Hopes have dimmed for a whale stranded in Germany’s Baltic Sea to return to the Atlantic.

Berlin—a stranded humpback whale in Germany.

The Baltic Sea looks weak, and experts fear it may still be unable to find its way back to the Atlantic.

There have been many attempts to save it this week.

A restricted zone of 500 meters (yards) was imposed around the whale to allow it to get some rest and hopefully free itself from where the giant cetacean was stuck, officials said at a news conference in the eastern German coastal city of Wismar on Sunday.

“If he regains his strength, he will be able to do so, and that’s why we have decided to leave him alone so he can actually move on and then successfully leave the area,” said Till Backhaus, environment minister for the state of Mecklenburg-Pomerania, where Wismar is located.

Backhaus said, “But we also have to recognise that he has become weak. And he is also sick.” He said humpback whales can suffer injuries due to contact with fishing nets.

Previous attempts to rescue 12–15 m (39–49 ft) whales from the sandbanks at Timmendorfer Strand beach and Wismar Bay enlisted the help of an excavator and boats, creating larger waves to help it swim freely. Earlier this week, Germans were captivated as the media sent news alerts about the updates and streamed live video from the scene.

The whale became a popular topic of conversation across the country, with people exchanging text messages about the rescue efforts.

But so far, hopes are fading that the whale is still strong enough to swim free and make its way back to the Atlantic via German and Danish waters.

“It is very noticeable that the animal is showing significantly less activity,” said Stefanie Groh of the Institute for Terrestrial and Aquatic Wildlife Research at the Veterinary University of Hanover. “His respiratory rate has reduced significantly. The animal is not moving. He did not react even when we went closer to him.”

It’s not clear why the whale swam into the waters of the Baltic Sea. Some experts say the animal may have lost its way while swimming after a pile of herring or during migration, as it is likely a male.

marine mammals cannot survive. The Baltic Sea has been like this for a long time because the amount of salt in the water is not sufficient. He is already suffering from skin disease. Another issue is that it does not get the right kind of nutrition, although whales can go without food for several weeks.

If it is to survive, it must return to the Atlantic Ocean via the North Sea.

“When you consider how narrow the straits are and there are still about 500 kilometres (310 miles) to go, you realise that the journey is a real obstacle that you have to overcome, and naturally, the chances of success are relatively low,” said Burkard Baesch, director of the German Maritime Museum in Stralsund.

The whale was first spotted swimming in the Baltic on March 3, but reports of its stranding emerged last week.