Single or multiple climate oscillations? Impacts on the Northwestern Pacific seabream fishery

Abstract

Introduction Comprehending species-specific reactions to climate variability is crucial for ecosystem-based fisheries management, especially for high-value multispecies fisheries. The waters of Taiwan harbour numerous commercially significant seabream species; nevertheless, the impact of large-scale climatic oscillations on their catch dynamics is inadequately characterised.Methods We examined catch trends of six principal seabream species (Acanthopagrus schlegelii, Dentex hypselosomus, Evynnis cardinalis, Pagrus major, Parargyrops edita, and Rhabdosargus sarba) employing Generalised Additive Models (GAM) to evaluate associations with significant climatic factors. Cross-spectrum analysis was utilised to identify predominant periodicities, whereas wavelet coherence analysis investigated temporal coherence and phase correlations between climate indices and catch rates.Results The Pacific Decadal Oscillation (PDO) was identified as the predominant predictor for all species, with explained deviance between 24.6% and 42.3%. Cross-spectrum analysis revealed notable low-frequency periodicities of around 2.4 years. Wavelet coherence demonstrated both immediate and lagged responses, exhibiting asynchronous species-specific patterns influenced by a shared PDO.Discussion These findings underscore the influence of decadal climate variability on the dynamics of multispecies fisheries in Taiwanese seas. Integrating species-specific and time-lagged responses into management techniques is essential for adaptive, climate-resilient fisheries governance. The results also offer evidence pertinent to international policy frameworks about the effects of climate change on marine ecosystems.