The sperm whale spotted off the coast at Den Helder does not appear to be well and will not be able to find enough food in the shallow waters of the North Sea, experts said on Tuesday.

Various eyewitnesses report seeing the whale on Monday but the last sighting was on Monday evening, coast guard Edwin Granneman told Radio 1. The coast guard are planning to have another look for the sea mammal on Tuesday.

Granneman said the whale appeared to be an adult, with a weight of between 30 and 50 tonnes and up to 20 metres long. As long as the whale is in the North Sea, it will be monitored so that shipping can be warned not to come to close.

Animal protection group SOS Dolfijn said it hoped the mammal would return to open waters under its own steam. ‘There is no point in trying make it move because that won’t help it find back the original route and will only cause extra stress,’ the organisation said.

According to sea life specialists at Ecomare, sperm whales move from north to south in the winter and are sometimes seen in the North Sea. However, it is odd for one to end up here in the summer, because this is not a period when they migrate along the North Sea, the organisation said on its website.

Last December, a 13.5 metre long sperm whale washed up on a beach in Domburg in the south of the country.

Joke Dijkstra assisteert #SOSDOLFIJN bij #potvis in Schulpengat. #KUSTWACHT #KNRM. pic.twitter.com/OEHHnZHqyf

— KNRM Den Helder (@KNRMDHE) June 25, 2018