The South China Sea is an important fishing area with an annual harvest of some 5 million tonnes, or 10% of the catches jointly taken by the developing nations of the world. Details are given of a model of the area describing fisheries catches and biological interactions. The area, viewed as a large marine ecosystem, was divided into 10 subsystems; each subsystem was then linked with adjacent subsystems by predatory links, and detritus flows. An analysis was then made of catch statistics for each of the subsystems. It is believed that if all systems could be harvested at around the highest efficiency, an additional 5-6 million tonnes could be taken annually from the South China Sea; however, more refined analyses are needed to further investigate these possibilities. If linked with careful studies of the economic and human aspects of fishing, such analyses will provide guidelines for integrated fisheries management advice.

Input restrictions are commonly used to prevent rent dissipation in fisheries. This paper examines whether these schemes are successful by calculating the degree of input substitution between restricted and unrestricted inputs. Conventional elasticities of substitution cannot be used when the firm faces controls on the use of some inputs. In this case, the appropriate measure of substitution, the elasticity of intensity, must be used. Data from the British Columbia salmon fishery provide evidence of input substitution possibilities for two vessel types. These results call into question the usefulness of input control schemes.

This project for the development of a fisheries management expert system (FMES) aims to provide computer based tools for fish stock assessment and fisheries management policy. This report outlines the objectives; approach; FMES ProTuna tuna fisheries management plan; the FMES ProFish more generalized fisheries management tool; and the choice of development software and product development involved in these expert systems.

In a deterministic setting, it has been demonstrated that taxes and quotas can be equivalent regulatory instruments and that both can in principle induce an optimal allocation of resources in markets where externalities are problematic. In this paper we consider growth, harvest, and demand uncertainty within the context of Canada's Pacific halibut fishery and find that, while taxes remain the preferred instrument, the welfare losses arising from the use of individual boat quotas are minor.

Overfishing in the Texas shrimp fishing industry by time period and fishing area is investigated. An optimal harvesting pattern is determined using a multiperiod mathematical programming model where prices, fishing effort, catch, and resource dynamics are treated endogenously. These results are then compared with actual effort. The comparison indicates substantial excess effort in spring and early summer, especially in the bays and shallow offshore areas. The peak fishing season also occurs later in the fall in optimal harvest pattern than in practice. The results indicate both producers and consumers gain from reduced fishing effort because of improved size composition of the harvest.

This report describes the development of the expert systems FMES ProTuna v2 (a tuna fisheries management plan) and FMES ProFish v3 (a more generalized fisheries management tool). Choice of development software and the product development are highlighted and the ProTuna FMES outlined. A review of the theoretical considerations of expert systems is presented in appendix 1. Appendix 2 focuses on the long term research considerations presenting a detailed design that concentrates on the specific problem of relating assessment methodologies to overall fisheries management and the data requirements that arise from this. Appendix 3 reviews existing expert systems in fisheries.