When the Ocean Moves: Why Cape Town's Tuna Fishing Feels Different This Year

Every now and then, the ocean delivers a season that fishermen will talk about for years to come.

Around Cape Town, this year feels like one of those seasons.

The tuna have been abundant. The size of the fish has been impressive. The consistency has been remarkable. For those of us who spend our lives on the water, it feels as though something special is happening beneath the surface.

Many people are quick to point to El Niño when unusual ocean conditions occur, and while that may be part of the wider story, the reality around Cape Town is far more fascinating.

Our ocean is not simply a body of water. It is a living, breathing engine.

Cape Town occupies one of the most unique marine environments on Earth. To the west lies the cold, nutrient-rich Benguela Current. To the east and south, the warmer influence of the Agulhas Current flows down from the Indian Ocean. Where these two powerful systems meet, the ocean becomes a constantly shifting puzzle of temperature breaks, current lines, upwellings, bait concentrations, and feeding zones.

This is where the magic happens.

Cold water rises from the depths carrying nutrients to the surface. These nutrients fuel blooms of plankton. Plankton feeds baitfish. Baitfish feed tuna, seabirds, dolphins, whales, and countless other marine predators.

What appears to be an endless expanse of blue water is actually a highly organised ecosystem, filled with invisible highways and feeding grounds.

And few animals are better designed to take advantage of it than tuna.

Unlike many fish species, tuna are partially warm-blooded. Built for speed, endurance, and long-distance travel, they can move between different water masses with incredible efficiency. They follow bait, temperature breaks, current edges, and food availability across vast stretches of ocean.

When conditions change, tuna respond almost immediately.

That is why some seasons feel extraordinary.

A small shift in water temperature, wind patterns, current direction, or bait concentration can suddenly bring fish closer to shore, keep them in an area longer, or create ideal feeding conditions that allow fishermen to find them consistently.

History has shown just how dramatically ocean systems can change. Major El Niño events such as those of 1982–83 and 1997–98 caused fish populations to shift, altered upwelling patterns, and saw species appearing in places they would not normally be found.

While Cape Town's tuna season cannot be attributed to El Niño alone, the same principle applies. When ocean temperatures, current boundaries, and food availability change, pelagic predators move with them.

This year, many Cape fishermen are witnessing signs of an exceptionally productive system. Tuna are being found in remarkable numbers. Baitfish appear concentrated in highly productive zones. Warm and cold water boundaries are creating ideal hunting conditions, and when tuna find these edges, they exploit them with incredible precision.

These invisible structures of the ocean—temperature breaks, plankton blooms, current lines, upwelling cells, and bait shoals—are the roads, feeding grounds, and gathering places of the open sea.

To fishermen, a great tuna season is not simply luck.

It is the ocean briefly revealing how its machinery works.

At Greenfish, this is what fascinates us most. We do not just see fish as a product. We see the story behind every catch: the weather systems, the currents, the plankton blooms, the baitfish, the birds, the dolphins, the boats, and the people who have learned to read the water.

Cape Town is blessed with one of the most productive marine environments in the world. The meeting of the cold Benguela and warm Agulhas systems creates an ocean that is wild, unpredictable, and incredibly rich in life.

Some years are difficult.

Some years are quiet.

And some years, like this one, everything seems to align.

Whether this will ultimately be remembered as a once-in-a-decade tuna season remains to be seen. But one thing is certain:

Something special is happening out there.

The ocean is moving.

And the tuna are following.