First, if you go on Marine Traffic you’ll see a bunch of ships clustered around the entrance to the Sea of Azov and nearly nothing in the sea itself. Probably because the ships are illegally turning off their AIS to avoid giving away the fact that they’re violating sanctions.
Most of the ships departing the sea southbound are Russian. Others are of various flags of convenience.
What now remains to be seen is if these ships are intercepted, boarded, inspected, and seized for carrying contraband. That can happen in Turkey at the strait or in the Med where NATO forces can get at these thieves.
What you call “contraband” others call “food”.
No other nation not participating in the sanctions need follow them. The sanctions are that the EU refuses to conduct business with Russia, that we refuse to buy from them, that we have cut them off from our financial system.
We have not insanely decided that trade with Russia is illegal for the world. For example Brazil is still buying Russian fertilizer. India is buying Russian oil. etc etc.
Russian cargo is not “contraband”. As for the Bosphorus, you might note that Turkey is facilitating the maritime trade in wheat, fertilizer, etc.