Mersey Docks and Harbour Co. has reported an increase in profits of nearly eight percent in the first half, its shares following suit with a similar rise. Representatives of Mersey, which owns the Port of Liverpool and the ports of Sheerness and Chatham in southeast England, said the company’s investment program was reaping rewards as it managed to push up profits despite flat volumes of cargo. The program was buoyed by achieving record volumes in two key market sectors — containers and Irish Sea roll-on roll-off freight — which gave it a better overall mix of cargo, officials added. This helped compensate for the loss of nearly a million tons of business due to the ban made effective Jan. 1 on the dumping of river sludge out at sea.