Some like it hot: Repeat migration and residency of whale sharks within an extreme natural environment.

摘要: The Arabian Gulf is the warmest sea in world and host to a globally significant population of whale shark Rhincodon typus. To investigate regional behaviour movements, 59 satellite-linked tags were deployed on sharks Al Shaheen area off Qatar from 2011-14. Four different models tag used throughout study, each model able collect differing data or quantities data. Retention varied one 227 days. While all tagged crossed international maritime boundaries, they typically stayed within Gulf. Only nine dispersed through narrow Strait Hormuz into Oman. Most close known suspected feeding aggregation sites over summer months, but winter. Sharks rarely ventured shallow areas (<40 m depth). A single, presumably pregnant female was sole animal disperse long distance, crossing five boundaries 37 days before detached at distance approximately 2644 km tagging site, Yemeni-Somali border. No clear space-use differentiation evident between years, for sizes, sexes. Whale spent most time (~66%) temperatures 24-30°C waters <100 depth (~60%). relatively more cooler (X2 = 121.692; p<0.05) deeper 46.402; water night. made dives than 100 m, reflecting bathymetric constraints environment. Kernel density analysis demonstrated that site hotspot these sharks, revealed probable secondary nearby Saudi waters. Analysis visual re-sightings 58% individuals re-sighted back course this with 40% recorded year following their initial identification. Two confirmed return years study.