Every year, in June or July along the KwaZulu-Natal coast, word gets out that the sardines have arrived and within hours crowds of people converge on the area to join sharks, game fish, marine mammals and birds in feasting on these little silver fishes.
The sight of wheeling gannets folding their wings to plummet into the water around schools of dolphins surging after a boiling mass of panic-stricken sardines moving in a band up the coast, is a spectacle not to be missed.
Particular wind and current conditions may force the sardines very close to the beach, where they are easily caught using baskets, hand nets or even skirts!
But why do the sardines travel up the coast?
Although the bulk of South Africa’s sardines are found in the cooler Cape waters, each winter a small proportion of the fish moves eastwards up the Wild Coast. These shoals take advantage of cool water on the continental shelf of the east coast that occurs seasonally as a narrow band between the coast and the warm, southward flowing Agulhas Current.
It is not clear what advantage the sardines gain by entering KwaZulu-Natal waters. In fact, local waters are less food-rich than the Cape waters. The favourable cooler conditions are only temporary and, to complicate matters the sardines are accompanied by many predators which prey on them mercilessly. Because the fish become concentrated near the surface in a narrow inshore band of water, the shoals are quickly located by schools of marauding predators that are whipped into a frenzy by this brief period of plenty in these otherwise less productive waters.
Nearly a quarter of the world’s fish
Although these fish are small, collectively they comprise nearly a quarter of the world’s fish catch by weight, making them one of our most valuable groups of fish.