Rock Lobster Post Harvest Subprogram: development of a method for alleviating leg loss during post-harvest handling of rock lobsters
University of Western Australia (UWA)
Glen A. Davidson
Principal Investigator: Dr Glen W. Davidson & Wayne W. Hosking
1. 1a) To identify a cold water immersion treatment that rapidly immobilises western rock lobsters, while allowing swift recovery from immobilisation upon return to ambient temperature sea water.1b) To investigate the effect of season/acclimation temperature on effectiveness of cold-stunning in western rock lobsters.1c) To investigate the use of sea water sprays vs immersion for inducing cold-stunning in western rock lobsters.
2. To investigate, in captivity, the effectiveness of the preferred treatment (identified in Objective 1) for reducing leg loss in western rock lobsters during handling.
3. To test the accuracy of factory grading of cold-stunned western rock lobsters versus untreated controls.
4. To describe the occurrence of leg loss, morbidity and mortality of western rock lobsters subjected to cold-stunning prior to episodes of handling during the post-harvest process (i.e. at the time of pot-pulling and sorting, prior to factory grading) and to compare these to the performance of animals handled using current methods.
5. To investigate, in captivity, the effects of multiple simulated pot capture and release events, either with or without cold-stunning, on growth, leg loss and survival of undersized western rock lobsters. (This objective is contingent upon outcomes of Objectives 1-4, see B10 Risk Analysis)
6. 6a) To compare, in captivity, the effects of handling, with and without cold-stunning, on the reproductive success of setose, tar spot and ovigerous female western rock lobsters.6b) To investigate the effects of limb loss on the reproductive success of female western rock lobsters. (This objective is contingent upon outcomes of Objectives 1-4, see B10 Risk Analysis)
7. To conduct a survey to determine the extent and nature of leg loss in the southen rock lobster fisheries of Tasmania and South Australia.
8. To determine, under a range of unique local conditions, the effectiveness of cold water stunning for preventing post harvest leg loss in western rock lobsters.
9. To facilitate widespread acceptance of cold-stunning by demonstrating and promoting, through field trials, its use for preventing post harvest leg loss in western rock lobster.