Whale sharks probably use multiple cues to locate the spawning clouds, including seasonal, visible, audible, and olfactory cues.
Clark & Nelson (1997) suggest that olfactory cues may be stronger than visual cues for whale sharks locating food.
Whale sharks at Gladden Spit are known to swim from out of sight range into concentrated bubble plumes of divers, which appear similar to white spawn clouds underwater.
Dive guides have begun to use air bubbles to attract whale sharks for tourists during daylight hours (B. Young pers. comm.).
Since bubbles have no scent, but are visible and associated with sounds, we believe that the sharks are using both visual and auditory cues to locate bubble plumes and, by extension, fish-spawn clouds.
From greater distances, whale sharks probably rely most heavily on auditory cues, since many fishes create distinctive sounds during courtship and spawning (e.g. Lobel 1992) and hydrodynamic noises while