Aquaculture for all

Breakthrough: Cod Farms Fit for the 21st Century

Nutrition Cod Biosecurity +14 more

Once described as the holy grail of aquaculture, a new breakthrough in cod may be about to change the way we farm fish forever, writes Adam Anson, TheFishSite.

There was a time when the idea of farming cod was a laughable notion. It was a time when cod were confined to the ocean and their stocks were so vast they were thought to be inexhaustible by mankind's appetite alone. Today, it is an idea that is not only possible, but also perhaps essential, if we are to continue to eat cod at all.

The slippery struggle for cod

The fate of cod
Photo: Stockxchng

Like many species of fish, the age of ocean trawlers, by-catch waste and over-fishing has slowly overwhelmed the cod. Consumers' appetite for this fish has led to increasing concerns over the trend of collapsing cod stocks around the world and many fisheries have been cut back as a response. In 2003, there was a full closure to North Sea cod fishing, when stocks fell to new low levels.

Whilst new data released by ICES recently revealed that numbers of cod in the North Sea sufficiently mature to reproduce are now 40 per cent higher than their average since the turn of the 21st century, the North American fisheries have now, in turn, largely collapsed. Cod prices have risen in response to low supply and cod has become a luxury seafood item for many. Some believe that cod stocks are, and will continue to be, unable to meet consumer demands. The answer, they say, lies in aquaculture - if only cod faming was so simple.

Ever since the beginning of cod farming, the industry has been hampered by problems. NoCatch, the company which claimed to possess 'the world's first organic cod farm', sank into administration with £40 million debt. The company was never even in a position to take returns from the project (Cod naturally takes three years to reach full maturity). The company's plight raised concerns about future of ethical whitefish farming and showed just how difficult success would be.

Yet cod farming continued and saw rapid expansion. Recently, Norway accounted for around 80 per cent of the world's farmed cod production, and it increased its national production by 59 per cent from 10,375 tonnes in 2007 to 16,523 tonnes in 2008. But, conservationists are concerned at this growth because no environmental impact studies have been carried out. They say escapes could jeopardise the gene pools of wild cod stocks - a scenario that is believed to be having disastrous consequences for wild salmon.

A further blow to cod farmers saw the Norwegian Directorate for Fisheries end cod-farming in the Trondheim fjord in case it jeopardises important wild salmon rivers.

A string of problematic issues seemed destined to follow in cods wake, but now, after 16 quiet, studious years, a research based company that claims to be solely concerned by 'data and ethics' is claiming to have solved all these issues and many more in one ingenious swoop.

Cod, but not as we know it.

Cheap, sustainable and environmentally friendly cod - this is the claim of DIOBAS, a research company that solves marine problems and prides itself on having "the best expertise available from Marine Biologists to Fish Behaviour Consultants, Geologists and Chemists."

The company have just completed their 16 year Freshwater Research Programme and say they have found a completely new way to rear cod.

"We had to design many new components including, revolutionary Particle Fractionators, with controlled natural daylight sequences, and even tide movements manipulated as part of the controlled environment."
Jean Marriot, Managing Director, DIOBAS

Rearing pens have proved unsatisfactory both in terms of disease vulnerability and practicality. DIOBAS believe their innovative freshwater approach will revolutionise the way cod is harvested and, indeed, many other endangered saltwater species such as Bluefin Tuna. The idea first made an impression on the team at DIOBAS when they accidentally chanced upon a saltwater fish - albeit of no commercial value - thriving in a freshwater lake. It was only when they saw this freak occurrence for the second time that the prospective opportunities of this were truly realised.

Cod cannot survive in a freshwater lake. However, they can be reared in freshwater tanks under computer controlled conditions and it is here that the success of DIOBAS began. According to the company, this allows cod farms to succeed "even on the most unproductive terrain any distance from the sea without quotas and approximately one third below current market price." The benefits to the environment, they say, are obvious, particularly when considering the reduced transport costs and the chance to rest and restock our oceans.

“At times it seemed that the problems associated with this new approach were frankly impossible to solve but the rewards were too great for us to give up on the Programme,” commented Jean Marriot, Managing Director. “We had to design many new components including, revolutionary Particle Fractionators, with controlled natural daylight sequences, and even tide movements manipulated as part of the controlled environment."

According to the company, the welfare of the fish has been the primary factor, which they have approached by keeping stress to a minimum and simulating their natural environment. "They literally grow in a marine version of The Savoy whilst their behaviour patterns remain the same as if they were in the wild."

Their predatory instincts are also catered for as the food is introduced in a unique way through turbulent currents and therefore ‘on the move’ which encourages competition and active feeding. Muscle tone is kept at its optimum as there are strong and varying currents designed within the environment so there is no difference between wild cod and those reared in DIOBAS's freshwater system.

"The entire system is self contained and once filled with water will not require a re-supply of fluids. The main tank is connected to the second tank and water is pumped between the two with a tidal replication sequence at twice the normal rate," explains DIOBAS.

"Coupled with simulated lighting operated with 12 hour daily cycles and seasonally comparative moon cycles, the fish are encouraged to develop at almost twice the normal metabolic rate, a further 30 per cent growth rate is achieved through an enriched feeding programme. A series of Ultra Violet units and our revolutionary Particle Fractionators have overcome the problem of efficient bacteria removal."

Whilst the main tank is almost entirely dedicated to the growth of the Cod, the second tank performs several tasks. Primarily it acts as a giant biological filter and as well as fingerlings, will contain a variety of secondary income sources with filter feeding crustaceans, algae, crayfish and other sought after shell fish. When the main tank is cropped, the fish from the second tank are added and the whole procedure replicated to provide continuity.

According to DIOBAS, once the water has circulated through this second tank it will be returned to the main tank in tidal sequence. The whole system is self contained and therefore cannot contaminate or interact with anything outside the building and there is virtually no waste as all the bacterial content is absorbed by the organisms in the second tank. This is the first time that a truly self contained environment has ever been achieved in either fresh or salt water.

The end result is strong healthy fish, free from disease and the usual parasites that plague attempts to rear these fish in salt water pens.

What Next?

"This success will remain our secret at this early stage," says Steve Marriot, Head of Research, "particularly as we would like to carry out research on other species in the future but suffice to say that no drugs or any genetic modification are used, the cod are entirely natural and thrive in this simulated environment."

DIOBAS have already said that it is not their intention to supply cod for the marketplace but purely to provide the means for others to do so.

Managing Director, Jean Marriot has said that they are expecting the international demand for what they say is "fundamentally the world’s most advanced Freshwater System" to be daunting.

Giving an indication into the potential numbers of Freshwater Systems DIOBAS say that to achieve a 1 per cent market share of the cod quota for UK, France, Germany, Norway and Russia, which is currently 625,000 tons per annum, still well below demand, then just 66 Freshwater Systems are required. Once you take into consideration the developing Asian and Chinese market and this figure is multiplied many fold.

"It is time that modern technology turned the very dangerous, heavily subsidised and often unproductive gathering of an important food source into a safe and reliable industry," says DIOBAS. The company appears very assured in its future role in the development of this industry, but the destiny of cod as both ocean dweller and food is yet to be written.

July 2009

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