The Process

Hatcheries

The Hatchery is the place where we incubate eggs and manage the salmon’s fresh water growth cycle until they reach their juvenile stage. The fish are grown for approximately 8 to 12 months. As they grow they are progressively transferred into larger tanks before they are ready to be transferred to sea and grown into adult Salmon.

Our hatcheries are located throughout the state on different river systems. This allows us to take advantage of different watersheds and environmental conditions providing us with the precise range of juveniles (smolt) that we need to deliver good quality and availability year round. HUON has built a state of the art hatchery in Southern Tasmania. This hatchery is the first of it’s size in Australia and uses the latest recirculation technology to ensure the best growing conditions for our fish, limiting any potential impact of drought conditions, whilst at the same time minimising the farms environmental footprint. The spring water utilised at the hatchery is recirculated many times before the minimal amount of waste water is then irrigated onto neighbouring tree plantations.

The hatcheries within the Huon Aquaculture Group [HUON] mimic the natural lifecycle of the Salmon. In the wild, the young salmon spend the first year of their lives, in rivers and streams before moving to the sea to feed, grow and return to lay their eggs. The Salmon naturally lay their eggs [spawn] in May of each year. As in the wild HUON salmon start their life as eggs in freshwater. We collect eggs in June/July from females and these are fertilised by male brood fish. The resultant fertilised eggs are then incubated in dark cool water until they hatch, a process that lasts almost 3 months. When they hatch and become known as Alevins.

Alevins have a large yolk sac that contains their food until they are ready to eat manufactured feed. When they have used up their yolk sac they are known as Fry. At the end of this incubation period they are ready to take food and are transferred into small tanks. Now having access to external feed they grow rapidly and become known as Parr, with distinctive patch markings on their sides. These marking where thought to help camouflage them from predators in their native streams.

The transformation from Parr to Smolt is very important. The smolting process in salmon is controlled by day length. In the spring of each year smolts will, in the wild, migrate to sea. This is triggered first by the short days of winter followed by the lengthening days of spring. By mimicking these day length changes in covered tanks we can put fish to sea from March to October every year. As the transition takes place they become silver and look very much like small salmon. During this phase, they adapt themselves for living in the open sea, rather than fresh water. In the hatchary we give the young salmon the best growing conditions and get them big enough to smolt at different times of year. When they are ready to be transferred to sea they are called smolts.

Each year we transfer around three million smolt to sea ensuring a regular supply of harvest fish to our customers. We avoid transferring fish during the warmer summer months, as this can be a little stressful on the fish, as they prefer cooler water temperatures. Smolts are transported by special truck fitted with tanks, oxygenation gear and are looked after by one of our specially trained technicians. Think of it as a mobile aquarium.

The smolts are then released into net pens at one of our range of brackish (low salinity) sites in the Huon Estuary.

The low salinity water helps the smolts adapt to marine life. As the fish get bigger over the next few months we move them further south into leases with more saline water finishing up in our furthest south leases on the edge of the southern ocean where the cooler waters provide them with a great summer environment.

Sea Farming

This phase covers the salmon’s life in brackish and seawater until they are ready for harvest. Once the smolts have been transferred they start out in brackish waters. They weigh around 100 grams and grow very quickly after transfer. The fish will reach market size (4Kg) usually within 14-16 months in seawater.

As the fish acclimatise to the salt water and continue their grow phase, they are transferred into larger sea pens and moved progressively further out into the ocean.

At HUON the day to day activities undertaken by farm operations are based around 4 key farming philosophies. Fish should be:

  1. Well Feed
  2. Stress Free
  3. Kept clean & nurtured
  4. Raised in a pristine environment

Fish size and year round availability are also key objectives. We are continuing to develop techniques that produce a more uniform size of fish through the year to meet our customer’s requirements.

Feeding and Meal

Farmed salmon in common with all other meat-producing animals must receive balanced nutrition if they are to develop normally, remain healthy and provide a high-quality end product. The diets that we buy are made for us specifically. Tasmania is a unique environment and our fish are truly a special breed, so our diets here have to meet some specific requirements. Our diets have to supply two main requirements; firstly they need to provide the fish with enough energy to live and thrive; secondly they must supply all the nutrients (proteins, fats, vitamins and minerals) to grow.

