Climate-driven shifts in narrow-barred Spanish mackerel ( Scomberomorus commerson ) distribution in the Taiwan Strait: Insights from remote sensing oceanography

The impact of increasing global temperatures, and changing ocean conditions affect the distribution of marine organisms as well as on the marine ecosystem. This study investigates the implications of predicted climate change on the distribution of Scomberomorus commerson in the Taiwan Strait (TS). Ensemble modelling (using generalized additive model, gradient boosting machine and random forest) and two shared socio-economic pathways (SSPs: SSP 2.6–1.2 to1.8°C increase in temperature expected by 2100, and SSP 8.5–3.8 to 5°C increase in temperature expected by 2100) scenarios were used in this study. Our results indicated that the current range of S. commerson in the TS is between 22°N–25°N and 117.5°E–119°E. Both SSPs demonstrated that over 2045–2050, a notable increase in habitat range area will occur in the extent of the distribution of S. commerson. However, after this period, more habitat loss will occur for this species under SSP 8.5 than under SSP 2.6 (60%–80% vs. 2%–10%). Given climate change, policymakers should establish sustainable and management strategies including the identification and protection of climate refugia, the implementation of seasonal closures in susceptible southern habitats, and the enhancement of regional collaboration to promote sustainable fisheries in the TS and to ensure the well-being of the communities dependent on them. These measures are essential not only for the sustainability of S. commerson but also for other small pelagic fisheries and gillnet-dependent groups in the Taiwan Strait, which are particularly vulnerable to climate-induced habitat degradation.