Freshwater Crayfish

Salmon

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New Zealand Clearwater Crayfish (Koura) Ltd



Sales

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NZCC Koura are also marketed by Dianne Appleton at Equagold.

 

 

Dianne Appleton

Managing Director

 

www.equagold.co.nz

 

Phone:   +64 9 2677367

Fax:      +64 9 2677365

Mobile:   +64 27 2358747

 

For direct sales please email David at dscltd(at)clear(dot)net(dot)nz.

 

Please note

we do not export our koura – only available in New Zealand

 

The Company

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New Zealand Clearwater Crayfish (Koura) Ltd (NZCC) is a private company established in 1996 by Peter Wilhelmus and David Smythe to farm and market the North Island species (Paranephrops planifrons) of New Zealand freshwater crayfish known as koura.

This new pioneering venture in New Zealand is now up to commercial production.

NZCC farms and markets Koura on the Ormond property under the fish farm licenses held by Ormond Aquaculture Ltd.

 

New Zealand Red Glory

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After finding some distinctively red coloured juvenile koura in the farm, those were set aside and raised in an independent circular tank. With careful selected breeding, a significant stock of pure red koura has been developed.   It appears that a red gene has been developed in the NZCC general stock and we have been able to isolate it by trial and error. 

 

We are now able to supply the aquarium market within New Zealand with this unique natural creature.  At the moment, purchase of NZ Red Glory is only available direct from the farm as shown in the Sales section previously.

 

All interest in this colourful species should directed by email.

 

 

 

New Zealand Red Glory

Bred at New Zealand Clearwater Crayfish farm

 

The Farm History

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When first established, the NZCC koura farm was part of an organic multi species freshwater aquaculture complex based on a small mixed sex salmon farm.   The farm is located in Wairau valley about 35km from Blenheim. Just “upstream” of the Wairau Valley settlement.

The farm was only the second in New Zealand to be established and market farmed koura. The first being near Alexandra.

There was no information or existing practical experience to build upon so the farm has been developed by the partners through hard work, trial and error, and reading literature from Australia, USA and Europe to glean ideas. David Smythe has visited yabbie farms in Australia.

After initial aquarium trials in 1993 and 1994, field trials began in 1995 and farm construction began in March 1997 with a broodstock pond of some 100m² and two races totalling about 80m in length and 5m wide.




Koura broodstock pond and first two growing-on races 22 November 1997

By March 2011 some 1300m of raceway are established and hatchery facilities expanded into the old salmon farm hatchery races and growing on ponds.   Since the demise of the salmon and loss of organic status the whole aquaculture area has been converted to farming koura and experimenting with other fish species.

Water is diverted from the original Ormond Aquaculture Ltd salmon farm settling pond via a rock screen and head race to the growing on races. The Koura environment has been developed and managed to achieve as closely as possible natural conditions but with considerable enhancement such as eliminating predators from all sources and providing abundant natural cover and a supplementary diet.




Berried female about 120gm and 140mm TL with about 350 eggs

Broodstock either mate in the broodstock pond or are collected and selectively mated in tanks.  While selective mating remains an ongoing experimental process, it is showing very good results and now all koura are farm bred. Berried females are collected from the broodstock pond about 4 months after mating and transferred to the hatchery. Females selectively mated are placed in the hatchery as soon as the fertilised eggs are cemented to the pleopods.


One of the Founding Fathers

When all the hatchlings have left the female she is returned to the broodstock pond and the hatchlings remain in the hatchery until about 10 to 15mm overall length (TL) then transferred to a growing-on race. During that time they have undergone at least four if not five molts and the shell has 'hardened up so that the translucent effect of the baby hatchlings has disappeared and they have taken on a brown-faun colouring.

We have often been asked by students if the colour of koura is influenced by their surroundings or container they are kept in. We have not been able to identify any colour change in adults, hatchlings, or juveniles that is attributable to the colour of the container. The only colour change we have seen is the natural change from translucent hatchlings to brown-faun juvenile.  Except, of course, for the new NZ Red Glory koura selectively bred in the farm.

