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the industry has not benefi ted from government initiatives. Freshwater aquaculture incentives are lacking. The koura industry is fragmented, with no measures in place to determine the state of the industry or ways to progress. To improve its status, farmers need to create formalised strategies and perform market research. The industry needs representation and a voice for lobbying. A Koura Farmers' Association would provide representation and promote collaborate efforts to establish viable markets and improve production yields. The Australian marron Cherax tenuimanus is the most similar freshwater crayfi sh to New Zealand koura. While production fi gures reached an impressive 90 tonnes per annum in 2006, it took almost 20 years of focused efforts for the industry to establish and consolidate. Perhaps New Zealand could benefi t examining case study examples of the Australian industry to identify initiatives which might enhance the local freshwater crayfi sh aquaculture sector. While there have been numerous scientifi c studies on a variety of koura biology-related topics, there is a need for an up-to-date review of the academic literature with an aquaculture context. Such information would be highly valuable for current and future koura farmers. For koura farming to be a viable and sustainable industry, research needs to focus on enhancing stocking densities and improving growth rates. While it is unlikely koura would be competitive in an open market against the American red swamp crayfi sh Procambarus clarkii or the Australian yabby Cherax destructor on price or volume, this does not mean a lucrative market cannot be established targeting high- end value product items. Contact Neil de Jong, AUT University. Phone 021 744-633 or email neildejong@gmail.com FARMING FISH in ponds should be encouraged BY VINCE SCULLY W hat is more important, solvency or the environment? Sustainable, non-polluting industries have been touted as a solution. I believe farming fi sh in ponds is one of these. My wife and I are developing a freshwater crayfi sh farm in Kaikoura. We recently harvested 250 kilos of freshwater crayfi sh, or koura, from a 1000sq m pond, for a yield of 2.5 tonnes/ha. On top of this, I wish to branch out and farm an omega 3 fi nfi sh with our koura. We effi ciently produce healthy protein with minimal or moderate use of renewable resources. We create ecosystems and we don't impact on the community or the environment. I estimate a water budget for a hectare of ponds of four litres per second. This rate of water consumption is so low it does not require metering under new legislation. Electricity consumption for mechanical aeration of a hectare of water is 10 kilowatts, infrequently at night, over the summer. Some households may have a bigger power bill. The food conversion ratio to grow protein can't be beaten with cold-blooded fi sh. Fish do not use energy to stay warm or buoyant. We are raising tens of thousands of a native species in decline. We also create habitat for threatened frogs and a food chain of phytoplankton and zooplankton. In essence, the latter is what we do. We apply just enough fertiliser to water to generate an algae bloom to support a sustainable food web. We focus on growing species that are herbivorous, detrivorous or omnivorous, or eat a wide range of insects, vegetables and decaying matter. The growing season ends with the coming of winter. We stop applying fertiliser to our ponds and the algae abate. The saturation level of oxygen in the water increases as the temperature decreases. The paddlewheels are turned off and whatever sediment they agitated has settled. Smelling the roses around the ponds becomes subtle with clear water. Then we drain the ponds. Our resource consent states water samples can be taken 50m downstream of our discharge point to allow for dilution, which in our case is 7:1. However, last winter, water samples were taken from inside all three of our ponds. We were looking at harmless data. We were 80 percent compliant with contaminant criteria at source, never mind the dilution. We were, proudly, squeaky clean. Vince Scully is a master mariner, the author of Poles Apart with Northanger and a koura farmer in Kaikoura SEPTEMBER/OCTOBER 2011 ■ NZ AQUACULTURE ■ 15