The Frenzy of the Sardine Run
Every year millions of sardines saturate the dark blue waters a shiny metallic silver in an unexplained natural phenomenon known as the Sardine Run. Their sheer numbers attract animals from land, sea and sky, creating a feeding extravaganza and a frenzy of excitement amongst all who come into contact with this spectacular marine event.
The Sardine run in South Africa is described as one of the greatest marine spectacles on earth. Annually, during the months of May through to July vast shoals of sardines migrate up the east coast of South Africa, travelling from the cooler waters of the Cape into the warm sub-tropical waters of KwaZulu-Natal. With shoals often being more than 7 km long, 1.5 km wide and 30 metres deep a large amount of attention is drawn to the Sardine run, especially because of the large concentration of marine predators that are always in close pursuit.
Following the shoals, above and below water is an unprecedented concentration of marine predators including birds, sharks, dolphins, whales, seals and fish. Schools of sharks including the Bronze Whaler, Dusky, Black Tip, Zambezi, Hammerhead and Copper can be seen in their hundreds. Bottle nose and common dolphins also join in the feeding frenzy and employ a hunting strategy to push the shoals into what is referred to as ‘bait balls’. Working together underwater the dolphins drive the bait balls to the surface. As the shoal moves closer to the surface the aerial assault on the sardines begins as hundreds of Cape Gannets, Cormorants and Gulls plummet out of the sky to gorge themselves on the shimmering ball of silver fish. In areas where the sardines swim close to the shore fishermen and local sardine lovers make sure to secure their share too.
Little is known about this phenomenon and the Sardine Run is still poorly understood from an ecological point of view. Sardines shoal closely together when they are threatened in an instinctual defensive behaviour, since individual sardines are more vulnerable than in large groups. It is also hypothesised that the water temperature has to drop below 21°C in order for the migration to take place and the Sardine Run is most likely as a result of a seasonal reproductive migration.
Despite little being understood about this natural phenomenon it is definitely a once in a life time opportunity to witness one of natures unexplained mysteries. This spectacular marine event is sure to be enjoyed by all, be it bird watchers, marine life enthusiasts, divers of varying levels of experience as well as snorkellers.