For the First Time in 40 Years, Panama’s Ocean “Lifeline” Suddenly Vanished and Left an Entire Ecosystem Without a Pulse

Panama’s Pacific coast has a rhythm fishermen have counted on for generations. Every dry season, when the trade winds build and push offshore, the ocean transforms. Cold water rises from the deep, nutrients flood the surface, and the Gulf of Panama erupts with life, anchovies in massive schools, pelicans diving in frenzies, coral reefs catching a rare thermal reprieve.

In 2025, none of that happened.

The waters stayed warm. The nutrients never arrived. The bloom never came. Scientists at the Smithsonian Tropical Research Institute had tracked this system for four decades without seeing it fail. Then, in a single dry season, it did. Their findings, published in September 2025 in Proceedings of the National Academy of Sciences, document the first complete collapse of the Gulf of Panama’s seasonal upwelling in at least 40 years of records.

The Engine Underneath Panama’s Fisheries

Each January through April, strong northern trade winds push the Gulf of Panama’s surface water offshore. As that warm layer moves away, colder water rises from depth to fill the gap. That cold water carries nutrients into the sunlit upper ocean, triggering a surge of algae growth that feeds everything above it in the food chain, from anchovies and sardines to the larger predators and seabirds that follow them.

For Panama’s Pacific coast, this is not an annual bonus. It is the foundation. The upwelling sustains commercially vital fisheries that coastal communities have depended on for thousands of years, gives coral reefs a thermal buffer when surrounding waters run warm, and keeps beach temperatures along the Pacific shore noticeably cooler during the country’s peak dry-season tourist period. Remove the upwelling, and you do not just lose the cold water. You lose everything it sets in motion.

What makes the Gulf of Panama’s system unusual is how dependable it has always been. Unlike upwelling zones in other parts of the world that fluctuate significantly from year to year, the Gulf of Panama‘s seasonal pulse has shown up in STRI’s records with almost mechanical regularity. Researchers tracking it over four decades had come to treat it less as a natural phenomenon subject to variation and more as a fixed feature of the regional calendar. That consistency is precisely what made 2025 so disorienting, and everything downstream went with it.

Why the Winds Gave Out

The research team, which includes scientists from the Max Planck Institute for Chemistry working aboard the institute’s vessel S/Y Eugen Seibold, traced the collapse to the trade winds. More specifically, to the gap winds: air masses that funnel through low mountain passes in the Central American cordillera from the Caribbean side. In 2025, those winds were weaker than at any point in the four-decade record. They blew less often, for shorter periods, and never with enough force to break up the warm, stable surface layer sitting above the cold water below.

The paper identifies the position of the Intertropical Convergence Zone, a band of low pressure and rising air near the equator, during the 2024-2025 La Niña as a likely factor. When that band shifts, it can reshape regional wind patterns across Central America. But the researchers do not claim a clean causal chain. The exact mechanism, they write, remains unclear.

“For the first time, we have observed how changes in an atmospheric and oceanic circulation system exceed a threshold and lead to reduced biological production,” said Dr. Ralf Schiebel, a group leader in the Climate Geochemistry Department at the Max Planck Institute for Chemistry.

The Dataset That Made the Difference

This finding was only possible because someone had been watching long enough. STRI’s Physical Monitoring Program has kept an unbroken record of sea surface temperatures in the tropical eastern Pacific off Panama for more than four decades. Every year, seasonal cooling showed up in the data like clockwork. In 2025, there was nothing, a flat line where a sharp dip should have been.

The S/Y Eugen Seibold supplied a second layer of evidence. Operating in the region since 2023, the vessel collected wind speed readings, water temperatures, and measurements of ocean layering that let researchers identify not just the failure, but its physical cause. Without both datasets, the event might have looked ambiguous. Together, they made it clear.

Gerald Haug, Director of the Climate Geochemistry Department at the Max Planck Institute for Chemistry, drew a careful line around what the data can support: “It is too early to conclude that the current climate and ocean warming could lead to reduced upwelling in the tropical eastern Pacific.”

What the Empty Maps Reveal

The satellite imagery makes the loss concrete. In a normal February, the Gulf of Panama glows in chlorophyll concentration maps, dense with reds and oranges marking algae blooms fed by upwelling nutrients. In February 2025, those colors were largely gone. The gulf stayed blue: low productivity across a system that should have been at its annual peak.

The full ecological cost is still being tallied. One failed upwelling season does not crash a fishery outright, but it removes the nutritional pulse that fish populations, seabirds, and marine mammals depend on each year. Coral reef thermal stress compounded the problem: stripped of the cold-water buffer that upwelling normally provides, reefs absorbed prolonged heat during a period when surrounding ocean temperatures were already running high.

The researchers also flag something the event exposed beyond Panama’s coast. Tropical upwelling systems are ecologically and economically vital yet remain poorly observed across most of the world. The 2025 failure was caught because STRI had maintained one of the few long-term ocean monitoring records in the tropics. Most comparable systems have nothing equivalent.

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