Legislative Council, Thursday 23 March 2023

Ms FORREST question to LEADER of the GOVERNMENT in the LEGISLATIVE COUNCIL, Mrs HISCUTT

With regard to the management of fish farms in Macquarie Harbour:

(1) Is in-water net cleaning continuing to be used in these farms in Macquarie Harbour;

(2) how is the waste including fish faeces and other matter prevented from entering the marine environment beyond the pen and lease;

(3) why are nets no longer taken to land for cleaning;

(4) are the so-called 'pen nappies' still being used in Macquarie Harbour, and if not, why not;

(5) how many reported mortalities have been made by companies over the last five years;

(6) what is the current numerical threshold for reporting, and how are the mortalities dealt with from the time of death to the end of disposal; and

(7) what is the amount of antibiotic used by companies being used throughout the life of the farmed fish, whether included in feed material or delivered by any other means for the last five years?

Because they removed that first question, I received a subsequent email saying 'this is about Macquarie Harbour'.

ANSWER

(1) Yes, the practice of in-water net cleaning continues to be used to manage the impact of biofouling on farming practices in Macquarie Harbour. Nets require cleaning to maintain adequate water flow through the nets to ensure sufficient oxygen levels to support fish health.

(2) Fish are farmed in nets that are open to the marine environment. Feed pellets, fed to fish, are designed to result in as little wastage as possible, and have been formulated to ensure maximum uptake and to minimise excretion to the environment.

Companies have also developed sophisticated feed systems including cameras deployed at various depths which are used to regulate feed input based on fish appetite and activity. Sensors and alarm systems are also utilised to shut off feeding should conditions leading to reduced fish appetite arise. Seabed environments, both inside leases and outside of leases, are surveyed regularly by companies to monitor seabed health and ensure that environmental licence conditions are being adhered to.

(3) Nets are kept clean on the pen system using modern net cleaners on a rotational schedule to keep biofouling to a minimum. When required, nets are taken to land for repairs and maintenance or when the nets are due for replacement. The time frame of this is dependent on the age of the net.

(4) In 2017, the Environment Protection Agency director issued determinations that significantly reduced the biomass of fish allowed to be farmed in Macquarie Harbour. These determinations allowed additional biomass to be held in pens with an approved waste capture system.

Tassal opted to utilise waste capture systems at that time, so Tassal could grow out their fish already in the water to full size. The use of waste capture systems, concluded in 2018 and reports were published on the EPA website at the time.

(5) In relation to Macquarie Harbour, there have been a total of 42 reportable mortality event notifications during the past five years in February 2018-23. Huon Aquaculture 14 notifications, Tassal - 12 notifications and Petuna -16 notifications.

(a) Environmental licences require the licence holder to report any suspected or known incidences of disease or mortality affecting greater than 0.25 per cent of fish per day for three consecutive days in any individual pen. Such reports must be provided as soon as possible to the EPA director.

(b) Mortalities are removed from pens daily, weather allowing. Using an air uplift system that draws mortalities from the bottom of the net to the surface collection. Transportation must be undertaken by a registered controlled waste transporter in accordance with conditions of registration, including a requirement to use enclosed bins. Mortalities are taken to an approved rendering, composting or land fill site where they must be handled in accordance with conditions of operation imposed by the EPA, as well as any biosecurity restrictions.

(6) Salmon companies are required to notify the EPA of any antibiotics used as part of the finfish farming activities. The EPA has not been notified of antibiotics used at any leases in Macquarie Harbour during the past five years.