Oceanic Movement, Behavior and Mortality of Chinook Salmon Off Alaska, Elucidated with Pop-up Satellite Tags

To examine the oceanic ecology of Chinook Salmon, about which little is known, we are conducting a proof-of-concept study in which large, immature Chinook Salmon are tagged with pop-up satellite archival transmitting (PSAT tags) off Alaska.  PSAT tags are an effective method for studying Chinook Salmon and have provided unprecedented insights into the oceanic ecology of this species.  While on the continental shelf, most tagged Chinook salmon have occupied relatively shallow depths (<100 m) and a wide range of water temperatures, depending on the season.  When Chinook Salmon move beyond the continental slope, they occupy deeper waters up to 500 m and frequently display diel vertical migration.  Perhaps the most surprising result of this project is the suggestion that predation by salmon sharks appears to be frequent and geographically widespread.  PSAT tags provide valuable information about regional oceanic ecology of Chinook salmon, which may be used in a variety of ways, such as for improving bioenergetics and population dynamics models, elucidating movement patterns, and avoiding bycatch in industrial groundfish fisheries.