Table_1_Seasonal Occurrence, Horizontal Movements, and Habitat Use Patterns of Whale Sharks (Rhincodon typus) in the Gulf of Mexico.docx

In the northern Gulf of Mexico (GOM), whale sharks (Rhincodon typus) form large aggregations at continental shelf-edge banks during summer; however, knowledge of movements once they leave aggregation sites is limited. Here we report on the seasonal occurrence of whale sharks in the northern GOM based on over 800 whale shark sightings from 1989 to 2016, as well as the movements of 42 whale sharks tagged with satellite-linked and popup satellite archival transmitting tags from 2008 to 2015. Sightings data were most numerous during summer and fall often with aggregations of individuals reported along the continental shelf break. Most sharks (66%) were tagged during this time at Ewing Bank, a known aggregation site off the coast of Louisiana. Whale shark track duration ranged from three to 366 days and all tagged individuals, which ranged from 4.5 to 12.0 m in total length, remained within the GOM. Sightings data revealed that whale sharks occurred primarily in continental shelf and shelf-edge waters (81%) whereas tag data revealed the sharks primarily inhabited continental slope and open ocean waters (91%) of the GOM. Much of their time spent in open ocean waters was associated with the edge of the Loop Current and associated mesoscale eddies. During cooler months, there was a net movement southward, corresponding with the time of reduced sighting reports. Several sharks migrated to the southwest GOM during fall and winter, suggesting this region could be important overwintering habitat and possibly represents another seasonal aggregation site. The three long-term tracked whale sharks exhibited interannual site fidelity, returning one year later to the vicinity where they were originally tagged. The increased habitat use of north central GOM waters by whale sharks as summer foraging grounds and potential interannual site fidelity to Ewing Bank demonstrate the importance of this region for this species.

在墨西哥湾（Gulf of Mexico，以下简称GOM）北部海域，鲸鲨（Rhincodon typus）会于夏季在大陆架边缘沙洲形成大规模聚集群，但目前学界对其离开聚集点后的移动模式所知有限。本研究基于1989年至2016年间的800余条鲸鲨目击记录，以及2008年至2015年间42头佩戴卫星关联式与弹出式卫星存档传输标签（satellite-linked and popup satellite archival transmitting tags）的鲸鲨移动数据，报道了GOM北部海域鲸鲨的季节性分布特征。
目击数据在夏秋两季最为丰富，多数记录显示个体沿大陆架坡折带聚集。其中66%的标记个体于该时段在路易斯安那州外海的已知聚集点——尤因沙洲（Ewing Bank）完成标记。鲸鲨的跟踪时长为3至366天不等，所有标记个体的总长度介于4.5至12.0米之间，且全程活动均未离开GOM海域。
目击数据显示，鲸鲨主要栖息于大陆架及架缘水域（占比81%）；而标签跟踪数据则表明，它们主要活动于GOM的大陆坡与公海水域（占比91%）。它们在公海水域停留的时段大多与环流经流（Loop Current）边缘及相关的中尺度涡旋（mesoscale eddies）密切相关。
在水温较低的月份，鲸鲨会向南方迁移，这与目击记录减少的时段相吻合。部分个体在秋冬季节迁移至GOM西南部海域，这表明该区域可能是重要的越冬栖息地，同时也可能是另一处季节性聚集点。三头长期跟踪的鲸鲨表现出年际位点保真度（interannual site fidelity），即会在次年返回最初的标记点附近区域。
鲸鲨对GOM中北部水域作为夏季觅食场的栖息地利用度提升，加之它们对尤因沙洲的潜在年际位点保真度，均证实了该区域对该物种的重要性。