Suitability and Carrying Capacity Analysis for Grouper Aquaculture in the Gili Ketapang Island Marine Conservation Area, East Java, Indonesia

The Gili Ketapang Aquatic Conservation Area, designated as a Marine Tourism Park by the Indonesian government, encompasses 476.78 ha, including 23.50 ha allocated for aquaculture. Floating-net-cage (FNC) aquaculture of hybrid grouper (Epinephelus fuscoguttatus × E. lanceolatus) is already practiced, but optimal utilization is hindered by the lack of a comprehensive suitability and carrying capacity assessment. This study evaluates the spatial suitability of the aquaculture sub-zone using Geographic Information System (GIS)-based multi-criteria evaluation and estimates the physical carrying capacity for FNC culture. Data were collected from nine sampling stations, measuring water quality parameters such as temperature, salinity, dissolved oxygen, and nutrient levels, and analyzed against established criteria for aquaculture suitability. Results indicate that 49% of the aquaculture zone (11.45 ha) is suitable for FNC systems, with an estimated carrying capacity upper limit of 336 rafts, each measuring 9×9 m. The methodology integrates GIS-based overlays and carrying capacity models, offering actionable insights for sustainable aquaculture management. This study contributes to the operationalization of the Ecosystem Approach to Aquaculture (EAA) within the Gili Ketapang, promoting balanced aquaculture expansion that respects environmental and socio-economic sustainability. The findings are significant for local aquaculture stakeholders and policymakers, providing a scientifically grounded framework for expanding sustainable aquaculture within the Gili Ketapang Marine Conservation Area while safeguarding the integrity of this critical coastal ecosystem.