The young male fur seal has been entertaining locals and tourists on the rocks and in the water upstream from Kings Bridge since Wednesday evening.

Wildlife biologist Sam Thalmann, of the Department of Primary Industries, Parks, Water and Environment said the seal's thick fur coat, pointed head and snout, large front flippers and external ears clearly identified it as a fur seal.

Leopard seals swim with their rear flippers, which makes the flippers stronger and more prominent, and they do not have external ears, he said.

``Certainly (fur seals) are more common,'' Mr Thalmann said.

``Every year Australian fur seals do follow the fish run, especially the elver run, up the Tamar River.''

Mr Thalmann said people should not approach the seal, and keep at least 20 metres away from it.

``They're not aggressive but sometimes they are very inquisitive; they are very powerful and they have significant teeth that could easily inflict damage, even without the animal showing any aggression.''

The animal would most likely make its way back down the Tamar River and out into Bass Strait to rejoin one of the many breeding colonies there, he said.

DPIPWE is interested in receiving information on local sightings and photographs of whales and seals, especially those showing any identifying marks, to help to track individual animals and chart migration patterns. To contact the department, phone 0427 942 537.