Movements of whale sharks (Rhincodon typus) tagged at Ningaloo Reef, Western Australia

Whale sharks (Rhincodon typus Smith) aggregate seasonally (March-June) to feed in coastal waters off Ningaloo Reef, Western Australia. Pop-up archival tags were attached to 19 individuals (total lengths 4.5-11.0 m) at this location in early May of 2003 and 2004 to examine their horizontal and vertical movements. The long-term movement patterns of six whale sharks were documented, all of which travelled northeast into the Indian Ocean after departing Ningaloo Reef. They used both inshore and offshore habitats and made extensive vertical movements, occasionally to a depth of at least 980 m. Frequent up-and-down movements, diel vertical migration, and crepuscular descents were evident in the depth records. The sharks experienced ambient temperatures ranging between 4.2 and 28.7 degrees C and encountered gradients of up to 20.8 degrees C on dives.