Science Proves Trout Can Fly

Beep, beep, beep goes the radio receiver. A radio frequency number appears on the miniature screen, Yellowstone cutthroat trout number 11 has just been found. The antenna mounted in the back of the pickup truck pinpoints the fish's location. Each week Idaho Fish and Game fisheries technician Casey Corrington slowly cruises the roads along the Upper Blackfoot River north of Soda Springs, trolling for trout with a radio receiver. He monitors the movement of 28 Yellowstone cutthroat trout with radio transmitters surgically implanted in them. Studying the cutthroat trout will help biologists find out what happens to them on their spawning migration. How many will complete spawning and return home to the Blackfoot Reservoir? Which tributaries are most important for spawning? How many will die along the way? What kills them? How long will the spawners spend in the river? Are anglers illegally keeping them? Answers to these questions and some unexpected results are starting to arrive. The receiver beeps rapidly as we drive around a bend in the river. One of the trout that has eluded Corrington's tracking efforts just showed up. Just as quickly the signal disappears. Stopping the truck, Corrington adjusts the tuning knob. The signal is gone; he cannot relocate the fish. What's up? The trout is in the river, where can it go? Or is it in the river? Looking down river, three big white birds sail out of sight. Three white pelicans took flight just as the signal was lost. Earlier in the week, a technician plotting fish movement from a fixed receiver called with an odd question. How fast can a fish travel? According to the data, one just set a new speed record swimming downstream past a fixed receiving station at something like 30 miles per hour. That signal was lost for several days before an IDFG wildlife biologist located the signal on an aerial flight survey. The signal came from the pelican colony on Bird Island in Blackfoot Reservoir 35 miles away from where it was last tracked on its spawning bed in Lanes Creek. Regional fisheries biologist David Teuscher is in charge of the project. Intrigued, he and his crew boated out to the island to retrieve the transmitter. Tracking the radio signal took him to the middle of the pelican-nesting colony. Here he found the transmitter. Before flipping off the receiver he switched it to the scan mode that runs through all 28 of the transmitters numbers looking for a signal. Beep, beep, beep. Teuscher walked towards the signal and it moved. The more he moved, the more the signal changed. Humm. A herd of baby pelicans grouped up and waddled away from him. Pointing the receiving wand at them the signal came in loud and clear. One of the little pelicans has the transmitter in its stomach. Mom delivered lunch whole and the baby gulped the fish and transmitter. The tracking study is yielding some interesting results which will help biologists learn more about spawning cutthroat trout and the perils they face. "Cutthroat trout face numerous perils on their spawning journey," Teuscher said. What the telemetry study will do is help us track down the sources of loss and hopefully help us plan strategies for improving the cutthroat run." The low water conditions because of drought affect the complete life cycle of the fish from birth to spawning. Low water also means some spawning areas go dry. Even more tragic is the loss of the precious eggs incubating in the gravel as water levels drop leaving them high and dry. Beep, beep, beep. "That fish is way up Lanes Creek spawning," said Corrington. "It will be interesting to see how it does."