Harvesting is generally quite straightforward, however if it is not managed carefully, the previous several months of production management can be wasted. Some form of sampling prior to harvest is important to gauge the size and number of crayfish expected. Harvesting may involve a number of methods, although the most effective is the application of a flow-trap. This trap exploits redclaw's strong response to flowing water. A slow but steady flow of water into the pond via a box and ramp will illicit movement of crayfish against the flow and into the box. Flow-trapping should involve 95 percent drainage of the pond over 24 hours from dawn to dawn. There should be several thousand litres of water remaining in the deepest part of the pond at dawn, when stock are removed. The slow drainage enables the crayfish to move out of shelters and with the main body of water, so they concentrate and respond most effectively to the flow trap. Both the flow trap and the last remaining water must be well aerated. The entire harvest can be easily lost if the flow trap or remaining pond water are not aerated. The stock should be quickly removed and transported to clean water in a tank system. Care should be taken to minimise crushing by not exceeding 15 kg of stock per transport container. Other harvesting methods include bait trapping and drain harvesting with manual collection of stock. The majority of redclaw are sold live, and so after harvesting stock are held in tanks with flow-through water supply or a recirculating system involving biological filtration. A period of at least 24 hours in the tank to permit purging of the gut is recommended prior to packing for transport. Redclaw can survive extended periods out of water provided they are kept cool and moist. Packing therefore involves insulated containers containing some moist packing material (foam rubber or wood shavings) and cooling packs. Road transport is used for local markets, however air transport is necessary to the large seafood markets in Sydney, Melbourne and for export. |