Integrated fisheries management using Bayesian multi-criterion decision making

Background

In small scale fisheries in developing countries, there is often limited data and capacity for undertaking resource assessments which are needed to evaluate management alternatives. This information is essential for maintaining equitable and sustainable exploitation. Participation of resource users in a co-management process is increasingly considered to be more effective in defining and achieving management objectives than conventional top-down approaches. There is a need for a stock assessment approach suitable for data-poor circumstances that utilises any available conventional data, such as catch and effort, and stakeholder knowledge and aspirations to derive rapid stock assessments which can be used as the starting point for an adaptive co-management system.

Approach

This project developed a generic methodology, applicable to any fishery, using standard stock assessment techniques with the addition of Bayesian decision-making components to allow the incorporation of fishers' views on the status of the fishery, and their preferences for fishing outcomes (and hence, indirectly, for management objectives). The methodology comprises a software package and supporting manual, and interview approaches. The interviews are based on participatory rural appraisals, and are used to gather fishers view on stock status, and their preferred fishing outcomes, in terms of catch and effort options. The methodology was developed and tested in Zanzibar, and the Turks and Caicos Islands (Caribbean).

Findings

The participatory fish stock assessment method successfully developed in this project enables stock assessments using a number of different data types, and the evaluation of alternative management options.

At the local level in Zanzibar, fishers were receptive to the results of applying the method, which suggested a reduction in fishing effort, and requested stakeholder meetings to discuss management options and implementation.

Applied to the Turks and Caicos conch fishery, the assessment supported existing management controls, and also demonstrated that, if catch and effort data had not been available, using fisher interviews alone would have produced management advice sufficient to prevent the stock collapse witnessed in the 1970s. This finding supports the application of this method elsewhere in data limited situations.

Participatory interview methods developed in the project were applicable in the culturally different field-test locations.

The methodology was promoted within the regions of the field testing locations, but was further developed, disseminated and promoted more widely in the follow-up project R8397, where supporting materials (a toolkit and software guide) for the use of the methodology were also developed.

For the latest version of the software and supporting materials, please see publications.