Pola Distribusi Suhu Permukaan Laut Dihubungkan dengan Kepadatan dan Sebaran Ikan Lemuru (Sardinella lemuru) Hasil Tangkapan Purse Seine di Selat Bali

Abstrak Penelitian ini bertujuan mengetahui pola distribusi Suhu Permukaan Laut (SPL), dan mengetahui hubungan antara pola distribusi SPL dengan kepadatan dan sebaran ikan. Penelitian dilakukan pada bulan April sampai Juli 2007. Data yang digunakan adalah data citra yang bebas awan dan data hasil serta lokasi penangkapan ikan lemuru. Nilai kepadatan ikan dihitung dengan pendekatan Fridman (1986). Perhitungan SPL dilakukan dengan pemrosesan citra kanal 4 dan 5 menggunakan program SPL diperoleh dari Pusat Pengembangan Pemanfaatan dan Teknologi Penginderaan Jauh (Pusbangja) - LAPAN, Pekayon, Jakarta Timur. Hasil penelitian mendapatkan bahwa daerah penangkapan ikan lemuru ada lima, yaitu Senggrong, Karang Ente, Pengambengan, Tabanan, dan Jimbaran. Nilai kepadatan pada bulan April sebesar 0,28 kgm-3, bulan Mei 0,19 kgm-3, bulan Juni 0,14 kgm-3, dan bulan Juli 0,17 kgm-3. Secara keseluruhan SPL bulan April – Juli 2007 berkisar antara 25-31 °C. Daerah penangkapan yang baik pada bulan April berada di Pengambengan dengan SPL 27,96 - 30,58 °C, bulan Mei berada di Tabanan dengan SPL berkisar antara 27,93 - 29,36 °C, bulan Juni dan Juli berada di Tabanan dengan SPL berkisar antara 25,32 - 27,90 °C. Suhu permukaan laut tidak memiliki hubungan yang nyata dengan kepadatan ikan. Kata Kunci: distribusi, lemuru, Selat Bali, SPL Abstract This research aimed to identify model of sea surface temperature distribution and illustrate its relation with spread and density of fish. The research was done at Bali Strait from April to July 2007 based on satellite signal and catch data. Fish density was calculated by using Fridman equation (1986). While calculation of sea surface temperature was conducted by applying fourth and fifth canal of satellite signal program obtained from Development Center of Utilization and Satellite Identification Technology (LAPAN) Jakarta. Result showed that there were five fishing grounds of sardine, namely Senggrong, Karang Ente, Pengambengan, Tabanan, and Jimbaran. Values of fish density in April, May, June, and July were 0.28 kgm-3, 0.19 kgm-3, 0.14 kgm-3, andi 0.17 kgm-3 respectively. Generally, monthly average of sea surface temperature from April to July 2007 was between 25 °C to 31 °C. High density level of fishing ground of each month was different. It was also found that Tabanan was the best fishing ground for lemuru in Bali Strait followed by Pengambengan. The highest fish density in April was taken place in Pengambengan with sea surface temperature level between 27.96 °C to 30.58 °C. Whilst In May, the highest fish density was occured in Tabanan with sea surface temperature level between 27.93 to 29.36 °C. In addition, the highest fish density in June and July was also occured in Tabanan with sea surface temperature level between 25.32 °C to 27.90 °C. The relation of sea surface temperature with fish density was not significantly different. Keywords: Bali Strait, distribution, sardine, sea surface, temperatur