Ingested Tag Retention in Striped Bass

Globally, researchers are increasingly using acoustic telemetry to monitor fish behavior and survival and to investigate population dynamics of many species. Managers use information gained through such studies to guide decision making for protected species or recreational and commercial fisheries management. Therefore, it is important for researchers to be confident they are monitoring their target specimens and not a predator that has consumed their target specimen and transmitter. An important variable in determining target movement versus predator movement is retention time of a consumed transmitter. We evaluated the tag retention rate of “shcoolie” sized Striped Bass (Morone saxatilis) that received a tag by two different methods.  The voluntary ingestion group (n = 20) consumed Atlantic salmon smolts surgically implanted with transmitters and the manual ingestion group (n = 6) had tags manually inserted into their stomachs. Gastric retention times were not significantly different between ingested and inserted groups (min, median, max = 3, 17, 58 and 6, 24, 76 (d) respectively). Knowing the potential retention times for specific predators of target specimens and associated movements of the detected tags will assist researchers in identifying suspicious detections and help ensure they are collecting accurate data on their target species.