DISTRIBUSI SPASIAL DAN TEMPORAL IKAN TUNA MATA BESAR (Thunnus obesus) DI SAMUDERA HINDIA BAGIAN TIMUR

Abstract

Ikan tuna mata besar (Thunnus obesus) merupakan salah satu hasil tangkapan yang penting bagi industri perikanan di Indonesia. Penelitian ini bertujuan untuk mengetahui distribusi spasial dan temporal ikan tuna mata besar di Samudera Hindia Bagian Timur. Pengumpulan data dilakukan oleh pemantau ilmiah (scientific observers) pada kapal rawai tuna yang berbasis di Pelabuhan Benoa Bali, mulai Agustus 2005 hingga November 2013. Ikan tuna mata besar yang tertangkap sebanyak 5.340 ekor dan dari jumlah tersebut sebanyak 5.253 ekor diukur panjangnya. Distribusi spasial ikan tuna mata besar yang tertangkap rawai tuna Indonesia membentang dari 0°-33° LS dan 76°-128° BT. Persentase tertinggi ikan tuna mata besar dengan panjang >110 cm (L_m) terdapat di sebelah barat Sumatera Barat dan di sebelah selatan Jawa Timur. Laju pancing menurut bulan penagkapan menunjukkan perbedaan yang nyata dengan laju pancing tertinggi terjadi pada Agustus sebesar 0,54 ekor/100 mata pancing. Nelayan direkomendasikan untuk melakukan operasi penangkapan di daerah dengan persentase ukuran panjang ikan tuna mata besar >110 cm (L_m) tertinggi, sehingga species tersebut mempunyai kesempatan untuk melakukan pemijahan minimal sekali sepanjang hidupnya. Hal ini dimaksudkan untuk menjaga kelestarian sumberdaya ikan tuna mata besar di Samudera Hindia.

Big eye tuna (Thunnus obesus) is one of the important catch of the fishing industry in Indonesia. The study is aimed to investigate the spatial and temporal distribution of big eye tuna in the Eastern Indian Ocean. Data were collected by scientific observers on tuna long line vessels which were mainly based in Port of Benoa Bali from August 2005 to November 2013. Total number of big eye tuna caught were 5,340 individuals and as many as 5,253 of them were measured in length. The spatial distribution of  big eye tuna caught by Indonesia tuna long line are in the area between 0°-33° S and 76°-128° E. The highest percentage of big eye tuna with length bigger than 110 cm (L_m) occurred in the west of West Sumatera and in the south of East Java. The hook rate by months was significantly different and the highest hook rate was in August with 0.54/100 hooks. The fishermen are recommended to fish in areas of  high percentage of big eye tuna with length more than 110 cm (L_m), to provide opportunities for the species to spawn at least once throughout their life. It is intended to sustain the big eye tuna resources in the Indian Ocean.