A passive integrated transponder (PIT) tag system for monitoring fishways

An application of passive integrated transponder (PIT) technology was used to monitor movements of adult American shad (Alosa sapidissima), blueback herring (A. aestivalis) and gizzard shad (Dorosoma cepedianum) in two experimental fishways. Tag reading efficiency was between 88–96%, detection ranges were 50–100 cm from orifices of 3100–9600 cm², and read rates were 5–7 Hz. The system was limited by the amount of time that tags were exposed to the energize/detect zone, and by simultaneous presences of large numbers of tags within this zone.