Site selection for finfish cage farming using spatial multi-criteria evaluation and their validation at field in the Bay of Souahlia (Algeria)

Abstract

The development of marine fish farming on the Algerian coast is facing a number of environmental and logistical constraints. In a multi-disciplinary approach, based on aquaculture activity planning and field validation, the aim of this study is to target suitable areas for the setting of floating cages for Sparus aurata breeding at the Bay of Souahlia, Algeria. Multi-criteria evaluation via GIS was applied, combining 3 sub-models (environmental, socioeconomic, and constraint sub-models). The field verification was carried out on El Mokretar Aqua farm, by comparing its position with the result of the multi-criteria evaluation and by studying the growth performance indicators, thermal unit growth coefficient, specific growth rate, and feed conversion ratio and biomass. The regeneration of the final suitability map allowed for the delimitation of the favorable area for the implantation of the floating cages, which corresponds to 32% of the total area, with 3 classes of suitability. The El Mokretar Aqua farm is located at station S11, with a significant relevance index of 0.69. The gilthead seabream reflects a good growth performance. It grows with an average weight of 5 to 305 g over a 306-day rearing period, due to the environmental conditions and the good management of the farm.