A humpback whale and its calf were injured on Monday after apparently being hit by a ferry in Sydney Harbour, with witnesses saying the animals had ugly gashes and cuts. The ferry \"Collaroy\" was sailing from Circular Quay to the beachside suburb of Manly when the whales \"just popped up\". \"There was nothing the ferry could do,\" said Richard Ford from Sydney Whale Watching, whose boats were on the water monitoring the whales at the time. \"Obviously if you get hit by a Manly ferry you are going to be in distress, but we watched afterwards and they seemed to be swimming in a normal pattern,\" he told the Sydney Morning Herald. Aerial photos showed a female humpback with a gaping wound near its dorsal fin and its calf with a long gash. The New South Wales Department of Transport said one of its ferries struck an unknown object and had been taken out of service for assessment, with reports saying it had a bent propeller. The state Department of Heritage and Environment said on its Twitter feed that the whale and her calf had since left the harbour for the open ocean. \"Injured humpback calf with mother making way out of Sydney Harbour. Injury serious but calf moving well which is a positive sign,\" it said. The department added in a second tweet: \"Hopefully will survive with just a nasty scar.\" Whales are often seen off Australia\'s coast at this time of the year as they make their annual winter migration from Antarctica up to the warmer waters off Queensland, and again as they return before November. Last week, a dead humpback whale washed up in a Sydney ocean pool.