Tesis ini membahas beberapa aspek yang mendukung upaya pengelolaan sumber daya ikan tuna sirip biru selatan (Thunnus macoyii Castelnau, 1872) yang tertangkap dari perairan Samudera Hindia dan didaratkan oleh kapal tuna longline di Pelabuhan Benoa Bali yang mencakup : sebaran panjang, hubungan panjang dan berat, faktor kondisi, panjang ikan pertama tertangkap (Lc) dan hasil tangkapan per unit upaya (CPUE). Penelitian dilaksanakan selama 7 (tujuh) bulan dari Maret - September 2011. Hasil penelitian menyimpulkan bahwa fishing ground ikan SBT di perairan selatan Jawa dan Bali Samudera Hindia terjadi pada akhir musim timur sampai awal musim barat. Distribusi frekuensi ukuran panjang ikan SBT terbanyak pada fork length (FL) antara 171 - 180 cm sebanyak 139 ekor. Hubungan panjang berat yang didapatkan adalah W=0,00002FL2,5925, R2=0,8172 sehingga pola pertumbuhan ikan SBT yang di daratkan di Pelabuhan Benoa bersifat alometrik negatif. Nilai faktor kondisi (K) diperoleh fluktuasi antara 2,29 - 3,37 yang diduga karena adanya perbedaan tingkat kematangan gonad. Panjang pertama kali tertangkap (length at first capture/Lc) ikan SBT selama masa penelitian adalah berukuran 158,2 cm yang diduga ukuran tersebut telah melewati masa ikan melakukan pemijahan/recruitment. Catch per unit effort (CPUE) selama masa penelitian didapatkan cenderung mengalami fluktuasi penurunan yang diindikasikan karena pada bulan masa penelitian telah melewati masa puncak musim penangkapan ikan SBT dari perairan Samudera Hindia.
This thesis discusses some aspects that support to management efforts for resource of southern bluefin tuna (Thunnus macoyii Castelnau, 1872) caught from the waters of the Indian Ocean and landed by tuna longline vessels in the port of Benoa Bali. The focus studies are: distribution of the length, length and weight relationship, condition factor, length at first fish capture (Lc) and the catch per unit effort (CPUE). Research carried out during 7 (seven) months from March to September 2011. The study concluded that the SBT fishing ground in the waters south of Java and Bali Indian Ocean occurs in late winter to early summer east west. Size frequency distributions of SBT at most fork length (FL) 171-180 cm by 139 SBT. Length and weight relationship obtained is W = 0.00002 FL2,5925, R2=0.8172 so that the growth pattern of SBT is negative allometric. The value of condition factor (K) obtained fluctuation between 2.29 to 3.37 is expected because of differences in levels of gonadal maturity. The length at first capture (Lc) of SBT during the study period was 158.2 cm, this length has passed the fish to spawning/recruitment. Catch per unit effort (CPUE) obtained during the study period tended to decrease as indicated due to fluctuation in the study period has passed the peak of SBT fishing season of the Indian Ocean waters. |
