Rescuers were called out after a young seal was spotted outside a South Shields pub.
Passersby became concerned after the sea mammal was found on the beach behind The Sundial on Sunday morning.
Karen Tehrani, who was visiting the seafront with her family, said she was worried the young seal could come to harm, so contacted British Divers Marine Life Rescue.
"It didn't seem injured, but it just looked so sad," she said. "A lot of people take their dogs to the beach and we were worried they would get to close to it before their owners realised what it was."
A spokeswoman for British Divers Marine Life Rescue said it dispatched two members to the scene, but the seal had returned to the water on its own.
"It's unlikely it would have been a newborn seal," she said. "There are a lot of young seals around at the moment, and they don't spend as much time in the water because they need to rest more.
"If people are concerned they are best to call someone out and leave them be."
Seals are occasionally spotted in the waters off South Shields' seafront, but are not a regular sight.
Further down the coast, they are known to swim up the Wear as far as Chester-le-Street.