At the 1998 FRDC Rock Lobster Post-Harvest Sub-program annual workshop (Hillary's Boat Harbour, Perth, W.A.), fishers, processors and scientists identified post-harvest leg loss as a major problem.
Industry incurs losses due to post-harvest leg loss in several ways:
1) Loss of weight.
2) Loss of value/restricted marketing opportunity.
3) Increased mortality of returned undersized animals and reproductive females.
4) Reduced growth of damaged undersized animals.
5) Reduced reproductive success of returned, damaged, breeding females.
NEED FOR REQUESTED EARLY START DATE (MAY 1, 2000)
Experiments addressing Objectives 2 & 4 are contingent upon the outcome of the experiments for Objective 1 (see B11 Methods). Therefore work on Objectives 2 & 4 cannot begin until Objective 1 is met. If the project were to start on 1 May 2000, there would be sufficient time left in 1999/2000 fishing season to identify preferred cold-stunning treatments for at least 2 of the 3 proposed acclimation temperatures (see B11 Methods). The preferred cold-stunnning treatment at the third acclimation temperature could then be tested early in the 2000/2001 season and work on Objectives 2 & 4 could be completed by the end of this season, in preparation for discussion at the 2001 annual subprogram workshop. Based on the outcomes of Objectives 2 & 4, the sub-program management will decide whether to continue the research and address Objectives 5 & 6. Should the research begin after May 1, 2000, experimenatal work could not begin until November, when the season starts. The desired acclimation temperatures to be used in Objective 1 occur in the wild over the course of an entire season, therefore work on Objectives 2 & 4 could not start until the following season (2001/2002) and work on Objectives 5 & 6 could not start until after discussion of results at the 2002 Sub-Program workshop in September. Thus by starting 2 months early, approximately 12 months advantage will be gained.
A novel brief application of cold-stunning was identified as a practical method for preventing post-harvest leg loss at several points in the post-harvest handling chain. Using this method, there is potential for the western rock lobster industry to save in excess of $2 million per season in lost catch weight attributable to leg loss. In addition, considerable value could be added to the catch through increases in the numbers of lobsters fit for exporting as premium product forms, such as live or whole frozen boiled. Rates of leg loss occurring in different zones of the fishery have been quantified, providing an objective basis for conducting cost-benefit analysis of any preventative measures under consideration.
During the course of this study hypersaline-induced leg loss was identified as a significant cause of post-harvest leg autotomy. This finding led to a second study (FRDC Project 2001/255) which in turn identified potential six figure savings using simple, cost-effective methods.
Rates of post-harvest appendage loss in the southern rock lobster fisheries of South Australia and Tasmania have been documented as being very low. The small amount of antennal damage occurring on board commercial boats appeared to be largely preventable by making simple changes to handling practices. Further investigation of this issue does not appear warranted.