Russia's Black Sea coast is shallow and lacks large, sheltered harbours. It would cost billions and takes decades to build a proper port there.
Russia had actually be leasing the port at Sevastopol from the Ukraine since the fall of the USSR and had their Mediterranean fleet based there even before the invasion in 2014. They had a lot to lose in an anti-Russian Ukrainian government.
It pains me that noise pollution isn't taken as seriously as other forms of environmental damage when it's the one that most directly impacts (urban) people's quality of life.
Russia had actually be leasing the port at Sevastopol from the Ukraine since the fall of the USSR and had their Mediterranean fleet based there even before the invasion in 2014. They had a lot to lose in an anti-Russian Ukrainian government.