<![CDATA[Fish cage culture in the Kapuas River, West Kalimantan, plays an important role in supporting local economic activities; however, increasing cultivation intensity may contribute to pollutant accumulation, reducing water quality and affecting aquatic ecosystem sustainability. This study aimed to identify pollutant characteristics from fish cage culture, analyze regulatory requirements for pollution mitigation, and develop an environmental monitoring system based on aquatic carrying capacity. A mixed methods approach was applied by integrating quantitative water quality analysis and qualitative stakeholder assessment. Quantitative analysis was conducted on 12 water samples collected using purposive sampling based on water depth, while qualitative data were obtained through interviews with relevant stakeholders. Data were analyzed using simple linear regression to determine the relationship between pollutant parameters and water quality. The results showed that organic pollutants were the dominant pressure, characterized by increased Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) and decreased Dissolved Oxygen (DO). Regression analysis revealed a strong negative relationship between BOD and DO (r=-0.949; R²=0.901) and COD and DO (r=-0.947; R²=0.896). The proposed regulatory framework applies a science-based regulation approach through zoning management, organic load control, and adaptive monitoring to support sustainable Kapuas River management]]>
