Hydrodynamic Behavior of Pop-Up Satellite Archival Tags (PSAT) Subject to Vortices

Abstract

Pop-up Satellite Archival Tags (PSATs) are a combination of satellite and archival tags used by marine biologists to collect large scale movement and behavioral data of large pelagic life for up to two years [1]. However, current commercial PSATs have an unusually high failure rate when tagged on tuna and cost upwards of $4000, making it both difficult and expensive to collect data [14]. Upon investigation, the top two failure modes of tuna-affixed PSATs have been identified as drag from movement/tissue healing and pressure cycling [14]. Current commercial PSAT manufacturers do not account for the vortices shed by fish when testing their designs— a large oversight that could account for their high failure rate [15]. The work herein determined the effects of vortex shedding on PSAT hydrodynamic behavior, used these results to inform the design of novel PSAT body shapes, and conducted a head-to-head comparison of these designs with existing commercial PSATs.