BACKGROUND AND OBJECTIVES: Illegal, unreported, and unregulated fishing threatens Indonesia’s marine biodiversity, economic security, and governance, causing estimated annual losses of ۱.۸۵ billion United States dollar. In spite of improvements in monitoring, there are still considerable enforcement gaps, especially in remote and ecologically significant waters like the Arafura, Natuna, and Java Seas. The purpose of this study was to merge the spatial-temporal persistence of fishing violations with economic valuation to detect high-risk hotspots and to direct targeted fisheries enforcement initiatives. METHODS: A total of ۷۷,۶۷۸,۹۳۷ vessel monitoring system records from October ۲۰۲۱ to July ۲۰۲۴ were analyzed on a ۰.۲۵-degree spatial grid and grouped monthly. Statistically significant hotspot areas were identified using a spatial clustering analysis with an eight-nearest-neighbor configuration. A persistence index was subsequently utilized to assess the percentage of months during which each grid cell retained hotspot status throughout the ۳۹-month observation period. The economic importance of each cell was assessed through landed catch values, which were normalized and integrated with the persistence measure to generate a composite patrol priority score.FINDINGS: There were two violations: the vessel monitoring system was turned off for more than ۲۴ hours, and the notice of sailing certificate was incomplete, which together represented over ۹۲ percent of legitimate national cases. Spatial analysis identified ۲۱ high-risk clusters, concentrated in the Java, Natuna, and Arafura Seas, representing over ۸۵ percent of top-decile hotspots. These areas persisted for more than ۸۰ percent of the study period and overlapped with zones of highest cumulative landed value (~۷۸ billion United States Dollars). Violation-specific mapping revealed distinct patterns: conservation zone incursions in eastern Indonesia, licensing violations in Papua and Maluku, and boundary-related offenses in smaller scattered clusters. CONCLUSION: Combining environmental durability with economic valuation shows that a small segment of Indonesia's territorial waters and exclusive economic zone is responsible for a large portion of the risks linked to illegal and unregulated fishing. Prioritizing enforcement in these zones—supported by advanced satellite monitoring, predictive analytics, and community-based surveillance can enhance compliance, reduce operational costs, and safeguard ecologically and economically critical waters. The framework provides a robust decision-support tool for the Ministry of Marine Affairs and Fisheries and various enforcement, facilitating improved targeted interventions for sustainable fisheries governance.
