Experts to consider critical listing for ancient fish

The ancient species is now only found in Macquarie Harbour in Tasmania. A recent survey found no evidence of another previously known population in Bathurst Harbour.

Despite being listed as endangered since 2004, the maugean skate has never had a recovery plan.

On Friday, senators were told the Threatened Species Scientific Committee, which advises the federal government on endangered species, considered the skate's plight last year.

But the committee decided not to change its status from endangered, a listing that's been in place since 2004.

Committee chair Helene Marsh says the issue will be reconsidered when the committee next meets.

"In two weeks time we will be considering - in light of all the scientific information - the case for listing the maugean skate as critically endangered," the professor told a budget estimates hearing.

"We are deeply concerned about the situation."

Prof Marsh said that in 2021 there was a public nomination for the species to be up-listed to critically endangered.

"We recommended to the then-minister that it be included on a final priority assessment list. A decision was made not to do that," she said, without providing further details.

"We looked at it again in 2022. By then - and I think partly catalysed by the concerns of the committee - we had discussions with the threatened species commissioner about this."

She said a survey looking for environmental DNA evidence of a skate population in Bathurst Harbour was underway at that time.

"So the committee looked at it in 2022 and we thought the data just aren't there yet and to put it, to recommend that it go on the final priority assessment list because we knew new data was coming. And so now, we're looking at it again."

Greens Senator Peter Whish-Wilson, from Tasmania, said he didn't want to cry over spilt milk but told the professor he'd written to the committee years ago, to express serious concerns about the skate.

"I did write to the Threatened Species Scientific Committee back in 2017, urging exactly the kind of action that's now underway," he said.

Prof Marsh said she'd heard the senator say that earlier this week and was surprised because she'd never seen the letter, despite being chair of the committee at that time.

"There is no record of the committee ever seeing that letter."

Earlier this week Threatened Species Commissioner Fiona Fraser said Environment Minister Tanya Plibersek intended to write to her Tasmanian counterpart, urging "extreme intervention" to save the fish.

Ms Plibersek has promised to ward off any new extinctions in Australia.

The action follows the release of an urgent report by the University of Tasmania's Institute for Marine and Antarctic Studies, which found the skate population had plunged by almost half in just seven years.

Environmental activists have blamed reduced oxygen levels in the harbour brought about by the local salmon farming industry, and climate change effects.