Submitter Withdrawn Australian Society for Fish Biology Conference 2017

Movement and diving behaviour of Whale Sharks (Rhincodon typus) tagged at Ningaloo Reef (#100)

Richard Pillans 1 , Mat Vanderklift , T Patterson , W Rochester
  1. CSIRO Oceans & Atmosphere, Dutton Park, QUEENSLAND, Australia

Movement, diving behaviour and habitat use of Whale Sharks remains a key knowledge gap in the international management of this highly migratory species. Annual aggregations of Whale Sharks along the North West Coast of Australia form the basis of a valuable tourism industry and allow sharks to be reliably encountered and tagged. Between 2015 – 2017, twenty-three Whale Sharks ranging in size from 4 – 10 m total length (spanning juveniles and adults) were tagged with a combination of acoustic tags, towed SPLASH satellite tags and fin clamp SPOT satellite tags. Tag attachment time varied from a few weeks to 10 months including return movements of sharks tagged at Ningaloo moving up to 1500 km before returning. The majority of tracks recorded movements along the North West Coast of Australia in a north easterly direction from Ningaloo Reef, however individuals were also recorded moving past Christmas Island and also north east along the continental shelf to outside Australian waters and into Indonesian Waters. The recovery of two towed SPLASH tags from animals that moved in opposite directions and were at liberty for 231 and 299 days, respectively, provided valuable insights into the diving behaviour of Whale Sharks. These tags recoded depth, temperature and light level every 10 seconds throughout the duration of the tracks enabling reconstruction of movement and diving behaviour. Movement data and diving behaviour are presented and discussed in relation to behavioural patterns during long distance movements, periods of residence and highlight the variability in behaviour.