Here, we demonstrate how large-scale climate forcing dictates the commercial collapse of the Japanese flying squid (Todarodes pacificus) fishery in the South Korea. Using multi-decadal observations (1993–2022), we identify a teleconnection where an intensified preceding summer La Niña significantly amplifies autumn marine heatwaves (MHWs) within traditional fishing grounds. Through mediation analysis, we reveal that these MHWs act as the direct physical mechanism driving abrupt catch declines, forcing a poleward displacement of squid populations. Furthermore, utilizing CMIP6 multi-model ensembles, we project that unabated ocean warming (SSP5-8.5) will lead to the complete commercial extinction of this regional fishery by 2050s. Our findings highlight that climate-induced spatial mismatches override traditional fishery boundaries, underscoring the urgent need for transboundary, climate-adaptive resource management.

Todarodes pacificus,Marine heatwaves,La Niña,Fishery collapse,Climate change