Performance of pop-up satellite archival tags

Abstract

Pop-up satellite archival tags (PSATs) are used to chronicle or 'archive' the habitat preferences, horizontal and vertical movements, fishery interaction, and post-release mortality rates of a variety of pelagic animals. Though PSATs are valuable research tools, lower-than-expected reporting rates, early detach- ment, and incomplete data return remain problematic. These issues were quantified by analysis of reporting rates, retention times (i.e. the time period PSATs re - mained attached), and the quantity of depth, tempera- ture, and geolocation data returned from 731 PSAT deployments on 19 species in the authors' database and 1433 PSAT deployments on 24 species taken from 53 published articles. The reporting rate of PSATs de - ployed by the authors (0.79, 95% CI = 0.76 to 0.82) was not significantly different from the reporting rate calcu- lated from published studies (0.76, 95% CI = 0.74 to 0.78). PSAT reporting rates were lowest in species undertaking large (~1000 m) vertical excursions (logis- tic regression, p = 0.006), and reporting rates have increased significantly over time (p = 0.02), presum- ably because of better PSAT design and construction. Tag retention increased with depth range of the tag - ged species and pop-off latitude (Cox proportional hazards models, p < 0.001), suggesting that pressure (and/or temperature), biofouling, and wound infection at the insertion site of the PSAT's anchoring device influenced this parameter. The quantity of data re - turned by Argos satellites was affected by tag produc- tion year, programmed pop-up period, depth range, and manufacturer. Species-specific reporting rates were used to make recommendations for future PSAT sampling designs.