Mapping Octopus (Octopus cyanea) Fishing Grounds Based on Sea Surface Temperature and Chlorophyll-a In the Waters of Langkai–Lanjukang

This study aims to map the distribution of octopus fishing grounds using a spatial-participatory approach based on Geographic Information Systems (GIS) and MODIS satellite data with a spatial resolution of 4 km. Spatial analysis was conducted by integrating participatory fishing location data with oceanographic parameters, followed by spatial overlay and distribution mapping to identify potential fishing zones. Primary data were obtained through interviews with fishers, recording of fishing location coordinates, and observations of oceanographic conditions including temperature, salinity, and depth. Secondary data such as satellite imagery and bathymetric maps were used to support the analysis. The results show that octopus fishing grounds are concentrated in the southwestern waters with sea surface temperatures ranging from 28.9–29.5°C and low to moderate chlorophyll-a concentrations (0.167–2.14 mg/m³). In contrast, areas with higher temperatures (>30°C) and high chlorophyll-a concentrations tend not to support octopus presence. This indicates that physical factors of the marine environment, particularly temperature, are the main determinants of octopus distribution compared to primary productivity. These findings have important implications for octopus fisheries management, where zones with optimal temperatures can be prioritized as potential fishing areas. This study produces a spatial map of octopus fishing grounds that can serve as a basis for developing adaptive ecosystem-based management strategies in the Spermonde Archipelago.

Mapping Octopus (Octopus cyanea) Fishing Grounds Based on Sea Surface Temperature and Chlorophyll-a In the Waters of Langkai–Lanjukang