We are farming crayfish in the crayfish capital of the country with 35 eating houses. How good is that?
The FAQ is what is the difference between fresh water and salt water crayfish? It's the point of sale.
The first question should be: do we have suitable water quality for aquaculture. Examining the water tests from two supplies of ground water, our consultant said "perfect for aquaculture."
And do we have reliability of supply of water? Waikoura Springs is sited on tiers of aquifers that are fed from mountain runoff. The mountain's contain limestone which is soluble, and give our water supply an ideal value of carbonate hardness. This is part of what our consultant regarded as perfect for aquaculture.
For the height of the mountains and the width of the Kaikoura Plains, the water allocation ( for our location on the plains) is comparably generous (11 litres per second). It is also, for our location on the plain, reliable, as the springs (including two wells) on our property, have remained as springs, in drought periods.
One well returns a value of iron oxide, and can be assumed to be from a top aquifer. (Iron in water is common in shallow wells on the plains. Hence a neighbouring named Red Swamp Road.) A second well, consistantly returns a nil value of iron oxide; and therefore can be assumed to come from an aquifer in a lower tier. This means less risk from contamination from discharges from other land based sources. This has been proven consistently with 12 water test comparisons of the two wells, at three monthly intervals.
We have a temperate maritime climate. That is: we rarely have extremes of water temperatures. This is important. Fish like stability.
Fresh water crayfish are valued throughout history by nationals that are our tourists ... Sweden, China and the USA.
In growout ponds, present development is 2,000 sq m. Full development would be 4,000 sq m. We can grow 10 koura at 50/60g, per surface sq m of water. Retail price is $80/kg. Wholesale $66/kg. Therefore present farm income has a potential of $96,000; and full farm development income of $192,000.
Or alternatively, stocking 50 juveniles per sq m, we could potentially supply to grow out farms, up to 150,000 now, and 250,000 juvenile koura when in full production.
We are not farming remotely and thereby forced to accept a wholesale price for our product. Rather, our location is ideal for a percentage of our product to be sold at both retail, and a value added price.
Koura have unique cost saving benefits to the grower.
1/. They are one fish species that will reproduce in captivity. Hence there is no cost to buy seedstock.
2/. Because we sell them live, there is no capital or compliance cost needed for on-site processing.
3/. Feed costs are economical ... fertiliser to grow algae to start a foodweb ... hay to grow microbes ... mealworms grown on site.
Saying the last few sentences again ... this is a popular, high value product, grown at minimal fixed costs.
16 years experience. We took over the dream of an estate of Peter Johnson to farm koura. It was bare land. Our original farm design was a flow-through system in raceways, supplied by diverting creek water by gravity. The concept was ahead of its time. Water quality of creek water was an issue for us. It has taken time for a collective approach to respect water. However now, we have it: clean water 24/7.
However then, we switched to farming in ponds. We found and employed a successful WA marron (crayfish) farmer as a consultant - to develop static water ponds. By using only ground water, we had secured water quality.
The switch was a good thing for us. Fresh water aquaculture in ponds, is a developed industry in many countries. There is an accessible, comprehensive, scientific knowledge base.
However as creek water - which was not in the past - but is now, running pollution free - 24/7. We could - legally, and physically - develop the last two ponds on a different design. One that could accommodate both static or running water. Why would we want to do that? Running and static water have different temperature characteristics. Running water is a more mean annual temperature and now within the range of farming whitebait and salmon. Koura could be farmed in both. A polyculture of koura and whitebait is a prosperous thought!
The creek is the true right branch of Lyell Creek which has been assessed in an engineers report to be "mostly spring fed ( of o.1 to 0.15 cu m) with only minor variations of water flow/levels occuring durings significant rainstorm events. The form of the stream, including the condition of the stream banks supports this view. Furthermore, the adjacent land north of the stream falls noticeably to the north towards a major stream ( true left branch of Lyell Creek, 10 metres from our property) providing the principal means of drainage to this area. The catchment (of our creek) is therefore limited."