Massive shoals gather in Algoa Bay for the 2021 sardine run
Durban - The first sardine shoal for 2021 has been spotted off the Eastern Cape coast this week ‒ and it's massive.
Durban’s well-known netter, Goolam Essack, said he hoped this year's sardine run would match the legendary sardine shoals of the 1970s.
"The shoal off PE (Gqeberha) is like a long tar road and it’s coming. There are millions of birds and dolphins around it," said Essack yesterday, adding that he hoped the first sardines would be spotted offshore in KwaZulu-Natal waters by the end of next month.
The annual Sardine Run is a huge drawcard for the tourism industry and such a majestic showing of the small fish will be welcomed throughout coastal towns.
Officially known as the South African pilchard, the sardines spawn in the cool waters of the Agulhas Bank and move north up the east coast of Africa. The run takes place when a cold front moves in and the water temperatures drop. It takes place from the Agulhas Bank up into Mozambican waters where it normally leaves the coastline and heads east. It is believed the water temperature has to drop below 21C for the shoal to start moving.
The billions of sardines create a feeding frenzy among predators such as dolphins, sharks, seals and even whales, and the run is normally spotted because of the thousands of birds above the waves as they follow and feed off the run.
In some years, there appears to have been no run. Scientists believe this may be because it was not detected by coastal observers because it could have been taking place further offshore and possibly deeper because of unusual conditions, or it simply did not take place.
Divers and camera operators from around the world arrive for the sardine run to dive around what is known as a “baitball” of sardines. This happens when the run is on the move, with predators chasing the shoals of fish which attempt to defend themselves by rounding up to create a wall.
According to research, the lateral lines on the sardines are highly sensitive to the slightest change in water pressure and when one fish in a shoal moves, the rest of the shoal does the same. This effect has been described as "mesmerising" and is the subject of numerous underwater documentaries.
The Independent on Saturday