Tagging Atlantic Salmon with Psats in West Greenland

Pop-up satellite archival tag (PSAT) technology facilitates fine-scale data collection on individuals when conventional methods are inadequate or impractical. Overcoming a suite of associated challenges is still necessary to capitalize on its utility. PSATs were attached to 25 Atlantic salmon in West Greenland to monitor thermal habitat, depth, and movement patterns to better understand seasonal distribution in the Labrador Sea. Multiple capture methods were employed with varying levels of efficiency. Thirteen tags reported between 41-100% of their archived data, which required evaluation for temporal biases associated with transmission gaps. Two tags remained attached for the programmed ~210 day duration while 11 tags released early, between 8 and 31 days post-release. Of those, three tags released from inferred predation/mortality and 8 released from time-at-depth early-release mechanism activation. Six of the 13 fish commonly occupied a narrow depth band (~3m) for 2-3 consecutive days, implicating swimming behavior as a potential trigger for early-release mechanism activation. Programming PSATs with wider early-release parameters to better reflect variability in species behavior may improve tag-retention and the temporal scale of data recovered. Acquiring novel information on marine phase Atlantic salmon adults has expanded understanding of this elusive life-stage and will improve the efficacy of future PSAT efforts.