Eight days.
That wasn’t exactly the ending anyone expected for Randy, the first red drum to be satellite-tagged this summer as part of our Foundation’s ongoing research partnership.
When we introduced you to Randy a few weeks ago, the plan was simple. A newly attached satellite tag would ride along for eight months, recording where he traveled, how deep he swam, and what habitats he used before releasing next spring to begin transmitting its data. Instead, just over a week later, the tag unexpectedly began transmitting on the Argos satellite network.
What happened? Had Randy died? Had the tag reached one of its emergency release conditions? Or had it somehow detached from the fish? Before anyone had the answer, a search and rescue mission quietly unfolded along the shores of the Croatan Sound.
As soon as the signal appeared, biologists with the North Carolina Division of Marine Fisheries mobilized. Crews from multiple field offices launched boats, searched marshes, battled relentless flies, and followed fresh satellite positions across the Sound. One supervisor later described the effort as “finding a needle in a seaweed stack,” and she wasn’t exaggerating. With one final stretch of shoreline left to search before an approaching squall arrived, the crew spotted it. Against incredible odds, they had recovered a satellite tag about the size of a candy bar, washed ashore among the marsh grass.
That recovery changed everything.
Without finding the tag, much of Randy’s story would have remained a mystery. Instead of relying only on information transmitted through satellites, biologists connected the tag directly to a computer and downloaded every measurement it had collected every 30 seconds since Randy was released. The graph below tells that story in remarkable detail. Light levels traced each sunrise and sunset. Water temperatures reflected the changing conditions of the Sound. Most importantly, the depth record showed Randy making the normal vertical movements expected from a healthy fish, right up until the tag detached.
These three panels track Randy’s tag readings, taken every 30 seconds throughout the eight-day deployment. Light (top) and temperature (middle) both show clear day-night cycles while the tag was traveling with him. The bottom panel shows depth, in blue, tracing his normal movements up and down the water column. The red stretch in the depth plot marks when the tag stayed shallower than one meter for more than eight hours, the condition that triggered its release. That shift shows up in the light and temperature readings too, once the tag was floating on its own.
Onto the Next
Working alongside engineers at Wildlife Computers, the tag’s manufacturer, biologists concluded the tether most likely pulled free from the fish while Randy continued swimming with only a small plastic anchor remaining. Rather than documenting where Randy would spend the winter, the first lesson turned out to be something equally valuable: learning how to reliably attach a small computer to a wild fish is a research project all its own.
That may not sound as exciting as following a red drum hundreds of miles along the Atlantic coast, but it is exactly how good science works. Before researchers can answer big biological questions, they first have to refine the tools that make those discoveries possible. Every deployment, whether it unfolds exactly as planned or not, teaches something that improves the next one.
Randy’s tag won’t swim again. Once recovered, these satellite tags cannot be redeployed. But its mission isn’t over. It has already been returned to the manufacturer through a recovery program that provides a substantial credit toward a replacement tag, one that will soon begin another chapter with a different red drum.
In fact, earlier this week, with the help of seasoned anglers, four more red drum were fitted with microPAT satellite tags. Each fish expands the study, strengthens the sample size, and helps researchers refine not only what they hope to learn about red drum movements, but also how to reliably attach a small computer to a wild fish for months at a time.
Scientific discovery rarely follows a perfectly written script. Sometimes the biggest breakthroughs come from unexpected detours, careful observation, and a willingness to adapt. Randy may not have carried his tag for eight months, but his short journey has already improved the next one. And somewhere off our coast today, four more red drum are already carrying his lessons forward.