Karst Geodiversity and Aquatic Habitat Diversity Supporting Endemic Species in Maybrat, Papua Indonesia: Urgency and Policy Implications for Conservation

Karst ecosystems play an important hydrological role in regulating regional water availability and supporting biodiversity, yet they face increasing threats from deforestation, land-use conversion, and limited scientific data to inform sustainable conservation efforts. This study aims to assess karst geodiversity, aquatic habitat diversity, and freshwater endemism in the Maybrat Karst, and to explain the linkages among these three aspects as a scientific basis for regional karst conservation. The research employed geospatial analysis and descriptive ecological analysis. Data were collected through satellite image interpretation, participatory mapping, field observations, and a comprehensive literature review. Results show that the Maybrat Karst has very high geodiversity, with ±2322.91 km2 (41.49%) of the region classified as karst. All seven karst elements were identified, including 40–56 hills/km2, 110 water-filled dolines, 334 springs, 178 subterranean rivers, 90 caves, and three major karst lakes. Aquatic habitat diversity is likewise very high, comprising seven habitat types across the full 100–500 m elevational range, accompanied by 17 Cherax morphotypes, indicating strong environmental differentiation. The literature review identified 18 endemic freshwater species, consisting of five Cherax species, ten rainbowfish species of the genus Melanotaenia, and three additional taxa: Pseudomugil reticulatus, Glossogobius hoesei, and Zenarchopterus ornithocephala. These findings confirm that high karst geodiversity and habitat heterogeneity make the Maybrat Karst a key aquatic endemism center, highlighting the urgent national and global imperative for comprehensive karst protection to safeguard long-term biodiversity and ecosystem sustainability.