Why shoals of sardines swim to the KwaZulu-Natal coast during the winter months, remains a mystery. The spawning grounds for the South African sardines, Sardinops sagax lie off the Southern Cape coast. They breed from spring to early summer. Their eggs are simply released into the water, fertilized and left to drift off in the open ocean. The ocean currents carry most of the developing larvae westwards and northwards into the waters of the Atlantic Ocean along the West Coast.
The annual Sardine Run has been described as one of the greatest marine events on earth. Every year, between the months of May and July, millions of sardines travel north from the cold southern oceans off South Africa's Cape Point, hugging the shore as they make their way up along the coastline.
Marine Scientists bring into focus factors like the weather, currents and their food source. A cold, narrow current flowing in a northerly direction with temperatures ranging from nineteen to twenty one degrees Celsius develops between the shore and the warm south-flowing Agulhas Current.
This current is rich with Plankton, kalenoides the sardine’s staple diet is a unicellular organism are left to the mercy of the wind and currents to travel. The first cold fronts of the season provide further stimulus for the sardines as they surge north whilst being carried by the current and pushed by the cold polar winds that move up the coast at this time of year.
There are no accurate figures on what tonnages of sardines come up the coast except that the volume that reaches the coastal waters of Kwa-Zulu/Natal is a mere fraction of the total sardine population. Shoals usually fifteen kilometres long, four kilometres wide and approximately forty metres deep are followed by thousands of dolphins, Gannets, sharks, seals, Whales and game fish.
Dolphins employ a hunting strategy with military precision and efficiency. They work together to herd the sardine shoal into what is referred to as a "baitball" to the surface. There is no escape once they are pinned to the sea surface. The dolphin’s whirl around and into the baitball from below. They are then joined in by Sharks, such as the Bronze Whaler (copper), Dusky and Black Tip, game fish such as shad, garrick and geelback, mammals like Humpback whales, Minke, the Cape fur seals, and thousands of Common and hundreds of Bottlenose dolphins are seen in hot pursuit of the reflective mass of pilchards. As the sardines are driven to the surface, Cape gannets other sea birds dive into the bait ball from above.
Traveling about 1,000 kilometers along South Africa’s east coast, they congregate within the vicinity of the Waterfall Bluff in the Transkei. Moving on to the shallow Port Edward shelf, the sardines are often squeezed over the sandbanks and become easy prey of shore anglers and beach netters who pack them into crates for selling. Some days they are easily found and for reasons unknown they seem difficult to track down if not impossible.
KwaZulu-Natal, the largest province in South Africa comprises 61 municipalities. One Metropolitan Municipality in addition to fifty Local Municipalities which are controled by the 10 District Municipalities below.