A correct scientific explanation about the formation of a chakara is debatable. However, a strongly supported theory is that during the monsoons, the water level of the backwaters rises which facilitates the movement of fine clay particles into the sea through the subterranean channels. The accumulation of organic material by this process in relatively calm regions of the sea during the monsoons attracts fish.
This phenomenon is demonstrated in Chemmeen. It is greeted, celebrated, and described in the song "Puththan Valakkare."