Movements, behavior, and habitat utilization of yellowfin tuna (Thunnus albacares) in the Pacific Ocean off Baja California, Mexico, determined from archival tag data analyses, including unscented Kalman filtering

作者：Schaefer Kurt M^*; Fuller Daniel W; Block Barbara A

来源：Fisheries Research, 2011, 112(1-2): 22-37.

DOI：10.1016/j.fishres.2011.08.006

• Behavior
• Habitat
• Movements
• Utilization distributions
• Yellowfin tuna

The movements, behavior, and habitat utilization of yellowfin tuna, Thunnus albacares, in the eastern Pacific Ocean off Baja California, Mexico, are described from analyses of 31,357 days of day-log and 28,835 days of time-series data, downloaded from 126 archival tags recovered from yellowfin (57-162 cm in length and 1.2-5.2 years of age) at liberty from 90 to 1161 d ((x) over bar = 273.2 d), collected during 2002-2010. An unscented Kalman filter model with sea-surface temperature measurements integrated (UKFsst) was used to process the archival tag data sets in order to obtain improved estimates of geographic positions and most probable tracks (MFTs) and parameters. The median parameter estimates from the UKFsst model for errors in longitude (sigma(x)) and latitude (sigma(y)) were 0.32 degrees and 1.36 degrees, respectively, for directed movements (u and v) were 0.27 and 0.77 nm/d, respectively, and for dispersive movement (D) was 144.3 nm(2)/d. The MPTs for 120 (95%) of the yellowfin remained within 1358 km of their release locations, indicating restricted horizontal utilization distributions, and fidelity to this area of high biological productivity. There are observed differences in the movement patterns and parameters for fish released in different areas. Analyses of daily timed depth and temperature records resulted in the classification of the data into four distinct behaviors. When exhibiting type-1 diving behavior (82.9% of all days at liberty) the fish remained at depths of less than 50 m at night and did not dive to depths greater than about 100 m during the day. Type-2 diving behavior (17.1% of all days at liberty) was characterized by 10 or more dives in excess of 150 m during the day. Spatial and temporal patterns are evident in the distributions of type-1 and type-2 diving behaviors. Surface-oriented behavior, defined as the time fish remained at depths less than 10 m for more than 10 min, was also evaluated. The mean number and duration of daytime surface-oriented events per day, for all fish, were 7.6 and 24.2 min, respectively. There are significant differences among ages in the percentages of days classified as type-1 and type-2 behaviors, durations of those events, and in the numbers and durations of surface-oriented events. Yellowfin tuna exhibited occasional deep-diving behavior, and some dives were to depths exceeding 1000 m, where ambient temperatures were less than 5 degrees C. There are significant differences among ages in the nighttime and daytime average depths. The differences are the result of the fish of ages greater than 3 years showing greater daytime average depths and lesser nighttime average depths.

• 出版日期2011-12