Rescue mission under way at Immingham to free 30ft minke calf stranded in one of UK’s biggest docks Fire crews are digging a trench in mudflats to try to rescue a young whale which has become stranded in one of Britain’s biggest docks. Hopes that high tide would raise the 30ft (9.1 metre) minke calf enough to ease its 15 tonnes off the estuary bed have been revised with the water level not expected to rise enough. A watch is also being kept on the whale’s mother, which is circling the area off Immingham docks where the pair became separated at around 4am. Emergency services think the calf may have been startled by ship movement in the busy seaway and became disoriented. Police and firefighters have been joined by vets from the RSPCA and the British Divers Marine Life Rescue Unit. A tweet from the RSPCA warns of previous failures at refloating the creatures: “Being realistic, they often do not survive.” Mike Puplett, of Humber coastguard, said 50 people were involved in the rescue attempt, which began at 8am when a passing ship raised the alarm. Low tide hampered initial approaches and the water level sank to cover only about a tenth of the whale. Puplett added: “At the moment, we believe the whale’s still alive. There’s signs of life, there’s still movement with it. We’ve got a lot of people down there and standing by to provide safety cover because it’s a dangerous area for people.” The main fear is that the calf will be crushed by its own weight, which is normally supported by water. Minkes prefer the open sea but are occasionally drawn close to land where they become vulnerable to unfamiliar tidal movements. Animals Martin Wainwright guardian.co.uk