Though still only a juvenile, it is hard not to be mesmerised by the wingspan of this white-bellied sea eagle taking its first tentative flaps after six months in captivity.

Key points: The juvenile white-bellied sea eagle was found coated in salmon oil on Bruny Island

The juvenile white-bellied sea eagle was found coated in salmon oil on Bruny Island Rescuers believe it may have been trapped in a "mortality bin", a dump of fish disposed of by commercial operators

Rescuers believe it may have been trapped in a "mortality bin", a dump of fish disposed of by commercial operators The bird spent six months at Raptor Refuge, south of Hobart, before its release

Loading

The bird of prey was rehabilitated at Raptor Refuge in Tasmania's south after being discovered coated in a thick layer of fish oil on Bruny Island late last year.

After a few unorthodox bubble baths its feathers were restored to reveal its burgeoning plumage.

Since then, conservationists at the park have been helping it rebuild its strength on a steady diet of fish and chicken.

It was released on Friday off the south-east coast with carers expecting it will return to its home patch on North Bruny Island.

But Raptor Refuge founder Craig Webb concedes: "I don't really know. Ask him".

While its feathers are currently a mottled mesh of brown and cream, as it grows the sea eagle will develop a proud white chest like its peers.

Its sharp talons will enable it to seamlessly lick the ocean surface and carry off a fish or two in one swift manoeuvre.

White-bellied sea eagles are considered a vulnerable species in Tasmania, with only about 1,000 occupying the skies.

Globally their populations are put at anywhere between 10,000 and 100,000.

Development, powerlines, cars and even wind turbines pose constant threats.

As birds of prey, once they hone in on their target they engage in a sharp dive and any interruption can be fatal.

For the Bruny Island juvenile, it was the unusual occurrence of a so-called mortality bin which threatened to take its life.

The bins are large dumps of fish, or other dead animals, usually disposed of by commercial operators.

The eagle spent six months in the care of Raptor Refuge. ( ABC News: Scott Ross )

Craig Webb said rescuers could smell the salmon oil emanating from the bird.

"It was in a really foul state," he said.

"It was really, really gooey and had matted feathers.

"This is a fairly rare occurrence. I thought it was in the past, these pits. "

To release the bird, Craig Webb walked to the end of a jetty opposite Bruny Island.

Like a surfer waiting to catch a wave, he read the wind rolling across the channel.

The juvenile white-bellied sea eagle was released near Bruny Island off Tasmania's south-east coast. ( Supplied: Bronwyn Scanlon )

Craig Webb from Raptor Refuge said the bird was found in a bad state. ( ABC News: Scott Ross )

Just as a gust approached, he threw the eagle up with force to help it catch swiftly rising air.

"This bird's ready to go and has been flying around beautifully," he said.

"He still could grow out a little more tail feathers … but rather than having him in this aviary losing his fitness, we believe it's a really good time to let him go."

Mr Webb said it was the perfect time for the juvenile bird to be released. ( ABC News: Scott Ross )

Raptor Rescue's main mission is to rescue and rehabilitate large birds and the operation also does private walking tours.

"It's all about getting them out there. Obviously not all of them can be fixed up but it's a great feeling to be able to get this bird going," Mr Webb said.

"It's about rehabilitation and education."

Mr Webb said if the sea eagle had not been rescued it would have been preyed on by other creatures and with its ultimate fate, death.

"These sea eagles they're a fantastic bird," he said.

"We've got to look after them, we've got to do all we can."