Seafood CRC: bioeconomic decision support tools for Southern Rock Lobster
The needs addressed by the project were identified and developed through the extensive consultation process. They were:
1. The collection of information on the economic performance of the fishery in each state and incorporation of this into the annual assessment process. The intent here was to better integrate economic and biological data into the decision making process for management.
2. Bioeconomic modelling capability is required by modifying the existing stock assessment model used across the fishery to incorporate economic data and an economic submodel to compute net economic return under different harvest strategies or management regimes. This economic analysis capability has been developed in Tasmania (and will be improved) but there is no capacity in the other two states. A bioeconomic model will provide the capacity for managers and industry to formally conduct cost-benefit analyses on decisions about future management of the fishery.
3. There needs to be effort put into exploring better management for the fisheries (using the bioeconomic model). This includes different TAC options, size limits, and seasons (ie harvest strategy evaluation, HSE). This requires industry and government steerage to propose new strategies and review model outputs. It also requires a shift in decision making where management tries to target the best economic outcome for industry rather than merely ensuring stock sustainability.
4. There needs to be testing of the pathway in making SRL fisheries more profitable. Steps 2 and 3 above can be used to define better management approaches but how would they be implemented? It's one thing to define a profit maximising TAC with a bioeconomic model, but would this system really work with year-to-year volatility in recruitment, prices and costs. (Formally, this means management strategy evaluation of economic control rules, which respond yearly to changing stock and economic indicators.)
Final report
The Southern Rocklobster fishery is the most developed of the fisheries included in this series of projects because sophisticated bioeconomic models and stock projection capacity had already been advanced through previous research. This research takes the process further to extend the modelling tools to other states and to examine the use of economic control rules. This means, for example, that it would be possible to evaluate how feasible it would be to target maximum economic yield in the face of price volatility. This level of bioeconomic analysis capability is only available elsewhere in Australia in the Northern Prawn Fishery, Australia's best example of the use of economic data for management to increase profits.
This project also aimed to produce bioeconomic analysis tools for Southern Rocklobster fisheries and determine management strategies using economic models. Economic data for Tasmania were collected, and a lobster fishery projection model was produced which permits the testing of a wide range of strategies, specifically to evaluate each strategy’s economic performance. Using this model, the profit expected under each strategy was estimated.While the analysis showed a small impact of opening the fishery for all 12 months, this analysis is only preliminary and is greatly limited by the lack of any data for winter fishing in South Australia since these two zones have been closed to winter fishing to date. The best policy was a yearly quota-setting harvest control rule designed to seek an approximately constant yearly harvest fraction (a constant exploitation rate). By setting the total allowable catch yearly to remove an approximately constant fraction of the available lobster biomass, three of four important management objectives were optimised.
