Observations on the short-term movements and behaviour of whale sharks (Rhincodon typus) at Ningaloo Reef, Western Australia

The short-term movements and behaviour of whale sharks (Rhincodon typus Smi th, 1828) during March 1994 and April 1997 are reported from data collected by acoustic tracking and archival tags, at Ningaloo Reef on the north west coast of Western Australia. Sharks were tracked for up to 26 h and general ly swam slowly at similar or equal to 0.7 m s(-1) parallel to the reef edge ; occasionally they swam in a wide are adjacent to passes in the reef. All tracked sharks made regular dives through the water column, mostly from the surface to near the bottom. These dives did not appear to be related to hy drographic features, and the sharks were probably searching the water colum n for food. Most sharks were accompanied by other fishes, usually the golde n trevally Gnathanodon speciosus.