In an effort to continue to track Northern pike numbers, DNR fisheries biologists will set traps in four northeast Indiana lakes this spring: Diamond Lake (Noble County), North and South Twin Lakes (LaGrange County), and Silver Lake (Steuben County).
Since 2012, DNR biologists have sampled pike in 17 lakes. To sample pike, biologists set large traps in areas that are likely to attract spawning pike. The typical catch is 18 pike per survey, and the majority are 21-28 inches long.
Northern pike serve as an indicator of fish habitat quality in Indiana lakes, as well as being popular among anglers. About one-third of northern Indiana's 450 glacial lakes still contain pike. Fisheries biologists' goal is to keep that number from dropping.
Matt Linn, one of those fisheries biologists, says Northern pike do best in lakes with cool water and plenty of oxygen down deep.
As lakes age and are degraded, these habitat conditions disappear and ultimately affect the quality of pike fishing. In general, lakes with better habitat tend to have more big pike.
"Over time many of our lakes have lost their cool-water layer due to declines in water quality," Linn said. "That forces pike into warm shallow areas and puts a lot of stress on them by disrupting their behavior, growth, and survival."
Various programs now in place are designed to keep numbers from dropping. Efforts to protect wetlands, reduce run-off of nutrients and sediments into lakes, curb man-made changes along lake shorelines, and better manage aquatic plants go a long way in preserving pike habitat.
"One measure of the success of these programs will be based on how well Northern pike survive and grow in the future," Linn said.
According to Linn, better pike lakes in the area include Clear and Hamilton lakes in Steuben County and Little Chapman and Winona in Kosciusko County. Winona Lake also has the highest number of large pike.
To learn more about pike, see the Animal Information Series at wildlife.IN.gov/files/fw-pikes.pdf.