The sound of crickets chirping filled the room, only this was a completely artificially produced sound. On the computer screen flashed “Code 17”, “Code 17”, “Code 17”. The radio-tag was sending out its signal, waiting to be heard by those who were interested. This small tag, measuring 5 mm by 10mm and weighing barely 0.3 grams, was placed into a bath of disinfectant, soon to be attached to a juvenile spring Chinook salmon. It would accompany the fish on its journey to the sea. The process had begun.
Jen placed an anesthetized fish onto the operating platform, belly up. A tube was placed into the mouth of the fish, and a stream of water began flowing over the gills. This water had a small concentration of anesthetic mixed in to keep the fish sedated throughout the procedure. The fish’s gills rhythmically contracted. Everything looked good. Jen took a micro-scalpel and carefully made a small incision in the fish’s belly, just below the pelvic girdle. She then used a small needle, covered by a plastic catheter to protect vital organs, to poke a hole in the fish’s abdominal wall. The antenna of the radio-tag was then threaded through the catheter so that the antenna trailed outside the body wall, while the radio-tag itself could be placed inside the fish at the point of the first incision. Satisfied that everything looked in place, Jen then proceeded to close the incision and finish the surgery. Two sutures, using a modified surgeon’s knot, were “thrown” to keep the incision point tight and allow for natural healing. After the first suture was complete, the flow of anesthetic water through the fish’s gills was switched so that only pure freshwater was flowing, beginning the process of recovery for the fish. As the second suture was finished, Brian prepared a recovery bucket full of water with elevated dissolved oxygen levels. Jen then placed the fish into the recovery bucket, and the time of surgery was called out and recorded. Four minutes twenty seconds. That was the length of time the surgery took, from placing the fish on the operating platform to depositing it into the recovery bucket. Thirty seconds. That was the time it took the fish to become fully awake and recovered from the surgery. The fish was then placed into a holding tank inside the hatchery. Code 17 was now the signal that would be broadcasting out from inside the fish for the next 42 days (the battery life of the radio-tag). Code 17 was how we would now refer to this previously anonymous fish. Code 17 was now part of our family, we would grow a special bond with it as we tracked its movement and progress on its journey to the sea.
|Top to Botton: Pencil, PIT tag in vial, and radio tag.|