One of the greatest migrations on Earth is the sardine run up the east coast of Africa.
This migration feeds many species of animals, such as dusky sharks.
The oldest known record of the run is a mention in the Natal Mercury newspaper of 4 August 1853. More recently, the run has been the subject of natural history documentaries (e.g., the BBC’s Nature’s Great Events).
The KwaZulu-Natal sardine run of southern Africa occurs from May through July when billions of sardines – or more specifically the Southern African pilchard Sardinops sagax – spawn in the cool waters of the Agulhas Bank and move northward along the east coast of South Africa. Their sheer numbers create a feeding frenzy along the coastline. The run, containing millions of individual sardines, occurs when a current of cold water heads north from the Agulhas Bank up to Mozambique where it then leaves the coastline and goes further east into the Indian Ocean.
The shoals are often more than 7 km long, 1.5 km wide and 30 metres deep and are clearly visible from spotter planes or from the surface.
Being a cold current, you might expect that global warming could disrupt it. But there are other factors in play, such a greater numbers of phytoplankton and zooplankton due to increased photosynthesis.
The good news. The 2023 sardine run is the largest ever recorded. Greatest biomass.

