Tasmania's second largest salmon producer Huon Aquaculture has condemned a proposed stock reduction for Macquarie Harbour, labelling it "window dressing" and "spin".
The comments were in response to today's draft determination by the Environment Protection Authority (EPA), telling salmon producers to reduce stock in the waterway on Tasmania's west coast.
EPA director Wes Ford said that while the current cap for the harbour was 21,500 tonnes, the current stock was about 16,000 tonnes.
He said that was still too much and the cap would be cut to about 14,000 tonnes.
The latest scientific data showed concerning levels of bacteria and low oxygen in the harbour and the inability of the waterway's ecosystem to cope, Mr Ford said.
Updated 30 Nov 2016, 6:57pm
"As a result, I have determined that the biomass needs to be lowered and a new limit needs to be set," he said.
"One of the concerns of overstocking the system in Macquarie Harbour is we see an ongoing degradation of the sea floor.
"That means the fish farming waste is not able to be processed and broken down by the animals that live in the sediments."
The three producers operating in Macquarie Harbour — Tassal, Huon Aquaculture and Petuna — have been given four weeks to respond and provide planning strategies in response to the new limit.
"It is important to remember that this is a limit, not a target," Mr Ford said.
"There are also mechanisms in place to further reduce the limit if conditions in the harbour deteriorate into the future."
But Huon Aquaculture's executive director Frances Bender said Mr Ford's proposed cut was a sham.
"The biomass is currently 14,000 tonnes, so effectively he's [Mr Ford] not taking any back," she said.
"So this draft determination is window dressing. It's smoke and mirrors and it's spin."
Ms Bender called on the Federal Government to intervene.
"This [State] Government and this regulator have failed our business, failed our industry and failed the people of Tasmania," she said.
"We do not have confidence in this regulator or the Government to appropriately regulate Macquarie Harbour."
Cap reduction shows system is working: Rockliff
The environmental impact of salmon farming in Macquarie Harbour has been contentious for years with temperature spikes and low oxygen putting fish under stress.
In May 2015, about 85,000 fish belonging to Petuna suffocated in the harbour.
In a recent Four Corners program, it was revealed Huon Aquaculture had briefed the Tasmanian Government on the need to reduce stocks three times this year alone.
Tassal, the biggest producer with 40 per cent of the market, released a statement to say it would abide by the EPA's decision.
"Though we note that the determination is a draft, I want to reassure the local community and our employees that the long-term sustainability of Macquarie Harbour continues to be our first priority," Tassal chief executive Mark Ryan said.
State Environment Minister Jeremy Rockliff said ensuring the industry was environmentally sustainable was key to its ongoing success.
"What the EPA's draft determination demonstrates is the system is working," he said.
"People in Tasmania can have greater confidence that their salmon industry, employing 5,200 people, can grow sustainably.
"We trust the science and the independent EPA to make those decision necessary to ensure the environment can cater for the salmon industry."