Sebaran Ikan Tuna Berdasarkan Suhu dan Kedalaman di Samudera Hindia - Abram Barata; Dian Novianto; Andi Bahtiar (Marine Science Department Diponegoro University, 2011)
Suhu dan kedalaman perairan memberikan pengaruh yang paling kuat dan utama terhadap penyebaran ikan tuna. Kenaikan suhu rata-rata global pada permukaan bumi turut mempengaruhi kenaikan suhu permukaan laut. Tulisan ini bertujuan untuk menganalisis sebaran ikan tuna berdasarkan suhu dan kedalaman penangkapan rawai tuna di Samudera Hindia. Penelitian dilakukan 9 trip observasi mulai Juni 2007 sampai Januari 2010. Hasil penelitian dengan menggunakan alat minilogger menunjukkan ikan tuna jenis yellowfin didominasi 80 % berukuran >100 cm tertangkap pada kedalaman 85,73-167,80 m dengan suhu 22,20- 26,40 °C, bigeye didominasi 60 % berukuran >100 cm tertangkap pada kedalaman 193,97-470,12 m dengan suhu 8,35-15,30 °C, albacore didominasi 64 % berukuran >100 cm pada kedalaman 85,73-124,74 m dengan suhu 21,41-26,40 °C dan bluefin berukuran >100 cm tertangkap pada kedalaman 190,15-194,21 m dengan suhu 14,99-15,12 °C. Suhu dan kedalaman sebaran tuna jenis yellowfin dan albacore memiliki kesamaan yaitu pada level lapisan permukaan, hal ini menunjukkan perairan tropis merupakan daerah yang cocok untuk menangkap yellowfin dan albacore di Samudera Hindia.Kata kunci: Tuna, suhu dan kedalaman, rawai tuna, Samudera Hindia Temperature and depth waters are the most powerful influence and the main contribution to the spread of tuna. The increase in global average temperature at the earth’s surface also influence the rise in sea surface temperature. This paper aims to analyze the distribution of tuna based on temperature and depth of tuna longline fishing in the Indian Ocean. The research were counducted in 9 trip observations starting in June 2007 until January 2010. The results using the tool minilogger showed that yellowfin tuna species dominated 80 % measuring >100 cm was caught at a depth of 85.73 to 167.80 m with temperature 22.20 to 26.40 °C, bigeye dominated 60% size >100 cm was caught at a depth of 193.97 to 470.12 with a temperature 8.35 to 15.30 °C, albacore dominated 64 % of size >100 cm in depth from 85.73 to 124.74 m with a temperature 21.41 to 26.40 °C and bluefin size >100 cm was caught at a depth of 190 0.15 to 194.21 m with temperature from 14.99 to 15.12 °C. Temperature and depth distribution of yellowfin and albacore tuna species have in common is at the level of the surface layer, this suggest the tropical waters is an area suitable to catch yellowfin and albacore in the Indian Ocean. Keywords : Tuna, temperature and depth, tuna longline, Indian Ocean