Under the Macquarie Harbour Area Management Agreement, each month we record and report to the Environment Protection Authority on:

  • Ambient salinity
  • Dissolved oxygen levels
  • Water temperatures
  • Phytoplankton (species and quantity)
  • Water quality
  • Benthic surveys, which assess sediment impacts (annual and as required)
  • Stock losses
  • Wildlife interactions

Frequently Asked Questions

What is the pen to plate story of your salmon?

Petuna understands consumers today want to know where their food comes from and that it is sustainably and ethically sourced, grown and processed. Follow our salmon’s story from farm to fork to learn more.

Does Petuna use pigments?

Salmon and Ocean Trout contain carotenoid pigments of which there are over 600 naturally occurring. Carotenoid pigments provide colour to carrots or the red colour in prawns, as an example.

Specific to salmon and Ocean Trout are a group of pigments called xanthophylls, of which astaxanthin is one. These are also found in krill, crayfish and crustaceans.

The red colour of salmon and Ocean Trout is generated from a diet that contains astaxanthin. In the wild, astaxanthin is sourced from krill or crustaceans that are eaten by the fish. A sustainable way to source astaxanthin is to manufacture a nature-identical form.

This has an identical chemical structure to ‘wild’ astaxanthin but does not require the depletion of krill stocks to source sufficient amounts.

In addition, astaxanthin is an incredibly powerful antioxidant. This is essential during egg development and helps maintain the health and wellbeing of our fish through all stages of development.

Petuna has also been trialling the use of a natural astaxanthin which has been synthesised by algae since 2014.

Do you feed your salmon antibiotics or growth hormones?

Antibiotics have and may be used during periods where stock have been diagnosed with a bacterial disease. The provision of antibiotics and the need to treat occurs only under the supervision of a registered veterinarian with a key focus on the health and wellbeing of the animal.

Petuna has only ever used antibiotics to treat diagnosed bacterial infection. We have never used antibiotics as a preventative treatment.

Antibiotics were last used in early 2015 in our freshwater operations to treat a gut bacteria (Yersinia), which is naturally occurring within the Tasmanian environment and proliferated in our stocks due to a period of heavy rain and flooding in the north of the state.

In any instance where antibiotics are administered, stocks are harvested well after the required withholding period.

Petuna has never used growth hormones.

How do you protect the environment in Macquarie Harbour?

Petuna understands and accepts its social obligation to help maintain the integrity of such a pristine environment. It is also in our commercial best interest to do so.

Our Environmental Management Plan stipulates how our aquaculture activities must be constantly monitored to ensure minimal impact on the environment.

We have invested in state-of-the-art feed systems and oxygen probes which, via underwater cameras, digitally monitor fish feeding behaviour to minimise waste and reduce the impact of any particulate nutrient inputs into the marine environment.

We use responsibly sourced fish feed, maintain low stocks of fish and use the best industry technology to prevent farmed fish escaping into the wild.

Petuna is acutely aware that Macquarie Harbour is vital for multiple industries as well as for its intrinsic value, which is why we’ve adopted a single strategy approach to farming in the area, with the lowest biomass per hectare of water space and lowest input stock ratio per cubic metre.

What and where are your plans for future expansion?

Market demand for Petuna’s premium product means there is the opportunity to expand, provided of course the community’s social and environmental expectations are met.

Expansion of Petuna’s operations will allow the company to meet this increasing demand as well as to fulfil its five-year growth strategy. It also supports the industry’s plan, supported by the Tasmanian Government, to double production by 2030.

Importantly, it will enable Petuna to continue to farm conservatively in Macquarie Harbour, while maintaining steady growth in a deep sea, off-shore environment.

We are currently exploring the possibility of future expansion in both Tasmania’s south east and far north west.

How do you manage seal interaction?

Petuna has a policy of no lethal interaction with seals. Any use of deterrents must, and is, consistent with the government’s Seal Management Framework. Petuna have never supported, or engaged in, seal relocation.

A Wildlife Interaction Plan has been developed as part of our commitment to minimising our wildlife interactions and our marine operations staff are professionally trained to care for wildlife in the event of an interaction on our sites.

Wildlife interactions are minimised by maintaining heavy netting over all our pens to avoid wildlife entanglement, keeping birds away from the fish and preventing seals from entering the pens. Our pen infrastructure maintains net wall integrity, which is integral in preventing below surface seal ingress.

We vigilantly monitor the condition of our pens and continue to invest in new netting technology. This, combined with a strong on water focus minimises seal access to the pens.

What are triploids?

A small percentage of farmed salmon makes up what is referred to as triploid. This means that the fish are infertile and cannot reproduce. The result is a juvenile fish that grows happily and healthily but cannot mature.


Eggs are treated with pressure for a short period of time following the fertilisation process. This treatment will cause the retention of three chromosomes not two.


Salmon naturally mature during their second summer at sea. For this, triploids are used for a three-month period to ensure the quality of product to the consumer is not compromised due to maturation. Triploid stock only contributes to a small proportion of fish harvested throughout a year to maintain quality through the year.

The use of triploid salmon helps support a year-round supply of salmon to the market and is used throughout the Tasmanian and global industry.

What proportion of your fish feed comes from wild fish stock?

Approximately 20 per cent. High quality fish meal and fish oil sourced from wild capture fisheries is used to ensure optimal diet performance (fish growth and health) and to maintain desirable flesh quality attributes, such as omega 3 and 6 fatty acid levels.

There is a continual focus on alternative protein and oil sources to reduce reliance on wild capture fisheries. Wild capture product is currently provided from sustainable sources and meets the criteria stipulated in audited, third party certifications such as BAP and ASC.

Do the pellets you feed your fish contain poultry? If so, where is the poultry sourced?

Petuna’s feeds can contain both poultry meal and oil, all sourced from Australian manufacturers that have been accredited by the Australian Renderers Association.

This makes use of what would otherwise be considered waste material from the poultry industry, reducing our overall carbon footprint.

It is important that a wide range of protein and fat sources are available for the manufacture of fish diets. The focus for nutrition is to ensure the welfare of the animal, support a reduced impact on wild fishery stocks, explore alternative raw materials that have sustainability benefits (i.e. poultry meal) as well as support Australian producers.