It had long been a dream of marine biologists to track fish. While archival tags had been on the market for some time, these required the recapture of the fish for data retrieval. Return rates were abysmally low.
The idea of remotely transmitting data from the fish to a satellite or other receiver was not new, but it wasn't until the advances in miniaturization that allowed us to produce our 20g battery powered PICO PTT, that the means existed to execute the idea. In February 1997, we tested the first prototypes of our PTT-100 Pop-up Tag off the Outer Banks of North Carolina. The concept of the tag was to have a device that would collect data while on the fish, then detach and float to the surface where it could transmit stored data and be located through the Argos system. We housed the Pop-up Tag in a composite, positively buoyant, low-drag housing.
It was designed to be towed by the fish via a short leader attached to a tagging dart. After a preprogrammed period, the release mechanism on the nose of the tag was activated by the internal microprocessor.
This first Pop-up Tag, our single-point Pop-up Tag, took hourly temperature readings while on the fish. After release from the fish the tag floated to the surface and began transmitting the stored data to Argos via its PTT. Argos collected the transmitted data, and within a few hours could provide a location for the transmitting tag. The single-point Pop-up Tag was initially used to track large pelagic fish such as bluefin tuna.
The knowledge acquired during testing of the single-point Pop-up Tags allowed for development and subsequent release of our Archival Pop-up Tag in 1999, followed by the X-Tag, in 2007.Photos by Alex Antoniou, Callaghan Fritz-Cope , Noel Hitchins