Crawling en masse from the sea, they are piling up on shore, providing a bonanza for beachcombers but a serious concern for fishermen.
A "red tide" of crayfish has accumulated on the shore 150 miles north of Cape Town. And residents have arrived from far away to see the odd spectacle and carry away the sea food delicacy.
A serving of crayfish usually costs about $22 at South African restaurants, so there was a party atmosphere at the bay over the weekend, when entire families arrived to gather as many fish as they could carry.
Only a few minutes work and a forager could walk away with a crateful of shellfish.
The crayfish have been coming out of the water for the last four weeks. They are trying to escape a red tide caused by a type of phytoplankton that depletes oxygen levels in the sea.
An estimated 1,000 tons of crayfish have walked out of the ocean so far and marine experts are worried -- as are local fishermen, whose livelihood has suffered due to the crayfish exodus.
CNN News Service Copyright.