Project Background

Walleye is an important commercial and recreational fish in Lake Erie and Lake Huron. Like many fish, walleye undergo seasonal movements, but how many move, when they move, where they go to, and why they move is not always clear. Understanding walleye movement patterns based on age, size, and sex will help better define stocks as units of management, and improve estimates of population size and total harvest. By surgically implanting 400 walleye (200 from a Lake Erie tributary and 200 from a Lake Huron tributary) with acoustic transmitters and tracking their movements through the use of autonomous hydrophone receivers we will determine 1) if source-sink population dynamics occur; 2) what environmental cues are associated with the movement of walleye, 3) if male and female walleye prefer different thermal conditions; 4) if walleye move through the Lake Huron-Lake Erie corridor; 5) if walleye return to the same spawning locations; and, 6) the natural mortality rate of different walleye stocks.

How it works

The transmitters, which are implanted in the walleye, send out an acoustic signal into the water at regular intervals. When they are in range of a hydrophone receiver, the signal from transmitter is picked up, and the ID of the fish is recorded, along with the date and time. Scientists will use this information to answer the questions outlined above. The transmitters have a battery in them that will last approximately 4 years allowing us to gather lots of information about their movements and what factors trigger walleye movement over time.