What is the believed purpose when a whale shark periodically coughs while feeding?

To clear buildup of food particles clogging the delicate filter pads

It is a commonly documented behavior that whale sharks will frequently perform a 'coughing' action while engaged in feeding activities. This is not a random occurrence but is considered a necessary physiological response integral to maintaining the functionality of their feeding system. The primary reason believed for this action is to clear any accumulation of food particles or debris that might have begun to clog the extremely delicate, sieve-like filter pads located within the gill slits. By periodically expelling this material, the shark ensures that the efficiency of its filtration mechanism remains high, allowing for uninterrupted, optimal nutrient extraction from the water passing through its mouth.