From today a more accountable system and preferred regulatory tool for limiting the production of finfish in Macquarie Harbour will be in place. A determination limiting Total Permissible Dissolved Nitrogen Output (TPDNO) will replace the standing biomass caps which have been used in previous determinations.
Finfish farming in Macquarie Harbour has expanded since 2005, peaking in 2014-15 with a standing biomass of over 20,000 tonnes.
In recent years, to reduce pressure on the harbour and allow for environmental recovery, biomass has been capped at 9,500 tonnes. However, despite compliance with the standing biomass being maintained, annual feed inputs have gradually increased since 2018. This increase in feed inputs appears to be due to a change in harvesting strategies in Macquarie Harbour and has resulted in an increase in total annual production.
By introducing a TPDNO, the EPA is confident that this regulatory tool will limit finfish production in Macquarie Harbour, and therefore build upon improvements in ecosystem function and dissolved oxygen levels that have been observed in Macquarie Harbour since 2017. Companies will need to carefully manage their feed inputs in order to comply with the TPDNO determination.
The TPDNO for Macquarie Harbour will be 500.1 tonnes applicable for any rolling 12-month period from 1 September 2022 to 31 August 2027. The EPA Director will continue to monitor the environmental health of Macquarie Harbour to assess whether further reductions in TPDNO are required over the period of this determination.
Further information about the new determination, including the statement of reasons can be found on the Macquarie Harbour page.
The international review of the Macquarie Harbour Broadscale Environmental Monitoring Program (BEMP) is also now complete, and outlines several recommendations for updating to rationalise, improve, and modernise the monitoring program.
This is the second review completed by the Scottish Association of Marine Sciences. The first of these reviews for Huon Estuary and D'Entrecasteaux Channel was completed and published in May this year.
Further information can be found at Macquarie Harbour BEMP Review.
When the remaining review, for Storm Bay, is completed this review will also be made available on this website.