Keanekaragaman Jenis Ikan Karang dan Karakteristik Ekosistem Terumbu Karang Perairan Pantai Sawakete Desa Afulu Kecamatan Afulu Kabupaten Nias Utara

Abstract

This study aims to determine the diversity of coral reef fish species and the characteristics of the coral reef ecosystem in the coastal waters of Sawakete, Afulu Village, North Nias Regency. Observations were conducted at three stations using the Underwater Photo Transect (UPT) method to assess coral cover percentage and the Underwater Visual Census (UVC) method to inventory coral reef fish. The results showed that water quality parameters such as temperature, salinity, pH, and current were within suitable ranges to support coral growth. Live coral cover percentages were 18% at Station 1 (poor category), 30% at Station 2 (moderate category), and 72% at Station 3 (good category). A total of 206 individual fish belonging to 8 species from 5 families were recorded, with the Pomacentridae family being the most dominant. The Shannon-Wiener diversity index (H’) was highest at Station 2 (2.27), followed by Station 3 (2.21) and Station 1 (1.89), indicating a moderate level of diversity. The evenness index (E) ranged from 0.91 to 1.09, indicating a stable community structure, while the dominance index (C) indicated low to moderate dominance. The positive correlation between coral cover percentage and the abundance and diversity of coral reef fish highlights the importance of conserving and managing coral reef ecosystems in this area. The results of this study are expected to serve as a reference for coastal management and sustainable reef fish resource planning.