Abundance of Tridacna (Family Tridacnidae) at Seribu Islands and Manado Waters, Indonesia - Candhika Yusuf; Ambariyanto Ambariyanto; Retno Hartati (Marine Science Department Diponegoro University, 2009)
Kima, yang merupakan salah satu hewan laut dilindungi, sejak lama banyak dieksploitasi di berbagai daerah di Indonesia. Apabila keadaan ini terus berlanjut maka akan terjadi penurunan populasi di alam yang berujung pada kepunahan dari berbagai spesies Kima tersebut di alam. Penelitian ini bertujuan untuk menganalisis kelimpahan Kima di beberapa pulau di Kepulauan Seribu dan perairan di sekitar Manado. Metode penelitian yang digunakan adalah deskriptif yang bersifat eksploratif. Sampling dilakukan dengan metode Line Intersept Transect (LIT) menggunakan garis transek sepanjang 100 meter sejajar dengan garis pantai pada kedalaman 5 meter. Pengamatan dilakukan pada tiap 2,5 meter di sebelah kanan dan kiri garis transek. Hasil penelitian, ditemukan total 167 individu Kima di Kepulauan seribu dan 61 individu di perairan Manado. Nilai kepadatan rata - rata pada lokasi Kep. Seribu adalah T. squamosa 0.026 indv/m2, T. maxima 0,016 indv/m2, T. crocea 0.028 indv/m2 sedangkan pada lokasi Manado adalah T. squamosa 0.021 indv/m2, T. maxima 0.0005 indv/m2, T. crocea 0.0085 indv/m2 dan T. gigas 0.002 indv/ m2. Hasil ini menunjukkan bahwa kepadatan Kima di dua lokasi penelitian masih lebih rendah dari beberapa lokasi di Indonesia dan luar negeri. Berdasarkan ukuran cangkang di dua lokasi penelitian diduga hanya T. crocea saja yang telah mencapai fase hermafroditiknya, sedangkan T. gigas dan sebagian besar T. squamosa serta T. maxima baru mencapai fase kematangan gonad jantan saja. Kebanyakan Kima ditemukan di karang mati beralga (Dead Coral Algae / DCA) dan tututan karang hidup (coral covered) dibandingkan dengan jenis substrat yang lain. Kata kunci : Kima, tridacna, kelimpahan, Kepulauan Seribu, Manado Giant clam, as a protected marine species, has been exploited massively in many regions in Indonesia. This has lead to the rapid extinction of the giant clam natural population. The purpose of the research is to obtain the abundance status of giant clam species in several island in Kepulauan Seribu and surroundings waters of Manado. Surveys were done by using the modification of Line Intercept Transect (LIT) methods. A hundred meter length of transect line were drawn, in depth of 5 meter and paralleled to the coast line. The observations were made in 2.5 meter to the left and right of the transect line. The results showed, there were total number of clams found at Seribu Islands and Manado waters were 106 and 61 individual, respectively. The average density in Seribu Islands were T. squamosa: 0.026 indv/m2, T. maxima: 0.016 indv/m2, and T. crocea: 0.028 indv/m2, and in Manado were T. squamosa: 0.021 indv/m2, T. maxima: 0.0005 indv/m2, T. crocea: 0.0085 indv/m2 and T. gigas: 0.002 indv/m2. These results showed that the density of giant clams in both places were found to be lower than other places in Indonesia and abroad. Based from the shell measurements on both locations, only T. crocea were suspected have reached its hermaphrodite phase, while T. gigas and most of T. squamosa and T. maxima were about to reached male gonad maturity phase. The most dominant substrate for the giant clam were the Dead Coral Algae (DCA) and the coral covered. Key words: Giant clam, tridacna, abundance, Seribu Islands, Manado