Specialist marine conservation staff have been deployed to the scene at Macquarie Harbour, near the town of Strahan.

The state's wildlife department says about 70 animals, believed to be pilot whales, are stuck on a sandbar at the harbour's head.

Strahan resident Georgia Grining said she believed the number was even higher.

"It's well and truly over the 70 that have been reported. It's probably closer to the 200 mark," she told AAP.

She said some in shallow water appeared to have died.

"There are quite a few that are still alive. They look quite distressed, flapping around and obviously trying to get themselves off the sandbar. It's not very nice."

Department of Primary Industry, Parks, Water and Environment staff and Tasmania Police are on site, while whale rescue equipment is being transported from Hobart.

Authorities are urging the public to give rescue crews space.

"Marine conservation program staff are travelling to the west coast to assess the stranding and what resources are required," the wildlife department said.

"If it is determined there is a need for help from the general public, a request will be made."

Australian Associated Press