Endangered salmon farm talk stirs hot political waters

The fish lives in Macquarie Harbour in the state's west where tonnes of salmon are farmed, and the federal government's own conservation advice calls for urgent action to eliminate or significantly reduce its impact on the harbour's oxygen levels.

But scientists at the University of Tasmania's Institute for Marine and Antarctic Studies released a new study that found a reversal in the decline in relative skate abundance between 2014 and 2022.

"We are pleased to report that these current estimates are similar to 2014, with the timing of this trend aligning with improved environmental conditions in the harbour, particularly an increase in dissolved oxygen levels," the institute's researcher and report lead author David Moreno said.

"We found the progression of juveniles to the adult population has shown a trend of year-on-year improvements up to at least 2019 ... meanwhile, the capture of young individuals in 2022 and 2023 suggests there was some hatching success until at least 2020-21."

The institute warned that the population had "a long way to go".

But News Corp papers reported Mr Albanese wrote to salmon industry leaders and cited the study as reason to introduce new laws ensuring sustainable salmon farming could continue.

"My commitment to you, your employees, suppliers and the community is that salmon farming operations on Macquarie Harbour will continue and that no jobs will be lost," the prime minister reportedly wrote.

His pledge drew a quick response from the federal opposition, which accused the prime minister of waiting too long to back the sector in.

"A government that is serious about the welfare of Tasmania's salmon communities would have already acted on this," shadow environment minister Jonno Duniam said.

"It is no surprise (the prime minister) has made this hollow commitment after the fact that he could have acted in the parliament over the last two weeks, let alone the last year."

The Australian Marine Conservation Society found a "high level of uncertainty" in the data, adding the fate of the skate "literally rises and falls alongside salmon production".

"The new report shows a strong correlation between increased salmon farming intensity and a drop in estimated Maugean skate numbers," the society's shark expert Leonardo Guida said.

"That's not surprising since we know salmon farming has dramatically depleted the oxygen levels in (the harbour)."

Greens senator Nick McKim accused Mr Albanese of selling out to the salmon industry.

"Labor has backed in the profits of foreign salmon-farming corporations over Tasmania's environment and the survival of the Maugean skate," he said.

The Bob Brown Foundation said an increase in skate numbers should trigger more action to protect them, rather than allow more salmon farming.

"If the population of white rhinos suddenly went up, would that be a signal to let poachers back in?" marine campaigner Alistair Allan said.

"No. It would be rightfully seen as the moment to protect those rhinos at all costs."