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Report of the Sub-Regional Workshop on Fishery Bio-Economic Modelling.







Horemans, B. Report of the Sub-regional Workshop on Fishery Bio-Economic Modelling,1992 17-21 February 1992, Kariba, Zimbabwe. UNDP/FAO Regional Project for Inland Fisheries Planning (IFIP), RAF1871099-TD/43192 (En): 25p.


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    Project
    Report of the bio-economic modelling workshop on the small pelagic fisheries of the west coast of peninsular Malaysia
    Vistana hotel, Penang, Malaysia. 12-16 February 2001
    2001
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    A bio-economic modelling workshop was organized in order to improve the information base for the preparation of a fisheries management plan of the small pelagic fisheries of the West Coast of Peninsular Malaysia. Plan preparation by the Department of Fisheries is supported by the FAO/Norway FishCode Project (see Field Reports F-13 and F-17). Two different modelling approaches have been applied to these fisheries. The surplus production bioeconomic model of the Gordon-Schaefer type sugg ests that effort at MSY is about 387,000 standard purse seine days producing a MSY of about 109,000 tonnes of small pelagics. At the MSY effort level, however, resource rent is completed dissipated and the fishery incurs an estimated loss of MR 25.6 million. As current effort level (data of 1997) is about 380,000 standardized fishing days, the analysis suggests that fishing effort and capacity are excessive. A resource rent of about MR 77 million might be attainable through the reducti on of fishing effort to 180,000 standardized fishing days, i.e. less than half of the current level. This result should be interpreted as providing an order of magnitude only because of the application of a single species model to an assemblage of small pelagic species. One species group, namely Rastrelliger, contributes 73 percent to the ex-vessel value of these fisheries. This result should also be interpreted cautiously because the shoaling nature of small pelagic species was not expl icitly taken into account in the modelling exercise....
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    Project
    Report of a bio-economic modelling workshop and a policy dialogue meeting on the Thai demersal fisheries in the Gulf of Thailand
    Hua Hin, Thailand, 31 May-9 June 2000
    2001
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    Similar to many marine fish stocks in Asia and elsewhere in the world, the demersal resources in the Gulf of Thailand have been subjected to excessive levels of fishing effort since perhaps as long as two to three decades. This has resulted in a change in catch composition with a higher share of short-lived species in the catch. The influence on the value of the catch is not unambiguously negative because several short-lived species including certain cephalopods and crustaceans fetch g ood prices in the market. In general, fish prices showed real increases over the last decade including so-called ‘trash-fish”, i.e. by-catches of small fishes that are converted into fishmeal. The rapid growth in feed-intensive livestock and shrimp culture production has resulted in a rapidly growing fishmeal market. However, there is certainly concern about the impact on the Gulf of Thailand ecosystem and on bio-diversity of a continuation of the very high levels of mostly indiscrim inate fishing effort, especially bottom trawling. While the immediate effect of a reduction of fishing effort could cause a decline in the quantity and value of the catch, the long-term benefit is likely to be very large. This is indicated by the findings of all three types of modelling approaches applied during this workshop, namely surplus production model (Gordon-Schaefer and Gordon-Fox), age-structured Thompson & Bell model (BEAM 5) and mass-balance eco-system model (ECOPATH).
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    Report on the Bioeconomic Modelling of Kapenta Fisheries on Lake Kariba
    GCP/RAF/466/EC SmartFish Project
    2013
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    This work on the bioeconomic modelling of the Kapenta fishery on Lake Kariba was conducted as part of a process of joint fisheries management of the fishery between the Governments of Zimbabwe and Zambia, and was supported by the IOC-SmartFish Project under its Fisheries management component (UNFAO). The first part of the report provides an overview of the Kapenta fishery: information about the bioecology of this resource; harvesting systems in operation on the Lake; management systems in both c ountries; as well as some elements of processing and marketing. The second part concerns the biological modelling. A summary of the work that has already been done is provided, together with an assessment of available data. Based on the information available, the dynamic population model was chosen and used (surplus production model of Fox 1970). Thereafter, the results of the biological modelling are presented and discussed. The third section of the report concerns the development of the econom ic part of the model. Previous economic assessments of Kapenta fisheries have been summarized. The results of the Economic Survey, carried out in 2013 to support the bioeconomic modelling exercise, are put forward. Assumptions and analyses to develop the economic part of the model (modelling demand and costs) are also presented in detail. Finally, the fourth section of the document details the bioeconomic model: the way it works and its results. This bioeconomic modelling exercise shows that in 2011, the Kapenta resource was overexploited with an excess of fishing effort of about 40 percent. Fisheries were operating almost at a situation of open-access equilibrium where the rent of the resource is fully dissipated. As a consequence, the fishing industry is achieving very poor economic returns and faced with numerous challenges, is also demonstrating a low level of sustainability. Other main findings of this report concern the overall performance of the Kapenta fishery: the potential of wealth for economic growth, in terms of rent (estimated at approximately US $24 million per year), is completely lost for the economy of both countries; Kapenta resource productivity and thus fisheries production is negatively affected due to overexploitation, in turn leading to a negative impact on the food security status of those consumers who strongly depend on Kapenta in their diet. The fisheries generate a substantial amount of ‘on-board’ work (crew), however, remuneration for this type o f labour tends to be very low compared to national wage standards. Furthermore, lower levels of production have no doubt had a negative impact on employment in Kapenta processing activities that take place along the lakeshore. This situation requires further study, during the Bioeconomic Working Group, and should be based on information provided by the industry on processing activities. In addition to the diagnosis of the Kapenta fisheries and the economic situation of the industry in 2011, this report illustrates the potential of the model in terms of simulation for management purposes and its prospects for development. 5 The main recommendations of this study concern how to improve the bioeconomic model that has been developed. Thus these recommendations are mainly focused on the need to improve the information necessary feed and to develop the model. Recommended approaches will require strengthening partnerships with the industry.

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