Know Your Instruments: Ensuring Depth and Temperature Data from Pop- Up Satellite Archival Tags Are Reported Correctly

Abstract

Pop-up satellite archival tags (PSATs) are electronic devices attached externally to aquatic animals that collect data such as light-level, pressure and temperature. After the PSAT has popped off and floats to the sea surface, archived data are transmitted via the Argos satellite system to the user, eventually providing insight into the spatial ecology of the study animals. Raw data received via the Argos satellite system are either processed directly by the manufacturer of the tag, or the tag manufacturer provides the user with custom-made analysis software, both resulting in data conditioned in files that can then be used for further analysis. Here I argue that insufficient knowledge by users about how PSATs record, archive and transmit data can be problematic. I revisit a dataset previously published from adult bull sharks Carcharhinus leucas to give an example of how erroneous depth and temperature data can slip into the peer-reviewed literature. I encourage PSAT users to engage in personal communication with tag manufacturers in order to understand how PSATs record, archive, process and transmit data. I argue that scientists must accurately report what data from PSATs they included and/or excluded in the analysis in order to avoid the publication of incomplete data.