A nationally renowned salmon producer will trial a world-first waste collection system.
ABC News reported in May the waste collection system would be trialled by Tasmania-based company Tassal at a cost of about $500,000, before being rolled out across all overstocked pens.
Tasmania’s Environmental Protection Authority (EPA) will as a result reduce fish stock numbers in Western Tasmania’s Macquarie Harbour, but will allow Tassal to exceed its limit.
The EPA will reduce the overall cap on production from 14,000 to 12,000 tonnes for the 12 months from June.
But companies can exceed the new limit if an approved waste collection system is installed under fish cages.
EPA director Wes Ford told ABC News if Tassal did not adopt the waste management system it would have to remove an extra 4,000 tonnes of fish, as it would exceed the limit.
“In economic terms that is more than $60 million of fish that is currently in the harbour that had I not allowed them to grow through it would obviously impact on the economy of the state, the economy of the west coast and the community,” he said.
“So Tassal has a choice, Tassal can either put fish waste collection systems in or they can remove fish from the harbour.
“The way the draft determination is written is the companies can’t grow more than 13 tonnes per hectare without collecting the fish waste.”
Mr Ford said the EPA would work with any of the companies that explore fish waste collection systems.
“This technique is not used anywhere else in the world, so it is novel, It has a risk associated with it but that’s what trials are about,” he said.
In a statement, Tassal said it respected the EPA’s decision which balanced “environmental, economic and social needs of the Strahan and wider Tasmanian community”.
ABC News reported it has agreed to install waste capture liners under pens to further minimise environmental impacts in the harbour.
Environment Tasmania’s Laura Kelly told ABC News there was no evidence that the fish waste collection system would work.
“This should not be allowed to progress as a so-called trial until there is an environmental impact assessment,” she said.
“There is absolutely no evidence to suggest that faecal mounds on top of a tarp will be any less damaging to oxygen levels in the harbour than faecal mounds on the sea floor.
“This is not the time to be trialling capturing of thousands of tonnes of faeces using a tarp. This is time to implement the law.”