The tugboats were involved in the transportation of barges with grain.

In the Nikolaev region, the enemy fired at two port civilian tugs. It is already known that as a result of the Russian attack there are dead and wounded.
This was announced by the speaker of the operational command “South” Vladislav Nazarov, commenting on the situation as of 14:00.
“The enemy continues shelling the port infrastructure in the Ochakovsky direction. As a result of a hit on two civilian port tugs that were involved in transporting a barge with grain, a fire broke out, control of the ships was lost. Two crew members died, one was rescued with injuries, the fate of another is unknown “, he said.
According to Nazarov, also in the Nikolaev region, the S-300 anti-aircraft missile systems were fired at at night on the Bereznegovatsky community. Private houses damaged. One person was injured.
(C)UNIAN 2022

They definitely need more cover by sea and air to continue transports unabated and to keep ports from being harassed. Unfortunately the balls to do this have apparently shriveled up and inverted.