It is a mid-morning day in June in the sleepy town of Port St Johns. The sky is a watercolour of greys and blues, as if the first traces of a cold front has cooled the sky. Off the coast of this Eastern Cape town the sea glistens in the miasma of the winter morning. Summer has come and gone, and the water is cooling. It’s the perfect weather, in fact, for taking a boat out in the briny water behind the surf line, because on this day, and for the next thirty days, there’s a good chance a spectacular sight awaits those who make the mission out to sea.
Dave Caravias travels to Port St Johns every year around this time with a group of eager guests. Men like Caravias call the spectacular event the ‘sardine run’, and apart from the migration of the wildebeest in the great plains of Africa’s arid interior, the sardine run is the biggest pilgrimage undertaken by any animal species, anywhere in the world.
Caravias never misses the sardine run, a time when billions of sardines (known officially as the Southern African pilchard) migrate up the east coast of South Africa, starting in the Algulhas Bank and ending up in Mozambique. Why do the sardines make the trek? No one knows the answer for sure, but Caravias proffers a theory that makes sense:
“The seasonal change in June and the start of winter [gives rise to] cold fronts that push cold currents from the Agulhas Bank up the east coast. The sardines follow this cold current up the coast.”
It happens like clockwork every year – except some years it doesn’t. During these sparse periods, experts believe the water temperature is too warm for the natural phenomena to occur. But even then, the water is still full of redeye (a type of sardine), meaning there are still thousands of predators lurking, and Dave allows his clients to get in the water each day with dolphins, sharks, whales and many more species.
When the sardines do migrate, you get billions of vulnerable fish grouped together in a pilgrimage for pastures new. For the predators in the area, Christmas comes early. Picture a shoal of fish seven kilometres long and over a kilometre wide moving across the coastline. For the sharks, cape gannets, dolphins and occasional whale who lie in wait, it causes a veritable feeding frenzy amongst these different species.
It’s seeing these predators up close, and seeing them flex their considerable evolutionary predatory prowess that gives Caravias an appreciation for the natural order of life.
Port St Johns is the best place to watch the action kick off, and Caravias not only offers clients the opportunity of watching from the safety of his boat, but invites them to get into the water too. A different world awaits beneath the water-line, and it’s here, immersed in the world of these glorious animals, that you get a sense for the tactical nous that underpins their predatory habits.
The dolphins begin by separating a group of sardines from the mega shoal. The frightened sardines find themselves stranded and group together in a ‘bait ball’. This is their defence mechanism, but also their weakness. Evolution has taught the predators to outwit the small fish. The dolphins push the ball to the surface, where it attracts other predators who surround the sardines. The small fish do their best to weave in and out of danger, but the death knell is tolling.
Each predator employs their preferred method of attack. Sharks tend to barrel through the ball, snapping at random. Gannets dive and skewer a sardine with their beak, then swim to the surface and fly back into the air. Dolphins attack from below, funnelling the sardines towards the surface and picking them off from there. The rarest sighting of all is the Bryde’s Whale. Caravias remarks wryly that it also happens to be a brief sighting. The Bryde’s, a 15-metre behemoth, drives up from the ocean floor and consumes the entire bait ball in one gulp.
Does it take courage to enter the water? Absolutely. “It’s pure impulse that drives you into the water,” Caravias says, and further explains:
“Everything is telling you to keep a distance and to be cautious as you watch gannets dive bombing into the water, dolphins rapidly moving on the surface and shark fins breaking the waterline.”
But once you break the surface and escape into the inky world below; once the bubbles clear and you’re ensconced in this water world; once you hear dolphins squealing and the whoosh of fish swimming past you – suddenly, it’s all worth it.
Coming across a bait ball surrounded by oceanic predators means, naturally, you need to be cautious. You’re in the middle of an uncontrolled event that Caravias says “evolves in front of you.”
He tells a story of a particular day when he and his team discovered a bait ball and noticed around one hundred dusky sharks in hot pursuit. The dusky shark is habitually bold, so Caravias and his cohorts formed a circle outwards to watch each other’s backs. As fate would have it, the sardines decided to shelter around Caravias and his guests, frenziedly shooting past the assembled spectators, kicking up bubbles, and accidentally slapping them in the face. Caravias says he expected at any minute to see a shark emerge from the wash of bubbles aiming straight for him. It never happened, but it got the experienced diver’s heart beating.
The sharks are there to hunt the sardine, of course, not large humanoid bodies that make a great deal of noise and flap around a lot. And in reality, the Sardine Run is relatively safe. Travelling with experienced men like Dave Caravias, you’re at your leisure to enjoy the event, rather than worrying about potential dangers.