The Diversity and Community Structure of Megabenthos in Coral Reef Ecosystems at Kano Island, North Maluku

Megabenthos in Coral Reef Ecosystems

Abstract

Coral reef ecosystems serve as critical habitats for megabenthos; however, ecological data on benthic communities in North Maluku, particularly in the waters of Kano Island, Taliabu Island Regency, remain critically scarce. This study aimed to identify species composition, analyze distribution patterns, and assess megabenthos community structure based on density, diversity, evenness, and dominance indices across three observation stations representing distinct habitat characteristics. Field sampling was conducted in January 2026 using the Benthos Belt Transect (BBT) method along 50 m transects with a 2 m observation width for megabenthos enumeration, and Underwater Photo Transect (UPT) analyzed with CPCe software for coral cover assessment. A total of 133 individuals belonging to 13 species from three phyla — Echinodermata, Mollusca, and Cnidaria — were recorded, with Protoreaster nodosus as the most abundant species. Live coral cover ranged from 20.27% to 62.80%, classifying Stations I and II as good condition while Station III was categorized as severely degraded. The Shannon diversity index (H') ranged from 1.51 to 1.95 (moderate), dominance index (D) from 0.18 to 0.34 (low to moderate), and evenness index (E) from 0.66 to 0.97 (high), collectively demonstrating that habitat quality exerts a significant influence on megabenthos community structure. These findings confirm that substrate quality and live coral cover are primary determinants of megabenthos density and diversity, underscoring the urgent need for coral reef rehabilitation at Station III and ecosystem-based management across the Taliabu Island region. Future research encompassing broader spatial and temporal scales is strongly recommended.