Volunteers have managed to rescue only five of 150 short-finned pilot whales that became stranded on a beach in Hamelin Bay, 315 km south of Western Australia’s capital, Perth. The surviving whales, up to 5 1/2 meters long, have been moved to deeper waters, but Parks and Wildlife Service Incident Controller Jeremy Chick warned Saturday that whales often return to dry land after mass stranding events. Hes asking the public at Hamelin Bay to keep an eye in case they spot a stranded whale. A sixth whale was freed into shallow waters overnight but it beached again and had to be euthanized. Authorities said they will continue to sweep the surrounding beaches by air and sea on Saturday. Rescue efforts were hampered by dead whales in the water, rocky terrain and rough seas. The beach has been temporarily closed as the carcasses were removed from the shore and authorities took DNA samples in an attempt to collect clues about why whales strand. Locals and tourists have also been warned to stay out of the water due to a likely increase in sharks attracted by the dead whales. In 2009, more than 80 whales and dolphins died on a beach in Hamelin Bay, named after French explorer Jacques Felix Emmanuel Hamelin who sailed through the area in about 1801. The biggest mass stranding of whales in Western Australia happened in 1996 in Dunsborough. That year, 320 long-finned pilot whales beached themselves.