Size composition and length-weight relationships of the Yellowfin Tuna (Thunnus albacares) in Bone Bay

¹ Doctoral Program of Marine Science and Fisheries Faculty of Hasanuddin University, Makassar, South Sulawesi, Indonesia ;
² Agribusiness Study Program, Science and Technology Faculty of Universitas Terbuka, Indonesia ;
³ Marine Science and Fisheries Faculty of Hasanuddin University, Makassar, South Sulawesi, Indonesia ;

Abstract

The size composition, length-weight relationship, and condition factor of Thunnus albacares were examined in Bone Bay. Sampling was conducted at two stations, i.e., Station I at Cimpu in Luwu Regency and Station II at Lonrae in Bone Regency between July 2018 and June 2019. 10246 and 2651 yellowfin tunas were captured in Station I and Station II, respectively. Measurement of the fork length ranged between 20 cm and 192 cm with an average length of 81,257 ± 33,456 cm in Station I, and between 26 to 162 cm with an average length of 95,479 cm in Station II. The weight measurement ranged between 0,35 and 99,21 kg with an average of 14,539 kg in Station I, and between 0,46 and 97,35 kg with an average of 26,978 kg in Station II. Calculation of the relationship was based on the formula W= 5,5⁻⁵FL^2,7454 (R² = 0,963) in Station I, and W=4,1⁻⁵FL^2,9103 (R² = 0,761) in Station II. The values of condition factor at Station I and Station II were 2,1395 and 3,4374, respectively. It is quite evident that the growth pattern of the yellowfin tunas at Bone Bay was negatively allometric, indicating that the length increased faster than the weight.