The South Australian lobster fishery management model

Modelling the rock lobster (Jasus edwardsii) fishery in South Australia was the focus of a three-year data gathering program. In collaboration with fi shers, a tool for assisting in the sustainable management of the resource w as developed. The goal was to test management policies to allow increases i n reproductive output while enhancing economic yield. The model's user inte rface was developed to an ease of use comparable to commercial software for use by fishers in comanagement of the resource. This paper describes the m odelling framework, user interface, and results for management strategies u nder consideration. The framework is comprised of five principle submodels: catch, effort, growth, economics, and population reproduction, with the lo bster population divided into 8 mm length classes by sex and spatial cell. The mortality of lobsters occurs by commercial harvest, natural mortality, incidental release mortality, predation inside pots before retrieval, illeg al harvesting, and recreational catch. Five categories of management contro l scenario were simulated: catch quota, effort regulation (as total pot ret rievals), size regulations (allowing minimum, maximum, and mid-range slice length protection), and seasonal and area closures. Model outputs imply tha t size strategies have limited potential compared with effort limitations a nd quota. (C) 1999 Elsevier Science Ltd.