Modelling prawn movement and spatial dynamics in the Spencer Gulf and West Coast Prawn Fisheries
There is a need for a better understanding of prawn movement and spatial dynamics for improved management and stock assessment in the Spencer Gulf and West Coast prawn fisheries. There is a need to analyse, document and publish information on harvest strategies, prawn movement, commercial logbook and survey spatial data. The ability to produce accurate annual stock assessment reports addressing biological and economic performance indicators is required utilising data from diverse sources including those detailed above. Most importantly, there is a need to develop an effective spatial data base system to handle large complex datasets, enabling analysts to undertake their work. The current data base systems are inefficient and cannot link the analytical software (GIS and statistical applications) effectively or handle the diverse range of data formats required. The project will enhance and develop a spatial data base system, which integrates closely with the statistical and communication software, thereby enabling analysis, plotting, visualisation, modeling and information dissemination. One important spatial module to be developed, relates to prawn tag recaptures and will require links to commercial logbook and survey data.
There is a need to improve management and stock assessment by receiving more detailed catch information in real time. Here communication from ship to base will allow accurate graded size data to be used in stock assessment and for evaluation of fishery performance indicators.
There is a need for better analysis, visualisation and communication of spatial datasets. This will increase the level of understanding of the complex results for industry and management. Harvest systems need to link real time spatial information to decision rules for effective management. Industry frequently raises questions relevant to adaptive change in fishing strategies. For example “When should different areas be fished if prawns move from location A to location B?” or another example “What are the benefits of different types of harvest strategies for stock maintenance and economic performance?” A major problem for management is the clear communication of complex information and processes to others. There is a need to enhance all levels of communication and understanding of the information; adequate visualisation of the data can only achieve this.
Despite the importance to management, little attention in Australia has focussed on adaptive management processes that actively involve industry. The Spencer Gulf prawn fishery provides a good example of a successful adaptive management system in which industry actively participates. There is a need to document the management approaches that have taken more than fifteen years to develop and test. There are likely to be other fisheries in Australia where real time management and monitoring systems can provide substantial economic gain and cost savings.
The application of modern computerised mapping systems, computer intensive statistical analysis and modeling provide enormous scope for fisheries science and management. There is a real need to develop and improve data collection and analytical techniques for stock assessment of dynamic populations (e.g. prawn), especially for those fisheries under high exploitation pressure.
In summary, the project will develop an efficient spatial database that:
- Integrates closely with GIS and statistical analysis,
- Improves catch data collection,
- Results in more reliable stock assessment,
- Improves the efficiency of management through electronic data transfer,
- Increases the understanding and communication of complex spatial information.
Finally, the work will enable substantial historical data obtained from the Spencer Gulf and West Coast fisheries to be integrated, analysed, documented and published.
Final report
Measuring, interpreting and monitoring economic productivity in commercial fisheries
The development of indicators to measure and monitor the performance of fisheries against economic objectives continues to challenge fisheries managers. To date economic metrics have focused on various measures of profitability, and this has been limited to relative few fisheries due to the costs and time involved in collecting the information.
The use of productivity analysis provides an alternative approach to measure and monitor performance in fisheries. It is a broad area of economic analysis that largely estimates how the level and combination of inputs used by fishers affects their level of output, revenue or profitability. From this, the level of efficiency within a fishery can be determined, and how this efficiency level changes over time can be monitored. The role of management in influencing efficiency can also be directly determined. Measures of capacity utilization also provide information on the level (and changes in) excess capacity, which can be used to develop a proxy measure for the optimal fleet size.
Many productivity measures can be derived from available logbook data, while more detailed measures can be obtained from the full economic data (e.g., socio-economics of fishers, vessel characteristics, environmental conditions). These approaches can also provide information about fisher behavior, such as targeting ability in multispecies fisheries, and their response to changes in price and costs, as well as provide information on what is driving changes in profitability (e.g., prices, costs or management). In addition, appropriate measures can be identified to assist managers bridge commercial and other fisheries sectors.
The application of these techniques in Australian fisheries has been limited, and their ability to provide cost-effective information useful for management has not been fully examined. Outside fisheries, productivity has proven to be a useful economic indicator and its potential in Australian fisheries needs to be assessed. This project will meet this need by asking: In what contexts do indicators of productivity and productivity change provide a useful addition to other measures of fisheries economic performance.
Seminar
View the webinar at https://youtu.be/DGDYhk3rITQ
The development of indicators to measure and monitor the performance of fisheries against economic objectives continues to challenge fisheries managers.
The purpose of this webinar is to provide an overview of productivity analysis and the role it can play in supporting fisheries management. In particular, the webinar illustrates how productivity analysis can provide information about relevant and cost-effective economic performance indicators for fisheries.
Three case studies - Commonwealth Northern Prawn, SA Spencer Gulf and West Coast Prawn, and Queensland Spanner Crab - are used as examples of what can be measured using typical Australian fisheries data.
Project products
View video at https://youtu.be/pb6buEp8FUE
This video features the topic of Measuring, Interpreting and Monitoring Economic Productivity in Commercial Fisheries.
View video at https://youtu.be/N0pbJYsiDWY
This video features the topic of Measuring, Interpreting and Monitoring Economic Productivity in the Commonwealth Northern Prawn Fishery.