Workers tried to wash off the black, tar-like substance at the Changi Point Ferry Terminal, as the cleanup from an oil spill on Tuesday night continued yesterday. Cleanup efforts were also still going on at Changi beach, with an 800m stretch still closed to the public, and at the fish farms in the Nenas Channel and Noordin beach on Pulau Ubin, the Maritime and Port Authority of Singapore said. The oil spill was caused by a damaged fuel bunker after two vessels collided off Pasir Gudang Port in Johor on Tuesday. Malaysia's New Straits Times reported on Thursday that the oil was identified as Marine Fuel Oil 500 CST. Professor Lua Aik Chong, executive director of the Maritime Institute @ Nanyang Technological University, said that this is a type of heavy fuel oil commonly used by ships.