Movements, behavior, and habitat utilization of yellowfin tuna ( Thunnus albacares ) in the northeastern Pacific Ocean, ascertained through archival tag data

摘要: Sixty-eight yellowfin tuna, Thunnus albacares, (60-135 cm fork length) were caught and released with implanted archival tags offshore off Baja California, Mexico, during October 2002 2003. Thirty-six fish (53%) recaptured the data downloaded from all 36 recovered tags. Time at liberty ranged 9 to 1,161 days, analyzed for 20 that 154 or more days. The accuracy in position estimates, derived light-level longitude sea-surface temperatures (SSTs) based latitude, is about 0.41° 0.82° this region. movement paths, indicated 19 (95%) remained within 1,445 km of their release locations. estimated mean velocity along paths was 77 km/day. southern northern seasonal observed California are influenced by movements 18°C SST isotherm. Cyclical suitable spawning habitat (≥24°C SST) only mature fish. For 12 demonstrated site fidelity, 95 50% utilization distributions 258,730 km2 41,260 km2, respectively. Evaluations timed depth records resulted discrimination four distinct behaviors. When exhibiting type-1 diving behavior (78.1% days liberty) depths less than 50 m night did not dive greater 100 day. Type-2 (21.2% characterized ten dives excess 150 apparently a foraging strategy targeting prey organisms deep-scattering layer day, following nighttime mixed on same prey. Yellowfin tuna exhibited occasional deep-diving behavior, some exceeded 1,000 m, where ambient 5°C. Surface-oriented defined as time 10 min, evaluated. number duration surface-oriented events per day 14.3 28.5 Habitat yellowfin, presented monthly composite horizontal vertical distributions, indicates confined geographical resulting an affinity area high availability. indicate daytime relation seasonally deeper proportion shallower layer.