Unveiling the status of Trichiurus lepturus (Actinopterygii, Scombriformes, Trichiuridae) stocks in the southern Java waters, Indonesia: A biological and length-based assessment approach

The southern Java waters are characterized by a strong upwelling process, making the region a potential hotspot for fishing activities, including the largehead hairtail, Trichiurus lepturus Linnaeus, 1758. This study provides data on various aspects of T. lepturus in the southern Java waters, including reproductive biology, growth parameters, mortality rates, spawning potential ratio (SPR), and yield per recruit (Y/R). The results are intended to help sustain the management of T. lepturus fisheries in the southern Java waters. A total of 19 587 fish specimens were collected monthly between January 2019 and December 2021 from fishermen’s catches in the southern Java waters at the Palabuhanratu Archipelago Fishing Port, West Java Province, Indonesia. The data collected involved information on length, weight, sex, and gonads. Length-frequency data were analyzed using various fisheries assessment models. A length–weight relationship follows a positive allometric growth pattern. The sex ratio was slightly female-biased. Gonadal maturity stages (GMS) and the gonadosomatic index (GSI) indicated a prolonged spawning period. The length at first maturity (Lm50) males and females was estimated at 84.5 cm and 77.0 cm, respectively. The von Bertalanffy growth equation of T. lepturus in southern Java waters is Lt = 131.67(1 – e–0.22(t + 0.5094)). Total mortality (Z), natural mortality (M), and fishing mortality (F) were 1.60 year−1, 0.44 year−1, and 1.16 year−1, respectively. The spawning potential ratio (SPR) was 26%, and the yield per recruit (Y/R) analysis suggested that the current fishing effort is above the maximum sustainable yield level. Trichiurus lepturus in southern Java waters is experiencing high fishing pressure, which may compromise its reproductive potential and long-term sustainability. Management measures should be implemented to regulate the fishing effort and ensure the sustainable exploitation of this vital fishery resource.