Weed Bonanza Walleyes
Find weedbeds other anglers miss
I’ve long been fascinated by the connection between walleyes and weeds, mostly because the more I understand it, the more I can find and catch fish that other anglers miss. And not just in the weedy, DNR-stocked waters of the late-mesotrophic lakes of my central Minnesota homeland. Weed patterns produce big results in classic walleye fisheries from Mille Lacs to Lake Michigan and virtually anywhere ‘eyes and aquatic vegetation mix.
Admittedly, many anglers have caught on to the notion that weeds mean walleyes. But many anglers who know the value of vegetation still fail to find the best beds in their favorite lakes, let alone identify must-fish new waters based on their greenery and other environmental factors. It’s a science worth mastering, because the ability to predict the location of overlooked weedbeds in your home lake—and anticipate where weeds help fuel world-class fisheries in unfamiliar systems—can help you pinpoint potential walleye hotspots.
Early Season
Let’s start with finding sweet spots in the early openwater season. On a late May trip two years ago, during an evening fishing foray on a central Minnesota lake, I noticed odd weedgrowth in the middle of a large bay. A thick stand of exotic curly-leaf pondweed broke the surface in a narrow band extending for several hundred yards over otherwise open water. I knew from past experience the weeds didn’t mirror a depth contour or bottom-content change; in fact the long, thin weedpatch had sprouted perpendicular to a slow taper from 5 to 10 feet.
Closer inspection revealed stands of pondweed on either side of the bed, but those weeds were still several feet from the surface. Why had the band of weeds topped out so much faster than its neighbors? And more importantly, how could I translate that knowledge into a plan to map out similar vegetative anomalies that could help me catch more walleyes? After all, such lush weededges would certainly attract patrolling predators—especially earlier in the season, when they were 2 to 3 feet high while surrounding weeds were mere sprouts. Best of all, if subsurface beds lacked telltale signs such as depth or bottom changes, I might well have them to myself.
I guessed the reason but didn’t have confirmation until the following winter, when I returned to the exact spot in January. The accompanying photos say it all: an ice road plowed over the area allows greater sunlight penetration. Since curly-leaf is one of the most active aquatic plants during fall and winter, the plants beneath the access road got a major head start on surrounding vegetation. However, even less winter-active species such as coontail and broadleaf pondweed (commonly called “cabbage”) may be similarly affected. Do I even need to suggest the value of mapping such a road with GPS during the winter for early season openwater action?
Of course, not all ice roads produce hidden treasures. Areas too deep to produce plantlife are a bust. While researching the ice road scenario I interviewed Donna Perleberg, aquatic plant ecologist with the Minnesota Department of Natural Resources. She offered a handy formula for determining the depth at which weeds grow: “As a general rule, multiply the midsummer water clarity by 1.5 to find the maximum depth of rooted vegetation,” she said. For example, in a fertile lake with 4-foot clarity in July, you could expect rooted plants in depths to about 6 feet. In such conditions, a plowed road or other snow-free area over deeper water would have little or no effect on vegetation. State fisheries agencies and aerial photos are good sources of water clarity information.
Chara is a wild card when gauging key depths. Also called musk- or sandgrass, this advanced form of algae doesn’t need as much sunlight as pondweeds and other rooted plants. “It typically forms on the deeper edge of the plant zone,” said Perleberg. However, it can also be found in shallow water. During winters of heavy snowcover—and early the following spring—it can produce fish-attracting near-shore cover when other weedbeds falter.
Other factors that can spur weedgrowth include bottom content and shelter from wave action. “You may find little vegetation along a windswept rocky shoreline, even if the depth is adequate, because wave action prevents plants from taking root,” she noted. As for bottom composition, it pays to know what your target species prefer. For example, hardstem bulrush favors firm sand or gravelly substrate, while water lilies like mucky or silty soils. Nutrient inputs and longterm but isolated changes in water clarity may also play a role in localized plantgrowth.
Exploring New Waters
Studying lakemaps and aerial photos, talking to resource managers, and watching for factors that can affect weed location, can help you develop milk runs of choice weedbeds on your favorite waters. But what about the lakes you don’t know? Meet Minnesota DNR senior research biologist Ray Valley. He’s spent years studying vegetation and its affect on fish, and is currently part of a project tracking the affect of climate change, development, runoff, and invasive species on the health of 24 “sentinal” lakes scattered across the Gopher State’s four ecoregions.
Valley has long been a believer in the power of shoreline and submerged offshore vegetation to support forage species and shelter juvenile predators. In a study on the role of submersed aquatic vegetation as fish habitat, he noted that in general, “Conditions for gamefish deteriorate when the percentage of a basin that is covered with (submergent vegetation) falls below 10 percent or exceeds 60 percent.” Valley has also observed how the amount of weed edges (both inside and outside, along with deep lanes cut by weed-control programs) can affect fish populations—more being better.
He cautions, however, that weed-related indicators can fluctuate from year to year—especially in fertile, highly productive lakes. Vegetation abundance as a predictor of the quality of fishing a lake might offer needs to be considered in the larger context of water chemistry, climate, overall productivity, glacial history, and physical characteristics such as shape, contours, and size.
Intel on fish communities is also key. Walleye population data from fisheries agency sampling, along with information on the forage base, helps paint an accurate picture of your prospects on a new lake. On the subject of forage, Valley notes, “One thing that’s impressed me in the sentinal lakes research is how the healthiest, most robust fisheries tend to be in lakes that harbor ciscoes (tullibees). An abundance of yellow perch is also a good sign, as is the presence of five lesser-known ‘indicator’ species that are intolerant of habitat disturbance: blackchin and blacknose darter, least and Iowa darter, and banded killifish.” Valley calls such species “canaries in the coal mine.” Indicator fish vary across the Walleye Belt, but knowledge of a region’s environmentally-sensitive species can help you zero in on its must-fish fisheries.
If it all sounds intimidating, it’s really not. The key is keeping an eye out for untapped weedbeds like the ice road gem at the beginning of this story. Once you find them, figuring out how to fish them effectively is the easy part. Cast a Lindy X-Change Jig or Shadling over the emergent weeds—or troll an Old Guide’s Secret spinner and crawler along the weedtops and edges—and you’re in for a good time with walleyes other anglers overlook.