ABSTRACT Global climate forcing and anthropogenic pressures are increasingly destabilizing marine ecosystems, pushing high‐productivity upwelling zones toward unpredictable ecological tipping points. In the southeastern Caribbean, the eastern Venezuelan coastal region supports one of the world's most significant fisheries for the sardine Sardinella aurita , a species whose population stability is governed by a narrow thermal window (18°C–25°C). Utilizing two decades (2002–2023) of high‐resolution MODIS‐Aqua satellite data, we applied an early warning signal (EWS) framework based on critical slowing down (CSD) theory to diagnose the loss of resilience in this vital habitat. By contrasting the coastal sardine fishing area (SFA) with the offshore exclusive economic zone (EEZ), we analyzed temporal trends in sea surface temperature (SST) variance (standard deviation) and temporal autocorrelation (AR(1)). Our results reveal a significant divergence in thermal stability: while minimum and mean SSTs show increasing persistence (AR(1)), signaling a classic loss of resilience, the maximum SST in the coastal domain exhibits a sharp increase in volatility (SD) and erratic behavior. These “anti‐CSD” signals in maximum SST indicate that extreme thermal events, such as marine heatwaves, are becoming more frequent and intense, frequently trespassing the physiological thresholds of S. aurita . By prioritizing physics‐based indicators of habitat stability over confounded fishery‐dependent data, this study demonstrates that the coastal sardine habitat is approaching a nonlinear regime shift. These findings provide a robust, proactive diagnostic tool for fisheries management, offering a critical lead time for adaptive strategies before biological collapses become statistically detectable.
Molero‐Lizarraga et al. (Thu,) studied this question.