Geospatial assessment of site suitability for seaweed cultivation in the Andaman and Nicobar Islands

Abstract

Geographic Information System (GIS) tools were used to analyze key environmental factors for seaweed cultivation, converting them into thematic layers. The study highlights the ample scope for seaweed farming in the Andaman and Nicobar (A&N) Islands, particularly in its enclosed bays. Of the 600,000 km² within India’s Exclusive Economic Zone (EEZ) around the A&N Islands, approximately 122,854 km² within the 1–50 m depth contour was assessed. The analysis identified 68,659 km² as appropriate for seaweed farming, with 5,363 km² classified as highly suitable and 63,296 km² as suitable. Commercially valuable seaweed species, such as Gracilaria spp., can be cultivated without disrupting the region’s natural ecosystem. This model also identifies areas that should be avoided, including coral reefs, natural seaweed habitats, national parks, sanctuaries, seagrass beds, and navigation routes. The present work also highlighted the comparison of different seaweed cultivation techniques in the A&N coastal waters. This study utilises a GIS-based multi-criteria approach to integrate key spatial datasets at the macro-level, generating a reliable, simple and useful model output for delineating the potential seaweed farming zones in the A&N Islands.