Electronic Theses and Dissertation

Penelitian ini bertujuan untuk mengevaluasi struktur komunitas ikan karang pada terumbu buatan model setengah-piramida berbahan beton di perairan pulau tuan, aceh besar. metode yang digunakan mencakup teknik point count (12,56 m²) dan belt transect (250 m²) pada 10 titik pengamatan, yang dilakukan pada pagi dan sore hari. hasil menunjukkan bahwa terumbu alami memiliki 13 spesies dari 11 famili dengan total 144 individu, sedangkan terumbu buatan hanya ditemukan 3 spesies indikator dengan total 26 individu. indeks keanekaragaman (h’) pada terumbu alami berada pada kategori tinggi (2,003–2,117), sedangkan pada terumbu buatan hanya 0,831 0,925 (kategori rendah–sedang). indeks keseragaman (e) pada terumbu buatan tergolong stabil (0,756–0,842), sementara dominansi (c) menunjukkan bahwa komunitas di terumbu buatan masih didominansi spesies tertentu seperti dascyllus trimaculatus. parameter lingkungan seperti suhu, salinitas, dan kedalaman berada dalam kisaran optimal. kesimpulannya, meskipun belum setara dengan terumbu alami, struktur buatan memiliki potensi untuk mendukung rehabilitasi ekosistem laut apabila didesain dan dikelola secara berkelanjutan. kata kunci: terumbu buatan, ikan karang, keanekaragaman, kelimpahan, pulau tuan

This study aimed to evaluate the structure of reef fish communities on half-pyramid shaped artificial reefs made of concrete in the waters of Tuan Island, Aceh Besar. Data were collected using point count (12.56 m²) and belt transect (250 m²) methods at 10 observation points during morning and afternoon sessions. Results showed that natural reefs contained 13 species from 11 families totaling 144 individuals, while artificial reefs only recorded three indicator species with a total of 26 individuals. The diversity index (H') on natural reefs ranged from 2.003 to 2.117 (high), whereas on artificial reefs it ranged from 0.831 to 0.925 (low to moderate). Evenness (E) was higher on artificial reefs (0.756–0.842), while dominance index (C) indicated that artificial reefs were still dominated by specific species such as Dascyllus trimaculatus. Environmental parameters including temperature, salinity, and depth were within optimal ranges. In conclusion, although artificial reefs have yet to match natural reefs in ecological complexity, they show strong potential as alternative habitats in support of marine ecosystem rehabilitation if sustainably managed. Keywords: artificial reef, reef fish, community, diversity, Pulau Tuan