Spatial prioritization of dugong habitats in India can contribute towards achieving the 30 x 30 global biodiversity target

Abstract

Abstract Indian coastal waters are critical for dugong populations, the largest in south Asia, in the western Indian Ocean. Spatial planning of these waters can help to achieve biodiversity conservation and area-based protection targets in the region. In this study, we employed environmental niche modelling to predict suitable dugong habitats and identify influencing factors along its entire distribution range in Indian waters. We examined data on fishing pressures collected through systematic interview surveys, citizen-science data, and field surveys to demarcate dugong habitats with varying risk. Seagrass presence was the major contributing factor in determining dugong habitat suitability across the study sites, though variables like depth, bathymetric slope, Euclidean distance from the shore were significant factors, particularly in the context of seasonal suitability. Predicted suitable habitats showed a remarkable shift from pre-monsoon in Palk Bay to post-monsoon in the Gulf of Mannar indicating seasonal movement. The entire coastline along the Palk Bay- Gulf of Mannar (PB-GoM) region were observed to be high to moderate risk, including the Gulf of Mannar Marine National Park as one of the high-risk areas. The Andaman Islands exhibited high suitability during pre and post monsoon, whereas the Nicobar Islands were highly suitable in the monsoon. Risk assessment of modelled suitable areas revealed that < 15% of high-risk areas across Andaman and Nicobar Islands (ANI) and Palk Bay and Gulf of Mannar, Tamil Nadu falls within the existing protected areas. At Gulf of Kutch (GoK), Gujarat few offshore reef islands are identified under high-risk zone. The study highlighted the utility of citizen science and secondary data, in performing large-scale spatial ecological analysis. The study identifies synoptic-scale ‘Critical Dugong Habitats’ with implications in achieving global 30x30 target through systematic conservation planning.