INLAND AQUACULTURE

1. Industry & Products

Aquaculture is the farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants. Farming implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of stock being cultivated.

With the move towards consumption of fish and other seafood products as part of a healthy well balanced diet, combined with the increase in world population, demand for seafoods is expected to increase by more than 20 million tonnes by the year 2000. The 1991 world seafood production was around 90 million tonnes, of which 15.8 million tonnes was produced by aquaculture. It is expected that the majority of the world demand will derive from aquaculture.

Australian aquaculture production has increased by nearly 80% in value since 1990. In 1995-96 production was valued at $396 million and is expected to reach $500m by the year 2000. The biggest earner is the pearl oyster, comprising one third of all aquaculture production. The fastest growing industries are salmon farming in Tasmania ($51.7m 1995-96), and southern bluefin tuna farming in South Australia ($40m from nothing in 1990).

Over the past few years, inland aquaculture of native fish species has focused on the production of Silver Perch (Bidyanus bidyanus), with small quantities of Golden Perch (Macquaria ambigua) and Murray Cod (Maccullochella peelii) being produced. Silver Perch production in the last three years increasing by some 400% from an estimated 15 tonnes in 1994-95 to 65 tonnes in 1996-97, this along with estimated figures for the 1997-98 season up around 230 tonnes of silver perch.

With the increasing awareness of the nutritional and health value of eating seafood, the aquaculture industry is set for even better figures over the next few years. Market prices have been relatively stable, the infrastructure for feeds, services, stock and so on is expanding, the work force is becoming more experienced, and industry issues are being addressed on a national basis through the development of a national strategy.

Overseas and local technology is well developed, and the industry has the potential to develop rapidly in a number of ways, these include: ·

• On farm ponds making double use of irrigation water.
• Cage culture in public and private waterways.
• Utilising tank culture technology to grow any species of fish, native or exotic, fresh or salt water, warm or cold water and double cropping, with minimal water use.

2. Physical Requirements

Due to the compact size of the systems, and the minimal use of water, the main requirements for consideration relating to the site location for recirculating tank culture systems are:

• Supply of quality water.
• Shedding, or other structures to assist in controlling the environmental conditions.
• Security.
• Power supply, to operate pumps, etc.

• Tanks generally self-cleaning fibreglass or “poly” or lined concrete tanks.
• Biological filter, to remove ammonia from the water.
• Mechanical filter, to remove any solids from the water.
• Foam fractionator (protein skimmer), removes dissolved organic material.
• Air pump, to increase the oxygen levels in the water.
• Optional Equipment includes:
• Ozone generator, to increase Oxidation Reduction Potential (ORP), which when low is dangerous to fish health.
• Ultraviolet Light (UV) can be used to sterilise the water, and remove any diseases, which may be present in the system.
• Heaters/Chillers, to control the water temperature at optimum growing levels.

3. Production

Modern recirculating systems, incorporating the latest technology can grow up to 200-300 kilograms of fish in a 2,000-litre tank per crop. The production per year will depend on the type of fish and the market size of the product. It is believe that selected strains of Silver Perch can be grown from a 20 mm fingerling to a market size of 500 grams in approximately 6 months. Based on this 400-600 kg of fish could be grown in a single year.
Alternatively species such as Barramundi can be grown from a fingerling to a market size of 350 grams in just over 100 days, giving three crops per year. With other culture methods, fish can take three times longer to grow to the same size and the stocking rates in earthen ponds are much lower.

At this time Silver Perch appears to be the species with the most aquaculture potential. The advantage of recirculating systems is that it enables total control of the fish’s environment to be exercised. This means that the optimum conditions for the fish can set up in the system. Therefore the systems are not species specific, meaning that any species of fish within reason, can be grown in any area. Suitable fish for these systems maybe Barramundi, Silver Perch, Golden Perch, Eels, Catfish, Australian Bass or Murray Cod, and marine species such as Whiting, Mulloway, Snapper and Black Bream. Also the current market prices for some of these fish may be much higher than Silver Perch.

4. Marketing

It is highly recommended that you investigate the best marketing methods for your species, and you should check out the going prices before investing. There are some individuals who buy live fish, and will collect them from your door. The market for these fish is widespread. On a small scale the fish are probably better to be sold locally, such as to restaurants, while on a large scale, they can be sold to live seafood wholesalers who export them live overseas.

Marketing options available to fish farmers include:

• Locally sold, either live, or gilled and gutted.
• Domestically sold, sent to fish markets, generally gilled and gutted; live to city restaurants.
• Exports markets, live product, or gilled and gutted.
• Value adding markets, eg fillets, smoking, or other processed forms.

• Fresh and high quality.
• No residues from chemicals, contaminants etc that may be found in fish from the wild.
• Even size. Size can be of your choosing (eg 350g, 500g).
• Sustainable. No depleting of natural fish resources.
• Perfect water quality 100% of the time, exceeds natural water conditions.
• Environmentally friendly, water is recycled therefore minimum water use, and no pollution.

5. Financial Situation

The current market prices for silver perch in the Sydney fish market for gilled and gutted Silver Perch range from $5-$9 per kilogram, with live product $10-15/kg. The Melbourne fish market prices are roughly the same, however very little Silver Perch is sent to the Melbourne fish market.

The current prices for Barramundi range from $8-$12 per kilogram gilled and gutted in Melbourne, with live prices higher, the Sydney market prices are much the same with live product around $14 per kilogram.

Other species which could be included, trout $4-$5/kg, Atlantic Salmon $12-$14/kg for gilled and gutted or dressed fish.

6. Organisations & Contacts

7. References