After many years of research we have a pretty good understanding of what the relative amounts and balances of each nutrient need to be in the range of environmental conditions we experience. This generates a specification for our diets for each stage of the salmon’s growth and our supplier’s manufacture to this specification.

There is some flexibility in which ingredients go into the recipe to deliver that specified feed but all ingredients must go through a battery of quality checks before they can be used. Aside from fishmeal and fish oil, our diets may contain wheat, soya derivatives, corn gluten, meat by-product meal, blood meal and vitamin and mineral supplements very similar to those taken by people. In fact most of the ingredients we use are commonly used in the pet-food industry and our diets look very like dry pet food – albeit with a very different nutrient profile, higher in energy and more digestible.

The pink colour of wild salmon flesh is species specific and results from the presence of carotenoid pigments. The wild salmon diet includes krill, zooplankton, small fish and crustaceans. Many of these, especially the crustaceans, contain these pigments and the salmon extract them and deposit them in skin, muscle and organs. There are more than 600 naturally occurring carotenoids, for example they produce the colours of autumn leaves, cherries and tomatoes. The groups of carotenoids found in fish are known as xanthophylls and include astaxanthin and canthaxanthin. Salmon are unable to synthesise these pigments and, just like vitamins and all other nutrients, they must receive them as part of their diet. Carotenoids are an excellent anti-oxidant, they are used by salmon for a variety of biological processes and play an important role in reproduction and fertility. The amount of carotenoid in the feed varies according to defined quality criteria and nutritional requirements. The carotenoid may come from crustaceans, from yeast culture or, more usually, from nature identical synthesised products.

Our fish are fed to on demand to satiation – that is to say that they eat as much as they want when they want. Unlike humans, our salmon tend to eat the right amount and stop when they are full! Our feeding systems are the most advanced available. Each pen of fish has an underwater sensor, which records feed pellets; a solar powered feed hopper sitting on the surface throws out a measured spread of feed and the sensor regulates the speed and amount of food given. When the fish stop eating – the feed stops flowing. This is the best and most efficient way to feed salmon and ensures that every fish has the opportunity to feed.

Low Stress Environment

Just like making sure that the fish have access to feed when they want, at HUON we extend this philosophy to all aspects of the salmon’s environment. Fish need to be cared for in an environment that meets their needs. This commitment to respect the fish means that we put them at the centre of our planning and operations.

Anything that leads to stress on our fish is managed out of our system. For example the warmer water temperatures that we see in Tasmania promotes weed growth on the nets, this cuts down the flow of water and stresses the fish, our dive teams check every net for weed growth twice per week and we change and clean nets as soon as they hit a trigger level.

Furthermore we practice the principles associated with low stocking density. While salmon are a species that like company and associate themselves in schools or shoals in the wild, we limit the number of salmon in each open sea pen to ensure that they will have plenty of oxygen and feed to ensure their health. Like the differences often highlighted between free range chickens and battery hens, HUON salmon spend their time in some of the largest open sea pens in the world.

Bathing

Tasmania is a unique environment when it comes to salmon farming. The relatively high water temperatures promote the settlement on the gills of Amoeba, a single celled microscopic animal. The Amoeba multiply and reduce water flow at the gill surface that can limit oxygen supply to the fish causing lethargy and, if untreated, death.

The way that we manage this is to bathe the fish in freshwater. The freshwater causes the Amoeba to burst and flushes any associated debris from the gill surface. We collect the freshwater as rainfall in our own dams or from the mouths of local rivers just as they meet the sea. Whilst freshwater is harmful to the Amoeba, salmon are happy in either freshwater or seawater.

Lighting

The salmon’s internal life cycle calendar is driven by changes to day-length. Their readiness to go to sea, their drive to return and to spawn is triggered by specific increases and decreases in daylight hours. With all the best practices in place, our fish grow very well, and combined with the day length can trigger them to sexually mature. When salmon become sexually mature their growth slows, their skin darkens, males develop a hooked lower jaw (Kype) and the flesh quality of both sexes declines sharply. To offset this we also use artificial lighting to lengthen the day at specific times of year. This again adjusts the salmon’s internal calendar and maintains fish quality.

Fallowing

At HUON we regularly rest our lease sites; a practice known as fallowing. Like in land based farming there is a need to give each lease area time to a replenish itself. This practice ensures that we maintain the pristine environment for the fish so they are strong and healthy.

