Fears are growing for a juvenile whale that has spent more than a week in a Western Australia estuary.

Experts say the southern right whale has lost its way as it’s unusual for the mammal to be so close to shore.

Fears are growing tonight for a juvenile whale that’s spent more than a week in the Peel-Harvey Estuary in Western Australia. Geographe Marine Research

“We know it’s a juvenile animal, so it’s probably about a year old, has weaned from mum but possibly only recently,” Geographe Marine Research head of research Dr Capri Jolliffe said.

The 10.6-metre animal has spent about nine days south of Perth in the Peel-Harvey Estuary, which has an opening just 200 metres wide.

The whale has been drawing crowds but the public has been warned to steer clear.

“So we’ve seen it going up and back, swimming around quite quickly, almost a bit panicked, looking for a way out,” Jolliffe said.

The animal appears distressed and disoriented, swimming at a speed of about 8km/h.

“All of this behaviour going back and forth quite quickly  is burning through energy stores and that’s concerning,” Jolliffe said.

Geographe Marine Research head of research Dr Capri Jolliffe called for people to be respectful of the whale. 9News

The Department of Biodiversity, Conservation and Attractions is monitoring the whale.

“While it is unusual for a southern right whale to be in the estuary, they do migrate from Antarctic waters annually and can often be seen close to the shore in sheltered waters during Perth winters,” a spokesperson said.

“On-water assessments currently indicate the whale is exhibiting normal behaviour.”

The advice to those on the water is to keep their distance, at least 100 metres by boat and 60 metres for drone operators.

Experts say the southern right whale has lost its way as it’s unusual for the mammal to be so close to shore. Geographe Marine Research

One small boat was filmed sailing directly above the whale.

“People really need to be respectful and observe from a distance,” Jolliffe said.

As for what happens next, that’s up to the DBCA. 

Among the options is closing the traffic bridge to reduce noise, in the hope the whale can navigate its way back out to the ocean.