A contract worth up to $10 million awarded to Digital Angel by the U.S. Army Corps of Engineers will let scientists continue to use the company's passive, integrated transponders to track migrating fish.

The transponders, or microchips, currently are in use by the Columbia River Basin Project, which studies fish populations migrating from spawning grounds in the Columbia River, which flows through British Columbia, Idaho, Oregon and Washington on its way to the Pacific Ocean.

The Columbia is the largest river by volume that flows into the Pacific from the Western Hemisphere — the second largest by volume in North America behind the Mississippi — and is home to several hydropower systems and dams. One of those dams — the McNary Dam in Umatilla, Ore. — is managed by the Army Corps of Engineers. It is a crossing that migrating salmon and steelhead species must traverse on their annual trip upstream to spawn, and it is this journey researchers are now tracking to determine the lifecycle of the species and the effects of habitat, harvest, hatcheries and hydropower on their survival.

Digital Angel has designed microchips since the 1980s. The microchip used for the Columbia River Basin project measures 2×12 mm and uses passive radio frequency identification (RFID) transponder technology to transmit data, said Keith Kuhnly, the company's vice president of research and design.

“It is a tubular, glass-encapsulated transponder about the size of a grain of rice that is injected into the body cavity of the fish,” he said.

Digital Angel provides the entire system for the project, including the hand-held readers, the transponders, the custom-made antennas and the graphical user interface. Onsite application engineers install the system, said Zeke Mejia, the company's chief technology officer.

The Army Corps uses the system to monitor fish populations, migration patterns, water levels and the flow of various dam passages and streams into the Columbia River, Mejia said. Fish are injected with the microchip by scientists who work for the Department of Energy in a catch-and-release system using fishing nets in streams and rivers throughout Idaho, Oregon and Washington.

Once injected, each fish's microchip is wirelessly scanned by a hand-held reader. The initial species data are then transmitted to the Portland, Ore.-based PTAGIS, or PIT (passive integrated transponder) Tag Information System. PTAGIS is the agency charged with managing and maintaining the data collected from the salmon and steelhead populations that hatch and develop in the river's fresh water before migrating to the ocean.

Fish must pass several electric dams during their various migrations, according to PTAGIS. Migrating fish are forced through what the agency calls a collection site. It is a series of separate, maze-like channels, pipes and concrete fish ladders that runs parallel to the dams and simulates the rapids fish would normally swim up, Mejia said.

An RFID-loop antenna developed by Digital Angel's research-and-design department is embedded into the pipe system and ranges from 12- to 48-inches long. The antenna activates the passive transponders, which transmit the fish's unique identification number to PTAGIS, Kuhnly said. The operations center logs the information transmitted, which includes species names, the starting point of the fish's journey and the age of each fish.

The system delivers a 99.5% data capture rate, Mejia said. To learn more about the project, visit www.ptagis.org.