Biological parameters estimate for the sickle pomfret (Taractichthys steindachneri) in the west-central and eastern Pacific Ocean

Abstract

This study was undertaken to provide some preliminary biological information for Sickle pomfrets<em> Taractichthys steindachneri </em>from length frequency data (LFD) obtained through the Chinese Longline Fisheries Observer Programme in the Pacific Ocean obtained from August 2016 to March 2017. We fitted the seasonally oscillating von Bertalanffy Growth Function (so VBGF) by applying two optimized ELEFAN approaches ('simulated annealing' ELEFAN S.A. and 'genetic algorithm' ELEFAN G.A.). ELEFAN S.A. presented the best score and was later used to obtain the following results: FL_∞ = 101 cm, <em>k</em> = 0.52 yr⁻¹, t_{_anchor} = 0.73, C = 0.75, ts = 0.2, and growth performance index of ∅ = 3.72; natural mortality M = 0.55 yr⁻¹, total mortality Z = 1.37 yr⁻¹, fishing mortality F = 0.82 yr⁻¹, exploitation rate E = 0.59, length at first sexual maturity Lm = 67.5 cm corresponding to 2.47 years (age at first sexual maturity); major recruitment and highest catch rate occurred in January. F and E at maximum sustainable yield were Fmsy = 1.7 yr^-1 and Emsy = 0.754, respectively. In this study, E and results of yield-per-recruit models indicate that these fisheries are sustainably harvested, and maximum sustainable yield could be acquired, if F is increased to Fmsy.