Throw Back Thursday: THE SARDINE RUN.
The sardine run of Southern Africa occurs from May through to July. Billions of sardines (Sardinops sagax) spawn in the cool waters of the Agulhas Bank and move northward along the east coast of South Africa. Their numbers of sardine create a feeding frenzy along the coastline. The run, containing millions of individual sardines, occurs annually between May and August when a coastal current of cold water heads north from the Agulhas Bank up to Mozambique.
In terms of biomass, researchers estimate the sardine run could rival East Africa’s great wildebeest migration. However, little is known of the phenomenon. It is believed that the water temperature has to drop below 21 °C in order for the migration to take place. The sardine shoals are often more than 7 km long, 1.5 km wide and 30 meters deep. These shoals are clearly visible from spotter planes or from the surface.
Drawn to this mass migration is a diverse array of marine predators. These include the Common dolphin (Delphinus capensis), Cape gannet (Morus capensis), Cape fur seals (Arctocephalus pusillus pusillus), Blacktip shark (Carcharhinus limbatus), Dusky shark (Carcharhinus obscurus) and Bryde’s whale (Balaenoptera brydei) amongst others. In addition, Humpback whales (Megaptera novaeangliae) are continuously encountered on the sardine run. Whilst not attracted to the sardines per se, these leviathans pass through the sardine run on their northern migration from Antarctica to Mozambique’s summer breeding grounds.