It’s that time of year when Freshwater and Saltwater King Salmon will begin the migration back to where they were born to spawn and die. Depending on their location, some salmon will travel over 1,000 miles to spawn. Over the past years, it has become necessary for the Alaska Department of Game and Fish to keep track of the number of spawning fish during this time. Why? Tracking fish numbers enables the Department to determine the following year’s fishing season lengths. The process is a simple one; technicians physically count the salmon. But to my way of thinking, the counting process could be expedited. If each fish contained an RFID tag, the counting process and accuracy of count would improve tremendously.

Salmon tracking with RFID
King Salmon “check point” on the Chena River in Alaska.

The counting process implemented in Alaska can be seen in the photo on the right. The image captures the Chena River near Fairbanks where large white tarp-like panels are placed in the river to assist the counting technicians with identifying salmon passing through. The white panels are utilized to physically see the fish, since their red bodies blend in easily with the dark river bottom. The King Salmon are counted 24 hours a day and seven days a week from late June through early August. The counting goes on in eight hour shifts and a sample count is taken for only 20 minutes of each hour. The average per hour and day is then calculated and reported via voicemail.
Since these are wild salmon, there would be no way to tag them as performed in a stocking scenario but imagine if they could embed a tiny passive RFID tag in the dorsal fin of each one? How cool would it be to set up an area on the river where all incoming fish would have to funnel through, allowing an RFID reader to scan each tag? Not only would it be effective but it would be extremely accurate. I do understand that the tag would have to be very small and waterproof but even with that said, I see something like this being feasible within a few years.
Technology and King Salmon working together? Who would have thought? Even the rivers have a reason to take inventory.