Panama’s Ocean Circulation Fails  

Feature image: This image from Copernicus Marine Service shows sea surface temperatures in March 2024 and 2025, highlighting warmer waters in 2025 due to the missing cold-water upwelling. Credit: European Union, Copernicus Marine Service Data.

In an unprecedented event, the Gulf of Panama’s seasonal upwelling system has completely failed to activate in 2025. A new study published in Proceedings of the National Academy of Sciences reveals that for the first time in over 40 years of satellite monitoring, the normally predictable ocean circulation that delivers cool, nutrient-rich waters each January through April simply shut down. 

Each January through April, northerly trade winds normally drive deep, nutrient-rich waters to the surface across approximately 60,000 km² of the Gulf of Panama. This upwelling fuels phytoplankton blooms that support marine food webs, sustains fisheries across Central America, and provides cooling that helps coral reefs survive thermal stress. The phenomenon has been so reliable across centuries that pre-Columbian societies, marine ecosystems, and modern economies have all become dependent on its annual rhythm. In 2025, winds weakened dramatically, waters remained stratified and warm, and the seasonal pulse never arrived.  

Key Developments 

• Extreme delay and shortened season: Surface waters didn’t drop below 25°C (77°F) until March 4, this was 42 days late and the upwelling lasted just 12 days, an 82% reduction from the typical 66-day season 

• Temperatures stayed unusually warm: Minimum sea surface temperatures reached only 23.3°C (73.9°F), far above the historical minimum of 19°C (66.2°F) 

• Wind events failed to materialize: Northerly wind events occurred 74% less frequently, and relaxation periods increased by 25%. When winds did blow, they matched historical strength but simply occurred far too rarely 

• Ecosystem collapse: Water column profiles showed strong thermal stratification blocking nutrients from reaching the surface, causing the phytoplankton bloom that fuels the marine food web to collapse 

Polar Change Link 

The 2025 collapse of Panama’s seasonal ocean circulation highlights how regional ocean and wind dynamics can drive major changes, even in systems previously considered reliable. Reduced frequency and duration of northerly winds prevented nutrient-rich waters from rising, disrupting plankton blooms and marine food webs. While climate patterns like La Niña can influence winds, this failure occurred during a weak La Niña, showing that local conditions are critical. 

These shifts in tropical ocean circulation are connected to broader climate processes, including polar and high-latitude changes. Altered wind patterns, ocean stratification(layering), and ice melt in polar regions influence global currents and nutrient flows, which in turn affect tropical systems like Panama. This underscores that polar and tropical ocean changes are linked, and disruptions in one region can ripple across global marine ecosystems. 

Global Implications 

• Fisheries that rely on the productive circulation region face lower yields and uncertain timing, impacting coastal economies. 

• Coral reefs and coastal ecosystems lose a natural cooling and nutrient boosting mechanism, increasing vulnerability to bleaching and collapse. 

Urgent Response Needed 

• Rapidly cut greenhouse gas emissions to restore stability in ocean atmosphere coupling and preserve reliable marine systems. 

• Protect and restore coastal ecosystems such as mangroves and seagrass that buffer impacts when circulation falters. 

• Develop adaptive fishery management based on early warning of circulation anomalies and nutrient decline. 

What happens in Panama’s waters doesn’t stay in Panama’s waters. This upwelling failure is a warning that ocean systems we’ve relied on for millennia are becoming unpredictable, with consequences for food security, livelihoods, and marine life worldwide. 

Read more: Extreme weather events | Health risks | Climate Risks Daily 

Original source: https://www.pnas.org/doi/10.1073/pnas.2512056122