The Sardine Run

The Migration of mega shoals of sardine up the east coast of South Africa has been called the greatest shoal on earth.

The wild coast on the east coast of South Africa is just that, 500 kilometers of spectacularly beautiful undeveloped coast. It’s a long drive on poorly maintained dirt roads to reach the tiny coastal settlement of Mdumbi where I have just spent a week filming the annual sardine run that passes these shores during the South African winter from May through July.

We have dragged our cameras, dive equipment and an 8 meter rib boat on the 1500 kilometers journey all the way from Cape Town to this place that barely features on the map. The attraction is an event that starts in the cold waters of South Africa’s west coast. Wind, currents and cold winter weather combine to drag a thin finger of cold water all the way up the coast into the subtropical waters of the country’s northeast shores. Enormous shoals of sardine are lured by the plankton rich cold water and they are in turn followed by predators of every shape and size.

Our days start as the sun’s first rays light the horizon, motors roar and adrenaline pumps as we launch through the pounding surf. Once clear of the surf we immediately start to search for telltale signs of the sardine shoals. It’s not long before we begin passing endless schools of common dolphins all heading purposefully southwards, many of them come across to our boat and play in the bow wave, after a while we spot a heaving cloud of squawking birds further down the coast. These are Cape Gannet, large black and white seabirds that are attracted in the tens of thousands by the sardines. It soon develops into a spectacular interaction as the dolphins work together to herd sardines into gigantic bait balls and the gannets take advantage of the distraction to make dive after dive on the shoal. They make dive after dive hitting the water at up to 120 kmh and plunging deep under the surface. The water boils as it becomes a feeding frenzy, the dolphins and gannets are joined by sharks, 15 metre long Brydes whales, and many other large marine predators all feasting on sardine.

When the shoal is eventually dispersed the gannet are so sated with sardine that they sit in their hundreds on the surface of the sea and the dolphins head off back up the coast to find the next shoal. In a good year this scene is repeated up and down the coast for almost three months. Like all marine resources the sardine  has come under a lot of pressure from industrial fishing on South Africa’s west coast, but judging from the regularity of the sardine run there still appears to be a healthy population. What does worry researchers is rising sea temperature, it is believed that the sardines do not run unless the water temperature along this stretch of coast drops below 19 degrees Celsius and there have been a few years in recent decades when water water has been blamed for a much diminished run.

A week is far too short for us to film and experience all aspects of the sardine run, wind, visibility underwater and the vagaries of the cold current force us to chase hard up and down the coast but we look forward to returning for a longer visit. The material filmed this year and the experience we have gained will help us to document the world’s greatest shoal next year.