Integrating participatory approaches and spatial analysis for potential mariculture site selection and marine resource management in Mohéli Island, Comoros

Mariculture, the cultivation of marine organisms in coastal environments, offered a promising alternative to overexploited fisheries, providing economic opportunities and a sustainable source of seafood. However, it also raised concerns about environmental degradation, user conflicts, and spatial planning challenges. This study aimed to identify suitable sites for potential mariculture development on Mohéli Island, Comoros, by integrating scientific analysis with local knowledge and socio-economic realities. Three participatory mapping sessions were conducted with local communities, including fishermen, NGO leaders, and other relevant stakeholders, to document traditional ecological knowledge and identify key marine areas used for fishing, conservation, and community activities. Field surveys and numerical modeling were also used to verify local insights and assess environmental conditions. These data were incorporated into Geographic Information Systems (GIS) to develop a spatial suitability map for mariculture based on seven ecological, social, and logistical parameters. The findings identified four main zones, totaling approximately 2,132.74 hectares, as suitable for mariculture. These zones minimized conflict with existing uses and ecological sensitivity while optimizing access and feasibility. To support decision-making, the Analytical Hierarchy Process (AHP) was applied to evaluate the relative importance of ecological, social, and economic aspects in mariculture planning. Ten marine resource experts participated in this process, comparing criteria and sub-criteria to establish priority weights. AHP results showed that the ecological aspect was most important, followed closely by the social aspect, while the economic aspect ranked lowest. This analysis supported the development of informed policy recommendations, ensuring that future mariculture initiatives considered the appropriate balance of environmental protection, community priorities, and economic feasibility.