Hundreds of whales have become stranded on Tasmania’s west coast, near the town of Strahan, just a day after a separate mass stranding event on King Island. The Tasmanian department of natural resources and environment confirmed that a pod of about 230 pilot whales stranded on Ocean Beach. Some animals were also stranded on a sand flat inside Macquarie Harbour. “It appears about half of the animals are alive,” the department said in a statement, adding that a team was assembling whale rescue gear and heading to the area. “Marine wildlife experts will assess the scene and the situation to plan an appropriate response.” Staff from the Tasmania Parks and Wildlife Service and Tasmanian Police will assist. “Stranding response in this area is complex,” the department said. “If it is determined there is a need for help from the general public, a request will be made through various avenues. Sam Gerrity of Southwest Expeditions, in Strahan, said: “There’s a few that are in the harbour that are still alive, and the majority of them are up on Ocean Beach.” Tom Mountney, of Petuna aquaculture, was on Ocean Beach with five colleagues to help with the rescue on Wednesday. He was a rescuer during the 2020 mass stranding in the same location. “It’s a surreal scene,” he said. “I’m seeing about 200 whales here on the beach. I’d say about half are alive. We are kicking off our rescue effort – getting them onto special blankets to right them. The biggest are over two to three tonnes. We are triaging the smaller ones.” Weather conditions were calm, he said, and some whales could be heard growling and clicking. Mountney said he had also seen about 20 to 30 pilot whales stuck on a sandbank in Macquarie Harbour earlier on Wednesday, and he could see some were still swimming. Multiple sources confirmed to Guardian Australia that roads leading to Ocean Beach and Macquarie Heads had been closed. A spokesperson said Tasmania Police were present in the area and assisting with safety. Sign up to receive an email with the top stories from Guardian Australia every morning The event comes exactly two years after Australia’s worst whale stranding on record, which occurred in the same location. On 21 September 2020, 470 long-finned pilot whales were found beached on sandbars. A week-long rescue effort saved 111 whales, but authorities had to dispose of more than 350 carcasses. Wednesday’s incident follows a separate whale stranding the previous day on King Island, north of Tasmania. At least 14 sperm whales died and washed ashore. Prof Karen Stockin, an expert on whale and dolphin strandings at Massey University in New Zealand, said the west coast of Tasmania was a hotspot for a type of oceanic dolphin known as the pilot whale. She said there were multiple reasons strandings could happen, including changes in water temperatures like in a La Niña or El Niño, with the animals coming closer to shore than normal. “In pilot whales, they are highly social and cohesive and if one is debilitated or comes too close to shore, hundreds can follow.” Earlier this week, Stockin led a study that found as members of the public pressured rescuers to help whales, this could lead to negative outcomes for stranded animals, prolonging their suffering. Commenting on Tuesday’s stranding, Dr Olaf Meynecke from Griffith University’s coastal and marine research centre said: “It is certainly highly unusual for such [a] large number of sperm whales to strand. They are highly intelligent. As was the case in Europe a few years ago, many of them were sick but stranded in various locations. Reported plans for seismic testing in that area are around the same location that these whales feed.” The National Offshore Petroleum Safety and Environmental Management Authority (Nopsema) has confirmed to Guardian Australia “there have been no seismic surveys undertaken in commonwealth waters off the northern or western coasts of Tasmania in the past week”.