Why recirculation aquaculture system....

The central argument is: The consumer demands quality fish!

In a closed system a high production of quality fish on a relatively small area is possible. Furthermore, an all year round a constant production of fish while farming in a closed system is independent of climate and environment. Another argument are major water savings; instead of a few hundred m³ per kilogram produced fish in flow through systems we need only 50 to 300 litres new water per kilogram produced fish. If really required HESY can come close to a zero new water requirement, but looking at the costs for such a filtration unit and increasing production costs HESY accepts new water intakes. Compared to a “controlled” open system, our systems save on heating or cooling costs by constant mechanical and biological filtration by re-circulating the water.

To establish new flow through systems is almost impossible in several countries, because the water use and costs are simply too high. Recirculating aquaculture systems are the solution for fish production in these countries. Another arguments is fish health improvement through recirculation systems, in Chile -e.g.- the control on the health of the fish in the pre-growing phase in open waters is a major problem, in a recirculation unit it’s easier and better to produce salmon fingerlings and salmon smolts than in the lakes. In Chile HESY made two farms 150 km away from Punta Arenas in the middle of nature. The electricity and oxygen is produced by generators. If it is no technical problem to do it there, you can farm on almost each spot of the world. But always keep an eye on the cost price and market price.

For West European countries, it is the environment and climate that concerns fish farming. To many changes in temperatures and environmental restrictions have pushed into the direction of re-circulation aquaculture technology. Recirculation systems are able to farm several interesting species on a constant optimum temperature without environmental problems.

What are the disadvantages?

There are hardly any disadvantages. However, to run a re-circulation system one needs a start-up capital for building -, installation- and running- costs. Also in open systems there are those running costs but in a re-circulation system the costs can be a higher. However, HESY can, with our technology, compete in production costs price with the cage farming in the Mediterranean.

What is the procedure to set-up a fish farm and what to keep in mind before starting a farm?

Enough willingness to give up a secured life for an unsure future.

The job of fish farmer is interesting and the profits are usually good but working with life stock can be also a risk. Enough financial backing by own capital and/or bank, eventual subsidies must be an extra foundation of a business. To establish a farm you need, wherever in the world; building licences and environmental licences. Take care of energy sources and water sources. Make a choice on the fish you want to farm in relation to your own feeling, the market and the water source. Take care of fingerlings, fry or eggs supply. Try to make contacts and eventual contracts for the sales. Find a good supplier of a fish farming system or fish farming elements. Ask for references and try to make visits to an existing farm.

Only accept a system when it includes a good training and after sales service. Contact feed suppliers and demand assistance for feeding regimes. Still when everything seems under control you need some luck while an accident can always happen. Insurance companies are getting attracted to this industry so it is possible to cover some of the risks.

What kind of rules to follow to get licences and grants?

Start with your own local government and make them part of your plan. Hopefully they get excited about your plan and see the advantage to have a fish farm in their community. For governments employment is often a main issue. Follow all the procedures; they often seem complicated and eccentric and take a lot of time, but if you can full fill all the demands of the law you will get at last the licences. Usually the decision makers know nothing of the technology. You will to explain here a lot. Some countries have grants some have not, some grants are interesting and some are not. If you can get a grant; follow the rules and try to get the best portion. But never let the grant be the base for your financial set up.

What guaranty to get eggs, fry or fingerlings and a guaranty to sell the fish?

For many species eggs, fry or fingerlings are available. Shipping is done in sophisticated ways to places all over the world. If you produce a good quality fish on regular base in an area where there is a market or even better a niche market there is no problem to sell direct or by a trader.

What is the best way to start a farm, buying fry or fingerlings or an average stock?

This depends also on the capital men can spend on this. HESY would advice, when financially possible, to start with eggs, fry or fingerlings especially when we have a fast growing fish. Even with a slow growing fish as eel it is hard to say what is best. A customer started in May 2005 with a full standing stock of 20 tons eel from a farmer who went into Sturgeon farming. He reached end of the year 2005 a stock of 35 tons and had sold already 20 tons. He took his first glass eels 10 months after he started with fingerlings. An other farmer started with 200 kilogram of glass eels, he reached a stock of 20 tons and sold 5 tons before the end of the year. He took 8 months after his first intake of glass eels already a new batch of glass eels. For us an very important issue to go for “new fish” You never know what you get when you buy bigger older fish.

How to keep your farm free of diseases or at least keep the risks as low as possible?

Buy eggs, fry or fingerlings from good suppliers. HESY does believe in normal protection rules that people can follow and are willing to follow. All these protections with foot baths, booths, shoe covers, hand cleanings, jackets, caps et cetera are to my opinion far overdone.

HESY believes in simple statements to visitors: No hands in the water and no touching.

Off course it shall depend on the lay-out of a farm. When you need to walk on a grit above the tanks you need more protection than when you walk on a concrete floor. The workers will know the rules very well. Each system must have it’s own working equipment like nets and baskets.

Are there major differences between designs with different species and in fresh water or salt water?

To our opinion, besides the right material choices, no major differences. There is a basic design for a HESY system with some loops for better water treatment and for waste water treatment. This depends often on the availability of enough water and on the species. Some fish can be farmed in pretty “dirty” water but for salmon and in hatcheries we need water as clean and clear as possible. In a salt water system we include a protein skimmer eventually with ozone dosing, but we are not so keen to use ozone. When possible we rinse the mechanical filter with fresh water so the waste water will be more or less fresh water.

What are the water consumption and waste discharges?

(COD, Nitrate, Phosphorus, Discharge equivalents).

This is an example of a waste water test in a 300 tonnes fish farm at full production:

This is an example of a sludge test in a 300 tonnes fish farm at full production:

 
An other test in an other farm before and after the use of a de-phosphate unit

What kind of advantage in water consumption can be expected when we use de-nitrification and de-phosphation?

(COD, Nitrate, Phosphorus, Discharge equivalents)

Quality of process water can be as mentioned above.

Quantity can be, as we accomplished in a practical situation, for a 300 tons farm less than 30% of the mentioned 50.000 m³ per annum.

What is the energy consumption in a fish farm and what can be done to minimize this?

In a system with all loops - for example a pike perch farm or eel farm - without energy to produce oxygen it shall be approximately 7 kW electrical energy per kilogram produced fish. For Oxygen supplied by a generator we calculate ± 1 kW per kilogram production.

On average we calculate 1 kg Oxygen per kg production. When we install a system according the Blue Label design we can run a system on ± 50% of these costs. We bring the filter system under level so the main flows are on gravity, in that case only one pump is required to run a system. On many places it is technically not possible to make a sump of 6 meters deep, in that case we must accept these higher energy costs.

Aquaculture can have a great future if we work together and deliver only good quality and share knowledge