First tests of hybrid acoustic/archival tags on squid and cuttlefish

This study demonstrates the simultaneous use of acoustic and archival tags for obtaining data for near-shore species. Australian giant cuttlefish Sepia apama (off Whyalla, South Australia) and the tropical squid Sepioteuthis lessoniana (off Magnetic Island, Queensland, Australia) were tagged using a 'hybrid' tag consisting of a Vemco V8 acoustic tag potted with a Vemco minilog temperature-depth archival tag. Four of these animals were released and monitored inside radio-acoustic-positioning-telemetry (RAPT) buoy-system arrays that included bottom-mounted sensors that transmitted independent temperature records and a reference standard for sound conductivity and position. All were subsequently located out of RAPT range and two of the four archival tags were recovered. Tags were located using a boat-mounted hydrophone and VR60 receiver and recovery was aided by a diver operating a hand-held VUR96 receiver. This technology provides a cost-effective alternative to expensive satellite pop-up tags and is suitable for much smaller species that return to near-shore environments.