Prioritising species for research, conservation and management: a case study of exploited fish species

Abstract

Studies that categorise species according to their conservation status often fall short in their implementation by not having taken into account the impacts on, or the response from, those that either benefit from, or exploit, the resource under consideration. This is especially true in multispecies fisheries where personnel and funding limitations often create the dilemma over which species should be the first to receive management and research attention. This study uses a multicriteria decision analysis approach to prioritise 176 South African linefish species on the basis of a number of criteria indicating conservation and socio-economic, including fishery sector, importance. For each species, conservation criteria were: abundance trend, level of knowledge, vulnerability, range, and relative exploitation throughout that range. Sectoral criteria were: total catch, degree of targeting, the number of participants and the economic value of each species. The scores given to each species on the basis of each of these criteria were summed to allow an examination of each fish’s importance from the points of view of (i) conservation, (ii) each fishery sector separately and combined, and (iii) the overall combined conservation and sectoral importance. Different weight sets were used in the weighted summation of the scores, and results were examined for sensitivity. The results were reasonably insensitive to these changes in weights. Relative scores within each of the fishery sectors were dominated by two or three species. Consequently, the scores separating the remaining species from each other were small. This meant that, in many cases, even when the rank of species changed by a number of places with a different weight set, the differences in score were slight. On the whole, the top fish included the most important species in each sector and biogeographical region and in terms of conservation. The separate and overall rankings should assist in the development of broadly acceptable management strategies for different fish species.

Keywords: importance ranking, multicriteria decision analysis, multispecies fisheries

African Journal of Marine Science 2014, 36(3): 345–360