Walleye, an iconic native fish species in Wisconsin, the upper Midwest and Canada, are in decline in northern Wisconsin lakes, according to a study published this week in the Canadian Journal of Fisheries and Aquatic Species.

Walleye, an iconic native fish species in Wisconsin, the upper Midwest and Canada, are in decline in northern Wisconsin lakes, according to a study published this week in the Canadian Journal of Fisheries and Aquatic Species.

The study does not pinpoint the exact causes for the decline, though it suggests it is likely a combination of factors, including climate change, habitat degradation and harvest rates that might at times outpace production levels if not monitored closely. Additional research is ongoing regarding what declining production means for future walleye harvests in this region.

For the study, researchers analyzed production statistics collected between 1990 and 2012 for adult walleye populations in Wisconsin lakes. They found that annual walleye production across all lakes decreased by 27 percent during that time. It takes 1.5 times longer to produce the same amount of walleye biomass, or fish weight, now as it did in 1990.

Read more at University of California, Davis

Photo: Walleye, like this one, is a popular game fish prized for its flaky meat and mild, sweet flavor. (Courtesy Andrew Rypel)