AHP-Based Prioritisation of Development Strategies for Semi-Intensive Nile Tilapia (Oreochromis niloticus) Farming in a Mining-Affected Area, Central Halmahera Regency

Nile tilapia (Oreochromis niloticus) farming is a growing livelihood in Central Halmahera Regency, where nickel mining raises fish demand but may also threaten shared water resources. Choosing among development strategies requires weighing economic, technical, environmental, and institutional considerations, yet such multi-criteria priorities have rarely been quantified for mining-affected smallholder farms. This study aimed to prioritise development strategies for semi-intensive tilapia farming and to test how robust the ranking is to changes in criteria weights. From January to April 2026, 40 purposively selected farmers in the Weda Tengah and Weda Selatan sub-districts and ten experts were surveyed. Eighteen strategy alternatives, derived from a strengths–weaknesses–opportunities–threats analysis reported elsewhere, were grouped into four operational strategies and ranked with the Analytic Hierarchy Process (AHP) under four criteria. Production improvement ranked first under every criterion and overall (global weight 0.532), followed by institutional strengthening (0.231), water-quality management (0.160), and production cost efficiency (0.077); consistency ratios were below 0.10. In recalculated weight scenarios, production improvement stayed first, and the second rank changed only when the environmental criterion exceeded about 66% of the total weight. Simulating 80% survival and a feed conversion ratio of 1.30 raised annual profit by 114.2% and net present value by 147.1% above a feasible but thin baseline (revenue–cost ratio 1.07). The priorities reflect expert judgement and rest on assumed technical targets; scale expansion was not evaluated.