OTHER AQUACULTURE POTENTIAL
There are two separate discussions. Firstly: what can be polycultured with koura? Mullet, whitebait and or carp. And secondly, what could be done to further a tourist venture? Tame eels in the creek, and salmon for tourists to pay to catch.
The option to expand to meet market growth, is physically possible with yet-to-be developed space. It is legally possible with our original consents. However it is only technically possible due to the new regard for water, plus an increase in creek flow rates since the earthquake. Together this allows for a reliable quantity and quality of water, in particular, clarity and temperature that is suitable to farm salmon. And also whitebait.
Waikoura Springs has the capacity for five of the 1,000 sq, m ponds. Three are operating and we have two more to develop.
Our three operating ponds, are referred to as “warm water ponds”. They are dished shaped, and warm with the season, to in summer, reach optimum growth temperatures, for farming crayfish and other finfish, of approximately 22 C, and but which can reach 26 C. This won’t harm crayfish or finfish but it is not suitable to farm salmon or whitebait.
However another type of pond is possible, such as the Burrow's recirculating, flow-through model, where constantly flowing water will not heat to the extent that static water does in warm water ponds.
PROPOSAL TO FARM SALMON IN ONE BURROWS POND WHICH FEEDS A SECOND POND FOR WHITEBAIT AND ADULT KOURA
The volume of suitable water will determine the capacity of the salmon farm. I suggest that our consent to use water at 11 l/p/s would be adequate for one Burrows pond of no more than 1,000 sq m.
Salmon fingerlings can be supplied. It is also possible to purchase, or contract to purchase, adult salmon. This may be at a premium cost. However the tourist venture of paying to catch salmon, could have a margin which makes this viable. The name Kaikoura Salmon, has not been claimed – yet.
We do not have permission to farm salmon. It will need to be added to our fish licence with MPI, and as a permitted use for water for our resource consent.
There should be no issue obtaining permission from MPI, since salmon smoult have, for five years, had permission to be released, in Lyell Creek, so as to further recreational fishing.
However water discharges into Lyell Creek have to meet mitigation critieria. The waste of salmon farming could be mitigated by passing through another pond, where the waste settled, and was fed to koura, who are waste, or detritus eaters; and to whitebait.
Having another pond to farm koura could be as a holding pond for koura that have grown to market, or near market size. Koura are a social hierarchy species. That means big dominate small. So by trapping for bigger koura in the grow- out ponds ( bigger koura are represented in traps with food) and transferring them, is better for koura farming.
Whitebait, like koura, are another fairytale product. High value, demand exceeding supply and distributed direct.
We, and another koura farmer, were approached and encouraged to trial whitebait farming in ponds, by aquaculture staff at Massey University. They could see export potential and therefore more funding for themselves. However that person then left the university and the concept of trials were abandoned.
There is multiple evidence of landlocked species of the whitebait species koaro, that reproduce and live their full life cycle in fresh water. This is the species that climb out of the whitebaiter’s bucket. However it follows, that if you can contain them, then being able to farm them is definitely possible.
There are many papers written on the life cycle of koaro that describe their climbing skills and spawning habits.
I kept and observed koaro in tanks and ponds, for months, but lost them in the summer temperatures of the warm water ponds.
TAMING EELS IN THE CREEK FOR VISITOR VIEWING.
I can readily catch large eels in the creek. They are a king predator in the food chain, and hence are a threat to farming koura. Enter tourism. And remembering that what may be ordinary to me, may be extraordinary for farm tour visitors; tame eels are an opportunity to develop farm tours.
Can we fence off the farm from eels and further attract eels into a pond which we can develop so that it is linked to the creek? Yes.
Is it in a convenient location for visitors? Yes.
With an increase in the creek flow rate since the earthquake, we have lost natural eddies where I could watch eels. Developing a pond linked to the creek will develop an area of benign flow. This could be ideal for taming eels.
FINFISH THAT CAN BE POLYCULTURED WITH KOURA
There are three obvious choices: grey mullet, grass and silver carp. All three can be cultured together in a pond. (refer www.fao.org)
GREY MULLET are herbivorous and hence can be polycultured with koura. Like salmon, their taste is their oily omega 3 flesh. This means by smoking them, they become both a value added product and have a longer shelf life. Unlike salmon, which are carnivorous, they do not require the cost to grow, of an exoensive food pellet. Hence mullet – if it passes the taste test – could compete with salmon.
To residents of the west coast of the North Island, the concept of mullet competing with salmon, is like holding up the laugh board. They are familiar of volumes of wild stocks of mullet, being erratically dumped on the market and where they are regarded as catfood.
Contrasting to that, mullet were the biggest selling fish in the Auckland Fish Market in the 1850s. This brought a fast sailing class of “mullet boats” to bring the catch to market. A class of vessel that still exist – at least in name - today.
The appeal of mullet was the cause of developing a cannery in Kaipara. However it failed, due to the inconsistency of supply of wild stocks.
The popularity of mullet throughout history has been acknowledged by anthropologists. When they looked to trace the migration route of Polynesian ancestry, they looked for five words that have always been in common use throughout the generations. One word they chose was mullet. FYI The maori word for mullet, kanae; in Samoan, is anae.
What is presently stopping us from farming mullet is two things.
First. The spawning of mullet occurs in summer, in seawater, soon after migration from estuaries. Although some nations, such as Egypt, have then gathered the mullet fingerlings and placed them in fresh water ponds to culture; this is a practice which other countries, such as ours, view as threatening conservation of wild fish stocks, and it is not permitted.
A solution, is to hormonally induce mullet in a laboratory, and to then pass the fingerlings on to the grower. Mullet were first hormonally induced in Taiwan approximately 60 years ago.
I have asked Cawthorn Institute if they were interested in doing this. They were, but in a joint venture with growers. What is stopping that for me, is cost, as I do not yet have many grower friends to share the cost with, so as to make this an economic proposal.
The second reason is temperature. Although grey mullet are regarded as a sub tropical species, they have been recorded in the Waikato River, at 7 Celcius.
My vision to farm mullet would be to winter over fingerlings in warmer water of the first winter so as to grow them out for one summer season. I have one heat pump and have allocated space to do this in an insulated Burrows tank.
I could not see a potential for carp. The bad name caused by the invasive European carp has tarnished other species of carp. Or one bad apple has discredited pears. A viewpoint that won't be revisited while there is a popular fish resource of blue cod.
However enter massive tourism and new market expectations. We have visitors who enjoy grass carp.
Grass carp fingerlings are available to supply for farmers to grow out. They have attractive growth rates.
Grass carp are neither on our fish license nor our consent to use water. The process will involve user pay processes and a deep breath, but ultimately should be successful after you have paid to educate others that grass carp, if they did escape into waterways, will be into water temperatures where breeding is not possible.
As Grass Carp will not like our winter temperatures. I am suggesting that they could be wintered with mullet fingerlings, outdoors, in an insulated Burrows tanks, supplied with a heat pump.
WATERCRESS AND HYDROPONICS.
Watercress grows abundantly in local creeks. However what stops restaurant staff from collecting it, is that tourists who come from countries such as England, where watercress is valued, have awareness of advisory health warnings on gathering wild cress, due to the risk of being infected with the liver fluke parasite. Therefore growing cress in a pond has potential.
Watercress planted in the pond will be attacked by koura, so that they can then eat the microbes that then form on the stems. Cress to culture for local market could be planted in cages floating on the pond. Hydroponics could also. They will need to be netted from ducks, but when grown on rafts on the water, they are away from the usual gardeners pests.