Supporting MCV has never been easier!

Contribute Now


Give a Gift Subscription

Update My Subscription

About MCV

Past Issues

School Resources

Contact Us

Annual report


Connect with us!

image of Facebook icon image of Twitter icon image of Google plus icon

Image of netting minnows.

For Love of Minnows

Essential to the food chain, native minnows are missing from some Minnesota lakes. One man is on a mission to restore them.

by Darby Nelson

Sitting in my car on the outskirts of Elysian in southern Minnesota, I wait to meet my companion for the day, Konrad Schmidt. We are going fishing. A boat and trailer soon arrive. I can tell it's him by the decal on his boat: SS Minnow. Schmidt is a devotee of minnows and darters. At age 15 he began keeping darters in an aquarium, and that eventually led to his 20-year career as a nongame fish specialist for the Department of Natural Resources.

Minnows and Darters

image of native shiners and darters

More than 150 fish species call Minnesota's lakes and streams home. Fewer than 10 percent are game fish. More than 40 native species are minnows.

Not all small fish are minnows, and not all minnows are small. True minnows are members of the Cyprinidae family, and all have naked, scaleless heads, except males in the breeding season, when they develop tubercles. Goldfish and common carp are minnows. Creek chubs, golden shiners, common shiners, and brassy minnows are all familiar baitfish.

Fathead minnows are also familiar to Minnesota anglers, who buy more than 1.5 million pounds of them each year. Tolerant of extremely low oxygen concentrations and high water temperature, fathead minnows are an ideal bait species. Unfortunately, they feed on aquatic invertebrates, many of which are important food for ducklings. Fatheads reproduce rapidly. Their excrement can stimulate algal growth and leave a shallow lake murky and degraded.

Minnesota also has 15 species of darters, minnowlike fish in a subgroup of the perch family. Ichthyologists like Konrad Schmidt consider darters to be among the most beautiful and fascinating of North American fish. Lacking swim bladders, darters lie motionless on a lake or stream bottom as though asleep. Reach out to catch one and it darts to safety faster than the eye can follow, hence its name.

The least darter (Etheostoma microperca), just over the length of a small paper clip at maturity, is the smallest backboned animal species in Minnesota. Capturing them requires a one-eighth-inch woven mesh net. Least darters prefer crystal-clear streams and lakes and habitats rich in aquatic vegetation, where they feed, avoid predators, and spawn. In spring the male stakes out a territory and awaits a female. Atypical for spawning fish, she attaches herself to a plant stem in a vertical position, nose up. The male clasps her with his large, bright red pelvic fins. They wiggle together, attach one or two eggs to the stem, then move to another stem to repeat the behavior.

The DNR has classified more than a dozen minnowlike fish as endangered, threatened, or species of special concern. Other species, including banded killifish, blacknose shiners, and blackchin shiners, are considered sensitive species. Though these species are doing well in northern Minnesota, they were among the first to disappear from lakes in the southern half of Minnesota.

The now-retired DNR biologist steps out of his pickup truck, and we shake hands. He impresses me as a teddy-bear kind of guy, as a warm smile spreads over his face. Schmidt introduces me to his son, Bryan, and another helper, Jenny Kruckenberg, an expert at the kind of fishing we will be doing. We have no rods, tackle boxes, or bait. We'll be fishing for four native species of minnows and the least darter. Schmidt has begun an experiment to see if he can re-establish these species in the metro lakes they once inhabited.

I follow Schmidt out of town to Fish Lake, and we park at the gravel landing. The water is clear and calm. Steep, heavily forested slopes surround the lake. We unload coolers, large pails, chest waders, and a seine with tiny mesh. An aerator remains in the back of the truck. We are ready to catch our quarry.

Net unfurled, chest waders on, Schmidt and Kruckenberg slowly wade into the lake, moving the seine along the water's edge. They soon return to shore to examine the catch. The mesh is heavy with a thick, green mass of plants and tiny, wiggling fish. Not all of the little fish are minnows. Schmidt and Kruckenberg remove tiny crappies, half-dollar-size sunfish, and other fish not of interest, tossing them back into the lake. Then, with quick eyes and nimble fingers, they deftly pick out the species of interest and slip them into a white plastic pail of water. Speed is critical.

There are not as many fish in the haul as expected, so the two now work the other side of the landing. A minute later, Schmidt steps too deep and cold water fills his waders. "It's just water," he says. He doesn't slow up, and his indomitable smile remains.

Another haul, and we are ecstatic: Iridescent slivers of silver leap and wiggle everywhere in the mesh.

"Oh, there's a killi!" Kruckenberg exclaims. "A batch of least darters over on your right."

"Got 'em," says Schmidt.

