Sardine run of Southern Africa
Today I want to share something with you that I’ve always considered to be one of nature’s most beautiful phenomenon. I was lucky to experience it on two occasions, during the time I lived in South Africa and it was a fantastic, a sight never to be forgotten.
Around June each year, word gets out along the KwaZulu-Natal coast that the sardines have arrived. They’ve swum for more than 30 days from their spawning ground in the Cape to reach South Africa's east coast. Scores of fishermen join the sharks, game fish, marine mammals and birds that gorge themselves on the shimmering band of silver fish.
Why large shoals of sardines swim to the KwaZulu-Natal coast during the winter months remains a mystery. And yet each year it's the same: starting in May, millions of small, shiny fish make the one-way journey from the cold waters of the Cape to the warmer tides of KwaZulu-Natal, coloring the shoreline silver as they convene close to the coast. By the end of July they’re gone – disappeared just as suddenly as they arrived, vanishing into the great blue beyond. Like whale watching in Hermanus or travelling to Namaqualand to see the wildflowers in bloom, South Africa’s famed sardine run is a seasonal peculiarity that is popular among local and international visitors. It’s a phenomenon certainly worth watching – from land, the ocean surface or underwater.
Typically, the sardine shoals are massive and can stretch for kilometers along the coast. And following the shoal – above and below water – is a caravan of predators in feeding-frenzy mode.
Schools of sharks, such as the bronze whaler (or copper shark), dusky and blacktip shark, follow the shimmering path of prey, feasting on the fish. Marine mammals and game fish follow in hot pursuit. Cape fur seals, humpback and minke whales, and thousands of dolphins are joined by shoals of shad, garrick and ‘geelbek’ (a type of kob) as they dive, snap and feed on what appears to be an unlimited supply of sardines. Dolphins employ a tactical hunting strategy by ‘herding’ part of the sardine shoal into densely packed groups, termed ‘bait balls’. Working together underwater the dolphins drive the bait ball toward the surface, whirling, twisting and swimming below the shoal.
As the sardines move closer to the surface of the water, birds plummet out of the sky to pillage from above. Cape gannets, cormorants, terns and gulls all dive-bomb the coast in an unrelenting aerial assault. In areas where the sardines swim very close to the coast, game fishermen and local sardine lovers wade into the water and secure their share.
This is a marine spectacle at its best – a once-in-a-lifetime opportunity to view creatures of the earth, sky and water taking part in one of nature’s unexplained mysteries.
Sardine-run shoals are usually 15km long, 4km wide and approximately 40m deep.