On 31 May 2017, the Director of the EPA determined that the biomass for Macquarie Harbour will be set at 12,036 tonnes for 2017-2018, or 13t/hectare of farmed lease areas. His decision notes:
- Long-term monitoring of dissolved oxygen confirms a steady decline in middle and bottom water oxygen concentrations since 2009 to the current extremely low levels.
- The environmental health of Macquarie Harbour is likely to represent a crucial factor in the future well-being of the critically endangered Maugean Skate population.
As flagged in his draft determination, despite the overall reduction in biomass limits, the Director will allow Tassal to exceed its allocated cap and stock up to 28t/hectare (about 4,000 extra tonnes), provided an “approved waste capture system” is installed.
The Director released guidelines for approved waste capture systems, and indicated that systems would be regulated under an Environment Protection Notice. Tassal has already received approval to trial five waste collection units during June 2017, with all waste collected to be taken ashore and treated prior to disposal. No EPN will be issued for the trial, as biomass limits are likely to remain below the 13t/ha cap during that period.
Huon Aquaculture’s submissions in response to the draft determination raised strong concerns about the effectiveness of waste collection systems, and the appropriateness of trialing unproven systems in an already compromised environment. The company responded to the final determination by announcing that they will continue their legal challenge, querying why complex waste capture provisions were developed rather than requiring Tassal to harvest its stock to comply with the biomass cap.
To see our timeline of Macquarie Harbour events, click here.