The annual Sardine Run, also known as ‘the greatest shoal on Earth’, is slowly making its way to Durban’s coastline.
IOL spoke to Greg Thomspon, acting head of operations at the KZN Sharks Board, who said that there has been activity in the Eastern Cape, specifically between the Haven Hotel and Hole in the Wall near Coffee Bay.
He said in a statement to IOL, ‘It is still very quiet further north with scattered Gannets seen in some areas but it does seem like they are feeding on mixed bait fish. There are a few south-westerly winds due in the next week which hopefully could get the sardines moving north.
‘At the moment, it does seem like the head of the sardine movement is still a couple weeks away from KZN but anything is possible. We have all been surprised by these fish before.’
The Sardine Run is an annual phenomenon marked by the entry of large shoals of sardines into the waters of southern KwaZulu-Natal during the winter months.
Although the great bulk of South Africa’s sardine stock is found in the cooler Cape waters, each winter a small proportion of this population 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. KZN waters are less food-rich than are Cape waters, the favourable cooler conditions are only temporary and, to make matters worse for the sardines, they are accompanied by many predators.
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.
Sharks, Cape fur seals and dolphins are among sardines’ predators.
As the shoals are driven to the surface, seabirds – Cape gannets, cormorants, terns and gulls – plummet out of the sky to pillage from above.
The appearance of common dolphins along the KwaZulu-Natal south coast is closely associated with the arrival of the Sardine Run and it has even been suggested that the female dolphins use the plentiful food supply to wean their calves and replenish their depleted fat stores.
The Sardine Run takes place in South Africa in winter, during June and July.
Image source: Lesley Rochat
