Distribution of Coral Reefs Stone at the Reef Flat of South Coast Putus-Putus Island East Ratatotok, Ratatotok District Southeast Minahasa Regency

Abstract

This research was conducted at the reef flat of south Putus-Putus Island, East Ratatotok, Ratatotok district, Southeast Minahasa Regency. This research was done no data of coral distribution available in Putus-Putus Island. This research aimed to describe the distribution of corals in Putus-Putus Island. The benefit of the study was to provide information and contribution to coral reef management efforts in the region. Data was collected using transect-quadrat methodt. There were 3 sampling points determined, the inner reef flats, the middle reef flats, and the outer reef flat. Each depth was laid five 50 m–transects, and each transect had 10 1x1-quadrats. The distance between quadrats was 5 m. Any coral found in the quadrat was recorded on a data sheet and photographed using an underwater camera. The highest percent cover was recorded at the outer reef flat, 57.32%, followed by the middle reef flat, 39.08%, and the lowest was found in the inner reef flat, 11.38%. The most coral lifeform cover in Putus-Putus Island reef flat was Coral Massive, 42.98%. General condition of coral reefs was good at the outer reef flat, moderate at the middle reef flat, and poor at the inner reef flat, respectively. Hard coral diversity index (H’) value was 0.36 at the inner reef flat, 0.56 at the middle reef flat, and 0.51 at the outer reef flat. Eveness index was 0.52 at the inner reef flats, 0.59 at the middle reef flat and 0.60 at the outer reef flat, respectively. Dominance index was 0.61 at the inner reef flat, 0.43 at the middle reef flat, and 0.45 at the outer reef flat. The distribution pattern was clustered in all sampling points.

Keyword : Distribution, Coral

Abstrak

Penelitian ini dilaksanakan di pantai selatan Pulau Putus-Putus Desa Ratatotok Timur Kecamatan Ratatotok Kabupaten Minahasa Tenggara. Penelitian ini dilakukan karena belum ada data distribusi karang batu di rataan terumbu Pulau Putus-Putus. Penelitian ini bertujuan untuk mengetahui distribusi karang batu di rataan terumbu Pulau Putus-Putus. Manfaat penelitian yaitu dapat menjadi sumber informasi dan mampu memberikan kontribusi bagi upaya pengelolaan terumbu karang di wilayah Ratatotok di masa yang akan datang. Pengambilan data dilakukan dengan menggunakan metode transek kuadran. Pada lokasi penelitian, ditentukan tiga titik pengambilan data, yaitu kedalaman inner reef flat, middle reef flat dan outer reef flat. Pada setiap kedalaman diletakkan 5 transek ulangan, dengan panjang 50 meter, pada setiap transek diletakkan 10 buah kuadran berukuran 1x1 meter dengan jarak antar kuadran  adalah 5 meter. Setiap karang yang ditemukan dalam kuadran dicatat pada data sheet dan mengambil gambar dengancamera underwater. Persentase tutupan karang batu tertinggi diperoleh pada kedalaman outer reef flat yaitu sebesar 57,32 % diikuti dengan middle reef flat 39,08 % dan tutupan terendah pada kedalaman inner reef flat yaitu 11,38 %. Bentuk pertumbuhan karang batu yang paling banyak menutupi rataan terumbu Pulau Putus-Putus adalah Coral massive sebesar 42,98%. Secara umum kondisi terumbu karang pada kedalaman outer reef flat dikategorikan baik, kedalaman middle reef flat dikategorikan cukup dan kedalaan inner reef flat dikategorikan rusak/buruk. Dari hasil analisis, nilai indeks keanekaragaman karang batu di tiap kedalaman sebagai berikut: kedalaman inner reef flat (H' = 0,36), kedalaman middle reef flat (H' = 0,56) dan kedalaman outer reef flat (0,51). Hasil indeks kesamarataan untuk tiap kedalaman adalah kedalaman inner reef flat (e = 0,52), kedalaman middle reef flat (e = 0,59) dan outer reef flat (e = 0,60). Nilai indeks dominasi pada kedalaman inner reef flat tergolong dalam kriteria dominasi sedang 0,61 dan kedalaman middle reef flat dan outer reef flat dominasi rendah 0,43 – 0,45. Pola distribusi karang batu pada ketiga kedalaman adalah mengelompok.

¹Staf pengajar Fakultas Perikanan dan Ilmu Kelautan Universitas Sam Ratulangi