For the past four decades, the Smithsonian Tropical Research Institute (STRI) has used satellite observations and oceanographic instruments to track the predictable seasonal upwelling that characterizes the Sea of Panama. Typically, the region experiences a marked cooling of surface waters between January and April, a pattern that has been consistently observed since the 1980s.
In 2025, that reliable temperature decline did not occur. The expected influx of cold, nutrient‑rich water failed to arrive, leaving the surface temperature hovering around 23 °C instead of the usual 19 °C. This anomaly disrupted the food web that depends on phytoplankton blooms triggered by upwelling.
The loss of cold waters has already had tangible effects on local fisheries and reef ecosystems. Reduced phytoplankton availability stresses coral reefs, which are already vulnerable to thermal stress, and limits the food supply for commercially important species such as sardines and squid.
While scientists have only monitored the area directly for forty years, paleoclimatic data indicate that the upwelling cycle has been stable for millennia. Consequently, the 2025 breakdown represents the first known interruption in thousands of years.
Anthropogenic climate change is widely regarded as the driving force behind the altered temperature regime. Rising atmospheric temperatures and changes in wind patterns are thought to weaken the Panama Wind Jet, the driver of the upwelling process.
However, the precise chain of events that translated global warming into the 2025 failure is still under investigation. Scientists are modeling oceanic currents and atmospheric circulation to determine how greenhouse gas emissions have reshaped local climate dynamics.
Local communities and scientists are concerned that this event may not be an isolated incident. Continued warming could lead to more frequent disruptions, jeopardizing both the ecological integrity of the Sea of Panama and the livelihoods of coastal populations.
