This topic has been addressed here previously. I’m of the opinion these are mines Ukraine has placed in the waters. By doing so they can continue to hold the grain shipments hostage that are in port.
And they can keep the Russian ships away.
The western media can then blame Russia for the global food shortages but this problem of explosives in the Black Sea has been on going for some time now.
Repeating below that which was stated previously in the above post:
Ukraine has the biggest advantage, gain, in keeping these ports blocked. They play the victim game, while being financially supported by international banking dollars and western money. Blocking forces the hands of the west. And it serves to tarnish Russia a bit more. Prevents Russia from advancing. While potentially causing huge problems for Turkey. -Which makes NATO happy. Can potentially create discord between Russia and Turkey- so despite claims made by them… the block potentially serves many of their goals.
This is from a week ago but it’s relevant to the ongoing situation with Ukraine/Russia and involves Turkey
https://www.romania-insider.com/Italy-minesweeper-naval-mines-black-sea
Romania, Bulgaria, Georgia, and Turkey, aside from Ukraine and Russia, have access to the Black Sea and use it for international trade, shipping oil, and agricultural products. They are increasingly worried that their commercial ships will become collateral damage in the conflict, as sea mines drift across the water.
Last month, the Turkish navy discovered and defused several sea mines near the Bosporus, a crucial trading channel connecting the Mediterranean with the Black Sea. The Romanian navy also had to disarm mines that had drifted into national waters.
“Though the origin of such mines remains unclear and disputed, their presence is almost certainly due to Russian naval activity in the area,”said the British Ministry of Defense in a statement at the beginning of April. Both Russia and Ukraine have accused each other of bearing the blame for drifting sea mines.
If the presence of the mines is due to (because of/ as a result of) Russian naval activity one can safely conclude that Ukraine has and is responsible for the mining of the waters. Period.