Hoosier Study Reveals Walleye Location Secrets

Indiana biologists have unlocked several twists to walleye location that can help walleye fans everywhere catch more fish. The project is currently underway on Lake Monroe, an 11,000-acre impoundment a short cast from Bloomington in southcentral Indiana.



In March 2008, the state Department of Natural Resources launched an ambitious radio-telemetry study. Naturally, one of the goals was learning more about walleye movements and habitat use. But another main objective was getting Hoosier anglers fired up about the walleye options in Monroe. Problem was, the DNR had built a respectable fishery, and almost nobody was making use of it. Although the reservoir has a healthy population of marble-eyes, a 2007 creel survey revealed that just 5 percent of fishing effort is directed toward them.



“The walleyes are there, but not enough people go after them,” said DNR fisheries biologist Dave Kittaka. “We’ve devoted considerable resources to stocking walleyes in Monroe and want to promote the fishery.”

The concept of using research to promote walleye fishing on a specific lake has a successful track record. A decade ago, John Williams, of the Kentucky Department of Fish and Wildlife Resources, conducted telemetry research on Kentucky’s Laurel River Lake—in large part to show people walleye patterns there. The project turned out to be a resounding success, and has been featured in major publications such as In-Fisherman several times.




Research Details


Back in Indiana, between March 31 and April 16 (during the walleye spawn), DNR fishery crews surgically implanted electronic transmitters in 33 walleyes, which were captured by electrofishing and large gillnets in two mainlake locations and one tributary, Saddle Creek. Since that time, 1 walleye was harvested, 5 went through the dam to points unknown, and 7 dropped their tags. Four additional walleyes have been fitted with transmitters, bringing the current total of “participants” to 24.



Tracked fish range in length from 17 to 25.8 inches and weigh from 1.8 to 6.7 pounds. Most are males. To simplify identification, a yellow spaghetti tag sporting the fish’s DNR serial number is attached to the back of each radio-tagged walleye. (Anglers who catch tagged fish are asked to write down the tag number, release the fish, and report the catch to the South Region Fisheries Office, 812/279-1215.) 



Through spring, summer, and well into fall, each tagged walleye was relocated weekly. Intensive, 24-hour tracking of select fish was conducted on a monthly basis. Walleye locations were plugged into detailed aerial maps and posted online for anglers to monitor. So far, the results have provided insight on walleye behaviors and habitat use, and piqued interest among the local fishing community.

Shallow Thinking


“One of the more interesting findings to us was how heavily walleyes utilize flooded timber in the spring,” said Sandy Clark-Kolaks, a DNR fisheries research biologist helping lead the Monroe study. The lake’s water levels typically rise 6 to 10 feet in late winter and early spring, mainly from rainfall, submerging brushy stands of shoreline willows and larger mature trees. “Postspawn walleyes, from both tributary and mainlake spawning populations, moved deep into the shallow, flooded cover—we believe to rest and feed after the rigors of spawning,” she noted. Indeed, the woody cover offers shelter and a baitfish buffet of bluegills, gizzard shad, perch, and other preyfish. In all, about half the walleyes occupied flooded timber when it was available.

This behavior is not uncommon in river and reservoir systems during spring, but the length of time walleyes perched in the trees is notable. Clark-Kolaks says many Monroe walleyes didn’t vacate the flooded timber until forced out by falling water levels in June and early July. As summer progressed, the fish moved out into bays and creek arms, where they typically held near secondary creek channels in 15 to 25 feet of water. 



While the 40-foot-deep main channel attracted little attention, Clark-Kolaks says another type of area received a surprising walleye presence. “They really liked the lake’s three marinas,” she said. “The facilities are just floating docks with no sunken brushpiles for habitat, but they still attract baitfish. One walleye stayed at a marina all summer; others moved in and out.” Overall walleye movements were variable. Some fish traveled up and down the lake, while others didn’t move much at all. Those tucked into timber or along shoreline riprap were least likely to move long distances.



Perhaps one of the oddest movement patterns recorded was what Clark-Kolaks thinks might be related to multiple spawning runs. “One of the male walleyes we captured at a spawning area near the dam was recaptured a week later halfway up the lake at another shoreline spawning site,” she said. Research junkies like myself find this particularly fascinating, since very little is known on the subject of multiple spawning runs by individual walleyes in a single season. Clark-Kolaks says further study is planned to determine whether water temperature or other conditions encourage fish to migrate up the impoundment as spawning conditions become more favorable in different areas.



Toward Better Fishing


To date, response from fishermen has been good. “I receive several e-mails a week from anglers with questions or comments,” Clark-Kolaks said. Based on the research, the DNR has identified numerous untapped fishing opportunities. For example, while most early season fishing pressure on the lake occurs at riprap near the dam, Clark-Kolaks says the study revealed easily accessible riprap banks across the reservoir. “Basically, wherever there’s riprap, there’s spawning activity and fishing opportunity,” she added. The marina connection is another overlooked possibility, as is the flooded timber pattern.



“Walleye anglers do fairly well in summer and fall but not in spring,” said Clark-Kolaks. “I don’t think they realize how far back in the cover the fish go.” Ultimately, the DNR hopes such information helps a growing number of Indiana walleye fans capitalize on this lightly fished Hoosier treasure.



Note: For the latest on the project, and a great video clip of implanting a transmitter into a walleye, visit: http://www.in.gov/dnr/fishwild/3280.htm.