ABARE is a professionally independent research organisation attached to

tables or diagrams may be reproduced for such purposes provided acknowledgment of the source is included. Major extracts or the entire document may not be reproduced by any process without the written permission of the Executive Director, ABARE. Foreword The southern shark fishery has shown signs of being overexploited and overcapitalised for a number of years. Despite the introduction of an input based management system in April 1988, effort in the fishery has not been reduced to levels where the conservation of the stock and profitability of the fishery are ensured. As a result urgent action is required to sustain the fishery. In order to assess the relative benefits likely to accrue from alternative management options, a bioeconomic model of the fishery was developed. The model incorporates the biological models and assumptions developed by the Southern Shark Research Group into an economic framework. In this research report the bioeconomic model of the southern shark fishery is described. The results of simulations of alternative management plans and their effect on the profitability of the fishery are presented to demonstrate how the model may be used. The sensitivity of the model to various biological and economic parameters is also evaluated. Implications for the long term management of the fishery were detailed in ABARE Acknowledgments The biological relationships used in the model presented in this paper were derived by a number of scientists who belong to the Southern Shark Service Consultant) has been drawn on heavily. The other members of the Research Group have also contributed to our understanding of the biological processes in the fishery and these contributions do not go unrecognised. Research into the major biological parameters is continuing and will no doubt lead to an improved understanding of the biological relationships that exist in the fishery. The logbook data used in formulating the model were provided by the Victorian Marine Science Laboratories. The Australian Fisheries Service also provided invaluable information on changes in the fleet structures over the past few years.