The resulting canal sludge was dredged for fertilizer. Usually dredged material is loaded in barges. The riverbed was dredged and reinforced with concrete in many locations. Canals have also been dredged to maximize lake frontage. The smaller sections of some creeks have been dredged and built over. Pearl Harbor was dredged and the channel enlarged to accommodate larger ships. The sandbar was dredged, but reformed almost immediately. These two inlets have been dredged to a greater depth to allow big ships through. The sand banks were finally dredged out in 1901, rendering the canal obsolete. Belfast harbour was dredged in 1845 to provide deeper berths for larger ships. There is also a wharf on the river called Eurowharf, which deals with dredged material. The current was dredged into a winding stream and directed into the Charles River. By 1748 the river was being manually dredged. Koxinga deployed cannons his uncle had dredged up years earlier from the sea. From 1862 the Brisbane River has been dredged for navigation purposes.