Environmental groups say plans to trial salmon farming in deeper offshore waters in Bass Strait are being progressed "by stealth" without proper calls for feedback.
The federal government is taking public submissions on an aquaculture "research trial" in a 50-hectare zone some six nautical miles off Burnie in Tasmania's northwest.
The plan comes after the federal government and Tasmanian government agreed in September to develop a framework to shift fish farming operations to deeper Commonwealth waters.
It followed intense criticism of the environmental impact of the industry, which the federal government wants to grow to $2 billion by 2027.
Feedback on the project opened on February 4 and will close on February 24.
The federal-funded company supporting the plan, Blue Economy Cooperative Research Centre, put a press release on their website about the plan on February 10.
Tasmanian federal Greens senator Peter Whish-Wilson says the consultation process hasn't been well publicised and it only came to his attention during senate estimates hearings on Tuesday night.
"This project is off to a bad start and the public now have just nine days to raise any concerns with the federal government," he said.
"I don't think putting a fish farm three to six nautical miles off the coast of one of our state's largest cities is what people would have in mind when they think about 'offshore' fisheries."
The Bob Brown Foundation claims the community consultation process hasn't been advertised in Tasmania's northwest.
"The long-predicted invasion of Bass Strait by industrial fish farming is underway by stealth," campaigner Bec Howarth said.
The trial, slated to run for three years, will initially focus on salmon and could be expanded to other aquaculture such as seaweed farming.
Once the trial has concluded there will be additional consultation before long-term arrangements are made, the federal government says.
Tasmanian Premier Peter Gutwein said trials had been "well discussed" last year in terms of the state's memorandum of understanding with the Commonwealth.
"For those people that don't believe there has been enough consultation, they should get out more. There has been plenty of discussion around this particular issue," he said.
"We believe that the future of salmon farming and aquaculture will be both on-land but also in deep water.
"To be able to look at Commonwealth waters is a great step forward."
If the trial is a success, the federal government intends to work with all states and territories to explore extending aquaculture into Commonwealth waters.
A federal government background paper says Blue Economy identified the area off Burnie after conducting a range of surveys of Commonwealth waters adjacent to Tasmania.
The site aims to provide a viable area for offshore aquaculture, while minimising impact on other users including offshore energy, recreational and commercial fishing and marine traffic, it adds.
Co-chair of the Tasmanian Alliance for Marine Protection, Peter George, said there has been "no public advertising" about public consultation.
"Tasmanians are being asked 'to tell us if you agree or disagree with the proposal' while all details of size, scope, duration or impact of the so-called trial (are being withheld)," he said.
According to the federal government 'have your say' website, a 'chosen area' will be announced in March or April.
"If allowed to proceed, this project will inevitably see the northern coastline and adjacent islands dominated by fish pens and resulting pollution," Glenn Sanders, secretary of Neighbours of Fish Farming, said.
"Atlantic salmon do not belong in the Bass Strait and (we) will ensure this becomes a issue in the forthcoming federal election."
The federal government has been contacted for comment.
