Media release – Environmental Protection Authority, 16 September 2024
Dissolved oxygen levels in Macquarie Harbour highest in more than a decade
EPA scientists have again reviewed long term data sets to create a status update report for dissolved oxygen levels in Macquarie Harbour. The August 2024 report shows that the trend of improving oxygen levels in the middle and deeper waters of the harbour have reached new heights.
EPA Director, Wes Ford, said the median dissolved oxygen levels across Macquarie Harbour are at their highest levels in more than a decade.
“Our scientists have used two independent data sets that have hundreds of data points across multiple sampling locations throughout the harbour, and I am pleased to report that two thirds of Macquarie Harbour now has dissolved oxygen levels within the range observed from 1993 to 2010,” Mr Ford said.
The data is collected through a monthly broadscale environmental monitoring program that salmon companies are required to undertake, and the EPA’s own quarterly monitoring program which has been ongoing since 1993. Both data sets show an overall improvement in dissolved oxygen levels.
For shallow waters, the southeastern segment of the harbour also shows dissolved oxygen levels in line with the range observed from 1993 to 2010. Below 16m depth, dissolved oxygen levels in the southeastern segment are now close to the historical range, with some further improvement needed.
The Macquarie Harbour Oxygenation Project is currently trialling technologies that are expected to sustain and further improve oxygen levels across the harbour. The salmon industry is finalising oxygen mitigation plans, which are due to be submitted to the EPA for approval in the coming days.
Commencing in 2017, the EPA Director progressively cut the scale of fish farming in Macquarie Harbour by half. “It is very encouraging to see that oxygen levels in Macquarie Harbour can improve while fish farming remains at this scale,” said Mr Ford.
Editor’s note: the EPA did not release the data.
Media release – Nick Duigan, Minister for Parks and Environment; Eric Abetz, Minister for Business, Industry and Resources, 17 September 2024
Another improvement for Macquarie Harbour’s dissolved oxygen levels
The Tasmanian Government welcomes the latest promising results of Environment Protection Authority oxygen level testing in Macquarie Harbour.
Minister for Parks and Environment, Nick Duigan, said the highest median dissolved oxygen levels in a decade were another endorsement of the National Recovery Team strategy, involving the Tasmanian Government, the Australian Government, West Coast Council, the salmon industry, IMAS and Hydro Tasmania.
“This excellent result comes as the Macquarie Harbour Oxygenation Project trials technologies that are expected to sustain and further improve oxygen levels across the harbour,” Minister Duigan said.
“The salmon industry is also finalising oxygen mitigation plans, which are due to be submitted to the EPA for approval in the coming days.
“The Tasmanian Government firmly believes that the Maugean skate and the salmon industry can continue to co-exist.”
Minister for Business, Industry and Resources, Eric Abetz, said this announcement builds on the promising results earlier this year, which confirmed that water quality has been improving.
“The effectiveness of this Government’s adaptive management framework is key to the result of the EPA finding that water quality across much of the harbour is now comparable to the ranges observed between ten and thirty years ago,” Minister Abetz said.
“Macquarie Harbour is perhaps the most intensively monitored and researched water body in Australia and this independent analysis demonstrates that farming operations at current production levels are not adversely effecting ecosystem function.
“Despite repeated requests for action and yet more evidence that demonstrates salmon and skate can coexist, one has to ask what is it about the science that this Federal Labor Environment Minister is choosing not to believe?
“This Government unequivocally backs salmon jobs on the west coast, and for Tania Plibersek to continue to disregard this information is insulting to the hundreds of Tasmanians whose livelihood is in the balance, and the integrity of the scientists and regulators who have worked tirelessly to monitor and analyse the health of the system. Again, we call on Tania Plibersek to consider the facts, listen to the science and make the right decision.
“Through our 2030 Strong Plan for Tasmania’s Future, we will stand up for our sustainable aquaculture industries as well as the unique natural environments in which they operate – not sacrificing either for the sake of the other.”
Media release – Bob Brown Foundation, 17 September 2024
The Maugean skate cannot coexist with big toxic salmon farms in their only habitat – Urgent response needed from Federal Environment Minister
Yesterday’s report by the Tasmanian Environmental Protection Agency shows that there has been a mild improvement in dissolved oxygen in some parts of the Harbour. The report makes no mention of the fact that over the summer of 2023/24 a large natural ocean driven reoxygenation event occurred. This was a fortunate event for the Maugean skate, but does nothing to address the number one threat to their survival, which is industrial fish farms.
“It is outrageous to suggest that fish farms can coexist with the Maugean skate based on this report. It’s akin to saying that humpback whales gave birth to lots of young this season, so let’s start commercial whaling again,” said Alistair Allan, Antarctic and Marine Campaigner at the Bob Brown Foundation.
“Macquarie Harbour is the only habitat in the world for the Maugean skate . Fish farms have been found to be a catastrophic impact on their survival. Fish farms must get out of Macquarie Harbour immediately.”
“The Maugean skate is teetering on the edge of extinction. Last week our lawyers wrote to the Federal Environment Minister, Tanya Plibersek, asking for an explanation within 21 days as to the reason or reasons for the delay in making her decision. We are currently urgently awaiting her response. The Minister could act today, remove fish farms, and save an animal from extinction,” said Alistair Allan.
