Study Of Hard Coral (Scleractinia) Recruitment In The Molas Waters, Manado City

Abstract
Coral recruitment is the entry of new coral individuals into coral reef populations due to reproduction or migration. Juvenile coral is the result of metamorphosis and growth of coral planula measuring 5 cm and attached to certain substrates. There are two types of substrates in the waters, stable substrates and unstable substrates such as rubble. The purpose of this study was to study hard coral recruitment, both in terms of density, the composition of juvenile coral colony types, size, and the type of substrate occupied by juvenile corals. This research was conducted in August 2021 in the waters of Molas, Bunaken District, Manado City. The method used for site selection is the purposive sampling method and data collection using a sampling method with quadrant transects. The results showed that the density of coral recruitment at the study site was 8,43 colonies/m2. The percentage of juvenile coral attachment on stable substrates is 90% and 10% on unstable substrates. The average size of juvenile corals at the study site was 2.4cm. The composition of the juvenile coral genus found at the research site were corals of the genus Acropora, Anacropora, Coeloseris, Cycloseris, Cyphastrea, Echinopora, Favites, Fungia, Galaxea, Goniastrea, Isopora, Leptastrea, Leptoseris, Lobophyllia, Merulina, Montastrea, Montipora, Oulophyllia, Pachyseris, Pavona, Platygyra, Plasiastrea, Pocillopora, Porites, Psammocora, Scolymia, Seriatopora, Symphyllia, and Trachyphyllia. Of the entire genus, corals of the genus Porites were dominated by the number of juveniles as many as 36 colonies. Keywords: Molas, coral, recruitment, Scleractinia Abstrak Rekrutmen karang adalah masuknya individu karang baru pada populasi terumbu karang dikarenakan reproduksi ataupun migrasi. Juvenil karang merupakan bentuk hasil metamorphosis dan pertumbuhan planula karang yang berukuran ≤ 5 cm dan menempel pada substrat tertentu. Terdapat dua tipe substrat di perairan, substrat yang stabil dan substrat yang tidak stabil seperti pecahan karang (rubble). Tujuan penelitian ini adalah untuk mempelajari tentang rekruitmen karang keras, baik dari densitas, komposisi jenis koloni juvenil karang, ukuran, hingga tipe substrat yang ditempati oleh juvenil karang. Penelitian ini dilakukan pada bulan Agustus 2021 di perairan Molas Kecamatan Bunaken Kota Manado. Metode yang digunakan untuk pemilihan lokasi adalah metode purposive sampling dan pengumpulan data menggunakan metode sampling dengan transek kuadran. Hasil penelitian menunjukan bahwa densitas rekruitmen karang pada lokasi penelitian sebesar 8,43 koloni/m2. Persentase penempelan juvenil karang pada substrat stabil sebesar 90% dan pada substrat yang tidak stabil sebesar 10%. Ukuran rata-rata dari juvenil karang pada lokasi penelitian adalah 2,4cm. Komposisi genus juvenil karang yang ditemukan pada lokasi penelitian adalah karang genus Acropora, Anacropora, Coeloseris, Cycloseris, Cyphastrea, Echinopora, Favites, Fungia, Galaxea, Goniastrea, Isopora, Leptastrea, Leptoseris, Lobophyllia, Merulina, Montastrea, Montipora, Oulophyllia, Pachyseris, Pavona, Platygyra, Plasiastrea, Pocillopora, Porites, Psammocora, Scolymia, Seriatopora, Symphyllia, dan Trachyphyllia. Dari keseluruhan genus, didominasi oleh karang genus Porites dengan jumlah juvenil sebanyak 36 koloni. Kata kunci: Molas, karang, rekrutmen, scleractinia