If cargo operations at Russian ports in the Black Sea are absolutely necessary, it is recommended that a declaration of security is first carried out with the port facility security officer,” Gard said. Commercial operations within the exclusive economic zones of Turkey, Georgia, Bulgaria and Romania remain unaffected at this time, the insurer added. Last week, Ukraine shut down Black Sea and Azov Sea ports of Odessa, Chernomorsk, Pivdenny (Yuzhny), Nikolaev, Dneprobugsky, Berdyansk and Mariupo.