Movements, behavior, and habitat utilization of yellowfin tuna (Thunnus albacares) in waters surrounding the Revillagigedo Islands Archipelago Biosphere Reserve, Mexico

The movements, behavior, and habitat utilization of yellowfin tuna, Thunnus albacares, following capture and release with archival tags in the Revillagigedo Islands Archipelago Biosphere Reserve (RIABR), Mexico, are described from analyses of 16578days of time-series data, downloaded from 52 archival tags recovered from yellowfin (78-173cm in length and 1.7-8.0yr of age) at liberty from 93 to 1773days (x = 411days), collected during 2006-2012. An unscented Kalman filter model with sea-surface temperature measurements integrated (UKFsst) was used to process the archival tag data sets to obtain improved estimates of geographic positions, most probable tracks (MPTs), and movement parameters. The MPTs indicate restricted movements, low levels of dispersion, and fidelity of yellowfin tuna to the RIABR. The median parameter estimates from the UKFsst model for errors in longitude (sigma(x)) and latitude (sigma(y)) were 0.46 degrees and 1.84 degrees, respectively, for directed movements (u and v) -0.05 NM day(-1) and -0.05 NM day(-1), respectively, and for dispersive movement (D) 117.99 NM2 day(-1). Analyses of daily timed depth and temperature records resulted in the classification of the data into four distinct behaviors. There are significant differences among ages in the durations of Type I and Type II diving behaviors and in the daytime and nighttime vertical habitat utilization distributions. The oceanography surrounding the RIABR appears to have a profound influence on the movements, behavior, and habitat utilization of yellowfin in this area.