Freshwater crayfish are in increasing global demand. Global markets are large (US$10 billion) however demand consistently exceeds supply. The Australian freshwater redclaw crayfish (Cherax quadricarinatus), endemic to northern parts of Queensland and Northern Territory, are considered an outstanding candidate for major industry development due to its rapid growth, ease of culture, and tolerance to a range of environmental factors. Despite the great potential and market demand widely recognised for redclaw crayfish, the development of large-scale production of redclaw has been limited by a lack of established and proven intensive production technologies. Traditional pond-based methods result in unpredictable yields primarily due to adverse environmental conditions, inbreeding, predation, cannibalism, large size variations and escapees. To date the Australian industry average is 3-4 tonne per hectare, falling well short of market demand.
Vertical farming technologies provide efficient use of space, increased yield/hectare, environmental control, year-round production, and can be established anywhere. It was proposed that redclaw could be well suited to vertical farming overcoming the issues associated with traditional production methods. Commercial crab fattening boxes from Thailand were used in this 4 year trial. A total of 1000 individual boxes were arranged in systems comprising of 6 boxes horizontally and 8 or 9 boxes high, each box holding a single crayfish (unless breeding). All systems were RAS with zero water exchange and a total footprint less than 300m2. Breeding and production of eggs was successful year round with 2nd and 3rd generation females producing significantly more eggs per spawning. All breeding crayfish were microchipped enabling full traceability and the establishment of a selective breeding program. There were no mortalities due to cannibalism in the individual culture and growth rates showed significantly less variation. The outcomes of this four-year trial prove that redclaw crayfish are well suited to vertical culture for breeding and growout with a potential yield of 16 tonne/hectare/yr. Vertical farming technologies will enable the redclaw industry to become one of the most sustainable and market competitive aquaculture industries globally.