Project Details

Helping to monitor fish migration with RFID.

To determine whether salmon migration is affected by a new dam, this leader in identification technology chose to partner with CES engineers to develop an RFID fish tracking system.


In recent years, more thoughtful consideration is given to animal ecosystems in urban areas. Increasing pressure is being placed on developers to find new ways to preserve animal habitats, especially for those that are near extinction. In the Pacific Northwest, a new dam threatened endangered salmon species that use that waterway to migrate to the ocean. Environmentalists worried about the effect of the dam on salmon migration patterns. Consequently, developers planned to incorporate a ladder into the design that the fish could use to bypass the dam. With environmentalists still concerned about the outcome, the customer, a leader in animal identification technology, was tasked with tagging and monitoring salmon to ensure that long term migration was not affected by the dam. To do this, the customer would implant Radio Frequency Identification (RFID) chips into juvenile salmon and track the fish as they travel through the dam. To accelerate development, the customer wanted to partner with an experienced RFID company, so they chose our team to help.


Collaborating with the customer throughout development, the our engineering team was responsible for the RFID reader that would identify the fish as they pass through the dam. Our electrical and mechanical engineers coordinated on the design and layout of the main circuit board for the reader, while concurrently designing the backplane. The backplane would allow the reader to scan and process multiple RFID chips at once. With thousands of salmon swimming at a rate of 40 feet per second, the backplane was crucial in providing accuracy in tracking.

Our engineers also developed the reader to perform automatic antenna tuning. Auto tuning would allow the reader to adjust the system’s antenna position as the load rate of the water changes, substantially increasing the efficiency.

Our software engineering team created the connection from the reader to the central database through a local network. The database would house and store the information obtained from the reader. Software engineers were also responsible for the tag decoding software. The RFID chip implanted in the salmon would carry information identifying the individual fish that would need to be decoded before being sent to the database for analysis.

Due to the sheer size of the dam, the customer developed a 16-foot square antenna to frame the largest area possible for tracking. However, after development it was found that the large size created a dead zone in the center of the antenna where the signal could not reach, allowing some fish to get by undetected. Beyond customer expectations, our team offered assistance to increase the signal processing in the reader system. This ultimately increased the range of the antenna and eliminated the dead zone for optimal tracking capability.


The RFID reader was delivered to the customer on time and was incorporated into the design of the flume of the dam during construction. Today, more than one million fish have the implanted RFID tags and are being tracked with the system. The advanced signal processing decodes the tags and sends through the connection in less than one second allowing for near real-time updates. This RFID tracking system still remains one of the most humane and safe ways for long-term fish monitoring.


The customer is a leader in radio-frequency identification (RFID) technology products for consumer, commercial, and government sectors. The company manufactures tracking devices for animals, food supply and for commercial use around the world.

  • Project Name RFID Tracking System