The mullet follow that cold water like a signal
Along the coast of Santa Catarina, a rare convergence of extratropical cyclones, southerly winds, and cold ocean currents has produced the most abundant mullet harvest in thirty years — nearly 400 tons pulled from waters that, in other seasons, offer far less. Nature, in its indifference, occasionally arranges conditions that feel like gifts: low-pressure systems over Argentina and southern Brazil reshaped ocean circulation, dropped water temperatures, and opened a corridor that guided the fish toward shore and into waiting nets. The bounty is real, but so is its fragility — dependent on atmospheric rhythms that El Niño could unwind, and on the biological health of stocks that no weather system alone can sustain.
- Extratropical cyclones — usually feared for destruction — quietly engineered ideal migration conditions by driving cold air and southerly winds down the Santa Catarina coastline.
- Cold water temperatures and altered ocean currents sent a biological signal to mullet schools, drawing them toward shore in numbers that surprised even veteran fishermen.
- The harvest has surpassed 400 tons, the highest in three decades, prompting fishing federations to declare 2026 an exceptional season by any historical measure.
- Success has created its own tension: supply now outpaces local demand, forcing fishing organizations to seek buyers in other Brazilian states before dock prices collapse.
- Researchers warn that El Niño warming events could reverse these gains, and that sustained abundance depends equally on stock preservation and the broader health of the marine ecosystem.
This year's mullet season in Santa Catarina has left fishing crews searching for words. The catch is approaching 400 tons — the best in thirty years — and the schools have appeared along the coast with a regularity that surprised even the most experienced hands. Meteorologist Piter Scheuer attributes the abundance not to fortune but to a precise alignment of atmospheric and oceanic forces.
Extratropical cyclones, positioned over Argentina and southern Brazil, generated persistent southerly winds and pushed cold air masses down the coast. These conditions are exactly what mullet migration requires. The winds churn surface water, redirect currents, and lower temperatures — signals the fish read as an invitation to move toward shore. In some cases, persistent coastal winds also trigger upwelling, drawing cold, nutrient-rich water from the depths and enriching the food chain near the shallows.
The inverse dynamic is equally important. El Niño events warm the southern Brazilian coast and scramble the atmospheric rhythms that normally guide migration. When ocean temperatures rise, mullet lose their incentive to approach land. Scheuer notes that neutral or cooling conditions transform the coast into a magnet, concentrating schools in ways that make large harvests possible.
Climate alone, however, does not explain a season this extraordinary. The biological health of the mullet population, the integrity of ocean currents, and the management of fish stocks all contribute in ways no storm system can substitute. The state fishing federation has called it the finest season in three decades — a judgment that reflects the full complexity behind the numbers.
The abundance has generated an unexpected difficulty: in some regions, supply has begun to outpace demand, and fishing organizations have had to seek buyers in other states to keep dock prices from collapsing. It is, by any measure, a welcome crisis — the kind that arrives when nature and human effort briefly move in the same direction.
The mullet season in Santa Catarina this year has become something fishermen are still trying to understand. The catch is approaching 400 tons—the best haul in thirty years—and the schools of fish have been appearing along the coast with a consistency that has surprised even experienced crews. The reason, according to meteorologist Piter Scheuer, lies not in luck but in a specific alignment of atmospheric and oceanic conditions that created a highway for the fish to travel.
Extratropical cyclones have been the quiet architects of this abundance. While these weather systems are usually remembered for their violence—the high winds, the rough seas, the sudden shifts in temperature—they also reshape the ocean itself. This year, low-pressure systems and cyclones positioned over Argentina and southern Brazil generated sustained winds from the south and pushed cold air masses down the Santa Catarina coast. These conditions, Scheuer explains, are precisely what trigger mullet migration. The southern winds churn the surface water, redirect ocean currents, and drop the temperature—all signals that tell the fish it is time to move toward shore.
Water temperature is the primary language the mullet understand. When cold water arrives at the coast, especially when it comes with southerly winds and the passage of cold fronts, the environment becomes hospitable. The fish respond by swimming closer to land, where fishermen are waiting. Scheuer notes that ocean currents, water temperature, salinity, and food availability all work together to shape the routes these schools take. Another mechanism at work is coastal transport—persistent winds can alter how the ocean circulates near the surface and sometimes trigger upwelling, which brings deeper, colder, nutrient-rich water toward the shallows. This enriches the food chain and makes the coastal zone more attractive to migrating fish.
The inverse is also true. El Niño events, which warm the ocean across the southern Brazilian coast, tend to disrupt these patterns. When the water heats up, the mullet lose their incentive to approach the shallows. The atmospheric and oceanic rhythms that normally guide migration become scrambled. Scheuer emphasizes that in neutral conditions or during periods of ocean cooling, the coast becomes a magnet for the schools, concentrating them in ways that make large catches possible.
Yet climate and weather alone do not explain a harvest this extraordinary. The biological health of the mullet population itself matters. The availability of food, the integrity of the ocean currents, the management and preservation of fish stocks, and the broader health of the marine environment all play roles that no storm system can override. The Federação dos Pescadores do Estado de Santa Catarina, the state fishing federation, has called this the finest season in three decades—a judgment that reflects not just the numbers but the overall conditions that allowed those numbers to be reached.
The abundance has created a new problem. In some regions, the supply of fish has begun to outpace demand. Fishing organizations have had to search for buyers in other states to prevent prices from collapsing at the dock. It is a pleasant crisis, the kind that comes when nature and human effort align, but it is a crisis nonetheless. As researchers continue to study what made 2026 different, the fishing communities are already moving forward, trying to find markets for fish that, just weeks ago, seemed impossible to catch in such quantity.
Notable Quotes
Southern winds cause ocean agitation, changes in currents, and drops in water temperature—factors that stimulate fish schools to move toward the Santa Catarina coast— Meteorologist Piter Scheuer
The historic harvest cannot be explained by climate alone; biological factors, food availability, ocean currents, and preservation of fish stocks all directly influence the season's success— Piter Scheuer
The Hearth Conversation Another angle on the story
So the cyclones themselves—they're not just making the weather rough. They're actually moving the fish?
Not directly. But they're changing the water in ways the fish respond to. The winds push cold water toward the coast, and the mullet follow that cold water like a signal. It's the environment shifting, and the fish moving with it.
And this has been happening all season?
Yes. The low-pressure systems and cyclones have been persistent enough that the southern winds didn't stop. That's unusual. Usually these systems come and go. This year they kept coming, kept pushing cold water down the coast.
What happens if El Niño shows up next year?
The ocean warms. The mullet lose interest in coming close to shore. The whole migration pattern breaks. You go from 400 tons to maybe a fraction of that.
So this isn't guaranteed to happen again?
Not at all. This was a specific set of conditions—the cyclones, the winds, the cold water, the food availability. Change any one of those pieces and the season looks different.
The fishing communities are already struggling to sell what they caught?
In some places, yes. They caught so much that the market can't absorb it locally. They're having to reach out to other states just to keep prices from falling through the floor.
Is that a sign the ocean is recovering?
It could be. Or it could just be that this year was perfect. The researchers are still trying to figure out what made 2026 different. The biology of the fish, the health of the stocks, the currents—all of it matters. Weather is only part of the story.