Macquarie Harbour seabed compliance results best on record since becoming EPA regulated

​​​Macquarie Harbour surveys have yielded improving compliance results since the EPA became responsible for environmental regulation of finfish farming in 2016. 

Finfish farmers are required to undertake four-monthly seabed video surveys at marine finfish farms in Macquarie Harbour for compliance assessment purposes. 

In January 2024 all 35m compliance points were found to be compliant with environmental licence requirements. This is a great improvement compared to previous January results. 

Seabed video surveys over the past 12 months have shown only one non-compliance at a 35m compliance point. These are the best consecutive survey results, as shown in the compliance history table. 

Commencing in 2017, the EPA Director progressively cut finfish farming in Macquarie Harbour by half. 

The latest dissolved oxygen data for Macquarie Harbour is also encouraging. Oxygen levels have gradually increased, and some deeper parts of the harbour are approaching the Interim Default Guideline Values (DGVs)  which were calculated based on data from before oxygen levels started to decline circa 2009. 

EPA Director, Wes Ford, said “I am cautiously optimistic that environmental conditions in Macquarie Harbour are improving, and this provides a foundation for further improvements through Salmon Tasmania's oxygenation research project, which is currently proving up oxygenation technology for use in the unique environment of Macquarie Harbour."​

Graph showing Dissolved oxygen levels at 6, 11 and 20 metres compare with interim DGV

​These graphs show dissolved oxyg​en levels at three depths across Macquarie Harbour. The 6m and 11m depths correspond to the Maugean Skate’s preferred depth. The red lines show the Interim Default Guidelines Values calculated from data before 2009 for this time of year. The blue lines show the median oxygen levels over the 12 months to April 2024. If the blue line is above the red line, then oxygen levels are within the target range for this time of year. The circled results show that oxygen levels remain below the target range at the 20m depth towards the eastern end of the harbour (i.e. furthest from the mouth of the harbour).
Source: EPA


Published on: 15/05/2024