POEL — Rescuers said they expect a humpback whale stranded off Germany's Baltic Sea coast to die in the inlet where it currently lies. The whale swam into an inlet on the small island of Poel, near the port city of Wismar, on Tuesday and became stuck again after repeated attempts over the preceding weeks to free the animal and return it to deeper water.

"We firmly believe that the animal will die there," said Burkard Baschek, the scientific director of the Ocean Museum Germany and the scientific coordinator of the rescue effort. "The approach of maximum rest and respect for nature demands at some point that we let it go."

The whale, which acquired the nickname "Timmy" during its coastal odyssey, was first spotted swimming in the region on March 3. The reason the animal swam into the Baltic Sea, which is far from the natural habitat of humpback whales, is not clear. To reach the open ocean, the whale would need to swim several hundred kilometers to get to the North Sea and then continue onward into the Atlantic Ocean.

Last week, rescuers used an excavator to free the whale from shallow water at Timmendorfer Strand, a resort town about 50 kilometers from the whale's current location on the island of Poel. Despite the use of heavy machinery to dislodge it from the shallows, the whale soon became stuck again. The animal eventually ended up in the inlet on Poel, where it became stranded once more on Tuesday.

In recent days, authorities tried to give the whale quiet and let it rest so it could regain enough strength to swim away under its own power. At other times, rescuers approached the animal with boats in an effort to encourage it to leave the shallow coastal waters and head toward the open sea.

By Wednesday, however, multiple signs indicated the whale's condition had declined. Baschek said the animal was breathing at very irregular intervals throughout the day. Drone photos taken of the inlet showed little sign of activity in the sediment beneath the 12-to-15-meter (39-to-49-foot) whale. The animal barely reacted when rescuers approached it, though it was a bit more active after they departed the area.