Comparative Analysis of Integration Indices and Object-Based Approach Using Sentinel-2 Data for Effective Monitoring of Aquaculture Fish Cages in Nasipit Port, Agusan Del Norte

Fish cages in Nasipit Port, Agusan del Norte, have experienced a decline in recent years, indicating a shift in aquaculture activity. To accurately detect and monitor these structures, a method using Segmentation and Combined Index generation with Sentinel 2 satellite data is proposed. A comparative assessment between integrated indices and object-based image analysis (OBIA) from 2019 to 2023 was conducted. Integrated Indices achieved higher accuracy with an average of 95.55% and a Kappa coefficient of 0.94734, it also demonstrated the Producer's and User's Accuracy of 97.42% and 94.46% for identifying fish cages. Over the years, fish cage areas decreased from 6.98 ha in 2019 to 3.18 ha in 2023, indicating a decline. The transition matrix revealed the probabilities of class changes, with fish cages showing retention probabilities of 42.26%, 57.63%, 55.51%, and 63.78% from 2019 to 2023, while the remaining percentage was attributed to the water class.