Into the Blue
The horizon is a slim band of pastel peach, the air is cool and rafts of Cape Gannets bob on the deep ocean swell while a few lone individuals flap listlessly above the rippled surface, unsure of which way to fly.
Phila, our captain, and I are scanning the morning ocean of the Eastern Cape for a telltale of a sardine baitball as we head out on a RIB with eager guests on a expedition to experience the Sardine Run.
The annual migration of sardines from Cape waters to Durban is locally referred to as the Sardine Run of South Africa.
Touted as the Greatest Shoal on Earth, the migration culminates in Durban in July each year with shoals of sardines coming into the shallow waters were they are netted and scooped up eagerly by local fishermen.
For divers, the focus on the Sardine Run is the migration through the Eastern Cape to watch masses of marine predators feeding on the sardines.
As a protective measure against dolphins, sharks and whales, the sardines form a bait ball, swirling mass 9f fish that reaches between 10m and 15m in diameter.
Watching the systematic feeding by sharks, gannets, seals and dolphins off the bait ball, it is difficult to think that a bait ball is an effective strategy.
One theory is that the surface to volume ratio of a bait ball reduces the number of sardines exposed to the predators.
Once a bait ball has formed, dolphins will work to maintain the ball in place while Bryde’s Whales will assist with bubble netting before lunging through the ball to scoop up sardines.
In Search of a Bait Ball
Locating a bait ball is an equal measure of luck and reading a few nature signs.
The luck is being in the right place at the right time. A shoal of sardines can move over 60km per day making the location of your launch crucial.
Knowing where to head after your launch requires some guidance. In the first hour after sunrise, gannets slowly take to the wing, circling to determine which way to go. Initially their uncertainty is evident in random directionless flight of individual birds, all flying on a different course. Then some concensus is reached and they set off purposefully, hopefully towards a sardine shoal. It is the first sign and time to follow them.
Following the gannets, we soon spot white water a kilometer away, a wedged shape moving rapidly in the direction of the Gannets. It is a pod of Common Dolphins, swimming fast.
Pods of Common Dolphins can range over 120km per day in search of shoals of fish and seeing the pods does not means that the sardines are close, but following them is definitely worthwhile.
As we approach them, some of the larger dolphins leave the pod and approach our boat, jumping clear of the ocean before tucking under the bow to swim in the bow wave. It is unsure if they are there to play, or if the larger dolphins have come to inspect the boat, a protective measure for the securityof the pod. The core pod, between 800 and 1000 dolphins doesn’t approach the boat, resolutely holding their course.
Half an hour later we see where they are heading. The gannet numbers have swelled and 5km ahead we see the signs of a shoal of sardines. A circling kettle of gannets punctuate the horizon. From a height of 20m to 30m they are diving, the ocean surface a froth of white beneath the flock.
They aren’t in tight formation, instead spread out over 1km. As the dolphins arrive they rush in, groups teaming up to direct the sardines into small balls to feed off. Rapidly three or four groups form, gannets above, dolphins below. Like acrobats, a few Cape Fur Seals join the action, performing a series of backwards somersaults, picking off a sardine with each loop.
The small balls don’t sustain, gannets and dolphins breaking off every 90 seconds to reform 300m to 400m away.
It is time to take the plunge and catch the action below the surface. With small unsustained bait balls, timing is vital. Reading the direction of a newly formed frenzy, Phila speeds in ahead of the activity and we bail out, instantly surrounded by fish, dolphins and a cacophony of clicks and squeaks punctuated by feathered missiles leaving a trail of bubbles as they plunge into the thick of the action.
When the bubbles have cleared, so too has the action. We regroup, climb aboard and hang on as Phila dashes to the next forming frenzy. We dive in, mesmerized by the activity till the bubbles clear, then clamber on board, ready for the next dive.
It is hard work, dive, board, speed, repeat. For the next hour we are in awe of the chaos, amazed that there are no collisions between dolphins, gannets and ourselves.
Then, in a blink, the action stops, the birds settle on the water and the dolphins mill around, scanning us with a few inquisitive clicks before regrouping and casually drifting off. They begin at a leisurely pace, gradually building up to a dolphin ‘canter’, their formation varying from a tight wedge to a spread out line.
Following the dolphins is definitely a highlight of the Sardine Run Expedition. Watching hundreds of dolphins cruising, sometimes breaking the surface in union, a few randomly jumping clear of the surface and simply ploughing through the ocean is captivating.
When they regroup in a tight formation, it is time to speed ahead of the pod, gear up and drop into the water in their path. As ther bear down on the group of divers floating in the vast ocean, there is a brief opportunity to dive down a few meters and watch the pod barrel past, a few slowing to a gentle glide for a quick inspection, but none interested in stopping to interact.
The Nat Geo moment of the Sardine Run is undisputedly diving on an established baitball. Measuring up to 10m in diameter, viewing a bait ball is a peak marine predator feast.
From above the gannets plunge in tight formation, turning the surface into a frothy white. Around the fringe of the ball, a pack of sharks circle, lunging with gaping jaws and flared out gill slits into the swirling sardines while squads of 2 to 5 dolphins dart through.
Accompanying the usual predators are Cape Fur Seals, Bryde’s Whales and, if you are lucky, some billfish.
Once the seals have overcome their curiosity of the arrive of a group of clumsy humans, the settle down to a clown like performance of acrobatic rolls on the edge of the ball, picking off a sardine on each roll.
The arrival of a Bryde’s Whale is either at high speed or at a stately pace of a submarine. Either way, as they penetrate the ball of sardines it is with a gaping mouth and their pleated throats extended, scooping up as many sardines as possible along their trajectory.
Suspended underwater, watching the swirling action of a bait ball, the first time you see a Bryde’s Whale torpedoing towards you is exhilarating, a split moment of uncertainty of the outcome, especially if the gaping mouth is aimed directly at you. Then, as it glides past, you are overcome with exhilaration, instantly eager for another encounter.
Initially, when booking for a sardine run expedition, the expectation is to dive on bait balls every day. In reality, the sardine shoals move daily, dolphins range and gannets fly over the horizon resulting in hours of cruising in search any action.
This presents the opportunity to see some of the other marine life, pelagic birds and migrating cetaceans. Humpback Whales from the Antarctic region migrateup the east coast of Africa to the equatorial region to calve. Their migration coincides with the sardine run and in June and July groups of whales can be seen heading birth at a stately pace.
There is something profound cruising alongside these gentle giants, their namesake hump glistening with rivulets of water as they slide beneath the surface. Then the anticipation of where they will surface with their distinct resonating blow and spout. After a series of four or five breaths, in unison the arch more acutely, slide beneath the water, raising their massive tail and dissappear for a few minutes.
Their progress is constant, intent on reaching the warm tropical waters off Mozambique and while they refrain from stopping, they will occasionally breach or engage in some tail slapping, producing impressive slashes visible from kilometers away.
The migration leaders seem reluctant to stop, almost shy of boats and humans. As the bulk of the migration arrives there can be as many as 100 whales passing each day. It is then, that larger groups appear more tolerant and will even briefly investigate divers on their course.
Projecting the direction that they are swimming, it is simply dropping into the water a few hundred meters ahead of them and waiting for them to swim past.
Cape Fur Seals rest in the vast ocean, head underwater and the flippers flopping above. When approached by swimmers, they hang upside down scanning with their large eyes before pirouetting a few meter underwater, approaching cautiously, nimbly circling between divers.