Out of the writhing splay, they instantaneously distinguish one species from another and flip those of interest into the pails, while Bryan searches the shore for other prospective sites.

The four of us haul the heavy pails onto the beach and assess the catch. The combined pails contain all five of the desired species: blackchin, blacknose, and pugnose shiners; a banded killifish; and a large number of least darters. Back at the landing, we quickly transfer the fish to the cooler equipped with an aerator. Then we take off for Lake Elmo, which is east of St. Paul.

I follow the SS Minnow north onto the interstate. Though Schmidt does not exceed the 70-mile-an-hour speed limit, he scoots around any vehicle traveling a smidgen slower.

Permit Required. On reaching Lake Elmo, we help acclimate the fish to the new lake by slowly and repeatedly removing a small quantity of Fish Lake water from the cooler and replacing it with an equal volume of Lake Elmo water. This process continues until the fish are fully submersed in Elmo water. Schmidt then wades out from shore with a pail of the tiny fish and sloshes them into the lake at several different locations.

Schmidt's permit from the DNR requires us to empty the transported lake water back on land over a permeable surface to make sure it does not contaminate the receiving lake by introducing new, undesirable species of plants, animals, or microbes. It is illegal in Minnesota for people to move fish from place to place without first acquiring DNR permits. Applicants must demonstrate skills necessary to protect the ecological integrity of the resource. Schmidt had to meet all requirements before he could begin his work.

Schmidt also had to find a way to finance his work on behalf of nongame native fish. "It doesn't bring in a paycheck," he says, "but the freedom to pursue my own research interest makes it worthwhile." And the funding? "It's an OOPS Project—Out of Pocket Support," he says. "If successful, the self-gratification will be tremendous."

A Way Back. Schmidt was aware that conditions in lakes and streams had changed since the late 1930s with rapid growth in the Twin Cities metropolitan area. Increases in impervious surfaces—roads, roofs, and parking lots—greatly increased runoff of nutrients and other chemicals entering waterways. Storm sewers were conduits delivering street waste into habitat for fish and other aquatic life. Intolerant of degraded waters, many minnow and darter species—including the blacknose shiner, blackchin shiner, pugnose shiner, banded killifish, and least darter—vanished from many metro lakes.

Then the federal Clean Water Act of 1972 triggered action, and government agencies and citizens began improving water quality. We banned phosphorous in lawn fertilizers, improved waste-collection practices, and reduced nasty chemicals reaching lakes and streams. Conditions have improved such that extirpated minnow and darter species may now be able to again live in some metro lakes. Unfortunately, drainage patterns that existed when the sensitive species originally entered these lakes no longer exist, so fish cannot return to the lakes on their own.

Aware of the improved habitat in several metro lakes, Schmidt wondered if he could successfully implement a stocking program for these tiny, sensitive fish. Then he learned of a similar restoration project in Chicago. "Their plan was beautifully simplistic," Schmidt says. "They transplanted hundreds of fish of intolerant species into a retention pond designated as Illinois' first fish refuge for endangered and threatened species." The fish were later transported to a nearby lake.

"All species not only survived but thrived," says Schmidt. "Their survey found thousands of each species."

Encouraged, Schmidt decided to proceed on his own, following the insights gleaned from the Illinois experiment. His first challenge was finding a source of the species extirpated from metro lakes. With the help of Professor Pat Ceas at St. Olaf College, he located Fish Lake. The lake's clear water contained all five species Schmidt hoped to relocate.

Re-establishment of these fish species will enhance the biological diversity of the lake ecosystems. As informed anglers know, minnows are critically important in the food web of a lake. They forage on aquatic plants and, in turn, become prey for game fish. Walleye young can't become 4 pounders without access to a plentiful stock of these small forage fish to eat.

In addition to boosting the food supply for largemouth bass, black crappies, and other game fish, Schmidt's project can benefit lake-property owners. Sensitive species are the most accurate monitors of a lake's water quality, and their presence can reassure property owners that their lake is in good health and their property values are maintained.

Beside his restoration work, Schmidt is working on the most comprehensive compendium of Minnesota fish ever attempted. Along with his colleagues Jay Hatch and Gary Phillips, he is gathering information on species distribution, habitats, and conservation status and creating a photo library. The book project began 12 years ago, and the group expects to complete it in 2015.

Likewise with his project on metro lakes, Schmidt is in it for the long haul. "Due to recent efforts in watershed restoration and stormwater management, many metro lakes have exhibited a remarkable improvement in water clarity," he says. "However, current fish communities do not reflect what these high-quality habitats can now support. Re-establishing the suite of species will return the once lost beauty to these lakes." And that is a very good thing for people, lakes, and fish.

Looking for volunteer opportunities?