Movements and migrations of North Atlantic Bluefin tuna tagged with pop-up satellite tags

摘要

A total of 84 bluefin tuna were tagged with two types of electronic pop-up satellite tags and released in the Mediterranean and the Strait of Gibraltar between June 1998 and August 2000. Twenty-three tags (30%) were located by the Argos satellite system and the location rates were 21% and 52%, respectively for pop-up single-point tags (PTT-100 tag made by Microwave Telemetry Inc., Columbia, Maryland, USA) and pop-up archival tags (PAT tag made by Wildlife Computers Inc., Redmond, Washington, USA). Most tags surfaced in the western Mediterranean and eastern Atlantic, but one archival tag transmitted from a position south of Iceland and one single-point tag transmitted from the Greenland Sea. No transatlantic migrations were observed. Most tags released in the western Mediterranean surfaced near the tagging location, suggesting local residency. Residency and spawning site fidelity (which was also indicated by our data) offer the potential for overexploitation, if the industry progressively catches more large bluefin tuna for fattening. Tag experiments using pop-up archival satellite tags were conducted in collaboration with the Tuna Research and Conservation Centre, USA.