Broad-scale movements and pelagic habitat of the dusky shark Carcharhinus obscurus off Southern Australia determined using pop-up satellite archival tags

We investigated the broad-scale movements and pelagic habitats of large juvenile dusky sharks (Carcharhinus obscurus) off Southern Australia. Pop-up satellite archival tags (PSATs) were deployed on three large juvenile dusky sharks (∼2.2-2.6 m total length) for 6 months in Spencer Gulf during 2010. Tagged dusky sharks all migrated westward and across the Great Australian Bight (GAB) during autumn to offshore shelf waters off Western Australia. Estimated minimum distances travelled ranged from 1760 to 2736 km. Depths occupied by tagged dusky sharks ranged from the surface to 355 m. The most common thermal ranges occupied were 19-22°C. Broad-scale movements of large juvenile dusky sharks across the continental shelves combined with periods of residency in semi-protected gulf waters indicated that a multi-jurisdictional management approach may be appropriate for this species.