HUBUNGAN ANTARA IKAN INDIKATOR (CHAETODONTIDAE) DAN KONDISI KARANG DI PESISIR PULAU BIAK DAN KEPULAUAN PADAIDO

Abstract

Tulisan ini membahas tentang keeratan hubungan antara ikan kepe-kepe terhadap kondisi terumbu karang. Kajian dilakukan di 13 titik pengamatan di wilayah pesisir Pulau Biak dan Kepulauan Padaido pada tahun 2007 yang merupakan bagian dari program Coral Reef Rehabilitation and Management Program-Lembaga Ilmu Pengetahuan Indonesia. Pada setiap titik pengamatan, metode transek garis (line intercept transek LIT) dipakai untuk mendapatkan data tentang kelimpahan (jumlah ikan atau specimen) dan keanekaragaman (jumlah jenis/species) ikan kepe-kepe serta kondisi karang (yang dikatakan dalam persentase tutupan karang hidup). Analisis regresi kemudian digunakan untuk mengetahui keeratan hubungan antara kelimpahan dan keanekaragaman ikan kepe-kepe terhadap kondisi karang. Dari hasil penelitian tersensus sejumlah 28 spesies ikan kepe-kepe (22 jenis dari marga Chaetodon, dua jenis marga Forcipiger, dan emapt jenis marga Heniocus) dengan kelimpahan total 661 individu (ekor). Kondisi persentase tutupan karang hidup berkisar antara 9,1-46,3% dengan nilai rata-rata 25,8% (terumbu dalam kondisi sedang). Dari 13 stasiun pengamatan, dua set data tidak digunakan karena terlalu tinggi. Plot antara kelimpahan (jumlah individu) ikan kepe-kepe sangat kuat berkorelasi terhadap keanekaragaman jenis (jumlah spesies) (R²=0,95). Kelimpahan dan keanekaragaman jenis ikan kepe-kepe juga berkorelasi cukup kuat terhadap kondisi karang (persen tutupan karang hidup). Dari total 28 spesies ikan kepe-kepe, tujuh spesies memiliki persen kehadiran (FA) > 50% dengan peringkat tertinggi mulai dari Chaetodon klenii, Chaetodon trifaciatus, Chaetodon vagabundus, Chaetodon rafflesii, Chaetodon trifacialis, Chaetodon baronessa, dan Chaetodon citrinellus, Beberapa dari spesies tersebut memiliki keeratan hubungan yang kuat dengan kondisi terumbu karang.

This paper discusses about the relationship between the butterfly fish and the condition of coral reef. This study was conducted in 13 observation sites of Biak and Padaido Islands coastal zones in 2007 as a part of Coral Reef Rehabilitation and Management Program-Lembaga Ilmu Pengetahuan Indonesia programs. In each observation site, line intercept transect method was used to collect the abundance (number of fish or specimen) and the diversity (number of species) data of butterfly fishes and the reef condition (expressed as percentage of living coral covers). Regression analysis was then applied to Investigate the relationship between the abundance and diversity of butterfly fishes to the reef condition. The result shows that there are 28 butterfly fishes consisted of 22 species belong to genus Chaetodon, 2 species belong to Forcipiger, and 4 species belong to Heniocus recorded, with the total abundance of 661 fishes. The percentage of living coral covers ranged between 9.1 and 46.3% with an average of 25.8% (coral reef in medium condition). From 13 observation sites, 2 sites were excluded due to high bias. Plot between the abundance of butterfly fishes (number of fishes/specimen) and their diversity (number of species) shows very significant correlation (R²=0.95). The abundance and the diversity of butterfly fishes show also significant relationship with the coral reef condition (percentage of living coral covers). From 28 species, 7 species have high percentage of frequency with the highest rank to the lowest are Chaetodon klenii, Chaetodon trifaciatus, Chaetodon vagabundus, Chaetodon rafflesii, Chaetodon trifacialis, Chaetodon baronessa, and Chaetodon citrinellus. Among of those 7 individual species, some are strongly correlated with the percentage of living corals. Therefore, the concept or hypotheses that butterfly fish can be used as an indicator of the health of coral reef was  in this study. However, more deeper study that cover large geographical areas are needed to prove the validity of the above hypotheses.