Wildlife rescuers are warning boat users in Melbourne’s inner east to take extra caution on the Yarra River, after several sightings of a lone fur seal splashing in the water.

The seal made its way up the river towards the Abbotsford Convent earlier this week and spotted several times in what has been described as a healthy condition.

Despite being 19 kilometres upstream, the seal did not look at all like a fish out of water.

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“He might just be coming out to have a bit of a rest – he seems to be really happy out here, he’s not in any harm,” Wildlife Victoria spokeswoman Amy Hidge said.

The last recorded seal sighting was on Wednesday morning near the Swan Street bridge in Hawthorn.

Seals are occasionally spotted in the Yarra River but rarely stay longer than a few days, Ms Hidge said.

“I can’t imagine he’d be staying too much longer before he’d want to go back out to the bay,” she said.

“I’m sure he’s got quite a few fish to eat here but it would be more comfortable out in the bay.”

Ms Hidge said seals were only deemed dangerous when provoked or approached closer than 30 metres.

“It’s not cause for concern at this stage, but if we do see him come out onto the banks, that’s more of a concern.”

In 2012 Wildlife Victoria helped rescue a seal in St Kilda when it attempted to cross a busy stretch of Beaconsfield Parade.

In 2014 a seal was spotted in the Yarra River near the Hawthorn Bridge but it returned to the ocean within several days.

Seal visits a potential attraction, riverkeeper says

Yarra riverkeeper Andrew Kelly said sightings in the river were becoming more frequent, with several recorded in the past 12 months.

“It could be the one seal, or maybe something is happening that’s bringing the seals back into the river,” Mr Kelly said.

“I suspect there’s good fishing in the river for the seals, it’s a good food source, so it could be opportunistic.”

Salvatore the seal is back in Abbotsford today. Happy swimming Salv! #yarraseal #sealofapproval pic.twitter.com/km1CIdapkn

— Wildlife Victoria (@wildlife_vic) February 17, 2016

Mr Kelly said the frequency of sightings also suggested the river’s water quality might be improving, thanks to relatively low rainfall over the past year which usually floods the river with dirt and chemicals from Melbourne’s roads.

Whatever the reason, Mr Kelly said the return of the seal – or seals – was good news for Melbourne.

“If they are coming back I think it’s really exciting – my one question is what can we do to bring more up the Yarra?”

-ABC