After spending the summer wowing British holidaymakers – and sometimes making a nuisance of himself by accidentally sinking boats – Wally the walrus appears to be trying to head home.

The British Divers Marine Life Rescue (BDMLR) said on Tuesday that Wally had departed the Isles of Scilly, where he had been in residence since June, and there has been a positive sighting of him in the waters off Ireland.

Marine experts hope that the creature is on his way back to the Norwegian archipelago of Svalbard between mainland Norway and the North Pole.

Lizzi Larbalestier, of BDMLR, said it was good news that Wally had left Scilly. “Hopefully he will continue to move. It’s good that he’s moving north,” she said. The BDMLR is not saying exactly where he has been spotted because they do not want anyone to pursue him. “We don’t want hundreds of people trying to find him,” said Larbalestier.

“He was in a very busy harbour in St Mary’s [the largest of the Isles of Scilly] and it wasn’t safe for him or for the other harbour users. We hope that people will give him the space he needs now.”

The walrus, thought be be about four years old, has travelled about 2,500 miles along the coast of western Europe, including Spain, Wales and Cornwall, since March.

While on Scilly, he caused a stir by sinking boats when he clambered on to them to try to rest. Eventually a pontoon was provided for him as a place for a break between his fishing trips for clams and shrimps in the clear, shallow water around the islands.

Larbalestier said the professional boat people who ran trips from St Mary’s had treated him with respect but he had sometimes been surrounded by too many small vessels. “Some of them just got too close,” she said.

The hope was that once he had fattened up on Scilly he would head home. “He shouldn’t have been here in the first place. His navigation must have been messed up and he just kept swimming until he got here,” said Larbalestier.

“He’s an amazing creature but we hope we don’t see him again. He was clearly looking for social contact and that’s why he ended up in the harbour. But the right thing is for him to be home with other walruses.”