Minimum marketable size of about 100mm TL and 45 to 55gms weight is achieved in about 20 months while up to 105-115mm TL and 90 to 110 gm is achieved in about 2 years 3 months.  Larger size Koura of around 130 to 150 mm TL and 120+ gms have grown in about 3 years.

Pincers on left: 160mm - 6 males with 3 females on right end.
Size range: males 150-165 gms, females 80 - 95 gms.

Fecundity has improved over the years with females carrying about 250 to 400 eggs on average by natural selection. The selectively mated females have had over 400 eggs.

In August 2000 females were found mating while some were found with eggs just hatched. This is both late (some two months) and very early (3 months) respectively and looks promising for possibly having a wide spread of breeding through the year, if the trend continues. However, the timing may be influenced by the La Nina weather pattern over New Zealand the last three years bringing gradually warmer temperatures.

The farm now keeps about 2000 breeding females which have been grown in the farm.  This broodstock provides the basis for continuity of supply for full commercial production. The first rotation was initiated in February 2000 when some 35000 hatchlings were transferred from the hatchery to the races. Many more hatchlings have been carried to survival in the hatchery each year, and our target annual commercial harvest of around 1.5t  is closer to being achieved.

 

Organic Status

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The farm complex was originally set up as an organic freshwater multi-species farm and OAL received two environmental awards in each of 1977 and 1979.  Sadly organic status no longer applies to the farm due to water pollution factors outside the control of farm management.  As a result of the water pollution, salmon are no longer farmed.  Fortunately, by August 2012 the water pollution factor has been resolved.

The total aquaculture complex remains GE free and organic farm principles are maintained.

The directors are confident that the system developed is sustainable and in harmony with the environment. Achieving organic certification for both the salmon and freshwater crayfish farms was a major achievement that sadly did not get the support it required from the local authority.

 

Feeding

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A feature of the farm is the careful management of the environment in which Koura thrive. A high level of natural nutrition is promoted but supplementary feeding is essential to achieve growth rates desirable for a commercially viable enterprise.

The original high protein organic food was originally developed utilising all solid waste from processing salmon.   At that point in development, the farm complex was operating as a zero waste entity.   For a time, suitable 'waste' fish was purchased and processed into our fish silage on site. The fish silage was mixed with other organic products to produce the koura food.   The koura food is now made at an organically certified commercial enterprise to the diet provided.

The koura are generally fed every second evening if all the previous feed out has been consumed.  However with the continual rise of the cost of food ingredients, alternatives are being explored.

At this stage there is no scientific data to show feed out rate per kg of koura or the conversion rate, but a procedure for achieving that is being developed.

No chemicals or hormones are used.

 

Harvest

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Koura are harvested by trapping in 'opera house' traps and by partially draining the race and collecting Koura by hand.

Before sent to market the koura must be held in clean running water without food for up to two days so that the gut line is purged. This enables the koura to be presented with a clean white tail meat.

 

Cooking

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As a general guide, koura should be treated similar to fresh scallops.  Do not over cook!!!.

Koura should be chilled in a freezer for about 2 - 3 hours before dropping into boiling water or putting on the barbeque. The shell will turn a bright red. Cook for about 1½ minutes then drop into a large bowl of iced cold water to arrest the cooking.  The cooked colour is a real stand-out in any food preparation or presentation.  Do not put so many koura into the water that will arrest the boiling as this will produce an unattractive blotchy red/brown colour.

There are several ways the cooked koura can be presented and it is really over to the imagination of the chef. If further cooking is to be done, such as sauté the tail meat in garlic or herbed butter, the initial cooking time should be no more than 1 minute and secondary cooking another minute.


One male and five females; four showing eggs cooked on body as 'crayfish caviar'


Pile of male koura


Koura tails, sautéed in butter and garlic with honey glaze and dipping sauce

 

Research and Development

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There are many things NZCC would like to do by way of research and development but several factors limit the immediate prospects for serious research.

Research and development is on going with the hatchery to increase survival rate of hatchlings and to develop a process to triploid koura.

Other research involves other fish species with potential to be farmed in a multi-species environment is progressing as funds allow.