Life-history strategies under exploitation: A long-term study of Azorean fisheries

This is the authors' abstract. We don't add key points for this paper.

Fishing pressure can affect marine fish species differently according to their biological traits. This study investigates how the trait composition of fish landed in the Azores changed over four decades of exploitation. Using landings data spanning 42 years (1980–2021), 103 fish species landed in the Azores were analysed. Archetypal analysis was used to summarize ecological and life-history traits into three strategy endpoints: periodic, opportunistic, and equilibrium. Interannual variability and long-term temporal patterns in richness, landings, and intrinsic vulnerability were analysed using the coefficient of variation, standard Generalized Additive Models, and Generalized Additive Mixed Models with AR(1) correlation structure. The results showed that richness of periodic-type species increased through time, indicating a greater contribution of periodic-type species to the landed catch. Landings of opportunistic-type species showed no robust long-term directional pattern, whereas their intrinsic vulnerability declined through most of the time series and stabilized in recent years. Landings of periodic-type species showed marked interannual variability, but this temporal pattern was not statistically significant after accounting for AR(1) autocorrelation. Landings of equilibrium-type species and intrinsic vulnerability declined over time, indicating a shift in the landed biomass and vulnerability composition associated with slow-turnover species. These findings suggest that long-term changes in Azorean landings reflect shifts in the representation of life-history trait composition rather than simple changes in species counts or total landing alone. Integrating the life-history strategies framework into fisheries management is essential for aligning exploitation with biodiversity conservation and ecosystem functions.