<abstract xmlns="http://www.w3.org/1999/xhtml">

Yellowfin tuna <italic>Thunnus albacares</italic> is one of the major species of tuna caught in the Fisheries Management Area (FMA) 573 of the Indian Ocean. Its production contributed to 35.83% of the total production of tuna in 2013. The study was conducted to assess the population dynamics of this species in FMA 573, based on length-frequency data collected in 2013-2017, and was analysed using FiSAT II software. The results obtained show length-weight relationship of W = 0.000052 FL2.78, negative allometric growth and growth equation of Lt = 194.25 (1-e-0.51 (t + 0.1889)). The length at first capture was estimated at 140 cm FL. Recruitment season occurs between July and September, with a peak in August. The rate of total mortality (Z) was 2.32 yr-1, including natural mortality rate (M) of 0.69 yr-1 and fishing mortality rate (F) of 1.63 yr-1. The exploitation rates of yellowfin tuna were estimated to be 0.70, indicating that it has exceeded the optimum exploitation rate (E = 0.5) and that overexploitation had occurred. There is an obvious need for consistent monitoring and surveillance of fishing fleet, type and size of fishing gear, as well as the fish size and quantity of the catch.
</abstract>

Yellowfin tuna Thunnus albacares is one of the major species of tuna caught in the Fisheries Management Area (FMA) 573 of the Indian Ocean. Its production contributed to 35.83% of the total production of tuna in 2013. The study was conducted to assess the population dynamics of this species in FMA 573, based on length-frequency data collected in 2013-2017, and was analysed using FiSAT II software. The results obtained show length-weight relationship of W = 0.000052 FL2.78, negative allometric growth and growth equation of Lt = 194.25 (1-e-0.51 (t + 0.1889)). The length at first capture was estimated at 140 cm FL. Recruitment season occurs between July and September, with a peak in August. The rate of total mortality (Z) was 2.32 yr-1, including natural mortality rate (M) of 0.69 yr-1 and fishing mortality rate (F) of 1.63 yr-1. The exploitation rates of yellowfin tuna were estimated to be 0.70, indicating that it has exceeded the optimum exploitation rate (E = 0.5) and that overexploitation had occurred. There is an obvious need for consistent monitoring and surveillance of fishing fleet, type and size of fishing gear, as well as the fish size and quantity of the catch.

Population Dynamics of Yellowfin Tuna <italic>Thunnus albacares</italic> (Bonnaterre, 1788) in the Fisheries Management Area 573 of the Indian Ocean

Aquatic Resources Department, Faculty of Fisheries and Marine Science

Marine Science Department, Faculty of Fisheries and Marine Science

Croatian Journal of Fisheries

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Population Dynamics of Yellowfin Tuna  (Bonnaterre, 1788) in the Fisheries Management Area 573 of the Indian Ocean

Yellowfin tuna Thunnus albacares is one of the major species of tuna caught in the Fisheries Management Area (FMA) 573 of the Indian Ocean. Its production...

Population Dynamics of Yellowfin Tuna Thunnus albacares (Bonnaterre, 1788) in the Fisheries Management Area 573 of the Indian Ocean

Publié en ligne: 26 mai 2021

Pages: 53 - 60

Reçu: 13 nov. 2020

Accepté: 12 janv. 2021

DOI: https://doi.org/10.2478/cjf-2021-0006

Mots clés
FMA, Growth pattern, Mortality rate, Exploitation rate, Effort distribution, Length-weight relationship

© 2021 Abdul Ghofar et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Population Dynamics of Yellowfin Tuna Thunnus albacares (Bonnaterre, 1788) in the Fisheries Management Area 573 of the Indian Ocean

Publié en ligne: 26 mai 2021

Pages: 53 - 60

Reçu: 13 nov. 2020

Accepté: 12 janv. 2021

DOI: https://doi.org/10.2478/cjf-2021-0006

Mots clésFMA, Growth pattern, Mortality rate, Exploitation rate, Effort distribution, Length-weight relationship

© 2021 Abdul Ghofar et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Mots clés
FMA, Growth pattern, Mortality rate, Exploitation rate, Effort distribution, Length-weight relationship