Transmitters Offer Intriguing Clues for Salmon Survival
While the first set of tracking data has also brought controversy — dam opponents doubt the accuracy of reports that mortality is just as high in free-flowing rivers — the privately funded transmitter networks are providing invaluable new information about the life cycle of northwest U.S. salmon populations. As an example, for the past several years the current administration made a full-court press to have hatchery fish counted with wild fish as a measure of the health of salmon populations, thereby avoiding endangered species protection rules. But the tracking data show that hatchery fish are proving to be slower and less able to adapt to salt water than their wild brethren.
Almond-sized transmitters that allow scientists to pick up signals from hundreds of miles away — and even track individual fish — promise to provide irrefutable data about how various factors influence salmon survival. “‘This is a revolution in being able to study marine animals that travel vast distances,’ said Fred Goetz, a fish biologist with the U.S. Army Corps of Engineers who’s been studying Puget Sound chinook, steelhead and bull trout. ‘This is a big breakthrough.'” Les Blumenthal for the McClatchy Washington Bureau.