Overfishing risk and population decline of Scomberomorus commerson (Actinopterygii, Scombriformes, Scombridae) in a data-poor fishery: First assessment from the eastern Mediterranean Sea

Between May 2023 and November 2024, 611 specimens of the narrow-barred Spanish mackerel, Scomberomorus commerson (Lacepède, 1800), were collected from artisanal landing sites along the Syrian coast (eastern Mediterranean Sea) to assess stock status in a data-poor fishery. Age was estimated using a multilayer perceptron neural network trained on fork length (FL); the oldest was age 5+ (109.58 cm). Growth conformed to the von Bertalanffy growth function, with K = 0.275 y−1 (95% CI: 0.266–0.284), FL∞ = 127 cm (95% CI: 125.69–128.31). The length–weight relationship indicated negative allometric growth (b = 2.89); and the growth performance index (Φ′) was 3.65, reflecting moderate growth potential. Total mortality (Z) was 1.22 y−1, comprising natural mortality (M) = 0.49 y−1 and fishing mortality (F) = 0.73 y−1, yielding an exploitation rate (E) of 0.60. This exceeds the E0.5 threshold (0.389) for 50% biomass depletion, confirming overfishing. Sensitivity analysis showed E > E0.5 across biologically plausible ranges of FL∞ and K values. A fuzzy logic expert system produced a fishing vulnerability (FV) index of 50.9 and a population growth potential (FP) index of 33.2, indicating high susceptibility to fishing and low recovery capacity. The age structure was severely truncated: only 0.82% reached age 5+, far below the 12–20 years reported in less-exploited populations. We recommend: (i) a minimum landing size of 75 cm FL, (ii) seasonal closures from May to July to protect spawning aggregations, and (iii) enhanced monitoring of artisanal fisheries. Despite uncertainties, integrating artificial neural networks and fuzzy logic offers a robust, transferable approach for stock assessment in data-limited, conflict-affected regions.