Harvesting & Wet Processing

Our goal is to produce fish that are over 4kg for our customers 365 days per year.  This can be a challenge due to the seasonal pattern of smolt introduction and the impact of temperature fluctuations. Generally we start the “season” in April with slightly smaller sizes and peak with our largest fish in October before closing in March with average sized fish.

After the 14-16 month growth period, the fish pens will be towed into Hideaway Bay for harvest. They are held just off shore in holding pens where they await harvest. Our harvesting system involves transfering the fish from their holding pen up to a purpose built harvest table. The transfer process was developed around the idea that in the wild, salmon like to swim upstream into a current. This method ensures that the fish are transferred with the minimum of stress.

We harvest our fish at night; we then process them quickly to ensure that they reach the market as fresh as possible. At the harvest table HUON use RSPCA award winning equipment to percussively stun the fish, the most humane way to slaughter salmon. Immediately after being stunned, the salmon are bleed and placed in an ice slurry ready for transport to our wet processing facility at Parramatta Creek.

In our Parramatta Creek facility the salmon are quickly transferred from the ice slurry into the processing line. Using the latest state of the art equipment, each fish is gutted, cleaned, check weighed and packed into ice filled polystyrene boxes and marked for shipment to our markets all around Australia and the world. These fish are known within the industry as HOG salmon or Head On Gutted Salmon. Because we harvest and process so quickly these fish can be seen in the mainland markets within 24 hours of harvesting.

Some fish move onto further processing if required by customers. At Parramatta Creek we also fillet salmon and can supply pre-rigor fillets to customers upon request.

Our west coast sites in MacQuarie Harbour allow us to grow fish specifically for harvest during the March to May period each year. This period is when we change from one year class to the next in our southern sites. At this time we transition from around a 5Kg average harvest weight as we harvest the last fish of the current year class to just below 4Kg average harvest weight as we start the new year class. Our west coast fish help smooth this step down in size because they are an intermediate size – around 4.5Kg on average – and this helps us provide a more uniform size range to our customers during this period.

Value Added Processing

The Huon Value Added (VA) business located in MT Barker is a highly automated operation, using the most advanced fish processing equipment and process control systems available to the industry.

Capable of processing over a 1000kg of fish per hour, converting fillets into a range of fresh fish products including skin-on or skin-off fillets; plain or flavoured hot smoked portions and sliced cold smoked.

Our smoking processes include sophisticated fully processed controlled hot smoke chambers and traditional cold smoke rooms, where the smoke from burning selected woods is introduced to the fish over a determined period of time depending on the size of the fish….within an environment of process automation, this ‘hands on’ approach is retained to provide the very best possible cold smoked salmon.

Included in our range of products is our prized caviar presented in stylish glass and gourmet dips that combine the distinctive flavours of hot smoked fish with matured cheeses and spices.

Our fresh chilled products are packed and delivered to our customers in a range of package sizes and forms, including skin (VSP) and thermoformed vacuum sealed barrier film packs from 100g to 1kg.

By combining the expertise of people who know and care about fish with the best technology available e.g. equipment that can slice, weigh and place salmon accurately and automatically on trays, Springs provides a high quality and competitive fish processing operation.

To Market – Fresh to the Trade

Huon’s unique location and harvesting techniques enable their Salmon to be ocean harvested and landed fresh to major fish markets around Australia overnight, typically one day faster than anyone else.
Appointed Distributors typically buy Huon Salmon Whole (HOG) and onsell to fish mongers and the trade. In turn, Fish Mongers typically scale and portion their whole Huon Salmon into Steaks or Cutlets at store level to suit their customers.
Choices
Although Whole (HOG) is the most popular order, Huon Salmon can also pre-ordered with skin on or off and pre-filleted and portioned into vacuum or bulk packing.

To Market – To Supermarkets

Caviar, Whole, Portioned, Smoked or Dip?

Through our Mt Barker facility located in South Australia, Huon provides a range of Salmon products flavoured the traditional way and conveniently packaged for supermarkets.
Caviar
Fresh Tasmanian Salmon roe with the distinctive red colouring.
Hot Smoked Salmon Steaks
Salmon Steaks cured and smoked the traditional way for a delicious addition to salads pastas or canapes.
Smoked Salmon Dip
Dip made with a high % of smoked salmon for a divinely smooth and delicious spread of salmon flavour.

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