A silent but alarming shift has taken place beneath the Pacific Ocean. For the first time in at least 40 years, a major equatorial upwelling system off the coast of Panama has failed—an event scientists describe as both unprecedented and potentially global in consequence.
This disruption, which occurred during early 2025, shut down a natural ocean “engine” responsible for cooling tropical waters, sustaining fisheries, and supporting coral reefs. Researchers warn that the collapse may signal deeper climate instabilities emerging across tropical oceans.
A Vital Ocean System Suddenly Falters
Every year from January to April, powerful trade winds sweep across Panama, pushing warm surface waters aside and allowing cool, nutrient-rich water to rise from the deep. This upwelling fuels blooms of phytoplankton—the foundation of the marine food chain—and provides a cooling buffer for coral reefs.
But in 2025, the system failed entirely.
Satellite data showed:
- Near-zero chlorophyll levels, indicating a collapse in biological productivity
- Persistently warm surface temperatures, which rarely dropped below 25°C
- A complete absence of vertical mixing, confirmed by scientists aboard the research vessel Eugen Seibold
A review of over 40 years of records revealed no historical precedent for such a shutdown—not even during strong ENSO years.
The Winds Didn’t Stop Blowing—They Just Stopped Showing Up
The surprising culprit was not weaker winds, but far fewer wind events.
Panama’s wind jets—short bursts of strong, localized gusts that trigger upwelling—occurred 74% less frequently than in previous decades. When they did occur, they were nearly as strong as usual, but the long pauses between events prevented upwelling from taking place.
Researchers point to a northward shift in the Intertropical Convergence Zone (ITCZ) during the 2024–2025 La Niña as a possible cause, though similar or stronger climate cycles in the past never triggered a total collapse.
This suggests deeper climate warming may be altering wind-driven systems in ways current models underestimate.
Ecological Damage Already Visible
The absence of upwelling triggered rapid and widespread biological consequences:
1. Fisheries Decline
With phytoplankton levels dropping sharply, fish populations dependent on plankton—such as sardines and mackerel—diminished along Panama’s coast. Local fishers reported significant declines in catch volume.
2. Coral Reefs Overheat
Without cool deep water rising to the surface, coral reefs faced prolonged thermal stress. Bleaching events intensified across early 2025.
3. Oxygen Levels Fell
Stratified waters prevented oxygen from reaching deeper layers, threatening benthic species and altering the structure of marine food webs.
The event highlights how a single missing seasonal process can create cascading ecological disruptions across an entire region.
A Critical Blind Spot in Global Climate Monitoring
One of the most concerning revelations is that the event nearly went unnoticed. Unlike temperate regions, tropical upwelling zones suffer from significant monitoring gaps. The only reason this collapse was detected is due to long-running observation programs maintained by regional and international research institutes.
Scientists caution that:
- Tropical upwelling systems play major roles in global carbon cycling
- They support important fisheries and coral ecosystems
- They are poorly integrated into global climate models
If similar failures begin emerging across the Eastern Tropical Pacific, the world may face faster and more unpredictable climate impacts.
A Warning Sign for the Planet
The study’s authors—representing the Smithsonian Tropical Research Institute, Max Planck Institute for Chemistry, and global partners—stress that this is likely a warning of vulnerabilities in Earth’s climate machinery.
They recommend:
- Expanding ocean monitoring networks
- Improving climate models to incorporate tropical wind-ocean interactions
- Strengthening international collaboration on tropical ocean data
The message is clear: the ocean’s “breathing” has changed, and the consequences could extend far beyond Panama’s shores.
